[PATCH v9 00/34] Introduce QC USB SND audio offloading support

[PATCH v9 00/34] Introduce QC USB SND audio offloading support

[Wesley Cheng]

Several Qualcomm based chipsets can support USB audio offloading to a
dedicated audio DSP, which can take over issuing transfers to the USB
host controller.  The intention is to reduce the load on the main
processors in the SoC, and allow them to be placed into lower power modes.
There are several parts to this design:
  1. Adding ASoC binding layer
  2. Create a USB backend for Q6DSP
  3. Introduce XHCI interrupter support
  4. Create vendor ops for the USB SND driver

      USB                          |            ASoC
--------------------------------------------------------------------
                                   |  _________________________
                                   | |sm8250 platform card     |
                                   | |_________________________|
                                   |         |           |
                                   |      ___V____   ____V____
                                   |     |Q6USB   | |Q6AFE    |  
                                   |     |"codec" | |"cpu"    |
                                   |     |________| |_________|
                                   |         ^  ^        ^
                                   |         |  |________|
                                   |      ___V____    |
                                   |     |SOC-USB |   |
   ________       ________               |        |   |
  |USB SND |<--->|QC offld|<------------>|________|   |
  |(card.c)|     |        |<----------                |
  |________|     |________|___     | |                |
      ^               ^       |    | |    ____________V_________
      |               |       |    | |   |APR/GLINK             |
   __ V_______________V_____  |    | |   |______________________|
  |USB SND (endpoint.c)     | |    | |              ^
  |_________________________| |    | |              |
              ^               |    | |   ___________V___________
              |               |    | |->|audio DSP              |
   ___________V_____________  |    |    |_______________________|
  |XHCI HCD                 |<-    |
  |_________________________|      |


Adding ASoC binding layer:
soc-usb: Intention is to treat a USB port similar to a headphone jack.
The port is always present on the device, but cable/pin status can be
enabled/disabled.  Expose mechanisms for USB backend ASoC drivers to
communicate with USB SND.

Create a USB backend for Q6DSP:
q6usb: Basic backend driver that will be responsible for maintaining the
resources needed to initiate a playback stream using the Q6DSP.  Will
be the entity that checks to make sure the connected USB audio device
supports the requested PCM format.  If it does not, the PCM open call will
fail, and userpsace ALSA can take action accordingly.

Introduce XHCI interrupter support:
XHCI HCD supports multiple interrupters, which allows for events to be routed
to different event rings.  This is determined by "Interrupter Target" field
specified in Section "6.4.1.1 Normal TRB" of the XHCI specification.

Events in the offloading case will be routed to an event ring that is assigned
to the audio DSP.

Create vendor ops for the USB SND driver:
qc_audio_offload: This particular driver has several components associated
with it:
- QMI stream request handler
- XHCI interrupter and resource management
- audio DSP memory management

When the audio DSP wants to enable a playback stream, the request is first
received by the ASoC platform sound card.  Depending on the selected route,
ASoC will bring up the individual DAIs in the path.  The Q6USB backend DAI
will send an AFE port start command (with enabling the USB playback path), and
the audio DSP will handle the request accordingly.

Part of the AFE USB port start handling will have an exchange of control
messages using the QMI protocol.  The qc_audio_offload driver will populate the
buffer information:
- Event ring base address
- EP transfer ring base address

and pass it along to the audio DSP.  All endpoint management will now be handed
over to the DSP, and the main processor is not involved in transfers.

Overall, implementing this feature will still expose separate sound card and PCM
devices for both the platorm card and USB audio device:
 0 [SM8250MTPWCD938]: sm8250 - SM8250-MTP-WCD9380-WSA8810-VA-D
                      SM8250-MTP-WCD9380-WSA8810-VA-DMIC
 1 [Audio          ]: USB-Audio - USB Audio
                      Generic USB Audio at usb-xhci-hcd.1.auto-1.4, high speed

This is to ensure that userspace ALSA entities can decide which route to take
when executing the audio playback.  In the above, if card#1 is selected, then
USB audio data will take the legacy path over the USB PCM drivers, etc...

This feature was validated using:
- tinymix: set/enable the multimedia path to route to USB backend
- tinyplay: issue playback on platform card

Changelog
--------------------------------------------
Changes in v9:
- Fixed the dt binding check issue with regards to num-hc-interrupters.

Changes in v8:
- Cleaned up snd_soc_usb_find_priv_data() based on Mark's feedback.  Removed some of
the duplicate looping code that was present on previous patches.  Also renamed the API.
- Integrated Mathias' suggestions on his new sideband changes:
https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=feature_interrupters
- Addressed some of Mathias' fixme tags, such as:
 - Resetting transfer ring dequeue/enqueue pointers
 - Issuing stop endpoint command during ep removal
 - Reset ERDP properly to first segment ring during interrupter removal. (this is currently
   just being cleared to 0, but should be pointing to a valid segment if controller is still
   running.

Changes in v7:
- Fixed dt check error for q6usb bindings
- Updated q6usb property from qcom,usb-audio-intr-num --> qcom,usb-audio-intr-idx
- Removed separate DWC3 HC interrupters num property, and place limits to XHCI one.
- Modified xhci_ring_to_sgtable() to use assigned IOVA/DMA address to fetch pages, as
it is not ensured event ring allocated is always done in the vmalloc range.

Changes in v6:
- Fixed limits and description on several DT bindings (XHCI and Q6USB)
- Fixed patch subjects to follow other ALSA/ASoC notations.

USB SND
- Addressed devices which expose multiple audio (UAC) interfaces.  These devices will
create a single USB sound card with multiple audio streams, and receive multiple
interface probe routines.  QC offload was not properly considering cases with multiple
probe calls.
- Renamed offload module name and kconfig to fit within the SND domain.
- Renamed attach/detach endpoint API to keep the hw_params notation.

Changes in v5:
- Removed some unnescessary files that were included
- Fixed some typos mentioned
- Addressed dt-binding issues and added hc-interrupters definition to usb-xhci.yaml

XHCI:
- Moved secondary skip events API to xhci-ring and updated implementation
   - Utilized existing XHCI APIs, such as inc_deq and xhci_update_erst_dequeue()

USB SND
- Renamed and reworked the APIs in "sound: usb: Export USB SND APIs for modules" patch to
include suggestions to utilize snd_usb_hw_params/free and to avoid generic naming.
- Added a resume_cb() op for completion sake.
- Addressed some locking concerns with regards to when registering for platform hooks.
- Added routine to disconnect all offloaded devices during module unbind.

ASoC
- Replaced individual PCM parameter arguments in snd_soc_usb_connect() with new
snd_soc_usb_device structure to pass along PCM info.
- Modified snd_jack set report to notify HEADPHONE event, as we do not support record path.

Changes in v4:
- Rebased to xhci/for-usb-next
- Addressed some dt-bindings comments

XHCI:
- Pulled in latest changes from Mathias' feature_interrupters branch:
https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=feature_interrupters

- Fixed commit text and signage for the XHCI sideband/interrupter related changes
- Added some logic to address the FIXME tags mentioned throughout the commits, such
as handling multi segment rings and building the SGT, locking concerns, and ep
cleanup operations.
- Removed some fixme tags for conditions that may not be needed/addressed.
- Repurposed the new endpoint stop sync API to be utilized in other places.
- Fixed potential compile issue if XHCI sideband config is not defined.

ASoC:
- Added sound jack control into the Q6USB driver.  Allows for userpsace to know when
an offload capable device is connected.

USB SND:
- Avoided exporting _snd_pcm_hw_param_set based on Takashi's recommendation.
- Split USB QMI packet header definitions into a separate commit.  This is used to
properly allow the QMI interface driver to parse and route QMI packets accordingly
- Added a "depends on" entry when enabling QC audio offload to avoid compile time
issues.

Changes in v3:
- Changed prefix from RFC to PATCH
- Rebased entire series to usb-next
- Updated copyright years

XHCI:
- Rebased changes on top of XHCI changes merged into usb-next, and only added
changes that were still under discussion.
- Added change to read in the "num-hc-interrupters" device property.

ASoC:
- qusb6 USB backend
  - Incorporated suggestions to fetch iommu information with existing APIs
  - Added two new sound kcontrols to fetch offload status and offload device
    selection.
    - offload status - will return the card and pcm device in use
        tinymix -D 0 get 1 --> 1, 0 (offload in progress on card#1 pcm#0)

    - device selection - set the card and pcm device to enable offload on. Ex.:
        tinymix -D 0 set 1 2 0  --> sets offload on card#2 pcm#0
                                    (this should be the USB card)

USB SND:
- Fixed up some locking related concerns for registering platform ops.
   - Moved callbacks under the register_mutex, so that 
- Modified APIs to properly pass more information about the USB SND device, so
that the Q6USB backend can build a device list/map, in order to monitor offload
status and device selection.

Changes in v2:

XHCI:
- Replaced XHCI and HCD changes with Mathias' XHCI interrupter changes
in his tree:
https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=feature_interrupters

Adjustments made to Mathias' changes:
  - Created xhci-intr.h to export/expose interrupter APIs versus exposing xhci.h.
    Moved dependent structures to this file as well. (so clients can parse out
    information from "struct xhci_interrupter")
  - Added some basic locking when requesting interrupters.
  - Fixed up some sanity checks.
  - Removed clearing of the ERSTBA during freeing of the interrupter. (pending
    issue where SMMU fault occurs if DMA addr returned is 64b - TODO)

- Clean up pending events in the XHCI secondary interrupter.  While testing USB
bus suspend, it was seen that on bus resume, the xHCI HC would run into a command
timeout.
- Added offloading APIs to xHCI to fetch transfer and event ring information.

ASoC:
- Modified soc-usb to allow for multiple USB port additions.  For this to work,
the USB offload driver has to have a reference to the USB backend by adding
a "usb-soc-be" DT entry to the device saved into XHCI sysdev.
- Created separate dt-bindings for defining USB_RX port.
- Increased APR timeout to accommodate the situation where the AFE port start
command could be delayed due to having to issue a USB bus resume while
handling the QMI stream start command.

USB SND:
- Added a platform ops during usb_audio_suspend().  This allows for the USB
offload driver to halt the audio stream when system enters PM suspend.  This
ensures the audio DSP is not issuing transfers on the USB bus.
- Do not override platform ops if they are already populated.
- Introduce a shared status variable between the USB offload and USB SND layers,
to ensure that only one path is active at a time.  If the USB bus is occupied,
then userspace is notified that the path is busy.

Mathias Nyman (4):
  xhci: split free interrupter into separate remove and free parts
  xhci: add support to allocate several interrupters
  xhci: add helper to stop endpoint and wait for completion
  xhci: sideband: add initial api to register a sideband entity

Wesley Cheng (30):
  usb: host: xhci-mem: Cleanup pending secondary event ring events
  usb: host: xhci-mem: Allow for interrupter clients to choose specific
    index
  ASoC: Add SOC USB APIs for adding an USB backend
  ASoC: dt-bindings: qcom,q6dsp-lpass-ports: Add USB_RX port
  ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp
  ASoC: qdsp6: q6afe: Increase APR timeout
  ASoC: qcom: qdsp6: Add USB backend ASoC driver for Q6
  ALSA: usb-audio: Introduce USB SND platform op callbacks
  ALSA: usb-audio: Export USB SND APIs for modules
  dt-bindings: usb: xhci: Add num-hc-interrupters definition
  dt-bindings: usb: dwc3: Limit num-hc-interrupters definition
  usb: dwc3: Specify maximum number of XHCI interrupters
  usb: host: xhci-plat: Set XHCI max interrupters if property is present
  ALSA: usb-audio: qcom: Add USB QMI definitions
  ALSA: usb-audio: qcom: Introduce QC USB SND offloading support
  ALSA: usb-audio: Check for support for requested audio format
  ASoC: usb: Add PCM format check API for USB backend
  ASoC: qcom: qdsp6: Ensure PCM format is supported by USB audio device
  ALSA: usb-audio: Prevent starting of audio stream if in use
  ASoC: dt-bindings: Add Q6USB backend
  ASoC: dt-bindings: Update example for enabling USB offload on SM8250
  ASoC: qcom: qdsp6: q6afe: Split USB AFE dev_token param into separate
    API
  ALSA: usb-audio: qcom: Populate PCM and USB chip information
  ASoC: qcom: qdsp6: Add support to track available USB PCM devices
  ASoC: qcom: qdsp6: Add SND kcontrol to select offload device
  ASoC: qcom: qdsp6: Add SND kcontrol for fetching offload status
  ASoC: qcom: qdsp6: Add headphone jack for offload connection status
  ALSA: usb-audio: qcom: Use card and PCM index from QMI request
  ALSA: usb-audio: Allow for rediscovery of connected USB SND devices
  ASoC: usb: Rediscover USB SND devices on USB port add

 .../devicetree/bindings/sound/qcom,q6usb.yaml |   55 +
 .../bindings/sound/qcom,sm8250.yaml           |   15 +
 .../devicetree/bindings/usb/snps,dwc3.yaml    |    4 +
 .../devicetree/bindings/usb/usb-xhci.yaml     |    6 +
 drivers/usb/dwc3/core.c                       |   12 +
 drivers/usb/dwc3/core.h                       |    2 +
 drivers/usb/dwc3/host.c                       |    5 +-
 drivers/usb/host/Kconfig                      |    9 +
 drivers/usb/host/Makefile                     |    4 +
 drivers/usb/host/xhci-debugfs.c               |    2 +-
 drivers/usb/host/xhci-mem.c                   |  136 +-
 drivers/usb/host/xhci-plat.c                  |    2 +
 drivers/usb/host/xhci-ring.c                  |   53 +-
 drivers/usb/host/xhci-sideband.c              |  372 ++++
 drivers/usb/host/xhci.c                       |  114 +-
 drivers/usb/host/xhci.h                       |   18 +-
 .../sound/qcom,q6dsp-lpass-ports.h            |    1 +
 include/linux/usb/xhci-sideband.h             |   67 +
 include/sound/q6usboffload.h                  |   20 +
 include/sound/soc-usb.h                       |   51 +
 sound/soc/Makefile                            |    2 +-
 sound/soc/qcom/Kconfig                        |    4 +
 sound/soc/qcom/qdsp6/Makefile                 |    1 +
 sound/soc/qcom/qdsp6/q6afe-dai.c              |   56 +
 sound/soc/qcom/qdsp6/q6afe.c                  |  206 +-
 sound/soc/qcom/qdsp6/q6afe.h                  |   36 +-
 sound/soc/qcom/qdsp6/q6dsp-lpass-ports.c      |   23 +
 sound/soc/qcom/qdsp6/q6dsp-lpass-ports.h      |    1 +
 sound/soc/qcom/qdsp6/q6routing.c              |    9 +
 sound/soc/qcom/qdsp6/q6usb.c                  |  450 ++++
 sound/soc/soc-usb.c                           |  201 ++
 sound/usb/Kconfig                             |   15 +
 sound/usb/Makefile                            |    2 +-
 sound/usb/card.c                              |  123 ++
 sound/usb/card.h                              |   23 +
 sound/usb/endpoint.c                          |    1 +
 sound/usb/helper.c                            |    1 +
 sound/usb/pcm.c                               |   94 +-
 sound/usb/pcm.h                               |   11 +
 sound/usb/qcom/Makefile                       |    2 +
 sound/usb/qcom/qc_audio_offload.c             | 1867 +++++++++++++++++
 sound/usb/qcom/usb_audio_qmi_v01.c            |  892 ++++++++
 sound/usb/qcom/usb_audio_qmi_v01.h            |  162 ++
 43 files changed, 5041 insertions(+), 89 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/sound/qcom,q6usb.yaml
 create mode 100644 drivers/usb/host/xhci-sideband.c
 create mode 100644 include/linux/usb/xhci-sideband.h
 create mode 100644 include/sound/q6usboffload.h
 create mode 100644 include/sound/soc-usb.h
 create mode 100644 sound/soc/qcom/qdsp6/q6usb.c
 create mode 100644 sound/soc/soc-usb.c
 create mode 100644 sound/usb/qcom/Makefile
 create mode 100644 sound/usb/qcom/qc_audio_offload.c
 create mode 100644 sound/usb/qcom/usb_audio_qmi_v01.c
 create mode 100644 sound/usb/qcom/usb_audio_qmi_v01.h

[PATCH v9 01/34] xhci: split free interrupter into separate remove and free parts

[Wesley Cheng]

From: Mathias Nyman <mathias.nyman@linux.intel.com>

The current function that both removes and frees an interrupter isn't
optimal when using several interrupters. The array of interrupters need
to be protected with a lock while removing interrupters, but the default
xhci spin lock can't be used while freeing the interrupters event ring
segment table as dma_free_coherent() should be called with IRQs enabled.

There is no need to free the interrupter under the lock, so split this
code into separate unlocked free part, and a lock protected remove part.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/xhci-mem.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 0a37f0d511cf..0994ca9fba44 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1797,23 +1797,14 @@ int xhci_alloc_erst(struct xhci_hcd *xhci,
 }
 
 static void
-xhci_free_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
+xhci_remove_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
 {
-	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
-	size_t erst_size;
 	u64 tmp64;
 	u32 tmp;
 
 	if (!ir)
 		return;
 
-	erst_size = sizeof(struct xhci_erst_entry) * ir->erst.num_entries;
-	if (ir->erst.entries)
-		dma_free_coherent(dev, erst_size,
-				  ir->erst.entries,
-				  ir->erst.erst_dma_addr);
-	ir->erst.entries = NULL;
-
 	/*
 	 * Clean out interrupter registers except ERSTBA. Clearing either the
 	 * low or high 32 bits of ERSTBA immediately causes the controller to
@@ -1828,10 +1819,28 @@ xhci_free_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
 		tmp64 &= (u64) ERST_PTR_MASK;
 		xhci_write_64(xhci, tmp64, &ir->ir_set->erst_dequeue);
 	}
+}
+
+static void
+xhci_free_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
+{
+	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+	size_t erst_size;
+
+	if (!ir)
+		return;
+
+	erst_size = sizeof(struct xhci_erst_entry) * ir->erst.num_entries;
+	if (ir->erst.entries)
+		dma_free_coherent(dev, erst_size,
+				  ir->erst.entries,
+				  ir->erst.erst_dma_addr);
+	ir->erst.entries = NULL;
 
-	/* free interrrupter event ring */
+	/* free interrupter event ring */
 	if (ir->event_ring)
 		xhci_ring_free(xhci, ir->event_ring);
+
 	ir->event_ring = NULL;
 
 	kfree(ir);
@@ -1844,6 +1853,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 
 	cancel_delayed_work_sync(&xhci->cmd_timer);
 
+	xhci_remove_interrupter(xhci, xhci->interrupter);
 	xhci_free_interrupter(xhci, xhci->interrupter);
 	xhci->interrupter = NULL;
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Freed primary event ring");

[PATCH v9 02/34] xhci: add support to allocate several interrupters

[Wesley Cheng]

From: Mathias Nyman <mathias.nyman@linux.intel.com>

Modify the XHCI drivers to accommodate for handling multiple event rings in
case there are multiple interrupters.  Add the required APIs so clients are
able to allocate/request for an interrupter ring, and pass this information
back to the client driver.  This allows for users to handle the resource
accordingly, such as passing the event ring base address to an audio DSP.
There is no actual support for multiple MSI/MSI-X vectors.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/xhci-debugfs.c |  2 +-
 drivers/usb/host/xhci-mem.c     | 99 ++++++++++++++++++++++++++++++---
 drivers/usb/host/xhci-ring.c    |  2 +-
 drivers/usb/host/xhci.c         | 51 +++++++++++------
 drivers/usb/host/xhci.h         |  5 +-
 5 files changed, 130 insertions(+), 29 deletions(-)

diff --git a/drivers/usb/host/xhci-debugfs.c b/drivers/usb/host/xhci-debugfs.c
index 99baa60ef50f..15a8402ee8a1 100644
--- a/drivers/usb/host/xhci-debugfs.c
+++ b/drivers/usb/host/xhci-debugfs.c
@@ -693,7 +693,7 @@ void xhci_debugfs_init(struct xhci_hcd *xhci)
 				     "command-ring",
 				     xhci->debugfs_root);
 
-	xhci_debugfs_create_ring_dir(xhci, &xhci->interrupter->event_ring,
+	xhci_debugfs_create_ring_dir(xhci, &xhci->interrupters[0]->event_ring,
 				     "event-ring",
 				     xhci->debugfs_root);
 
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 0994ca9fba44..ded105a23cce 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1846,6 +1846,31 @@ xhci_free_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
 	kfree(ir);
 }
 
+void xhci_remove_secondary_interrupter(struct usb_hcd *hcd, struct xhci_interrupter *ir)
+{
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	unsigned int intr_num;
+
+	/* interrupter 0 is primary interrupter, don't touch it */
+	if (!ir || !ir->intr_num || ir->intr_num >= xhci->max_interrupters)
+		xhci_dbg(xhci, "Invalid secondary interrupter, can't remove\n");
+
+	/* fixme, should we check xhci->interrupter[intr_num] == ir */
+	/* fixme locking */
+
+	spin_lock_irq(&xhci->lock);
+
+	intr_num = ir->intr_num;
+
+	xhci_remove_interrupter(xhci, ir);
+	xhci->interrupters[intr_num] = NULL;
+
+	spin_unlock_irq(&xhci->lock);
+
+	xhci_free_interrupter(xhci, ir);
+}
+EXPORT_SYMBOL_GPL(xhci_remove_secondary_interrupter);
+
 void xhci_mem_cleanup(struct xhci_hcd *xhci)
 {
 	struct device	*dev = xhci_to_hcd(xhci)->self.sysdev;
@@ -1853,10 +1878,14 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 
 	cancel_delayed_work_sync(&xhci->cmd_timer);
 
-	xhci_remove_interrupter(xhci, xhci->interrupter);
-	xhci_free_interrupter(xhci, xhci->interrupter);
-	xhci->interrupter = NULL;
-	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Freed primary event ring");
+	for (i = 0; i < xhci->max_interrupters; i++) {
+		if (xhci->interrupters[i]) {
+			xhci_remove_interrupter(xhci, xhci->interrupters[i]);
+			xhci_free_interrupter(xhci, xhci->interrupters[i]);
+			xhci->interrupters[i] = NULL;
+		}
+	}
+	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "Freed interrupters");
 
 	if (xhci->cmd_ring)
 		xhci_ring_free(xhci, xhci->cmd_ring);
@@ -1926,6 +1955,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 	for (i = 0; i < xhci->num_port_caps; i++)
 		kfree(xhci->port_caps[i].psi);
 	kfree(xhci->port_caps);
+	kfree(xhci->interrupters);
 	xhci->num_port_caps = 0;
 
 	xhci->usb2_rhub.ports = NULL;
@@ -1934,6 +1964,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 	xhci->rh_bw = NULL;
 	xhci->ext_caps = NULL;
 	xhci->port_caps = NULL;
+	xhci->interrupters = NULL;
 
 	xhci->page_size = 0;
 	xhci->page_shift = 0;
@@ -2286,6 +2317,13 @@ xhci_add_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir,
 		return -EINVAL;
 	}
 
+	if (xhci->interrupters[intr_num]) {
+		xhci_warn(xhci, "Interrupter %d\n already set up", intr_num);
+		return -EINVAL;
+	}
+
+	xhci->interrupters[intr_num] = ir;
+	ir->intr_num = intr_num;
 	ir->ir_set = &xhci->run_regs->ir_set[intr_num];
 
 	/* set ERST count with the number of entries in the segment table */
@@ -2305,10 +2343,52 @@ xhci_add_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir,
 	return 0;
 }
 
+struct xhci_interrupter *
+xhci_create_secondary_interrupter(struct usb_hcd *hcd)
+{
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	struct xhci_interrupter *ir;
+	unsigned int i;
+	int err = -ENOSPC;
+
+	if (!xhci->interrupters)
+		return NULL;
+
+	ir = xhci_alloc_interrupter(xhci, GFP_KERNEL);
+	if (!ir)
+		return NULL;
+
+	spin_lock_irq(&xhci->lock);
+
+	/* Find available secondary interrupter, interrupter 0 is reserved for primary */
+	for (i = 1; i < xhci->max_interrupters; i++) {
+		if (xhci->interrupters[i] == NULL) {
+			err = xhci_add_interrupter(xhci, ir, i);
+			break;
+		}
+	}
+
+	spin_unlock_irq(&xhci->lock);
+
+	if (err) {
+		xhci_warn(xhci, "Failed to add secondary interrupter, max interrupters %d\n",
+			  xhci->max_interrupters);
+		xhci_free_interrupter(xhci, ir);
+		return NULL;
+	}
+
+	xhci_dbg(xhci, "Add secondary interrupter %d, max interrupters %d\n",
+		 i, xhci->max_interrupters);
+
+	return ir;
+}
+EXPORT_SYMBOL_GPL(xhci_create_secondary_interrupter);
+
 int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 {
-	dma_addr_t	dma;
+	struct xhci_interrupter *ir;
 	struct device	*dev = xhci_to_hcd(xhci)->self.sysdev;
+	dma_addr_t	dma;
 	unsigned int	val, val2;
 	u64		val_64;
 	u32		page_size, temp;
@@ -2432,11 +2512,14 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	/* Allocate and set up primary interrupter 0 with an event ring. */
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init,
 		       "Allocating primary event ring");
-	xhci->interrupter = xhci_alloc_interrupter(xhci, flags);
-	if (!xhci->interrupter)
+	xhci->interrupters = kcalloc_node(xhci->max_interrupters, sizeof(*xhci->interrupters),
+					  flags, dev_to_node(dev));
+
+	ir = xhci_alloc_interrupter(xhci, flags);
+	if (!ir)
 		goto fail;
 
-	if (xhci_add_interrupter(xhci, xhci->interrupter, 0))
+	if (xhci_add_interrupter(xhci, ir, 0))
 		goto fail;
 
 	xhci->isoc_bei_interval = AVOID_BEI_INTERVAL_MAX;
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 3e5dc0723a8f..d6fd1588cb67 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3076,7 +3076,7 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 	writel(status, &xhci->op_regs->status);
 
 	/* This is the handler of the primary interrupter */
-	ir = xhci->interrupter;
+	ir = xhci->interrupters[0];
 	if (!hcd->msi_enabled) {
 		u32 irq_pending;
 		irq_pending = readl(&ir->ir_set->irq_pending);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index e1b1b64a0723..2c7b888d44fc 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -456,7 +456,7 @@ static int xhci_init(struct usb_hcd *hcd)
 
 static int xhci_run_finished(struct xhci_hcd *xhci)
 {
-	struct xhci_interrupter *ir = xhci->interrupter;
+	struct xhci_interrupter *ir = xhci->interrupters[0];
 	unsigned long	flags;
 	u32		temp;
 
@@ -508,7 +508,7 @@ int xhci_run(struct usb_hcd *hcd)
 	u64 temp_64;
 	int ret;
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-	struct xhci_interrupter *ir = xhci->interrupter;
+	struct xhci_interrupter *ir = xhci->interrupters[0];
 	/* Start the xHCI host controller running only after the USB 2.0 roothub
 	 * is setup.
 	 */
@@ -572,7 +572,7 @@ void xhci_stop(struct usb_hcd *hcd)
 {
 	u32 temp;
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-	struct xhci_interrupter *ir = xhci->interrupter;
+	struct xhci_interrupter *ir = xhci->interrupters[0];
 
 	mutex_lock(&xhci->mutex);
 
@@ -668,36 +668,51 @@ EXPORT_SYMBOL_GPL(xhci_shutdown);
 #ifdef CONFIG_PM
 static void xhci_save_registers(struct xhci_hcd *xhci)
 {
-	struct xhci_interrupter *ir = xhci->interrupter;
+	struct xhci_interrupter *ir;
+	unsigned int i;
 
 	xhci->s3.command = readl(&xhci->op_regs->command);
 	xhci->s3.dev_nt = readl(&xhci->op_regs->dev_notification);
 	xhci->s3.dcbaa_ptr = xhci_read_64(xhci, &xhci->op_regs->dcbaa_ptr);
 	xhci->s3.config_reg = readl(&xhci->op_regs->config_reg);
 
-	if (!ir)
-		return;
+	/* save both primary and all secondary interrupters */
+	/* fixme, shold we lock  to prevent race with remove secondary interrupter? */
+	for (i = 0; i < xhci->max_interrupters; i++) {
+		ir = xhci->interrupters[i];
+		if (!ir)
+			continue;
 
-	ir->s3_erst_size = readl(&ir->ir_set->erst_size);
-	ir->s3_erst_base = xhci_read_64(xhci, &ir->ir_set->erst_base);
-	ir->s3_erst_dequeue = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
-	ir->s3_irq_pending = readl(&ir->ir_set->irq_pending);
-	ir->s3_irq_control = readl(&ir->ir_set->irq_control);
+		ir->s3_erst_size = readl(&ir->ir_set->erst_size);
+		ir->s3_erst_base = xhci_read_64(xhci, &ir->ir_set->erst_base);
+		ir->s3_erst_dequeue = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
+		ir->s3_irq_pending = readl(&ir->ir_set->irq_pending);
+		ir->s3_irq_control = readl(&ir->ir_set->irq_control);
+	}
 }
 
 static void xhci_restore_registers(struct xhci_hcd *xhci)
 {
-	struct xhci_interrupter *ir = xhci->interrupter;
+	struct xhci_interrupter *ir;
+	unsigned int i;
 
 	writel(xhci->s3.command, &xhci->op_regs->command);
 	writel(xhci->s3.dev_nt, &xhci->op_regs->dev_notification);
 	xhci_write_64(xhci, xhci->s3.dcbaa_ptr, &xhci->op_regs->dcbaa_ptr);
 	writel(xhci->s3.config_reg, &xhci->op_regs->config_reg);
-	writel(ir->s3_erst_size, &ir->ir_set->erst_size);
-	xhci_write_64(xhci, ir->s3_erst_base, &ir->ir_set->erst_base);
-	xhci_write_64(xhci, ir->s3_erst_dequeue, &ir->ir_set->erst_dequeue);
-	writel(ir->s3_irq_pending, &ir->ir_set->irq_pending);
-	writel(ir->s3_irq_control, &ir->ir_set->irq_control);
+
+	/* FIXME should we lock to protect against freeing of interrupters */
+	for (i = 0; i < xhci->max_interrupters; i++) {
+		ir = xhci->interrupters[i];
+		if (!ir)
+			continue;
+
+		writel(ir->s3_erst_size, &ir->ir_set->erst_size);
+		xhci_write_64(xhci, ir->s3_erst_base, &ir->ir_set->erst_base);
+		xhci_write_64(xhci, ir->s3_erst_dequeue, &ir->ir_set->erst_dequeue);
+		writel(ir->s3_irq_pending, &ir->ir_set->irq_pending);
+		writel(ir->s3_irq_control, &ir->ir_set->irq_control);
+	}
 }
 
 static void xhci_set_cmd_ring_deq(struct xhci_hcd *xhci)
@@ -1059,7 +1074,7 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg)
 		xhci_dbg(xhci, "// Disabling event ring interrupts\n");
 		temp = readl(&xhci->op_regs->status);
 		writel((temp & ~0x1fff) | STS_EINT, &xhci->op_regs->status);
-		xhci_disable_interrupter(xhci->interrupter);
+		xhci_disable_interrupter(xhci->interrupters[0]);
 
 		xhci_dbg(xhci, "cleaning up memory\n");
 		xhci_mem_cleanup(xhci);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 8342076cb309..97e313d8a03c 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1772,7 +1772,7 @@ struct xhci_hcd {
 	struct reset_control *reset;
 	/* data structures */
 	struct xhci_device_context_array *dcbaa;
-	struct xhci_interrupter *interrupter;
+	struct xhci_interrupter **interrupters;
 	struct xhci_ring	*cmd_ring;
 	unsigned int            cmd_ring_state;
 #define CMD_RING_STATE_RUNNING         (1 << 0)
@@ -2088,6 +2088,9 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 		int type, gfp_t flags);
 void xhci_free_container_ctx(struct xhci_hcd *xhci,
 		struct xhci_container_ctx *ctx);
+struct xhci_interrupter *xhci_create_secondary_interrupter(struct usb_hcd *hcd);
+void xhci_remove_secondary_interrupter(struct usb_hcd
+				       *hcd, struct xhci_interrupter *ir);
 
 /* xHCI host controller glue */
 typedef void (*xhci_get_quirks_t)(struct device *, struct xhci_hcd *);

[PATCH v9 03/34] xhci: add helper to stop endpoint and wait for completion

[Wesley Cheng]

From: Mathias Nyman <mathias.nyman@linux.intel.com>

Expose xhci_stop_endpoint_sync() which is a synchronous variant of
xhci_queue_stop_endpoint().  This is useful for client drivers that are
using the secondary interrupters, and need to stop/clean up the current
session.  The stop endpoint command handler will also take care of cleaning
up the ring.

Modifications to repurpose the new API into existing stop endpoint
sequences was implemented by Wesley Cheng.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Co-developed-by: Wesley Cheng <quic_wcheng@quicinc.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/xhci.c | 61 ++++++++++++++++++++++++++++++-----------
 drivers/usb/host/xhci.h |  2 ++
 2 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 2c7b888d44fc..6465acca7c79 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2760,6 +2760,47 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,
 	return -ENOMEM;
 }
 
+/*
+ * Synchronous XHCI stop endpoint helper.  Issues the stop endpoint command and
+ * waits for the command completion before returning.
+ */
+int xhci_stop_endpoint_sync(struct xhci_hcd *xhci, struct xhci_virt_ep *ep, int suspend,
+			    gfp_t gfp_flags)
+{
+	struct xhci_command *command;
+	unsigned long flags;
+	int ret;
+
+	command = xhci_alloc_command(xhci, true, GFP_KERNEL);
+	if (!command)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&xhci->lock, flags);
+	ret = xhci_queue_stop_endpoint(xhci, command, ep->vdev->slot_id,
+				       ep->ep_index, suspend);
+	if (ret < 0) {
+		spin_unlock_irqrestore(&xhci->lock, flags);
+		goto out;
+	}
+
+	xhci_ring_cmd_db(xhci);
+	spin_unlock_irqrestore(&xhci->lock, flags);
+
+	ret = wait_for_completion_timeout(command->completion, msecs_to_jiffies(3000));
+	if (!ret)
+		xhci_warn(xhci, "%s: Unable to stop endpoint.\n",
+				__func__);
+
+	if (command->status == COMP_COMMAND_ABORTED ||
+	    command->status == COMP_COMMAND_RING_STOPPED) {
+		xhci_warn(xhci, "Timeout while waiting for stop endpoint command\n");
+		ret = -ETIME;
+	}
+out:
+	xhci_free_command(xhci, command);
+
+	return ret;
+}
 
 /* Issue a configure endpoint command or evaluate context command
  * and wait for it to finish.
@@ -3080,7 +3121,7 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 	struct xhci_virt_device *vdev;
 	struct xhci_virt_ep *ep;
 	struct xhci_input_control_ctx *ctrl_ctx;
-	struct xhci_command *stop_cmd, *cfg_cmd;
+	struct xhci_command *cfg_cmd;
 	unsigned int ep_index;
 	unsigned long flags;
 	u32 ep_flag;
@@ -3120,10 +3161,6 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 	if (ep_flag == SLOT_FLAG || ep_flag == EP0_FLAG)
 		return;
 
-	stop_cmd = xhci_alloc_command(xhci, true, GFP_NOWAIT);
-	if (!stop_cmd)
-		return;
-
 	cfg_cmd = xhci_alloc_command_with_ctx(xhci, true, GFP_NOWAIT);
 	if (!cfg_cmd)
 		goto cleanup;
@@ -3146,23 +3183,16 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 		goto cleanup;
 	}
 
-	err = xhci_queue_stop_endpoint(xhci, stop_cmd, udev->slot_id,
-					ep_index, 0);
+	spin_unlock_irqrestore(&xhci->lock, flags);
+
+	err = xhci_stop_endpoint_sync(xhci, ep, 0, GFP_NOWAIT);
 	if (err < 0) {
-		spin_unlock_irqrestore(&xhci->lock, flags);
-		xhci_free_command(xhci, cfg_cmd);
 		xhci_dbg(xhci, "%s: Failed to queue stop ep command, %d ",
 				__func__, err);
 		goto cleanup;
 	}
 
-	xhci_ring_cmd_db(xhci);
-	spin_unlock_irqrestore(&xhci->lock, flags);
-
-	wait_for_completion(stop_cmd->completion);
-
 	spin_lock_irqsave(&xhci->lock, flags);
-
 	/* config ep command clears toggle if add and drop ep flags are set */
 	ctrl_ctx = xhci_get_input_control_ctx(cfg_cmd->in_ctx);
 	if (!ctrl_ctx) {
@@ -3194,7 +3224,6 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 
 	xhci_free_command(xhci, cfg_cmd);
 cleanup:
-	xhci_free_command(xhci, stop_cmd);
 	spin_lock_irqsave(&xhci->lock, flags);
 	if (ep->ep_state & EP_SOFT_CLEAR_TOGGLE)
 		ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 97e313d8a03c..4b8caaed6f95 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -2174,6 +2174,8 @@ void xhci_ring_doorbell_for_active_rings(struct xhci_hcd *xhci,
 void xhci_cleanup_command_queue(struct xhci_hcd *xhci);
 void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring);
 unsigned int count_trbs(u64 addr, u64 len);
+int xhci_stop_endpoint_sync(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
+			    int suspend, gfp_t gfp_flags);
 
 /* xHCI roothub code */
 void xhci_set_link_state(struct xhci_hcd *xhci, struct xhci_port *port,

[PATCH v9 04/34] xhci: sideband: add initial api to register a sideband entity

[Wesley Cheng]

From: Mathias Nyman <mathias.nyman@linux.intel.com>

Introduce XHCI sideband, which manages the USB endpoints being requested by
a client driver.  This is used for when client drivers are attempting to
offload USB endpoints to another entity for handling USB transfers.  XHCI
sideband will allow for drivers to fetch the required information about the
transfer ring, so the user can submit transfers independently.  Expose the
required APIs for drivers to register and request for a USB endpoint and to
manage XHCI secondary interrupters.

Multiple ring segment page linking and proper endpoint clean up added by
Wesley Cheng to complete original concept code by Mathias Nyman.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Co-developed-by: Wesley Cheng <quic_wcheng@quicinc.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/Kconfig          |   9 +
 drivers/usb/host/Makefile         |   4 +
 drivers/usb/host/xhci-sideband.c  | 371 ++++++++++++++++++++++++++++++
 drivers/usb/host/xhci.h           |   4 +
 include/linux/usb/xhci-sideband.h |  66 ++++++
 5 files changed, 454 insertions(+)
 create mode 100644 drivers/usb/host/xhci-sideband.c
 create mode 100644 include/linux/usb/xhci-sideband.h

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 4448d0ab06f0..923af11c1982 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -104,6 +104,15 @@ config USB_XHCI_RZV2M
 	  Say 'Y' to enable the support for the xHCI host controller
 	  found in Renesas RZ/V2M SoC.
 
+config USB_XHCI_SIDEBAND
+	bool "xHCI support for sideband"
+	help
+	  Say 'Y' to enable the support for the xHCI sideband capability.
+	  provide a mechanism for a sideband datapath for payload associated
+	  with audio class endpoints. This allows for an audio DSP to use
+	  xHCI USB endpoints directly, allowing CPU to sleep while playing
+	  audio
+
 config USB_XHCI_TEGRA
 	tristate "xHCI support for NVIDIA Tegra SoCs"
 	depends on PHY_TEGRA_XUSB
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index be4e5245c52f..4df946c05ba0 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -32,6 +32,10 @@ endif
 xhci-rcar-hcd-y				+= xhci-rcar.o
 xhci-rcar-hcd-$(CONFIG_USB_XHCI_RZV2M)	+= xhci-rzv2m.o
 
+ifneq ($(CONFIG_USB_XHCI_SIDEBAND),)
+	xhci-hcd-y		+= xhci-sideband.o
+endif
+
 obj-$(CONFIG_USB_PCI)	+= pci-quirks.o
 
 obj-$(CONFIG_USB_EHCI_HCD)	+= ehci-hcd.o
diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c
new file mode 100644
index 000000000000..cc4f90375e00
--- /dev/null
+++ b/drivers/usb/host/xhci-sideband.c
@@ -0,0 +1,371 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * xHCI host controller sideband support
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ *
+ * Author: Mathias Nyman
+ */
+
+#include <linux/usb/xhci-sideband.h>
+#include <linux/dma-direct.h>
+
+#include "xhci.h"
+
+/* sideband internal helpers */
+static struct sg_table *
+xhci_ring_to_sgtable(struct xhci_sideband *sb, struct xhci_ring *ring)
+{
+	struct xhci_segment *seg;
+	struct sg_table	*sgt;
+	unsigned int n_pages;
+	struct page **pages;
+	struct device *dev;
+	size_t sz;
+	int i;
+
+	dev = xhci_to_hcd(sb->xhci)->self.sysdev;
+	sz = ring->num_segs * TRB_SEGMENT_SIZE;
+	n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
+	pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL);
+	if (!pages)
+		return NULL;
+
+	sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
+	if (!sgt) {
+		kvfree(pages);
+		return NULL;
+	}
+
+	seg = ring->first_seg;
+	/*
+	 * Rings can potentially have multiple segments, create an array that
+	 * carries page references to allocated segments.  Utilize the
+	 * sg_alloc_table_from_pages() to create the sg table, and to ensure
+	 * that page links are created.
+	 */
+	for (i = 0; i < ring->num_segs; i++) {
+		dma_get_sgtable(dev, sgt, seg->trbs, seg->dma,
+					TRB_SEGMENT_SIZE);
+		pages[i] = sg_page(sgt->sgl);
+		sg_free_table(sgt);
+		seg = seg->next;
+	}
+
+	if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) {
+		kvfree(pages);
+		kfree(sgt);
+
+		return NULL;
+	}
+	/*
+	 * Save first segment dma address to sg dma_address field for the sideband
+	 * client to have access to the IOVA of the ring.
+	 */
+	sg_dma_address(sgt->sgl) = ring->first_seg->dma;
+
+	return sgt;
+}
+
+static void
+__xhci_sideband_remove_endpoint(struct xhci_sideband *sb, struct xhci_virt_ep *ep)
+{
+	/*
+	 * Issue a stop endpoint command when an endpoint is removed.
+	 * The stop ep cmd handler will handle the ring cleanup.
+	 */
+	xhci_stop_endpoint_sync(sb->xhci, ep, 0, GFP_KERNEL);
+
+	ep->sideband = NULL;
+	sb->eps[ep->ep_index] = NULL;
+}
+
+/* sideband api functions */
+
+/**
+ * xhci_sideband_add_endpoint - add endpoint to sideband access list
+ * @sb: sideband instance for this usb device
+ * @host_ep: usb host endpoint
+ *
+ * Adds an endpoint to the list of sideband accessed endpoints for this usb
+ * device.
+ * After an endpoint is added the sideband client can get the endpoint transfer
+ * ring buffer by calling xhci_sideband_endpoint_buffer()
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+int
+xhci_sideband_add_endpoint(struct xhci_sideband *sb,
+			   struct usb_host_endpoint *host_ep)
+{
+	struct xhci_virt_ep *ep;
+	unsigned int ep_index;
+
+	ep_index = xhci_get_endpoint_index(&host_ep->desc);
+	ep = &sb->vdev->eps[ep_index];
+
+	if (ep->ep_state & EP_HAS_STREAMS)
+		return -EINVAL;
+
+	/*
+	 * Note, we don't know the DMA mask of the audio DSP device, if its
+	 * smaller than for xhci it won't be able to access the endpoint ring
+	 * buffer. This could be solved by not allowing the audio class driver
+	 * to add the endpoint the normal way, but instead offload it immediately,
+	 * and let this function add the endpoint and allocate the ring buffer
+	 * with the smallest common DMA mask
+	 */
+
+	if (sb->eps[ep_index] || ep->sideband)
+		return -EBUSY;
+
+	ep->sideband = sb;
+	sb->eps[ep_index] = ep;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_add_endpoint);
+
+/**
+ * xhci_sideband_remove_endpoint - remove endpoint from sideband access list
+ * @sb: sideband instance for this usb device
+ * @host_ep: usb host endpoint
+ *
+ * Removes an endpoint from the list of sideband accessed endpoints for this usb
+ * device.
+ * sideband client should no longer touch the endpoint transfer buffer after
+ * calling this.
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+int
+xhci_sideband_remove_endpoint(struct xhci_sideband *sb,
+			      struct usb_host_endpoint *host_ep)
+{
+	struct xhci_virt_ep *ep;
+	unsigned int ep_index;
+
+	ep_index = xhci_get_endpoint_index(&host_ep->desc);
+	ep = sb->eps[ep_index];
+
+	if (!ep || !ep->sideband)
+		return -ENODEV;
+
+	__xhci_sideband_remove_endpoint(sb, ep);
+	xhci_initialize_ring_info(ep->ring, 1);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_remove_endpoint);
+
+int
+xhci_sideband_stop_endpoint(struct xhci_sideband *sb,
+			    struct usb_host_endpoint *host_ep)
+{
+	struct xhci_virt_ep *ep;
+	unsigned int ep_index;
+
+	ep_index = xhci_get_endpoint_index(&host_ep->desc);
+	ep = sb->eps[ep_index];
+
+	if (!ep || ep->sideband != sb)
+		return -EINVAL;
+
+	return xhci_stop_endpoint_sync(sb->xhci, ep, 0);
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_stop_endpoint);
+
+/**
+ * xhci_sideband_get_endpoint_buffer - gets the endpoint transfer buffer address
+ * @sb: sideband instance for this usb device
+ * @host_ep: usb host endpoint
+ *
+ * Returns the address of the endpoint buffer where xHC controller reads queued
+ * transfer TRBs from. This is the starting address of the ringbuffer where the
+ * sidband cliend should write TRBs to.
+ *
+ * Caller needs to free the returned sg_table
+ *
+ * Return: struct sg_table * if successful. NULL otherwise.
+ */
+struct sg_table *
+xhci_sideband_get_endpoint_buffer(struct xhci_sideband *sb,
+			      struct usb_host_endpoint *host_ep)
+{
+	struct xhci_virt_ep *ep;
+	unsigned int ep_index;
+
+	ep_index = xhci_get_endpoint_index(&host_ep->desc);
+	ep = sb->eps[ep_index];
+
+	if (!ep)
+		return NULL;
+
+	return xhci_ring_to_sgtable(sb, ep->ring);
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_get_endpoint_buffer);
+
+/**
+ * xhci_sideband_get_event_buffer - return the event buffer for this device
+ * @sb: sideband instance for this usb device
+ *
+ * If a secondary xhci interupter is set up for this usb device then this
+ * function returns the address of the event buffer where xHC writes
+ * the transfer completion events.
+ *
+ * Caller needs to free the returned sg_table
+ *
+ * Return: struct sg_table * if successful. NULL otherwise.
+ */
+struct sg_table *
+xhci_sideband_get_event_buffer(struct xhci_sideband *sb)
+{
+	if (!sb->ir)
+		return NULL;
+
+	return xhci_ring_to_sgtable(sb, sb->ir->event_ring);
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_get_event_buffer);
+
+/**
+ * xhci_sideband_create_interrupter - creates a new interrupter for this sideband
+ * @sb: sideband instance for this usb device
+ *
+ * Sets up a xhci interrupter that can be used for this sideband accessed usb
+ * device. Transfer events for this device can be routed to this interrupters
+ * event ring by setting the 'Interrupter Target' field correctly when queueing
+ * the transfer TRBs.
+ * Once this interrupter is created the interrupter target ID can be obtained
+ * by calling xhci_sideband_interrupter_id()
+ *
+ * Returns 0 on success, negative error otherwise
+ */
+int
+xhci_sideband_create_interrupter(struct xhci_sideband *sb)
+{
+	if (sb->ir)
+		return -EBUSY;
+
+	sb->ir = xhci_create_secondary_interrupter(xhci_to_hcd(sb->xhci));
+	if (!sb->ir)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_create_interrupter);
+
+/**
+ * xhci_sideband_remove_interrupter - remove the interrupter from a sideband
+ * @sb: sideband instance for this usb device
+ *
+ * Removes a registered interrupt for a sideband.  This would allow for other
+ * sideband users to utilize this interrupter.
+ */
+void
+xhci_sideband_remove_interrupter(struct xhci_sideband *sb)
+{
+	if (!sb || !sb->ir)
+		return;
+
+	xhci_remove_secondary_interrupter(xhci_to_hcd(sb->xhci), sb->ir);
+
+	sb->ir = NULL;
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_remove_interrupter);
+
+/**
+ * xhci_sideband_interrupter_id - return the interrupter target id
+ * @sb: sideband instance for this usb device
+ *
+ * If a secondary xhci interrupter is set up for this usb device then this
+ * function returns the ID used by the interrupter. The sideband client
+ * needs to write this ID to the 'Interrupter Target' field of the transfer TRBs
+ * it queues on the endpoints transfer ring to ensure transfer completion event
+ * are written by xHC to the correct interrupter event ring.
+ *
+ * Returns interrupter id on success, negative error othgerwise
+ */
+int
+xhci_sideband_interrupter_id(struct xhci_sideband *sb)
+{
+	if (!sb || !sb->ir)
+		return -ENODEV;
+
+	return sb->ir->intr_num;
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_interrupter_id);
+
+/**
+ * xhci_sideband_register - register a sideband for a usb device
+ * @udev: usb device to be accessed via sideband
+ *
+ * Allows for clients to utilize XHCI interrupters and fetch transfer and event
+ * ring parameters for executing data transfers.
+ *
+ * Return: pointer to a new xhci_sideband instance if successful. NULL otherwise.
+ */
+struct xhci_sideband *
+xhci_sideband_register(struct usb_device *udev)
+{
+	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	struct xhci_virt_device *vdev;
+	struct xhci_sideband *sb;
+
+	/* make sure the usb device is connected to a xhci controller */
+	if (!udev->slot_id)
+		return NULL;
+
+	sb = kzalloc_node(sizeof(*sb), GFP_KERNEL, dev_to_node(hcd->self.sysdev));
+	if (!sb)
+		return NULL;
+
+	/* check this device isn't already controlled via sideband */
+	spin_lock_irq(&xhci->lock);
+
+	vdev = xhci->devs[udev->slot_id];
+
+	if (!vdev || vdev->sideband) {
+		xhci_warn(xhci, "XHCI sideband for slot %d already in use\n",
+			  udev->slot_id);
+		spin_unlock_irq(&xhci->lock);
+		kfree(sb);
+		return NULL;
+	}
+
+	sb->xhci = xhci;
+	sb->vdev = vdev;
+	vdev->sideband = sb;
+
+	spin_unlock_irq(&xhci->lock);
+
+	return sb;
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_register);
+
+/**
+ * xhci_sideband_unregister - unregister sideband access to a usb device
+ * @sb: sideband instance to be unregistered
+ *
+ * Unregisters sideband access to a usb device and frees the sideband
+ * instance.
+ * After this the endpoint and interrupter event buffers should no longer
+ * be accessed via sideband. The xhci driver can now take over handling
+ * the buffers.
+ */
+void
+xhci_sideband_unregister(struct xhci_sideband *sb)
+{
+	int i;
+
+	for (i = 0; i < EP_CTX_PER_DEV; i++)
+		if (sb->eps[i])
+			__xhci_sideband_remove_endpoint(sb, sb->eps[i]);
+
+	xhci_sideband_remove_interrupter(sb);
+
+	sb->vdev->sideband = NULL;
+	kfree(sb);
+}
+EXPORT_SYMBOL_GPL(xhci_sideband_unregister);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 4b8caaed6f95..339d37c3a3d9 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -947,6 +947,8 @@ struct xhci_virt_ep {
 	int			next_frame_id;
 	/* Use new Isoch TRB layout needed for extended TBC support */
 	bool			use_extended_tbc;
+	/* set if this endpoint is controlled via sideband access*/
+	struct xhci_sideband			*sideband;
 };
 
 enum xhci_overhead_type {
@@ -1010,6 +1012,8 @@ struct xhci_virt_device {
 	u16				current_mel;
 	/* Used for the debugfs interfaces. */
 	void				*debugfs_private;
+	/* set if this device is registered for sideband access */
+	struct xhci_sideband			*sideband;
 };
 
 /*
diff --git a/include/linux/usb/xhci-sideband.h b/include/linux/usb/xhci-sideband.h
new file mode 100644
index 000000000000..c1457d1800f4
--- /dev/null
+++ b/include/linux/usb/xhci-sideband.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * xHCI host controller sideband support
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ *
+ * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
+ */
+
+#ifndef __LINUX_XHCI_SIDEBAND_H
+#define __LINUX_XHCI_SIDEBAND_H
+
+#include <linux/scatterlist.h>
+#include <linux/usb.h>
+
+#define	EP_CTX_PER_DEV		31	/* FIMXME defined twice, from xhci.h */
+
+struct xhci_sideband;
+
+/**
+ * struct xhci_sideband - representation of a sideband accessed usb device.
+ * @xhci: The xhci host controller the usb device is connected to
+ * @vdev: the usb device accessed via sideband
+ * @eps: array of endpoints controlled via sideband
+ * @ir: event handling and buffer for sideband accessed device
+ *
+ * FIXME usb device accessed via sideband Keeping track of sideband accessed usb devices.
+ */
+
+struct xhci_sideband {
+	struct xhci_hcd                 *xhci;
+	struct xhci_virt_device         *vdev;
+	struct xhci_virt_ep             *eps[EP_CTX_PER_DEV];
+	struct xhci_interrupter         *ir;
+};
+
+struct xhci_sideband *
+xhci_sideband_register(struct usb_device *udev);
+void
+xhci_sideband_unregister(struct xhci_sideband *sb);
+int
+xhci_sideband_add_endpoint(struct xhci_sideband *sb,
+			   struct usb_host_endpoint *host_ep);
+int
+xhci_sideband_remove_endpoint(struct xhci_sideband *sb,
+			      struct usb_host_endpoint *host_ep);
+int
+xhci_sideband_stop_endpoint(struct xhci_sideband *sb,
+			    struct usb_host_endpoint *host_ep);
+struct sg_table *
+xhci_sideband_get_endpoint_buffer(struct xhci_sideband *sb,
+				  struct usb_host_endpoint *host_ep);
+struct sg_table *
+xhci_sideband_get_event_buffer(struct xhci_sideband *sb);
+
+int
+xhci_sideband_create_interrupter(struct xhci_sideband *sb);
+
+void
+xhci_sideband_remove_interrupter(struct xhci_sideband *sb);
+
+int
+xhci_sideband_interrupter_id(struct xhci_sideband *sb);
+
+#endif /* __LINUX_XHCI_SIDEBAND_H */
+

[PATCH v9 05/34] usb: host: xhci-mem: Cleanup pending secondary event ring events

[Wesley Cheng]

As part of xHCI bus suspend, the XHCI is halted.  However, if there are
pending events in the secondary event ring, it is observed that the xHCI
controller stops responding to further commands upon host or device
initiated bus resume.  Iterate through all pending events and update the
dequeue pointer to the beginning of the event ring.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/xhci-mem.c  | 13 +++++----
 drivers/usb/host/xhci-ring.c | 51 +++++++++++++++++++++++++++++++++++-
 drivers/usb/host/xhci.c      |  2 +-
 drivers/usb/host/xhci.h      |  6 +++++
 4 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index ded105a23cce..b8936daf6cf5 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1815,9 +1815,7 @@ xhci_remove_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
 		tmp &= ERST_SIZE_MASK;
 		writel(tmp, &ir->ir_set->erst_size);
 
-		tmp64 = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
-		tmp64 &= (u64) ERST_PTR_MASK;
-		xhci_write_64(xhci, tmp64, &ir->ir_set->erst_dequeue);
+		xhci_update_erst_dequeue(xhci, ir, ir->event_ring->first_seg->trbs);
 	}
 }
 
@@ -1855,11 +1853,12 @@ void xhci_remove_secondary_interrupter(struct usb_hcd *hcd, struct xhci_interrup
 	if (!ir || !ir->intr_num || ir->intr_num >= xhci->max_interrupters)
 		xhci_dbg(xhci, "Invalid secondary interrupter, can't remove\n");
 
-	/* fixme, should we check xhci->interrupter[intr_num] == ir */
-	/* fixme locking */
-
 	spin_lock_irq(&xhci->lock);
-
+	/*
+	 * Cleanup secondary interrupter to ensure there are no pending events.
+	 * This also updates event ring dequeue pointer back to the start.
+	 */
+	xhci_skip_sec_intr_events(xhci, ir->event_ring, ir);
 	intr_num = ir->intr_num;
 
 	xhci_remove_interrupter(xhci, ir);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index d6fd1588cb67..eedbc7496769 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2994,7 +2994,7 @@ static int xhci_handle_event(struct xhci_hcd *xhci, struct xhci_interrupter *ir)
  * - When all events have finished
  * - To avoid "Event Ring Full Error" condition
  */
-static void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
+void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
 				     struct xhci_interrupter *ir,
 				     union xhci_trb *event_ring_deq,
 				     bool clear_ehb)
@@ -3028,6 +3028,55 @@ static void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
 	xhci_write_64(xhci, temp_64, &ir->ir_set->erst_dequeue);
 }
 
+/*
+ * Move the event ring dequeue pointer to skip events kept in the secondary
+ * event ring.  This is used to ensure that pending events in the ring are
+ * acknowledged, so the XHCI HCD can properly enter suspend/resume.  The
+ * secondary ring is typically maintained by an external component.
+ */
+void xhci_skip_sec_intr_events(struct xhci_hcd *xhci,
+	struct xhci_ring *ring,	struct xhci_interrupter *ir)
+{
+	union xhci_trb *erdp_trb, *current_trb;
+	struct xhci_segment	*seg;
+	u64 erdp_reg;
+	u32 iman_reg;
+	dma_addr_t deq;
+	unsigned long segment_offset;
+
+	/* disable irq, ack pending interrupt and ack all pending events */
+	xhci_disable_interrupter(ir);
+	iman_reg = readl_relaxed(&ir->ir_set->irq_pending);
+	if (iman_reg & IMAN_IP)
+		writel_relaxed(iman_reg, &ir->ir_set->irq_pending);
+
+	/* last acked event trb is in erdp reg  */
+	erdp_reg = xhci_read_64(xhci, &ir->ir_set->erst_dequeue);
+	deq = (dma_addr_t)(erdp_reg & ~ERST_PTR_MASK);
+	if (!deq) {
+		xhci_dbg(xhci, "event ring handling not required\n");
+		return;
+	}
+
+	seg = ring->first_seg;
+	segment_offset = deq - seg->dma;
+
+	erdp_trb = current_trb = ir->event_ring->dequeue;
+	/* read cycle state of the last acked trb to find out CCS */
+	ring->cycle_state = le32_to_cpu(current_trb->event_cmd.flags) & TRB_CYCLE;
+
+	while (1) {
+		inc_deq(xhci, ir->event_ring);
+		erdp_trb = ir->event_ring->dequeue;
+		/* cycle state transition */
+		if ((le32_to_cpu(erdp_trb->event_cmd.flags) & TRB_CYCLE) !=
+		    ring->cycle_state)
+			break;
+	}
+
+	xhci_update_erst_dequeue(xhci, ir, current_trb);
+}
+
 /*
  * xHCI spec says we can get an interrupt, and if the HC has an error condition,
  * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6465acca7c79..f947526ce3ff 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -309,7 +309,7 @@ static int xhci_enable_interrupter(struct xhci_interrupter *ir)
 	return 0;
 }
 
-static int xhci_disable_interrupter(struct xhci_interrupter *ir)
+int xhci_disable_interrupter(struct xhci_interrupter *ir)
 {
 	u32 iman;
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 339d37c3a3d9..7161b0841368 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -2095,6 +2095,9 @@ void xhci_free_container_ctx(struct xhci_hcd *xhci,
 struct xhci_interrupter *xhci_create_secondary_interrupter(struct usb_hcd *hcd);
 void xhci_remove_secondary_interrupter(struct usb_hcd
 				       *hcd, struct xhci_interrupter *ir);
+void xhci_skip_sec_intr_events(struct xhci_hcd *xhci,
+	struct xhci_ring *ring,	struct xhci_interrupter *ir);
+int xhci_disable_interrupter(struct xhci_interrupter *ir);
 
 /* xHCI host controller glue */
 typedef void (*xhci_get_quirks_t)(struct device *, struct xhci_hcd *);
@@ -2180,6 +2183,9 @@ void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring);
 unsigned int count_trbs(u64 addr, u64 len);
 int xhci_stop_endpoint_sync(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
 			    int suspend, gfp_t gfp_flags);
+void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
+				     struct xhci_interrupter *ir,
+				     union xhci_trb *event_ring_deq);
 
 /* xHCI roothub code */
 void xhci_set_link_state(struct xhci_hcd *xhci, struct xhci_port *port,

[PATCH v9 06/34] usb: host: xhci-mem: Allow for interrupter clients to choose specific index

[Wesley Cheng]

Some clients may operate only on a specific XHCI interrupter instance.
Allow for the associated class driver to request for the interrupter that
it requires.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/xhci-mem.c       | 30 ++++++++++++++++--------------
 drivers/usb/host/xhci-sideband.c  |  5 +++--
 drivers/usb/host/xhci.h           |  3 ++-
 include/linux/usb/xhci-sideband.h |  3 ++-
 4 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index b8936daf6cf5..3d6ee70bd6f7 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2343,7 +2343,7 @@ xhci_add_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir,
 }
 
 struct xhci_interrupter *
-xhci_create_secondary_interrupter(struct usb_hcd *hcd)
+xhci_create_secondary_interrupter(struct usb_hcd *hcd, int intr_num)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 	struct xhci_interrupter *ir;
@@ -2358,28 +2358,30 @@ xhci_create_secondary_interrupter(struct usb_hcd *hcd)
 		return NULL;
 
 	spin_lock_irq(&xhci->lock);
-
-	/* Find available secondary interrupter, interrupter 0 is reserved for primary */
+	/* Find available secondary interrupter, interrupter 0 is reserverd for primary */
 	for (i = 1; i < xhci->max_interrupters; i++) {
-		if (xhci->interrupters[i] == NULL) {
-			err = xhci_add_interrupter(xhci, ir, i);
-			break;
+		if ((intr_num > 0 && i == intr_num) || intr_num <= 0) {
+			if (xhci->interrupters[i] == NULL) {
+				err = xhci_add_interrupter(xhci, ir, i);
+				if (err) {
+					spin_unlock_irq(&xhci->lock);
+					goto free_ir;
+				}
+				break;
+			}
 		}
 	}
-
 	spin_unlock_irq(&xhci->lock);
 
-	if (err) {
-		xhci_warn(xhci, "Failed to add secondary interrupter, max interrupters %d\n",
-			  xhci->max_interrupters);
-		xhci_free_interrupter(xhci, ir);
-		return NULL;
-	}
-
 	xhci_dbg(xhci, "Add secondary interrupter %d, max interrupters %d\n",
 		 i, xhci->max_interrupters);
 
 	return ir;
+
+free_ir:
+	xhci_free_interrupter(xhci, ir);
+
+	return NULL;
 }
 EXPORT_SYMBOL_GPL(xhci_create_secondary_interrupter);
 
diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c
index cc4f90375e00..13a8a260b024 100644
--- a/drivers/usb/host/xhci-sideband.c
+++ b/drivers/usb/host/xhci-sideband.c
@@ -242,12 +242,13 @@ EXPORT_SYMBOL_GPL(xhci_sideband_get_event_buffer);
  * Returns 0 on success, negative error otherwise
  */
 int
-xhci_sideband_create_interrupter(struct xhci_sideband *sb)
+xhci_sideband_create_interrupter(struct xhci_sideband *sb, int intr_num)
 {
 	if (sb->ir)
 		return -EBUSY;
 
-	sb->ir = xhci_create_secondary_interrupter(xhci_to_hcd(sb->xhci));
+	sb->ir = xhci_create_secondary_interrupter(xhci_to_hcd(sb->xhci),
+			intr_num);
 	if (!sb->ir)
 		return -ENOMEM;
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 7161b0841368..23d26f44e9b5 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -2092,7 +2092,8 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 		int type, gfp_t flags);
 void xhci_free_container_ctx(struct xhci_hcd *xhci,
 		struct xhci_container_ctx *ctx);
-struct xhci_interrupter *xhci_create_secondary_interrupter(struct usb_hcd *hcd);
+struct xhci_interrupter *xhci_create_secondary_interrupter(struct usb_hcd *hcd,
+		int intr_num);
 void xhci_remove_secondary_interrupter(struct usb_hcd
 				       *hcd, struct xhci_interrupter *ir);
 void xhci_skip_sec_intr_events(struct xhci_hcd *xhci,
diff --git a/include/linux/usb/xhci-sideband.h b/include/linux/usb/xhci-sideband.h
index c1457d1800f4..7f4080f530d3 100644
--- a/include/linux/usb/xhci-sideband.h
+++ b/include/linux/usb/xhci-sideband.h
@@ -54,7 +54,8 @@ struct sg_table *
 xhci_sideband_get_event_buffer(struct xhci_sideband *sb);
 
 int
-xhci_sideband_create_interrupter(struct xhci_sideband *sb);
+xhci_sideband_create_interrupter(struct xhci_sideband *sb,
+				 int intr_num);
 
 void
 xhci_sideband_remove_interrupter(struct xhci_sideband *sb);

[PATCH v9 07/34] ASoC: Add SOC USB APIs for adding an USB backend

[Wesley Cheng]

Some platforms may have support for offloading USB audio devices to a
dedicated audio DSP.  Introduce a set of APIs that allow for management of
USB sound card and PCM devices enumerated by the USB SND class driver.
This allows for the ASoC components to be aware of what USB devices are
available for offloading.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 include/sound/soc-usb.h |  48 +++++++++++
 sound/soc/Makefile      |   2 +-
 sound/soc/soc-usb.c     | 186 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 235 insertions(+), 1 deletion(-)
 create mode 100644 include/sound/soc-usb.h
 create mode 100644 sound/soc/soc-usb.c

diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
new file mode 100644
index 000000000000..1fa671924018
--- /dev/null
+++ b/include/sound/soc-usb.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef __LINUX_SND_SOC_USB_H
+#define __LINUX_SND_SOC_USB_H
+
+/**
+ * struct snd_soc_usb_device
+ * @card_idx - sound card index associated with USB device
+ * @chip_idx - USB sound chip array index
+ * @num_playback - number of playback streams
+ * @num_capture - number of capture streams
+ **/
+struct snd_soc_usb_device {
+	int card_idx;
+	int chip_idx;
+	int num_playback;
+	int num_capture;
+};
+
+/**
+ * struct snd_soc_usb
+ * @list - list head for SND SOC struct list
+ * @dev - USB backend device reference
+ * @component - reference to ASoC component
+ * @connection_status_cb - callback to notify connection events
+ * @priv_data - driver data
+ **/
+struct snd_soc_usb {
+	struct list_head list;
+	struct device *dev;
+	struct snd_soc_component *component;
+	int (*connection_status_cb)(struct snd_soc_usb *usb,
+			struct snd_soc_usb_device *sdev, bool connected);
+	void *priv_data;
+};
+
+int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
+int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
+void *snd_soc_usb_get_priv_data(struct device *usbdev);
+
+struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
+			int (*connection_cb)(struct snd_soc_usb *usb,
+			struct snd_soc_usb_device *sdev, bool connected));
+int snd_soc_usb_remove_port(struct device *dev);
+#endif
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index 8376fdb217ed..d597cda11abc 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-utils.o soc-dai.o soc-component.o
+snd-soc-core-objs := soc-core.o soc-dapm.o soc-jack.o soc-usb.o soc-utils.o soc-dai.o soc-component.o
 snd-soc-core-objs += soc-pcm.o soc-devres.o soc-ops.o soc-link.o soc-card.o
 snd-soc-core-$(CONFIG_SND_SOC_COMPRESS) += soc-compress.o
 
diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
new file mode 100644
index 000000000000..73b1bcc3b506
--- /dev/null
+++ b/sound/soc/soc-usb.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#include <linux/of.h>
+#include <linux/usb.h>
+#include <sound/soc.h>
+#include <sound/soc-usb.h>
+#include "../usb/card.h"
+
+static DEFINE_MUTEX(ctx_mutex);
+static LIST_HEAD(usb_ctx_list);
+
+static struct device_node *snd_soc_find_phandle(struct device *dev)
+{
+	struct device_node *node;
+
+	node = of_parse_phandle(dev->of_node, "usb-soc-be", 0);
+	if (!node)
+		return ERR_PTR(-ENODEV);
+
+	return node;
+}
+
+static struct snd_soc_usb *snd_soc_find_usb_ctx(struct device_node *node)
+{
+	struct snd_soc_usb *ctx;
+
+	mutex_lock(&ctx_mutex);
+	list_for_each_entry(ctx, &usb_ctx_list, list) {
+		if (ctx->dev->of_node == node) {
+			mutex_unlock(&ctx_mutex);
+			return ctx;
+		}
+	}
+	mutex_unlock(&ctx_mutex);
+
+	return NULL;
+}
+
+/**
+ * snd_soc_usb_find_priv_data() - Retrieve private data stored
+ * @dev: device reference
+ *
+ * Fetch the private data stored in the USB SND SOC structure.
+ *
+ */
+void *snd_soc_usb_find_priv_data(struct device *dev)
+{
+	struct snd_soc_usb *ctx;
+	struct device_node *node;
+
+	node = snd_soc_find_phandle(dev);
+	if (!IS_ERR(node)) {
+		ctx = snd_soc_find_usb_ctx(node);
+		of_node_put(node);
+	} else {
+		/* Check if backend device */
+		ctx = snd_soc_find_usb_ctx(dev->of_node);
+	}
+
+	return ctx ? ctx->priv_data : NULL;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_find_priv_data);
+
+/**
+ * snd_soc_usb_add_port() - Add a USB backend port
+ * @dev: USB backend device
+ * @priv: private data
+ * @connection_cb: connection status callback
+ *
+ * Register a USB backend device to the SND USB SOC framework.  Memory is
+ * allocated as part of the USB backend device.
+ *
+ */
+struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
+			int (*connection_cb)(struct snd_soc_usb *usb,
+			struct snd_soc_usb_device *sdev, bool connected))
+{
+	struct snd_soc_usb *usb;
+
+	usb = devm_kzalloc(dev, sizeof(*usb), GFP_KERNEL);
+	if (!usb)
+		return ERR_PTR(-ENOMEM);
+
+	usb->connection_status_cb = connection_cb;
+	usb->dev = dev;
+	usb->priv_data = priv;
+
+	mutex_lock(&ctx_mutex);
+	list_add_tail(&usb->list, &usb_ctx_list);
+	mutex_unlock(&ctx_mutex);
+
+	return usb;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_add_port);
+
+/**
+ * snd_soc_usb_remove_port() - Remove a USB backend port
+ * @dev: USB backend device
+ *
+ * Remove a USB backend device from USB SND SOC.  Memory is freed when USB
+ * backend is removed.
+ *
+ */
+int snd_soc_usb_remove_port(struct device *dev)
+{
+	struct snd_soc_usb *ctx, *tmp;
+
+	mutex_lock(&ctx_mutex);
+	list_for_each_entry_safe(ctx, tmp, &usb_ctx_list, list) {
+		if (ctx->dev == dev) {
+			list_del(&ctx->list);
+			break;
+		}
+	}
+	mutex_unlock(&ctx_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_remove_port);
+
+/**
+ * snd_soc_usb_connect() - Notification of USB device connection
+ * @usbdev: USB bus device
+ * @card_idx: USB SND card instance
+ *
+ * Notify of a new USB SND device connection.  The card_idx can be used to
+ * handle how the DPCM backend selects, which device to enable USB offloading
+ * on.
+ *
+ */
+int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev)
+{
+	struct snd_soc_usb *ctx;
+	struct device_node *node;
+
+	if (!usbdev)
+		return -ENODEV;
+
+	node = snd_soc_find_phandle(usbdev);
+	if (IS_ERR(node))
+		return -ENODEV;
+
+	ctx = snd_soc_find_usb_ctx(node);
+	of_node_put(node);
+	if (!ctx)
+		return -ENODEV;
+
+	if (ctx->connection_status_cb)
+		ctx->connection_status_cb(ctx, sdev, true);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_connect);
+
+/**
+ * snd_soc_usb_disconnect() - Notification of USB device disconnection
+ * @usbdev: USB bus device
+ *
+ * Notify of a new USB SND device disconnection to the USB backend.
+ *
+ */
+int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev)
+{
+	struct snd_soc_usb *ctx;
+	struct device_node *node;
+
+	if (!usbdev)
+		return -ENODEV;
+
+	node = snd_soc_find_phandle(usbdev);
+	if (IS_ERR(node))
+		return -ENODEV;
+
+	ctx = snd_soc_find_usb_ctx(node);
+	of_node_put(node);
+	if (!ctx)
+		return -ENODEV;
+
+	if (ctx->connection_status_cb)
+		ctx->connection_status_cb(ctx, sdev, false);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_disconnect);

[PATCH v9 08/34] ASoC: dt-bindings: qcom,q6dsp-lpass-ports: Add USB_RX port

[Wesley Cheng]

Q6DSP supports handling of USB playback audio data if USB audio offloading
is enabled.  Add a new definition for the USB_RX AFE port, which is
referenced when the AFE port is started.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 include/dt-bindings/sound/qcom,q6dsp-lpass-ports.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/dt-bindings/sound/qcom,q6dsp-lpass-ports.h b/include/dt-bindings/sound/qcom,q6dsp-lpass-ports.h
index 39f203256c4f..6d1ce7f5da51 100644
--- a/include/dt-bindings/sound/qcom,q6dsp-lpass-ports.h
+++ b/include/dt-bindings/sound/qcom,q6dsp-lpass-ports.h
@@ -139,6 +139,7 @@
 #define DISPLAY_PORT_RX_5	133
 #define DISPLAY_PORT_RX_6	134
 #define DISPLAY_PORT_RX_7	135
+#define USB_RX			136
 
 #define LPASS_CLK_ID_PRI_MI2S_IBIT	1
 #define LPASS_CLK_ID_PRI_MI2S_EBIT	2

[PATCH v9 09/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

[Wesley Cheng]

The QC ADSP is able to support USB playback endpoints, so that the main
application processor can be placed into lower CPU power modes.  This adds
the required AFE port configurations and port start command to start an
audio session.

Specifically, the QC ADSP can support all potential endpoints that are
exposed by the audio data interface.  This includes, feedback endpoints
(both implicit and explicit) as well as the isochronous (data) endpoints.
The size of audio samples sent per USB frame (microframe) will be adjusted
based on information received on the feedback endpoint.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6afe-dai.c         |  56 +++++++
 sound/soc/qcom/qdsp6/q6afe.c             | 183 ++++++++++++++++++++++-
 sound/soc/qcom/qdsp6/q6afe.h             |  35 ++++-
 sound/soc/qcom/qdsp6/q6dsp-lpass-ports.c |  23 +++
 sound/soc/qcom/qdsp6/q6dsp-lpass-ports.h |   1 +
 sound/soc/qcom/qdsp6/q6routing.c         |   9 ++
 6 files changed, 305 insertions(+), 2 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6afe-dai.c b/sound/soc/qcom/qdsp6/q6afe-dai.c
index 3faa7e0eb0dd..e46c064253d7 100644
--- a/sound/soc/qcom/qdsp6/q6afe-dai.c
+++ b/sound/soc/qcom/qdsp6/q6afe-dai.c
@@ -91,6 +91,40 @@ static int q6hdmi_hw_params(struct snd_pcm_substream *substream,
 	return 0;
 }
 
+static int q6usb_hw_params(struct snd_pcm_substream *substream,
+			   struct snd_pcm_hw_params *params,
+			   struct snd_soc_dai *dai)
+{
+	struct q6afe_dai_data *dai_data = dev_get_drvdata(dai->dev);
+	int channels = params_channels(params);
+	int rate = params_rate(params);
+	struct q6afe_usb_cfg *usb = &dai_data->port_config[dai->id].usb_audio;
+
+	usb->sample_rate = rate;
+	usb->num_channels = channels;
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_U16_LE:
+	case SNDRV_PCM_FORMAT_S16_LE:
+	case SNDRV_PCM_FORMAT_SPECIAL:
+		usb->bit_width = 16;
+		break;
+	case SNDRV_PCM_FORMAT_S24_LE:
+	case SNDRV_PCM_FORMAT_S24_3LE:
+		usb->bit_width = 24;
+		break;
+	case SNDRV_PCM_FORMAT_S32_LE:
+		usb->bit_width = 32;
+		break;
+	default:
+		dev_err(dai->dev, "%s: invalid format %d\n",
+			__func__, params_format(params));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int q6i2s_hw_params(struct snd_pcm_substream *substream,
 			   struct snd_pcm_hw_params *params,
 			   struct snd_soc_dai *dai)
@@ -391,6 +425,10 @@ static int q6afe_dai_prepare(struct snd_pcm_substream *substream,
 		q6afe_cdc_dma_port_prepare(dai_data->port[dai->id],
 					   &dai_data->port_config[dai->id].dma_cfg);
 		break;
+	case USB_RX:
+		q6afe_usb_port_prepare(dai_data->port[dai->id],
+				       &dai_data->port_config[dai->id].usb_audio);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -617,6 +655,9 @@ static const struct snd_soc_dapm_route q6afe_dapm_routes[] = {
 	{"TX_CODEC_DMA_TX_5", NULL, "TX_CODEC_DMA_TX_5 Capture"},
 	{"RX_CODEC_DMA_RX_6 Playback", NULL, "RX_CODEC_DMA_RX_6"},
 	{"RX_CODEC_DMA_RX_7 Playback", NULL, "RX_CODEC_DMA_RX_7"},
+
+	/* USB playback AFE port receives data for playback, hence use the RX port */
+	{"USB Playback", NULL, "USB_RX"},
 };
 
 static int msm_dai_q6_dai_probe(struct snd_soc_dai *dai)
@@ -644,6 +685,18 @@ static int msm_dai_q6_dai_remove(struct snd_soc_dai *dai)
 	return 0;
 }
 
+static const struct snd_soc_dai_ops q6usb_ops = {
+	.probe		= msm_dai_q6_dai_probe,
+	.prepare	= q6afe_dai_prepare,
+	.hw_params	= q6usb_hw_params,
+	.shutdown	= q6afe_dai_shutdown,
+	/*
+	 * Startup callback not needed, as AFE port start command passes the PCM
+	 * parameters within the AFE command, which is provided by the PCM core
+	 * during the prepare() stage.
+	 */
+};
+
 static const struct snd_soc_dai_ops q6hdmi_ops = {
 	.probe			= msm_dai_q6_dai_probe,
 	.remove			= msm_dai_q6_dai_remove,
@@ -942,6 +995,8 @@ static const struct snd_soc_dapm_widget q6afe_dai_widgets[] = {
 		0, SND_SOC_NOPM, 0, 0),
 	SND_SOC_DAPM_AIF_IN("RX_CODEC_DMA_RX_7", "NULL",
 		0, SND_SOC_NOPM, 0, 0),
+
+	SND_SOC_DAPM_AIF_IN("USB_RX", NULL, 0, SND_SOC_NOPM, 0, 0),
 };
 
 static const struct snd_soc_component_driver q6afe_dai_component = {
@@ -1056,6 +1111,7 @@ static int q6afe_dai_dev_probe(struct platform_device *pdev)
 	cfg.q6i2s_ops = &q6i2s_ops;
 	cfg.q6tdm_ops = &q6tdm_ops;
 	cfg.q6dma_ops = &q6dma_ops;
+	cfg.q6usb_ops = &q6usb_ops;
 	dais = q6dsp_audio_ports_set_config(dev, &cfg, &num_dais);
 
 	return devm_snd_soc_register_component(dev, &q6afe_dai_component, dais, num_dais);
diff --git a/sound/soc/qcom/qdsp6/q6afe.c b/sound/soc/qcom/qdsp6/q6afe.c
index 919e326b9462..f49c69472b5c 100644
--- a/sound/soc/qcom/qdsp6/q6afe.c
+++ b/sound/soc/qcom/qdsp6/q6afe.c
@@ -34,6 +34,8 @@
 #define AFE_MODULE_TDM			0x0001028A
 
 #define AFE_PARAM_ID_CDC_SLIMBUS_SLAVE_CFG 0x00010235
+#define AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS    0x000102A5
+#define AFE_PARAM_ID_USB_AUDIO_DEV_LPCM_FMT 0x000102AA
 
 #define AFE_PARAM_ID_LPAIF_CLK_CONFIG	0x00010238
 #define AFE_PARAM_ID_INT_DIGITAL_CDC_CLK_CONFIG	0x00010239
@@ -43,6 +45,7 @@
 #define AFE_PARAM_ID_TDM_CONFIG	0x0001029D
 #define AFE_PARAM_ID_PORT_SLOT_MAPPING_CONFIG	0x00010297
 #define AFE_PARAM_ID_CODEC_DMA_CONFIG	0x000102B8
+#define AFE_PARAM_ID_USB_AUDIO_CONFIG    0x000102A4
 #define AFE_CMD_REMOTE_LPASS_CORE_HW_VOTE_REQUEST	0x000100f4
 #define AFE_CMD_RSP_REMOTE_LPASS_CORE_HW_VOTE_REQUEST   0x000100f5
 #define AFE_CMD_REMOTE_LPASS_CORE_HW_DEVOTE_REQUEST	0x000100f6
@@ -71,12 +74,16 @@
 #define AFE_PORT_CONFIG_I2S_WS_SRC_INTERNAL	0x1
 #define AFE_LINEAR_PCM_DATA				0x0
 
+#define AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG 0x1
 
 /* Port IDs */
 #define AFE_API_VERSION_HDMI_CONFIG	0x1
 #define AFE_PORT_ID_MULTICHAN_HDMI_RX	0x100E
 #define AFE_PORT_ID_HDMI_OVER_DP_RX	0x6020
 
+/* USB AFE port */
+#define AFE_PORT_ID_USB_RX                       0x7000
+
 #define AFE_API_VERSION_SLIMBUS_CONFIG 0x1
 /* Clock set API version */
 #define AFE_API_VERSION_CLOCK_SET 1
@@ -512,12 +519,109 @@ struct afe_param_id_cdc_dma_cfg {
 	u16	active_channels_mask;
 } __packed;
 
+struct afe_param_id_usb_cfg {
+/* Minor version used for tracking USB audio device configuration.
+ * Supported values: AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG
+ */
+	u32                  cfg_minor_version;
+/* Sampling rate of the port.
+ * Supported values:
+ * - AFE_PORT_SAMPLE_RATE_8K
+ * - AFE_PORT_SAMPLE_RATE_11025
+ * - AFE_PORT_SAMPLE_RATE_12K
+ * - AFE_PORT_SAMPLE_RATE_16K
+ * - AFE_PORT_SAMPLE_RATE_22050
+ * - AFE_PORT_SAMPLE_RATE_24K
+ * - AFE_PORT_SAMPLE_RATE_32K
+ * - AFE_PORT_SAMPLE_RATE_44P1K
+ * - AFE_PORT_SAMPLE_RATE_48K
+ * - AFE_PORT_SAMPLE_RATE_96K
+ * - AFE_PORT_SAMPLE_RATE_192K
+ */
+	u32                  sample_rate;
+/* Bit width of the sample.
+ * Supported values: 16, 24
+ */
+	u16                  bit_width;
+/* Number of channels.
+ * Supported values: 1 and 2
+ */
+	u16                  num_channels;
+/* Data format supported by the USB. The supported value is
+ * 0 (#AFE_USB_AUDIO_DATA_FORMAT_LINEAR_PCM).
+ */
+	u16                  data_format;
+/* this field must be 0 */
+	u16                  reserved;
+/* device token of actual end USB audio device */
+	u32                  dev_token;
+/* endianness of this interface */
+	u32                   endian;
+/* service interval */
+	u32                  service_interval;
+} __packed;
+
+/**
+ * struct afe_param_id_usb_audio_dev_params
+ * @cfg_minor_version: Minor version used for tracking USB audio device
+ * configuration.
+ * Supported values:
+ *     AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG
+ * @dev_token: device token of actual end USB audio device
+ **/
+struct afe_param_id_usb_audio_dev_params {
+	u32	cfg_minor_version;
+	u32	dev_token;
+} __packed;
+
+/**
+ * struct afe_param_id_usb_audio_dev_lpcm_fmt
+ * @cfg_minor_version: Minor version used for tracking USB audio device
+ * configuration.
+ * Supported values:
+ *     AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG
+ * @endian: endianness of this interface
+ **/
+struct afe_param_id_usb_audio_dev_lpcm_fmt {
+	u32	cfg_minor_version;
+	u32	endian;
+} __packed;
+
+/**
+ * struct afe_param_id_usb_audio_dev_latency_mode
+ * @cfg_minor_version: Minor version used for tracking USB audio device
+ * configuration.
+ * Supported values:
+ *     AFE_API_MINOR_VERSION_USB_AUDIO_LATENCY_MODE
+ * @mode: latency mode for the USB audio device
+ **/
+struct afe_param_id_usb_audio_dev_latency_mode {
+	u32	minor_version;
+	u32	mode;
+} __packed;
+
+#define AFE_PARAM_ID_USB_AUDIO_SVC_INTERVAL     0x000102B7
+
+/**
+ * struct afe_param_id_usb_audio_svc_interval
+ * @cfg_minor_version: Minor version used for tracking USB audio device
+ * configuration.
+ * Supported values:
+ *     AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG
+ * @svc_interval: service interval
+ **/
+struct afe_param_id_usb_audio_svc_interval {
+	u32	cfg_minor_version;
+	u32	svc_interval;
+} __packed;
+
 union afe_port_config {
 	struct afe_param_id_hdmi_multi_chan_audio_cfg hdmi_multi_ch;
 	struct afe_param_id_slimbus_cfg           slim_cfg;
 	struct afe_param_id_i2s_cfg	i2s_cfg;
 	struct afe_param_id_tdm_cfg	tdm_cfg;
 	struct afe_param_id_cdc_dma_cfg	dma_cfg;
+	struct afe_param_id_usb_cfg usb_cfg;
 } __packed;
 
 
@@ -832,6 +936,7 @@ static struct afe_port_map port_maps[AFE_PORT_MAX] = {
 				RX_CODEC_DMA_RX_6, 1, 1},
 	[RX_CODEC_DMA_RX_7] = { AFE_PORT_ID_RX_CODEC_DMA_RX_7,
 				RX_CODEC_DMA_RX_7, 1, 1},
+	[USB_RX] = { AFE_PORT_ID_USB_RX, USB_RX, 1, 1},
 };
 
 static void q6afe_port_free(struct kref *ref)
@@ -1289,6 +1394,79 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port,
 }
 EXPORT_SYMBOL_GPL(q6afe_tdm_port_prepare);
 
+static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
+{
+	union afe_port_config *pcfg = &port->port_cfg;
+	struct afe_param_id_usb_audio_dev_params usb_dev;
+	struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
+	struct afe_param_id_usb_audio_svc_interval svc_int;
+	int ret = 0;
+
+	if (!pcfg) {
+		dev_err(port->afe->dev, "%s: Error, no configuration data\n", __func__);
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	memset(&usb_dev, 0, sizeof(usb_dev));
+	memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
+	memset(&svc_int, 0, sizeof(svc_int));
+
+	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
+	ret = q6afe_port_set_param_v2(port, &usb_dev,
+				      AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
+				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
+	if (ret) {
+		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
+			__func__, ret);
+		goto exit;
+	}
+
+	lpcm_fmt.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
+	lpcm_fmt.endian = pcfg->usb_cfg.endian;
+	ret = q6afe_port_set_param_v2(port, &lpcm_fmt,
+				      AFE_PARAM_ID_USB_AUDIO_DEV_LPCM_FMT,
+				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(lpcm_fmt));
+	if (ret) {
+		dev_err(port->afe->dev, "%s: AFE device param cmd LPCM_FMT failed %d\n",
+			__func__, ret);
+		goto exit;
+	}
+
+	svc_int.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
+	svc_int.svc_interval = pcfg->usb_cfg.service_interval;
+	ret = q6afe_port_set_param_v2(port, &svc_int,
+				      AFE_PARAM_ID_USB_AUDIO_SVC_INTERVAL,
+				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(svc_int));
+	if (ret)
+		dev_err(port->afe->dev, "%s: AFE device param cmd svc_interval failed %d\n",
+			__func__, ret);
+
+exit:
+	return ret;
+}
+
+/**
+ * q6afe_usb_port_prepare() - Prepare usb afe port.
+ *
+ * @port: Instance of afe port
+ * @cfg: USB configuration for the afe port
+ *
+ */
+void q6afe_usb_port_prepare(struct q6afe_port *port,
+			     struct q6afe_usb_cfg *cfg)
+{
+	union afe_port_config *pcfg = &port->port_cfg;
+
+	pcfg->usb_cfg.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
+	pcfg->usb_cfg.sample_rate = cfg->sample_rate;
+	pcfg->usb_cfg.num_channels = cfg->num_channels;
+	pcfg->usb_cfg.bit_width = cfg->bit_width;
+
+	afe_port_send_usb_dev_param(port, cfg);
+}
+EXPORT_SYMBOL_GPL(q6afe_usb_port_prepare);
+
 /**
  * q6afe_hdmi_port_prepare() - Prepare hdmi afe port.
  *
@@ -1611,7 +1789,10 @@ struct q6afe_port *q6afe_port_get_from_id(struct device *dev, int id)
 		break;
 	case AFE_PORT_ID_WSA_CODEC_DMA_RX_0 ... AFE_PORT_ID_RX_CODEC_DMA_RX_7:
 		cfg_type = AFE_PARAM_ID_CODEC_DMA_CONFIG;
-	break;
+		break;
+	case AFE_PORT_ID_USB_RX:
+		cfg_type = AFE_PARAM_ID_USB_AUDIO_CONFIG;
+		break;
 	default:
 		dev_err(dev, "Invalid port id 0x%x\n", port_id);
 		return ERR_PTR(-EINVAL);
diff --git a/sound/soc/qcom/qdsp6/q6afe.h b/sound/soc/qcom/qdsp6/q6afe.h
index 30fd77e2f458..ef47b4ae9e27 100644
--- a/sound/soc/qcom/qdsp6/q6afe.h
+++ b/sound/soc/qcom/qdsp6/q6afe.h
@@ -5,7 +5,7 @@
 
 #include <dt-bindings/sound/qcom,q6afe.h>
 
-#define AFE_PORT_MAX		129
+#define AFE_PORT_MAX		137
 
 #define MSM_AFE_PORT_TYPE_RX 0
 #define MSM_AFE_PORT_TYPE_TX 1
@@ -205,6 +205,36 @@ struct q6afe_cdc_dma_cfg {
 	u16	active_channels_mask;
 };
 
+/**
+ * struct q6afe_usb_cfg
+ * @cfg_minor_version: Minor version used for tracking USB audio device
+ * configuration.
+ * Supported values:
+ *     AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG
+ * @sample_rate: Sampling rate of the port
+ *    Supported values:
+ *      AFE_PORT_SAMPLE_RATE_8K
+ *      AFE_PORT_SAMPLE_RATE_11025
+ *      AFE_PORT_SAMPLE_RATE_12K
+ *      AFE_PORT_SAMPLE_RATE_16K
+ *      AFE_PORT_SAMPLE_RATE_22050
+ *      AFE_PORT_SAMPLE_RATE_24K
+ *      AFE_PORT_SAMPLE_RATE_32K
+ *      AFE_PORT_SAMPLE_RATE_44P1K
+ *      AFE_PORT_SAMPLE_RATE_48K
+ *      AFE_PORT_SAMPLE_RATE_96K
+ *      AFE_PORT_SAMPLE_RATE_192K
+ * @bit_width: Bit width of the sample.
+ *    Supported values: 16, 24
+ * @num_channels: Number of channels
+ *    Supported values: 1, 2
+ **/
+struct q6afe_usb_cfg {
+	u32	cfg_minor_version;
+	u32     sample_rate;
+	u16	bit_width;
+	u16	num_channels;
+};
 
 struct q6afe_port_config {
 	struct q6afe_hdmi_cfg hdmi;
@@ -212,6 +242,7 @@ struct q6afe_port_config {
 	struct q6afe_i2s_cfg i2s_cfg;
 	struct q6afe_tdm_cfg tdm;
 	struct q6afe_cdc_dma_cfg dma_cfg;
+	struct q6afe_usb_cfg usb_audio;
 };
 
 struct q6afe_port;
@@ -221,6 +252,8 @@ int q6afe_port_start(struct q6afe_port *port);
 int q6afe_port_stop(struct q6afe_port *port);
 void q6afe_port_put(struct q6afe_port *port);
 int q6afe_get_port_id(int index);
+void q6afe_usb_port_prepare(struct q6afe_port *port,
+			     struct q6afe_usb_cfg *cfg);
 void q6afe_hdmi_port_prepare(struct q6afe_port *port,
 			    struct q6afe_hdmi_cfg *cfg);
 void q6afe_slim_port_prepare(struct q6afe_port *port,
diff --git a/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.c b/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.c
index 4919001de08b..4a96b11f7fd1 100644
--- a/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.c
+++ b/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.c
@@ -97,6 +97,26 @@
 	}
 
 static struct snd_soc_dai_driver q6dsp_audio_fe_dais[] = {
+	{
+		.playback = {
+			.stream_name = "USB Playback",
+			.rates = SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |
+					SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 |
+					SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
+					SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000 |
+					SNDRV_PCM_RATE_192000,
+			.formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
+					SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_U16_BE |
+					SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |
+					SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_U24_BE,
+			.channels_min = 1,
+			.channels_max = 2,
+			.rate_min =	8000,
+			.rate_max = 192000,
+		},
+		.id = USB_RX,
+		.name = "USB_RX",
+	},
 	{
 		.playback = {
 			.stream_name = "HDMI Playback",
@@ -624,6 +644,9 @@ struct snd_soc_dai_driver *q6dsp_audio_ports_set_config(struct device *dev,
 		case WSA_CODEC_DMA_RX_0 ... RX_CODEC_DMA_RX_7:
 			q6dsp_audio_fe_dais[i].ops = cfg->q6dma_ops;
 			break;
+		case USB_RX:
+			q6dsp_audio_fe_dais[i].ops = cfg->q6usb_ops;
+			break;
 		default:
 			break;
 		}
diff --git a/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.h b/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.h
index 7f052c8a1257..d8dde6dd0aca 100644
--- a/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.h
+++ b/sound/soc/qcom/qdsp6/q6dsp-lpass-ports.h
@@ -11,6 +11,7 @@ struct q6dsp_audio_port_dai_driver_config {
 	const struct snd_soc_dai_ops *q6i2s_ops;
 	const struct snd_soc_dai_ops *q6tdm_ops;
 	const struct snd_soc_dai_ops *q6dma_ops;
+	const struct snd_soc_dai_ops *q6usb_ops;
 };
 
 struct snd_soc_dai_driver *q6dsp_audio_ports_set_config(struct device *dev,
diff --git a/sound/soc/qcom/qdsp6/q6routing.c b/sound/soc/qcom/qdsp6/q6routing.c
index bba07899f8fc..a57f45950ae3 100644
--- a/sound/soc/qcom/qdsp6/q6routing.c
+++ b/sound/soc/qcom/qdsp6/q6routing.c
@@ -514,6 +514,9 @@ static int msm_routing_put_audio_mixer(struct snd_kcontrol *kcontrol,
 	return 1;
 }
 
+static const struct snd_kcontrol_new usb_mixer_controls[] = {
+	Q6ROUTING_RX_MIXERS(USB_RX) };
+
 static const struct snd_kcontrol_new hdmi_mixer_controls[] = {
 	Q6ROUTING_RX_MIXERS(HDMI_RX) };
 
@@ -949,6 +952,10 @@ static const struct snd_soc_dapm_widget msm_qdsp6_widgets[] = {
 	SND_SOC_DAPM_MIXER("MultiMedia8 Mixer", SND_SOC_NOPM, 0, 0,
 		mmul8_mixer_controls, ARRAY_SIZE(mmul8_mixer_controls)),
 
+	SND_SOC_DAPM_MIXER("USB Mixer", SND_SOC_NOPM, 0, 0,
+			   usb_mixer_controls,
+			   ARRAY_SIZE(usb_mixer_controls)),
+
 };
 
 static const struct snd_soc_dapm_route intercon[] = {
@@ -1042,6 +1049,8 @@ static const struct snd_soc_dapm_route intercon[] = {
 	{"MM_UL6", NULL, "MultiMedia6 Mixer"},
 	{"MM_UL7", NULL, "MultiMedia7 Mixer"},
 	{"MM_UL8", NULL, "MultiMedia8 Mixer"},
+
+	Q6ROUTING_RX_DAPM_ROUTE("USB Mixer", "USB_RX"),
 };
 
 static int routing_hw_params(struct snd_soc_component *component,

[PATCH v9 10/34] ASoC: qdsp6: q6afe: Increase APR timeout

[Wesley Cheng]

For USB offloading situations, the AFE port start command will result in a
QMI handshake between the Q6DSP and the main processor.  Depending on if
the USB bus is suspended, this routine would require more time to complete,
as resuming the USB bus has some overhead associated with it.  Increase the
timeout to 3s to allow for sufficient time for the USB QMI stream enable
handshake to complete.

Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6afe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/qcom/qdsp6/q6afe.c b/sound/soc/qcom/qdsp6/q6afe.c
index f49c69472b5c..72c4e6fe20c4 100644
--- a/sound/soc/qcom/qdsp6/q6afe.c
+++ b/sound/soc/qcom/qdsp6/q6afe.c
@@ -365,7 +365,7 @@
 #define AFE_API_VERSION_SLOT_MAPPING_CONFIG	1
 #define AFE_API_VERSION_CODEC_DMA_CONFIG	1
 
-#define TIMEOUT_MS 1000
+#define TIMEOUT_MS 3000
 #define AFE_CMD_RESP_AVAIL	0
 #define AFE_CMD_RESP_NONE	1
 #define AFE_CLK_TOKEN		1024

[PATCH v9 11/34] ASoC: qcom: qdsp6: Add USB backend ASoC driver for Q6

[Wesley Cheng]

Create a USB BE component that will register a new USB port to the ASoC USB
framework.  This will handle determination on if the requested audio
profile is supported by the USB device currently selected.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 include/sound/q6usboffload.h  |  20 ++++
 sound/soc/qcom/Kconfig        |   4 +
 sound/soc/qcom/qdsp6/Makefile |   1 +
 sound/soc/qcom/qdsp6/q6usb.c  | 200 ++++++++++++++++++++++++++++++++++
 4 files changed, 225 insertions(+)
 create mode 100644 include/sound/q6usboffload.h
 create mode 100644 sound/soc/qcom/qdsp6/q6usb.c

diff --git a/include/sound/q6usboffload.h b/include/sound/q6usboffload.h
new file mode 100644
index 000000000000..fdc1f5c53a3b
--- /dev/null
+++ b/include/sound/q6usboffload.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/sound/q6usboffload.h -- QDSP6 USB offload
+ *
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+/**
+ * struct q6usb_offload
+ * @dev - dev handle to usb be
+ * @sid - streamID for iommu
+ * @intr_num - usb interrupter number
+ * @domain - allocated iommu domain
+ **/
+struct q6usb_offload {
+	struct device *dev;
+	long long sid;
+	u16 intr_num;
+	struct iommu_domain *domain;
+};
diff --git a/sound/soc/qcom/Kconfig b/sound/soc/qcom/Kconfig
index e7b00d1d9e99..bb285af6bb04 100644
--- a/sound/soc/qcom/Kconfig
+++ b/sound/soc/qcom/Kconfig
@@ -114,6 +114,9 @@ config SND_SOC_QDSP6_APM
 config SND_SOC_QDSP6_PRM_LPASS_CLOCKS
 	tristate
 
+config SND_SOC_QDSP6_USB
+	tristate
+
 config SND_SOC_QDSP6_PRM
 	tristate
 	select SND_SOC_QDSP6_PRM_LPASS_CLOCKS
@@ -134,6 +137,7 @@ config SND_SOC_QDSP6
 	select SND_SOC_TOPOLOGY
 	select SND_SOC_QDSP6_APM
 	select SND_SOC_QDSP6_PRM
+	select SND_SOC_QDSP6_USB
 	help
 	 To add support for MSM QDSP6 Soc Audio.
 	 This will enable sound soc platform specific
diff --git a/sound/soc/qcom/qdsp6/Makefile b/sound/soc/qcom/qdsp6/Makefile
index 3963bf234664..c9457ee898d0 100644
--- a/sound/soc/qcom/qdsp6/Makefile
+++ b/sound/soc/qcom/qdsp6/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_SND_SOC_QDSP6_APM_DAI) += q6apm-dai.o
 obj-$(CONFIG_SND_SOC_QDSP6_APM_LPASS_DAI) += q6apm-lpass-dais.o
 obj-$(CONFIG_SND_SOC_QDSP6_PRM) += q6prm.o
 obj-$(CONFIG_SND_SOC_QDSP6_PRM_LPASS_CLOCKS) += q6prm-clocks.o
+obj-$(CONFIG_SND_SOC_QDSP6_USB) += q6usb.o
diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
new file mode 100644
index 000000000000..dd664ad41668
--- /dev/null
+++ b/sound/soc/qcom/qdsp6/q6usb.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/iommu.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
+
+#include <sound/pcm.h>
+#include <sound/soc.h>
+#include <sound/soc-usb.h>
+#include <sound/pcm_params.h>
+#include <sound/asound.h>
+#include <sound/q6usboffload.h>
+
+#include "q6dsp-lpass-ports.h"
+#include "q6afe.h"
+
+#define SID_MASK	0xF
+
+struct q6usb_port_data {
+	struct q6afe_usb_cfg usb_cfg;
+	struct snd_soc_usb *usb;
+	struct q6usb_offload priv;
+	int active_idx;
+};
+
+static const struct snd_soc_dapm_widget q6usb_dai_widgets[] = {
+	SND_SOC_DAPM_HP("USB_RX_BE", NULL),
+};
+
+static const struct snd_soc_dapm_route q6usb_dapm_routes[] = {
+	{"USB Playback", NULL, "USB_RX_BE"},
+};
+
+static int q6usb_hw_params(struct snd_pcm_substream *substream,
+			   struct snd_pcm_hw_params *params,
+			   struct snd_soc_dai *dai)
+{
+	return 0;
+}
+
+static const struct snd_soc_dai_ops q6usb_ops = {
+	.hw_params = q6usb_hw_params,
+};
+
+static struct snd_soc_dai_driver q6usb_be_dais[] = {
+	{
+		.playback = {
+			.stream_name = "USB BE RX",
+			.rates = SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |
+				SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 |
+				SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
+				SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000 |
+				SNDRV_PCM_RATE_192000,
+			.formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
+				SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_U16_BE |
+				SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |
+				SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_U24_BE,
+			.channels_min = 1,
+			.channels_max = 2,
+			.rate_max =     192000,
+			.rate_min =	8000,
+		},
+		.id = USB_RX,
+		.name = "USB_RX_BE",
+		.ops = &q6usb_ops,
+	},
+};
+
+static int q6usb_audio_ports_of_xlate_dai_name(struct snd_soc_component *component,
+					const struct of_phandle_args *args,
+					const char **dai_name)
+{
+	int id = args->args[0];
+	int ret = -EINVAL;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(q6usb_be_dais); i++) {
+		if (q6usb_be_dais[i].id == id) {
+			*dai_name = q6usb_be_dais[i].name;
+			ret = 0;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
+			struct snd_soc_usb_device *sdev, bool connected)
+{
+	struct q6usb_port_data *data;
+
+	if (!usb->component)
+		return -ENODEV;
+
+	data = dev_get_drvdata(usb->component->dev);
+
+	if (connected) {
+		/* We only track the latest USB headset plugged in */
+		data->active_idx = sdev->card_idx;
+	}
+
+	return 0;
+}
+
+static int q6usb_component_probe(struct snd_soc_component *component)
+{
+	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
+
+	data->usb = snd_soc_usb_add_port(component->dev, &data->priv, q6usb_alsa_connection_cb);
+	if (IS_ERR(data->usb)) {
+		dev_err(component->dev, "failed to add usb port\n");
+		return -ENODEV;
+	}
+
+	data->usb->component = component;
+
+	return 0;
+}
+
+static void q6usb_component_remove(struct snd_soc_component *component)
+{
+	snd_soc_usb_remove_port(component->dev);
+}
+
+static const struct snd_soc_component_driver q6usb_dai_component = {
+	.probe = q6usb_component_probe,
+	.remove = q6usb_component_remove,
+	.name = "q6usb-dai-component",
+	.dapm_widgets = q6usb_dai_widgets,
+	.num_dapm_widgets = ARRAY_SIZE(q6usb_dai_widgets),
+	.dapm_routes = q6usb_dapm_routes,
+	.num_dapm_routes = ARRAY_SIZE(q6usb_dapm_routes),
+	.of_xlate_dai_name = q6usb_audio_ports_of_xlate_dai_name,
+};
+
+static int q6usb_dai_dev_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct q6usb_port_data *data;
+	struct device *dev = &pdev->dev;
+	struct of_phandle_args args;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ret = of_property_read_u16(node, "qcom,usb-audio-intr-idx",
+				&data->priv.intr_num);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to read intr idx.\n");
+		return ret;
+	}
+
+	ret = of_parse_phandle_with_fixed_args(node, "iommus", 1, 0, &args);
+	if (ret < 0)
+		data->priv.sid = -1;
+	else
+		data->priv.sid = args.args[0] & SID_MASK;
+
+	data->priv.domain = iommu_get_domain_for_dev(&pdev->dev);
+
+	data->priv.dev = dev;
+	dev_set_drvdata(dev, data);
+
+	return devm_snd_soc_register_component(dev, &q6usb_dai_component,
+					q6usb_be_dais, ARRAY_SIZE(q6usb_be_dais));
+}
+
+static const struct of_device_id q6usb_dai_device_id[] = {
+	{ .compatible = "qcom,q6usb" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, q6usb_dai_device_id);
+
+static struct platform_driver q6usb_dai_platform_driver = {
+	.driver = {
+		.name = "q6usb-dai",
+		.of_match_table = of_match_ptr(q6usb_dai_device_id),
+	},
+	.probe = q6usb_dai_dev_probe,
+	/*
+	 * Remove not required as resources are cleaned up as part of
+	 * component removal.  Others are device managed resources.
+	 */
+};
+module_platform_driver(q6usb_dai_platform_driver);
+
+MODULE_DESCRIPTION("Q6 USB backend dai driver");
+MODULE_LICENSE("GPL");

[PATCH v9 12/34] ALSA: usb-audio: Introduce USB SND platform op callbacks

[Wesley Cheng]

Allow for different platforms to be notified on USB SND connect/disconnect
seqeunces.  This allows for platform USB SND modules to properly initialize
and populate internal structures with references to the USB SND chip
device.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/card.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++
 sound/usb/card.h |  9 ++++++++
 2 files changed, 69 insertions(+)

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 1b2edc0fd2e9..1ef6d144aa51 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -118,6 +118,49 @@ MODULE_PARM_DESC(skip_validation, "Skip unit descriptor validation (default: no)
 static DEFINE_MUTEX(register_mutex);
 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
 static struct usb_driver usb_audio_driver;
+static struct snd_usb_platform_ops *platform_ops;
+
+/*
+ * Register platform specific operations that will be notified on events
+ * which occur in USB SND.  The platform driver can utilize this path to
+ * enable features, such as USB audio offloading, which allows for audio data
+ * to be queued by an audio DSP.
+ *
+ * Only one set of platform operations can be registered to USB SND.  The
+ * platform register operation is protected by the register_mutex.
+ */
+int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops)
+{
+	int ret;
+
+	mutex_lock(&register_mutex);
+	if (platform_ops) {
+		ret = -EEXIST;
+		goto out;
+	}
+
+	platform_ops = ops;
+out:
+	mutex_unlock(&register_mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_usb_register_platform_ops);
+
+/*
+ * Unregisters the current set of platform operations.  This allows for
+ * a new set to be registered if required.
+ *
+ * The platform unregister operation is protected by the register_mutex.
+ */
+int snd_usb_unregister_platform_ops(void)
+{
+	mutex_lock(&register_mutex);
+	platform_ops = NULL;
+	mutex_unlock(&register_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
 
 /*
  * disconnect streams
@@ -910,7 +953,11 @@ static int usb_audio_probe(struct usb_interface *intf,
 	chip->num_interfaces++;
 	usb_set_intfdata(intf, chip);
 	atomic_dec(&chip->active);
+
+	if (platform_ops && platform_ops->connect_cb)
+		platform_ops->connect_cb(chip);
 	mutex_unlock(&register_mutex);
+
 	return 0;
 
  __error:
@@ -947,6 +994,9 @@ static void usb_audio_disconnect(struct usb_interface *intf)
 	card = chip->card;
 
 	mutex_lock(&register_mutex);
+	if (platform_ops && platform_ops->disconnect_cb)
+		platform_ops->disconnect_cb(chip);
+
 	if (atomic_inc_return(&chip->shutdown) == 1) {
 		struct snd_usb_stream *as;
 		struct snd_usb_endpoint *ep;
@@ -1090,6 +1140,11 @@ static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 		chip->system_suspend = chip->num_suspended_intf;
 	}
 
+	mutex_lock(&register_mutex);
+	if (platform_ops && platform_ops->suspend_cb)
+		platform_ops->suspend_cb(intf, message);
+	mutex_unlock(&register_mutex);
+
 	return 0;
 }
 
@@ -1130,6 +1185,11 @@ static int usb_audio_resume(struct usb_interface *intf)
 
 	snd_usb_midi_v2_resume_all(chip);
 
+	mutex_lock(&register_mutex);
+	if (platform_ops && platform_ops->resume_cb)
+		platform_ops->resume_cb(intf);
+	mutex_unlock(&register_mutex);
+
  out:
 	if (chip->num_suspended_intf == chip->system_suspend) {
 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 6ec95b2edf86..2884912adc96 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -207,4 +207,13 @@ struct snd_usb_stream {
 	struct list_head list;
 };
 
+struct snd_usb_platform_ops {
+	void (*connect_cb)(struct snd_usb_audio *chip);
+	void (*disconnect_cb)(struct snd_usb_audio *chip);
+	void (*suspend_cb)(struct usb_interface *intf, pm_message_t message);
+	void (*resume_cb)(struct usb_interface *intf);
+};
+
+int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
+int snd_usb_unregister_platform_ops(void);
 #endif /* __USBAUDIO_CARD_H */

[PATCH v9 13/34] ALSA: usb-audio: Export USB SND APIs for modules

[Wesley Cheng]

Some vendor modules will utilize useful parsing and endpoint management
APIs to start audio playback/capture.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/card.c     |  4 +++
 sound/usb/endpoint.c |  1 +
 sound/usb/helper.c   |  1 +
 sound/usb/pcm.c      | 75 +++++++++++++++++++++++++++++++-------------
 sound/usb/pcm.h      | 11 +++++++
 5 files changed, 71 insertions(+), 21 deletions(-)

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 1ef6d144aa51..c0b312e264bf 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -1068,6 +1068,7 @@ int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
 		wake_up(&chip->shutdown_wait);
 	return err;
 }
+EXPORT_SYMBOL_GPL(snd_usb_lock_shutdown);
 
 /* autosuspend and unlock the shutdown */
 void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
@@ -1076,6 +1077,7 @@ void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
 	if (atomic_dec_and_test(&chip->usage_count))
 		wake_up(&chip->shutdown_wait);
 }
+EXPORT_SYMBOL_GPL(snd_usb_unlock_shutdown);
 
 int snd_usb_autoresume(struct snd_usb_audio *chip)
 {
@@ -1098,6 +1100,7 @@ int snd_usb_autoresume(struct snd_usb_audio *chip)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(snd_usb_autoresume);
 
 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 {
@@ -1111,6 +1114,7 @@ void snd_usb_autosuspend(struct snd_usb_audio *chip)
 	for (i = 0; i < chip->num_interfaces; i++)
 		usb_autopm_put_interface(chip->intf[i]);
 }
+EXPORT_SYMBOL_GPL(snd_usb_autosuspend);
 
 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 {
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 8f65349a06d3..9876abb80853 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -1513,6 +1513,7 @@ int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
 	mutex_unlock(&chip->mutex);
 	return err;
 }
+EXPORT_SYMBOL_GPL(snd_usb_endpoint_prepare);
 
 /* get the current rate set to the given clock by any endpoint */
 int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock)
diff --git a/sound/usb/helper.c b/sound/usb/helper.c
index bf80e55d013a..4322ae3738e6 100644
--- a/sound/usb/helper.c
+++ b/sound/usb/helper.c
@@ -62,6 +62,7 @@ void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype
 	}
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(snd_usb_find_csint_desc);
 
 /*
  * Wrapper for usb_control_msg().
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 08bf535ed163..3adb09ce1702 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -148,6 +148,16 @@ find_format(struct list_head *fmt_list_head, snd_pcm_format_t format,
 	return found;
 }
 
+const struct audioformat *
+snd_usb_find_format(struct list_head *fmt_list_head, snd_pcm_format_t format,
+	    unsigned int rate, unsigned int channels, bool strict_match,
+	    struct snd_usb_substream *subs)
+{
+	return find_format(fmt_list_head, format, rate, channels, strict_match,
+			subs);
+}
+EXPORT_SYMBOL_GPL(snd_usb_find_format);
+
 static const struct audioformat *
 find_substream_format(struct snd_usb_substream *subs,
 		      const struct snd_pcm_hw_params *params)
@@ -157,6 +167,14 @@ find_substream_format(struct snd_usb_substream *subs,
 			   true, subs);
 }
 
+const struct audioformat *
+snd_usb_find_substream_format(struct snd_usb_substream *subs,
+		      const struct snd_pcm_hw_params *params)
+{
+	return find_substream_format(subs, params);
+}
+EXPORT_SYMBOL_GPL(snd_usb_find_substream_format);
+
 bool snd_usb_pcm_has_fixed_rate(struct snd_usb_substream *subs)
 {
 	const struct audioformat *fp;
@@ -461,20 +479,9 @@ static void close_endpoints(struct snd_usb_audio *chip,
 	}
 }
 
-/*
- * hw_params callback
- *
- * allocate a buffer and set the given audio format.
- *
- * so far we use a physically linear buffer although packetize transfer
- * doesn't need a continuous area.
- * if sg buffer is supported on the later version of alsa, we'll follow
- * that.
- */
-static int snd_usb_hw_params(struct snd_pcm_substream *substream,
-			     struct snd_pcm_hw_params *hw_params)
+int snd_usb_hw_params(struct snd_usb_substream *subs,
+				struct snd_pcm_hw_params *hw_params)
 {
-	struct snd_usb_substream *subs = substream->runtime->private_data;
 	struct snd_usb_audio *chip = subs->stream->chip;
 	const struct audioformat *fmt;
 	const struct audioformat *sync_fmt;
@@ -499,7 +506,7 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 	if (fmt->implicit_fb) {
 		sync_fmt = snd_usb_find_implicit_fb_sync_format(chip, fmt,
 								hw_params,
-								!substream->stream,
+								!subs->direction,
 								&sync_fixed_rate);
 		if (!sync_fmt) {
 			usb_audio_dbg(chip,
@@ -579,15 +586,28 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(snd_usb_hw_params);
 
 /*
- * hw_free callback
+ * hw_params callback
  *
- * reset the audio format and release the buffer
+ * allocate a buffer and set the given audio format.
+ *
+ * so far we use a physically linear buffer although packetize transfer
+ * doesn't need a continuous area.
+ * if sg buffer is supported on the later version of alsa, we'll follow
+ * that.
  */
-static int snd_usb_hw_free(struct snd_pcm_substream *substream)
+static int snd_usb_pcm_hw_params(struct snd_pcm_substream *substream,
+			     struct snd_pcm_hw_params *hw_params)
 {
 	struct snd_usb_substream *subs = substream->runtime->private_data;
+
+	return snd_usb_hw_params(subs, hw_params);
+}
+
+int snd_usb_hw_free(struct snd_usb_substream *subs)
+{
 	struct snd_usb_audio *chip = subs->stream->chip;
 
 	snd_media_stop_pipeline(subs);
@@ -603,6 +623,19 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(snd_usb_hw_free);
+
+/*
+ * hw_free callback
+ *
+ * reset the audio format and release the buffer
+ */
+static int snd_usb_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_usb_substream *subs = substream->runtime->private_data;
+
+	return snd_usb_hw_free(subs);
+}
 
 /* free-wheeling mode? (e.g. dmix) */
 static int in_free_wheeling_mode(struct snd_pcm_runtime *runtime)
@@ -1746,8 +1779,8 @@ static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream
 static const struct snd_pcm_ops snd_usb_playback_ops = {
 	.open =		snd_usb_pcm_open,
 	.close =	snd_usb_pcm_close,
-	.hw_params =	snd_usb_hw_params,
-	.hw_free =	snd_usb_hw_free,
+	.hw_params =	snd_usb_pcm_hw_params,
+	.hw_free =	snd_usb_pcm_hw_free,
 	.prepare =	snd_usb_pcm_prepare,
 	.trigger =	snd_usb_substream_playback_trigger,
 	.sync_stop =	snd_usb_pcm_sync_stop,
@@ -1758,8 +1791,8 @@ static const struct snd_pcm_ops snd_usb_playback_ops = {
 static const struct snd_pcm_ops snd_usb_capture_ops = {
 	.open =		snd_usb_pcm_open,
 	.close =	snd_usb_pcm_close,
-	.hw_params =	snd_usb_hw_params,
-	.hw_free =	snd_usb_hw_free,
+	.hw_params =	snd_usb_pcm_hw_params,
+	.hw_free =	snd_usb_pcm_hw_free,
 	.prepare =	snd_usb_pcm_prepare,
 	.trigger =	snd_usb_substream_capture_trigger,
 	.sync_stop =	snd_usb_pcm_sync_stop,
diff --git a/sound/usb/pcm.h b/sound/usb/pcm.h
index 388fe2ba346d..be2dd9478982 100644
--- a/sound/usb/pcm.h
+++ b/sound/usb/pcm.h
@@ -15,4 +15,15 @@ void snd_usb_preallocate_buffer(struct snd_usb_substream *subs);
 int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
 				    struct audioformat *fmt);
 
+const struct audioformat *
+snd_usb_find_format(struct list_head *fmt_list_head, snd_pcm_format_t format,
+	    unsigned int rate, unsigned int channels, bool strict_match,
+	    struct snd_usb_substream *subs);
+const struct audioformat *
+snd_usb_find_substream_format(struct snd_usb_substream *subs,
+		      const struct snd_pcm_hw_params *params);
+
+int snd_usb_hw_params(struct snd_usb_substream *subs,
+				struct snd_pcm_hw_params *hw_params);
+int snd_usb_hw_free(struct snd_usb_substream *subs);
 #endif /* __USBAUDIO_PCM_H */

[PATCH v9 14/34] dt-bindings: usb: xhci: Add num-hc-interrupters definition

[Wesley Cheng]

Add the definition for how many interrupts the XHCI host controller should
allocate.  XHCI can potentially support up to 1024 interrupters, which
implementations may want to limit.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 Documentation/devicetree/bindings/usb/usb-xhci.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.yaml b/Documentation/devicetree/bindings/usb/usb-xhci.yaml
index 180a261c3e8f..4238ae896ef6 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.yaml
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.yaml
@@ -29,6 +29,12 @@ properties:
     description: Interrupt moderation interval
     default: 5000
 
+  num-hc-interrupters:
+    description: Maximum number of interrupters to allocate
+    $ref: /schemas/types.yaml#/definitions/uint16
+    minimum: 1
+    maximum: 1024
+
 additionalProperties: true
 
 examples:

[PATCH v9 15/34] dt-bindings: usb: dwc3: Limit num-hc-interrupters definition

[Wesley Cheng]

Ensure that the number of XHCI secondary interrupters defined for a DWC3
based implementation is limited to 8.  XHCI in general can potentially
support up to 1024 interrupters.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
index d81c2e849ca9..3e9141e8a005 100644
--- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
+++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
@@ -433,6 +433,10 @@ properties:
     items:
       enum: [1, 4, 8, 16, 32, 64, 128, 256]
 
+  num-hc-interrupters:
+    maximum: 8
+    default: 1
+
   port:
     $ref: /schemas/graph.yaml#/properties/port
     description:

[PATCH v9 16/34] usb: dwc3: Specify maximum number of XHCI interrupters

[Wesley Cheng]

Allow for the DWC3 host driver to pass along XHCI property that defines
how many interrupters to allocate.  This is in relation for the number of
event rings that can be potentially used by other processors within the
system.

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/dwc3/core.c | 12 ++++++++++++
 drivers/usb/dwc3/core.h |  2 ++
 drivers/usb/dwc3/host.c |  5 ++++-
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index d25490965b27..0fa986fd34ca 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1496,6 +1496,7 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 	u8			tx_thr_num_pkt_prd = 0;
 	u8			tx_max_burst_prd = 0;
 	u8			tx_fifo_resize_max_num;
+	u16			num_hc_interrupters;
 	const char		*usb_psy_name;
 	int			ret;
 
@@ -1518,6 +1519,9 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 	 */
 	tx_fifo_resize_max_num = 6;
 
+	/* default to a single XHCI interrupter */
+	num_hc_interrupters = 1;
+
 	dwc->maximum_speed = usb_get_maximum_speed(dev);
 	dwc->max_ssp_rate = usb_get_maximum_ssp_rate(dev);
 	dwc->dr_mode = usb_get_dr_mode(dev);
@@ -1569,6 +1573,12 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				&tx_thr_num_pkt_prd);
 	device_property_read_u8(dev, "snps,tx-max-burst-prd",
 				&tx_max_burst_prd);
+	device_property_read_u16(dev, "num-hc-interrupters",
+				&num_hc_interrupters);
+	/* DWC3 core allowed to have a max of 8 interrupters */
+	if (num_hc_interrupters > 8)
+		num_hc_interrupters = 8;
+
 	dwc->do_fifo_resize = device_property_read_bool(dev,
 							"tx-fifo-resize");
 	if (dwc->do_fifo_resize)
@@ -1657,6 +1667,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 	dwc->imod_interval = 0;
 
 	dwc->tx_fifo_resize_max_num = tx_fifo_resize_max_num;
+
+	dwc->num_hc_interrupters = num_hc_interrupters;
 }
 
 /* check whether the core supports IMOD */
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index c6c87acbd376..2ce5e1e59380 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1060,6 +1060,7 @@ struct dwc3_scratchpad_array {
  * @tx_max_burst_prd: max periodic ESS transmit burst size
  * @tx_fifo_resize_max_num: max number of fifos allocated during txfifo resize
  * @clear_stall_protocol: endpoint number that requires a delayed status phase
+ * @num_hc_interrupters: number of host controller interrupters
  * @hsphy_interface: "utmi" or "ulpi"
  * @connected: true when we're connected to a host, false otherwise
  * @softconnect: true when gadget connect is called, false when disconnect runs
@@ -1294,6 +1295,7 @@ struct dwc3 {
 	u8			tx_max_burst_prd;
 	u8			tx_fifo_resize_max_num;
 	u8			clear_stall_protocol;
+	u16			num_hc_interrupters;
 
 	const char		*hsphy_interface;
 
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 61f57fe5bb78..79ce359c342a 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -61,7 +61,7 @@ static int dwc3_host_get_irq(struct dwc3 *dwc)
 
 int dwc3_host_init(struct dwc3 *dwc)
 {
-	struct property_entry	props[4];
+	struct property_entry	props[5];
 	struct platform_device	*xhci;
 	int			ret, irq;
 	int			prop_idx = 0;
@@ -107,6 +107,9 @@ int dwc3_host_init(struct dwc3 *dwc)
 	if (DWC3_VER_IS_WITHIN(DWC3, ANY, 300A))
 		props[prop_idx++] = PROPERTY_ENTRY_BOOL("quirk-broken-port-ped");
 
+	props[prop_idx++] = PROPERTY_ENTRY_U16("num-hc-interrupters",
+						dwc->num_hc_interrupters);
+
 	if (prop_idx) {
 		ret = device_create_managed_software_node(&xhci->dev, props, NULL);
 		if (ret) {

[PATCH v9 17/34] usb: host: xhci-plat: Set XHCI max interrupters if property is present

[Wesley Cheng]

Some platforms may want to limit the number of XHCI interrupters allocated.
This is passed to xhci-plat as a device property.  Ensure that this is read
and the max_interrupters field is set.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/xhci-plat.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 28218c8f1837..d01318f89278 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -251,6 +251,8 @@ int xhci_plat_probe(struct platform_device *pdev, struct device *sysdev, const s
 
 		device_property_read_u32(tmpdev, "imod-interval-ns",
 					 &xhci->imod_interval);
+		device_property_read_u16(tmpdev, "num-hc-interrupters",
+					 &xhci->max_interrupters);
 	}
 
 	hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev, "usb-phy", 0);

[PATCH v9 18/34] ALSA: usb-audio: qcom: Add USB QMI definitions

[Wesley Cheng]

The Qualcomm USB audio offload driver utilizes the QMI protocol to
communicate with the audio DSP.  Add the necessary QMI header and field
definitions, so the QMI interface driver is able to route the QMI packet
received to the USB audio offload driver.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/qcom/usb_audio_qmi_v01.c | 892 +++++++++++++++++++++++++++++
 sound/usb/qcom/usb_audio_qmi_v01.h | 162 ++++++
 2 files changed, 1054 insertions(+)
 create mode 100644 sound/usb/qcom/usb_audio_qmi_v01.c
 create mode 100644 sound/usb/qcom/usb_audio_qmi_v01.h

diff --git a/sound/usb/qcom/usb_audio_qmi_v01.c b/sound/usb/qcom/usb_audio_qmi_v01.c
new file mode 100644
index 000000000000..bdfd67d980eb
--- /dev/null
+++ b/sound/usb/qcom/usb_audio_qmi_v01.c
@@ -0,0 +1,892 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/soc/qcom/qmi.h>
+
+#include "usb_audio_qmi_v01.h"
+
+static struct qmi_elem_info mem_info_v01_ei[] = {
+	{
+		.data_type	= QMI_UNSIGNED_8_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u64),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct mem_info_v01, va),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_8_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u64),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct mem_info_v01, pa),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct mem_info_v01, size),
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+	},
+};
+
+static struct qmi_elem_info apps_mem_info_v01_ei[] = {
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct mem_info_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct apps_mem_info_v01, evt_ring),
+		.ei_array	= mem_info_v01_ei,
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct mem_info_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct apps_mem_info_v01, tr_data),
+		.ei_array	= mem_info_v01_ei,
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct mem_info_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct apps_mem_info_v01, tr_sync),
+		.ei_array	= mem_info_v01_ei,
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct mem_info_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct apps_mem_info_v01, xfer_buff),
+		.ei_array	= mem_info_v01_ei,
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct mem_info_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct apps_mem_info_v01, dcba),
+		.ei_array	= mem_info_v01_ei,
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+	},
+};
+
+static struct qmi_elem_info usb_endpoint_descriptor_v01_ei[] = {
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						bLength),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						bDescriptorType),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						bEndpointAddress),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						bmAttributes),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_2_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u16),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						wMaxPacketSize),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						bInterval),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						bRefresh),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_endpoint_descriptor_v01,
+						bSynchAddress),
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+	},
+};
+
+static struct qmi_elem_info usb_interface_descriptor_v01_ei[] = {
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bLength),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bDescriptorType),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bInterfaceNumber),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bAlternateSetting),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bNumEndpoints),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bInterfaceClass),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bInterfaceSubClass),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						bInterfaceProtocol),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0,
+		.offset		= offsetof(struct usb_interface_descriptor_v01,
+						iInterface),
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+	},
+};
+
+struct qmi_elem_info qmi_uaudio_stream_req_msg_v01_ei[] = {
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x01,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						enable),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x02,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						usb_token),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x10,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						audio_format_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x10,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						audio_format),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x11,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						number_of_ch_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x11,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						number_of_ch),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x12,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						bit_rate_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x12,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						bit_rate),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x13,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						xfer_buff_size_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x13,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						xfer_buff_size),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x14,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						service_interval_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x14,
+		.offset		= offsetof(struct qmi_uaudio_stream_req_msg_v01,
+						service_interval),
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+	},
+};
+
+struct qmi_elem_info qmi_uaudio_stream_resp_msg_v01_ei[] = {
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct qmi_response_type_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x02,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					resp),
+		.ei_array	= qmi_response_type_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x10,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					status_valid),
+	},
+	{
+		.data_type	= QMI_SIGNED_4_BYTE_ENUM,
+		.elem_len	= 1,
+		.elem_size	= sizeof(enum usb_qmi_audio_stream_status_enum_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x10,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					status),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x11,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					internal_status_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x11,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					internal_status),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x12,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					slot_id_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x12,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					slot_id),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x13,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					usb_token_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x13,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					usb_token),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x14,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					std_as_opr_intf_desc_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct usb_interface_descriptor_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x14,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					std_as_opr_intf_desc),
+		.ei_array	= usb_interface_descriptor_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x15,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					std_as_data_ep_desc_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct usb_endpoint_descriptor_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x15,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					std_as_data_ep_desc),
+		.ei_array	= usb_endpoint_descriptor_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x16,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					std_as_sync_ep_desc_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct usb_endpoint_descriptor_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x16,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					std_as_sync_ep_desc),
+		.ei_array	= usb_endpoint_descriptor_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x17,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					usb_audio_spec_revision_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_2_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u16),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x17,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					usb_audio_spec_revision),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x18,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					data_path_delay_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x18,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					data_path_delay),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x19,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					usb_audio_subslot_size_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x19,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					usb_audio_subslot_size),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1A,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					xhci_mem_info_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct apps_mem_info_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1A,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					xhci_mem_info),
+		.ei_array	= apps_mem_info_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1B,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					interrupter_num_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1B,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					interrupter_num),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1C,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					speed_info_valid),
+	},
+	{
+		.data_type	= QMI_SIGNED_4_BYTE_ENUM,
+		.elem_len	= 1,
+		.elem_size	= sizeof(enum usb_qmi_audio_device_speed_enum_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1C,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					speed_info),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1D,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					controller_num_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x1D,
+		.offset		= offsetof(
+					struct qmi_uaudio_stream_resp_msg_v01,
+					controller_num),
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+	},
+};
+
+struct qmi_elem_info qmi_uaudio_stream_ind_msg_v01_ei[] = {
+	{
+		.data_type	= QMI_SIGNED_4_BYTE_ENUM,
+		.elem_len	= 1,
+		.elem_size	= sizeof(
+				enum usb_qmi_audio_device_indication_enum_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x01,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						dev_event),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x02,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						slot_id),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x10,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						usb_token_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_4_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u32),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x10,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						usb_token),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x11,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						std_as_opr_intf_desc_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct usb_interface_descriptor_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x11,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						std_as_opr_intf_desc),
+		.ei_array	= usb_interface_descriptor_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x12,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						std_as_data_ep_desc_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct usb_endpoint_descriptor_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x12,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						std_as_data_ep_desc),
+		.ei_array	= usb_endpoint_descriptor_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x13,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						std_as_sync_ep_desc_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct usb_endpoint_descriptor_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x13,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						std_as_sync_ep_desc),
+		.ei_array	= usb_endpoint_descriptor_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x14,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						usb_audio_spec_revision_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_2_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u16),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x14,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						usb_audio_spec_revision),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x15,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						data_path_delay_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x15,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						data_path_delay),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x16,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						usb_audio_subslot_size_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x16,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						usb_audio_subslot_size),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x17,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						xhci_mem_info_valid),
+	},
+	{
+		.data_type	= QMI_STRUCT,
+		.elem_len	= 1,
+		.elem_size	= sizeof(struct apps_mem_info_v01),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x17,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						xhci_mem_info),
+		.ei_array	= apps_mem_info_v01_ei,
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x18,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						interrupter_num_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x18,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						interrupter_num),
+	},
+	{
+		.data_type	= QMI_OPT_FLAG,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x19,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						controller_num_valid),
+	},
+	{
+		.data_type	= QMI_UNSIGNED_1_BYTE,
+		.elem_len	= 1,
+		.elem_size	= sizeof(u8),
+		.array_type	= NO_ARRAY,
+		.tlv_type	= 0x19,
+		.offset		= offsetof(struct qmi_uaudio_stream_ind_msg_v01,
+						controller_num),
+	},
+	{
+		.data_type	= QMI_EOTI,
+		.array_type	= NO_ARRAY,
+		.tlv_type	= QMI_COMMON_TLV_TYPE,
+	},
+};
diff --git a/sound/usb/qcom/usb_audio_qmi_v01.h b/sound/usb/qcom/usb_audio_qmi_v01.h
new file mode 100644
index 000000000000..68e3842affc5
--- /dev/null
+++ b/sound/usb/qcom/usb_audio_qmi_v01.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef USB_QMI_V01_H
+#define USB_QMI_V01_H
+
+#define UAUDIO_STREAM_SERVICE_ID_V01 0x41D
+#define UAUDIO_STREAM_SERVICE_VERS_V01 0x01
+
+#define QMI_UAUDIO_STREAM_RESP_V01 0x0001
+#define QMI_UAUDIO_STREAM_REQ_V01 0x0001
+#define QMI_UAUDIO_STREAM_IND_V01 0x0001
+
+
+struct mem_info_v01 {
+	u64 va;
+	u64 pa;
+	u32 size;
+};
+
+struct apps_mem_info_v01 {
+	struct mem_info_v01 evt_ring;
+	struct mem_info_v01 tr_data;
+	struct mem_info_v01 tr_sync;
+	struct mem_info_v01 xfer_buff;
+	struct mem_info_v01 dcba;
+};
+
+struct usb_endpoint_descriptor_v01 {
+	u8 bLength;
+	u8 bDescriptorType;
+	u8 bEndpointAddress;
+	u8 bmAttributes;
+	u16 wMaxPacketSize;
+	u8 bInterval;
+	u8 bRefresh;
+	u8 bSynchAddress;
+};
+
+struct usb_interface_descriptor_v01 {
+	u8 bLength;
+	u8 bDescriptorType;
+	u8 bInterfaceNumber;
+	u8 bAlternateSetting;
+	u8 bNumEndpoints;
+	u8 bInterfaceClass;
+	u8 bInterfaceSubClass;
+	u8 bInterfaceProtocol;
+	u8 iInterface;
+};
+
+enum usb_qmi_audio_stream_status_enum_v01 {
+	USB_QMI_STREAM_STATUS_ENUM_MIN_VAL_V01 = INT_MIN,
+	USB_QMI_STREAM_REQ_SUCCESS_V01 = 0,
+	USB_QMI_STREAM_REQ_FAILURE_V01 = 1,
+	USB_QMI_STREAM_REQ_FAILURE_NOT_FOUND_V01 = 2,
+	USB_QMI_STREAM_REQ_FAILURE_INVALID_PARAM_V01 = 3,
+	USB_QMI_STREAM_REQ_FAILURE_MEMALLOC_V01 = 4,
+	USB_QMI_STREAM_STATUS_ENUM_MAX_VAL_V01 = INT_MAX,
+};
+
+enum usb_qmi_audio_device_indication_enum_v01 {
+	USB_QMI_DEVICE_INDICATION_ENUM_MIN_VAL_V01 = INT_MIN,
+	USB_QMI_DEV_CONNECT_V01 = 0,
+	USB_QMI_DEV_DISCONNECT_V01 = 1,
+	USB_QMI_DEV_SUSPEND_V01 = 2,
+	USB_QMI_DEV_RESUME_V01 = 3,
+	USB_QMI_DEVICE_INDICATION_ENUM_MAX_VAL_V01 = INT_MAX,
+};
+
+enum usb_qmi_audio_device_speed_enum_v01 {
+	USB_QMI_DEVICE_SPEED_ENUM_MIN_VAL_V01 = INT_MIN,
+	USB_QMI_DEVICE_SPEED_INVALID_V01 = 0,
+	USB_QMI_DEVICE_SPEED_LOW_V01 = 1,
+	USB_QMI_DEVICE_SPEED_FULL_V01 = 2,
+	USB_QMI_DEVICE_SPEED_HIGH_V01 = 3,
+	USB_QMI_DEVICE_SPEED_SUPER_V01 = 4,
+	USB_QMI_DEVICE_SPEED_SUPER_PLUS_V01 = 5,
+	USB_QMI_DEVICE_SPEED_ENUM_MAX_VAL_V01 = INT_MAX,
+};
+
+struct qmi_uaudio_stream_req_msg_v01 {
+	u8 enable;
+	u32 usb_token;
+	u8 audio_format_valid;
+	u32 audio_format;
+	u8 number_of_ch_valid;
+	u32 number_of_ch;
+	u8 bit_rate_valid;
+	u32 bit_rate;
+	u8 xfer_buff_size_valid;
+	u32 xfer_buff_size;
+	u8 service_interval_valid;
+	u32 service_interval;
+};
+#define QMI_UAUDIO_STREAM_REQ_MSG_V01_MAX_MSG_LEN 46
+extern struct qmi_elem_info qmi_uaudio_stream_req_msg_v01_ei[];
+
+struct qmi_uaudio_stream_resp_msg_v01 {
+	struct qmi_response_type_v01 resp;
+	u8 status_valid;
+	enum usb_qmi_audio_stream_status_enum_v01 status;
+	u8 internal_status_valid;
+	u32 internal_status;
+	u8 slot_id_valid;
+	u32 slot_id;
+	u8 usb_token_valid;
+	u32 usb_token;
+	u8 std_as_opr_intf_desc_valid;
+	struct usb_interface_descriptor_v01 std_as_opr_intf_desc;
+	u8 std_as_data_ep_desc_valid;
+	struct usb_endpoint_descriptor_v01 std_as_data_ep_desc;
+	u8 std_as_sync_ep_desc_valid;
+	struct usb_endpoint_descriptor_v01 std_as_sync_ep_desc;
+	u8 usb_audio_spec_revision_valid;
+	u16 usb_audio_spec_revision;
+	u8 data_path_delay_valid;
+	u8 data_path_delay;
+	u8 usb_audio_subslot_size_valid;
+	u8 usb_audio_subslot_size;
+	u8 xhci_mem_info_valid;
+	struct apps_mem_info_v01 xhci_mem_info;
+	u8 interrupter_num_valid;
+	u8 interrupter_num;
+	u8 speed_info_valid;
+	enum usb_qmi_audio_device_speed_enum_v01 speed_info;
+	u8 controller_num_valid;
+	u8 controller_num;
+};
+#define QMI_UAUDIO_STREAM_RESP_MSG_V01_MAX_MSG_LEN 202
+extern struct qmi_elem_info qmi_uaudio_stream_resp_msg_v01_ei[];
+
+struct qmi_uaudio_stream_ind_msg_v01 {
+	enum usb_qmi_audio_device_indication_enum_v01 dev_event;
+	u32 slot_id;
+	u8 usb_token_valid;
+	u32 usb_token;
+	u8 std_as_opr_intf_desc_valid;
+	struct usb_interface_descriptor_v01 std_as_opr_intf_desc;
+	u8 std_as_data_ep_desc_valid;
+	struct usb_endpoint_descriptor_v01 std_as_data_ep_desc;
+	u8 std_as_sync_ep_desc_valid;
+	struct usb_endpoint_descriptor_v01 std_as_sync_ep_desc;
+	u8 usb_audio_spec_revision_valid;
+	u16 usb_audio_spec_revision;
+	u8 data_path_delay_valid;
+	u8 data_path_delay;
+	u8 usb_audio_subslot_size_valid;
+	u8 usb_audio_subslot_size;
+	u8 xhci_mem_info_valid;
+	struct apps_mem_info_v01 xhci_mem_info;
+	u8 interrupter_num_valid;
+	u8 interrupter_num;
+	u8 controller_num_valid;
+	u8 controller_num;
+};
+#define QMI_UAUDIO_STREAM_IND_MSG_V01_MAX_MSG_LEN 181
+extern struct qmi_elem_info qmi_uaudio_stream_ind_msg_v01_ei[];
+
+#endif

[PATCH v9 19/34] ALSA: usb-audio: qcom: Introduce QC USB SND offloading support

[Wesley Cheng]

Several Qualcomm SoCs have a dedicated audio DSP, which has the ability to
support USB sound devices.  This vendor driver will implement the required
handshaking with the DSP, in order to pass along required resources that
will be utilized by the DSP's USB SW.  The communication channel used for
this handshaking will be using the QMI protocol.  Required resources
include:
- Allocated secondary event ring address
- EP transfer ring address
- Interrupter number

The above information will allow for the audio DSP to execute USB transfers
over the USB bus.  It will also be able to support devices that have an
implicit feedback and sync endpoint as well.  Offloading these data
transfers will allow the main/applications processor to enter lower CPU
power modes, and sustain a longer duration in those modes.

Audio offloading is initiated with the following sequence:
1. Userspace configures to route audio playback to USB backend and starts
playback on the platform soundcard.
2. The Q6DSP AFE will communicate to the audio DSP to start the USB AFE
port.
3. This results in a QMI packet with a STREAM enable command.
4. The QC audio offload driver will fetch the required resources, and pass
this information as part of the QMI response to the STREAM enable command.
5. Once the QMI response is received the audio DSP will start queuing data
on the USB bus.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 include/sound/soc-usb.h           |    2 +-
 sound/usb/Kconfig                 |   15 +
 sound/usb/Makefile                |    2 +-
 sound/usb/qcom/Makefile           |    2 +
 sound/usb/qcom/qc_audio_offload.c | 1843 +++++++++++++++++++++++++++++
 5 files changed, 1862 insertions(+), 2 deletions(-)
 create mode 100644 sound/usb/qcom/Makefile
 create mode 100644 sound/usb/qcom/qc_audio_offload.c

diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
index 1fa671924018..58c686f4f7ba 100644
--- a/include/sound/soc-usb.h
+++ b/include/sound/soc-usb.h
@@ -39,7 +39,7 @@ struct snd_soc_usb {
 
 int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
 int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
-void *snd_soc_usb_get_priv_data(struct device *usbdev);
+void *snd_soc_usb_find_priv_data(struct device *usbdev);
 
 struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
 			int (*connection_cb)(struct snd_soc_usb *usb,
diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index 4a9569a3a39a..4c842fbe6365 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -176,6 +176,21 @@ config SND_BCD2000
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-bcd2000.
 
+config SND_USB_AUDIO_QMI
+	tristate "Qualcomm Audio Offload driver"
+	depends on QCOM_QMI_HELPERS && SND_USB_AUDIO && USB_XHCI_SIDEBAND
+	select SND_PCM
+	help
+	  Say Y here to enable the Qualcomm USB audio offloading feature.
+
+	  This module sets up the required QMI stream enable/disable
+	  responses to requests generated by the audio DSP.  It passes the
+	  USB transfer resource references, so that the audio DSP can issue
+	  USB transfers to the host controller.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-usb-audio-qmi.
+
 source "sound/usb/line6/Kconfig"
 
 endif	# SND_USB
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index db5ff76d0e61..fa624a4052ae 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -34,5 +34,5 @@ obj-$(CONFIG_SND_USB_UA101) += snd-usbmidi-lib.o
 obj-$(CONFIG_SND_USB_USX2Y) += snd-usbmidi-lib.o
 obj-$(CONFIG_SND_USB_US122L) += snd-usbmidi-lib.o
 
-obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/ bcd2000/
+obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/ bcd2000/ qcom/
 obj-$(CONFIG_SND_USB_LINE6)	+= line6/
diff --git a/sound/usb/qcom/Makefile b/sound/usb/qcom/Makefile
new file mode 100644
index 000000000000..a81c9b28d484
--- /dev/null
+++ b/sound/usb/qcom/Makefile
@@ -0,0 +1,2 @@
+snd-usb-audio-qmi-objs := usb_audio_qmi_v01.o qc_audio_offload.o
+obj-$(CONFIG_SND_USB_AUDIO_QMI) += snd-usb-audio-qmi.o
\ No newline at end of file
diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
new file mode 100644
index 000000000000..320ce3a6688f
--- /dev/null
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -0,0 +1,1843 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/ctype.h>
+#include <linux/moduleparam.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/init.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/xhci-sideband.h>
+#include <linux/usb/quirks.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/audio-v2.h>
+#include <linux/usb/audio-v3.h>
+#include <linux/soc/qcom/qmi.h>
+#include <linux/iommu.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
+#include <sound/q6usboffload.h>
+
+#include <sound/control.h>
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/initval.h>
+
+#include <sound/soc.h>
+#include <sound/soc-usb.h>
+#include "../usbaudio.h"
+#include "../card.h"
+#include "../endpoint.h"
+#include "../helper.h"
+#include "../pcm.h"
+#include "../format.h"
+#include "../power.h"
+#include "usb_audio_qmi_v01.h"
+
+/* Stream disable request timeout during USB device disconnect */
+#define DEV_RELEASE_WAIT_TIMEOUT 10000 /* in ms */
+
+/* Data interval calculation parameters */
+#define BUS_INTERVAL_FULL_SPEED 1000 /* in us */
+#define BUS_INTERVAL_HIGHSPEED_AND_ABOVE 125 /* in us */
+#define MAX_BINTERVAL_ISOC_EP 16
+
+#define QMI_STREAM_REQ_CARD_NUM_MASK 0xffff0000
+#define QMI_STREAM_REQ_DEV_NUM_MASK 0xff00
+#define QMI_STREAM_REQ_DIRECTION 0xff
+
+/* iommu resource parameters and management */
+#define PREPEND_SID_TO_IOVA(iova, sid) ((u64)(((u64)(iova)) | \
+					(((u64)sid) << 32)))
+#define IOVA_BASE 0x1000
+#define IOVA_XFER_RING_BASE (IOVA_BASE + PAGE_SIZE * (SNDRV_CARDS + 1))
+#define IOVA_XFER_BUF_BASE (IOVA_XFER_RING_BASE + PAGE_SIZE * SNDRV_CARDS * 32)
+#define IOVA_XFER_RING_MAX (IOVA_XFER_BUF_BASE - PAGE_SIZE)
+#define IOVA_XFER_BUF_MAX (0xfffff000 - PAGE_SIZE)
+
+#define MAX_XFER_BUFF_LEN (24 * PAGE_SIZE)
+
+struct iova_info {
+	struct list_head list;
+	unsigned long start_iova;
+	size_t size;
+	bool in_use;
+};
+
+struct intf_info {
+	unsigned long data_xfer_ring_va;
+	size_t data_xfer_ring_size;
+	unsigned long sync_xfer_ring_va;
+	size_t sync_xfer_ring_size;
+	unsigned long xfer_buf_va;
+	size_t xfer_buf_size;
+	phys_addr_t xfer_buf_pa;
+	unsigned int data_ep_pipe;
+	unsigned int sync_ep_pipe;
+	u8 *xfer_buf;
+	u8 intf_num;
+	u8 pcm_card_num;
+	u8 pcm_dev_num;
+	u8 direction;
+	bool in_use;
+};
+
+struct uaudio_qmi_dev {
+	struct device *dev;
+	u32 sid;
+	u32 intr_num;
+	struct xhci_ring *sec_ring;
+	struct iommu_domain *domain;
+
+	/* list to keep track of available iova */
+	struct list_head xfer_ring_list;
+	size_t xfer_ring_iova_size;
+	unsigned long curr_xfer_ring_iova;
+	struct list_head xfer_buf_list;
+	size_t xfer_buf_iova_size;
+	unsigned long curr_xfer_buf_iova;
+
+	/* bit fields representing pcm card enabled */
+	unsigned long card_slot;
+	/* indicate event ring mapped or not */
+	bool er_mapped;
+	/* reference count to number of possible consumers */
+	atomic_t qdev_in_use;
+	/* idx to last udev card number plugged in */
+	unsigned int last_card_num;
+};
+
+struct uaudio_dev {
+	struct usb_device *udev;
+	/* audio control interface */
+	struct usb_host_interface *ctrl_intf;
+	unsigned int usb_core_id;
+	atomic_t in_use;
+	struct kref kref;
+	wait_queue_head_t disconnect_wq;
+
+	/* interface specific */
+	int num_intf;
+	struct intf_info *info;
+	struct snd_usb_audio *chip;
+
+	/* xhci sideband */
+	struct xhci_sideband *sb;
+
+	/* SoC USB device */
+	struct snd_soc_usb_device *sdev;
+};
+
+static struct uaudio_dev uadev[SNDRV_CARDS];
+static struct uaudio_qmi_dev *uaudio_qdev;
+static struct uaudio_qmi_svc *uaudio_svc;
+static DEFINE_MUTEX(qdev_mutex);
+
+struct uaudio_qmi_svc {
+	struct qmi_handle *uaudio_svc_hdl;
+	struct work_struct qmi_disconnect_work;
+	struct workqueue_struct *uaudio_wq;
+	struct sockaddr_qrtr client_sq;
+	bool client_connected;
+};
+
+enum mem_type {
+	MEM_EVENT_RING,
+	MEM_XFER_RING,
+	MEM_XFER_BUF,
+};
+
+/* Supported audio formats */
+enum usb_qmi_audio_format {
+	USB_QMI_PCM_FORMAT_S8 = 0,
+	USB_QMI_PCM_FORMAT_U8,
+	USB_QMI_PCM_FORMAT_S16_LE,
+	USB_QMI_PCM_FORMAT_S16_BE,
+	USB_QMI_PCM_FORMAT_U16_LE,
+	USB_QMI_PCM_FORMAT_U16_BE,
+	USB_QMI_PCM_FORMAT_S24_LE,
+	USB_QMI_PCM_FORMAT_S24_BE,
+	USB_QMI_PCM_FORMAT_U24_LE,
+	USB_QMI_PCM_FORMAT_U24_BE,
+	USB_QMI_PCM_FORMAT_S24_3LE,
+	USB_QMI_PCM_FORMAT_S24_3BE,
+	USB_QMI_PCM_FORMAT_U24_3LE,
+	USB_QMI_PCM_FORMAT_U24_3BE,
+	USB_QMI_PCM_FORMAT_S32_LE,
+	USB_QMI_PCM_FORMAT_S32_BE,
+	USB_QMI_PCM_FORMAT_U32_LE,
+	USB_QMI_PCM_FORMAT_U32_BE,
+};
+
+static enum usb_qmi_audio_device_speed_enum_v01
+get_speed_info(enum usb_device_speed udev_speed)
+{
+	switch (udev_speed) {
+	case USB_SPEED_LOW:
+		return USB_QMI_DEVICE_SPEED_LOW_V01;
+	case USB_SPEED_FULL:
+		return USB_QMI_DEVICE_SPEED_FULL_V01;
+	case USB_SPEED_HIGH:
+		return USB_QMI_DEVICE_SPEED_HIGH_V01;
+	case USB_SPEED_SUPER:
+		return USB_QMI_DEVICE_SPEED_SUPER_V01;
+	case USB_SPEED_SUPER_PLUS:
+		return USB_QMI_DEVICE_SPEED_SUPER_PLUS_V01;
+	default:
+		return USB_QMI_DEVICE_SPEED_INVALID_V01;
+	}
+}
+
+static struct snd_usb_substream *find_substream(unsigned int card_num,
+	unsigned int pcm_idx, unsigned int direction)
+{
+	struct snd_usb_stream *as;
+	struct snd_usb_substream *subs = NULL;
+	struct snd_usb_audio *chip;
+
+	chip = uadev[card_num].chip;
+	if (!chip || atomic_read(&chip->shutdown))
+		goto done;
+
+	if (pcm_idx >= chip->pcm_devs)
+		goto done;
+
+	if (direction > SNDRV_PCM_STREAM_CAPTURE)
+		goto done;
+
+	list_for_each_entry(as, &chip->pcm_list, list) {
+		if (as->pcm_index == pcm_idx) {
+			subs = &as->substream[direction];
+			goto done;
+		}
+	}
+
+done:
+	return subs;
+}
+
+static int info_idx_from_ifnum(int card_num, int intf_num, bool enable)
+{
+	int i;
+
+	/*
+	 * default index 0 is used when info is allocated upon
+	 * first enable audio stream req for a pcm device
+	 */
+	if (enable && !uadev[card_num].info)
+		return 0;
+
+	for (i = 0; i < uadev[card_num].num_intf; i++) {
+		if (enable && !uadev[card_num].info[i].in_use)
+			return i;
+		else if (!enable &&
+				uadev[card_num].info[i].intf_num == intf_num)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static int get_data_interval_from_si(struct snd_usb_substream *subs,
+	u32 service_interval)
+{
+	unsigned int bus_intval, bus_intval_mult, binterval;
+
+	if (subs->dev->speed >= USB_SPEED_HIGH)
+		bus_intval = BUS_INTERVAL_HIGHSPEED_AND_ABOVE;
+	else
+		bus_intval = BUS_INTERVAL_FULL_SPEED;
+
+	if (service_interval % bus_intval)
+		return -EINVAL;
+
+	bus_intval_mult = service_interval / bus_intval;
+	binterval = ffs(bus_intval_mult);
+	if (!binterval || binterval > MAX_BINTERVAL_ISOC_EP)
+		return -EINVAL;
+
+	/* check if another bit is set then bail out */
+	bus_intval_mult = bus_intval_mult >> binterval;
+	if (bus_intval_mult)
+		return -EINVAL;
+
+	return (binterval - 1);
+}
+
+/* maps audio format received over QMI to asound.h based pcm format */
+static snd_pcm_format_t map_pcm_format(enum usb_qmi_audio_format fmt_received)
+{
+	switch (fmt_received) {
+	case USB_QMI_PCM_FORMAT_S8:
+		return SNDRV_PCM_FORMAT_S8;
+	case USB_QMI_PCM_FORMAT_U8:
+		return SNDRV_PCM_FORMAT_U8;
+	case USB_QMI_PCM_FORMAT_S16_LE:
+		return SNDRV_PCM_FORMAT_S16_LE;
+	case USB_QMI_PCM_FORMAT_S16_BE:
+		return SNDRV_PCM_FORMAT_S16_BE;
+	case USB_QMI_PCM_FORMAT_U16_LE:
+		return SNDRV_PCM_FORMAT_U16_LE;
+	case USB_QMI_PCM_FORMAT_U16_BE:
+		return SNDRV_PCM_FORMAT_U16_BE;
+	case USB_QMI_PCM_FORMAT_S24_LE:
+		return SNDRV_PCM_FORMAT_S24_LE;
+	case USB_QMI_PCM_FORMAT_S24_BE:
+		return SNDRV_PCM_FORMAT_S24_BE;
+	case USB_QMI_PCM_FORMAT_U24_LE:
+		return SNDRV_PCM_FORMAT_U24_LE;
+	case USB_QMI_PCM_FORMAT_U24_BE:
+		return SNDRV_PCM_FORMAT_U24_BE;
+	case USB_QMI_PCM_FORMAT_S24_3LE:
+		return SNDRV_PCM_FORMAT_S24_3LE;
+	case USB_QMI_PCM_FORMAT_S24_3BE:
+		return SNDRV_PCM_FORMAT_S24_3BE;
+	case USB_QMI_PCM_FORMAT_U24_3LE:
+		return SNDRV_PCM_FORMAT_U24_3LE;
+	case USB_QMI_PCM_FORMAT_U24_3BE:
+		return SNDRV_PCM_FORMAT_U24_3BE;
+	case USB_QMI_PCM_FORMAT_S32_LE:
+		return SNDRV_PCM_FORMAT_S32_LE;
+	case USB_QMI_PCM_FORMAT_S32_BE:
+		return SNDRV_PCM_FORMAT_S32_BE;
+	case USB_QMI_PCM_FORMAT_U32_LE:
+		return SNDRV_PCM_FORMAT_U32_LE;
+	case USB_QMI_PCM_FORMAT_U32_BE:
+		return SNDRV_PCM_FORMAT_U32_BE;
+	default:
+		/*
+		 * We expect the caller to do input validation so we should
+		 * never hit this. But we do have to return a proper
+		 * snd_pcm_format_t value due to the __bitwise attribute; so
+		 * just return the equivalent of 0 in case of bad input.
+		 */
+		return SNDRV_PCM_FORMAT_S8;
+	}
+}
+
+/* Offloading IOMMU management */
+static unsigned long uaudio_get_iova(unsigned long *curr_iova,
+	size_t *curr_iova_size, struct list_head *head, size_t size)
+{
+	struct iova_info *info, *new_info = NULL;
+	struct list_head *curr_head;
+	unsigned long va = 0;
+	size_t tmp_size = size;
+	bool found = false;
+
+	if (size % PAGE_SIZE) {
+		dev_dbg(uaudio_qdev->dev, "size %zu is not page size multiple\n",
+			size);
+		goto done;
+	}
+
+	if (size > *curr_iova_size) {
+		dev_dbg(uaudio_qdev->dev, "size %zu > curr size %zu\n",
+			size, *curr_iova_size);
+		goto done;
+	}
+	if (*curr_iova_size == 0) {
+		dev_dbg(uaudio_qdev->dev, "iova mapping is full\n");
+		goto done;
+	}
+
+	list_for_each_entry(info, head, list) {
+		/* exact size iova_info */
+		if (!info->in_use && info->size == size) {
+			info->in_use = true;
+			va = info->start_iova;
+			*curr_iova_size -= size;
+			found = true;
+			dev_dbg(uaudio_qdev->dev, "exact size: %zu found\n", size);
+			goto done;
+		} else if (!info->in_use && tmp_size >= info->size) {
+			if (!new_info)
+				new_info = info;
+			dev_dbg(uaudio_qdev->dev, "partial size: %zu found\n",
+					info->size);
+			tmp_size -= info->size;
+			if (tmp_size)
+				continue;
+
+			va = new_info->start_iova;
+			for (curr_head = &new_info->list; curr_head !=
+			&info->list; curr_head = curr_head->next) {
+				new_info = list_entry(curr_head, struct
+						iova_info, list);
+				new_info->in_use = true;
+			}
+			info->in_use = true;
+			*curr_iova_size -= size;
+			found = true;
+			goto done;
+		} else {
+			/* iova region in use */
+			new_info = NULL;
+			tmp_size = size;
+		}
+	}
+
+	info = kzalloc(sizeof(struct iova_info), GFP_KERNEL);
+	if (!info) {
+		va = 0;
+		goto done;
+	}
+
+	va = info->start_iova = *curr_iova;
+	info->size = size;
+	info->in_use = true;
+	*curr_iova += size;
+	*curr_iova_size -= size;
+	found = true;
+	list_add_tail(&info->list, head);
+
+done:
+	if (!found)
+		dev_err(uaudio_qdev->dev, "unable to find %zu size iova\n",
+			size);
+	else
+		dev_dbg(uaudio_qdev->dev,
+			"va:0x%08lx curr_iova:0x%08lx curr_iova_size:%zu\n",
+			va, *curr_iova, *curr_iova_size);
+
+	return va;
+}
+
+static void uaudio_put_iova(unsigned long va, size_t size, struct list_head
+	*head, size_t *curr_iova_size)
+{
+	struct iova_info *info;
+	size_t tmp_size = size;
+	bool found = false;
+
+	list_for_each_entry(info, head, list) {
+		if (info->start_iova == va) {
+			if (!info->in_use) {
+				dev_err(uaudio_qdev->dev, "va %lu is not in use\n",
+					va);
+				return;
+			}
+			found = true;
+			info->in_use = false;
+			if (info->size == size)
+				goto done;
+		}
+
+		if (found && tmp_size >= info->size) {
+			info->in_use = false;
+			tmp_size -= info->size;
+			if (!tmp_size)
+				goto done;
+		}
+	}
+
+	if (!found) {
+		dev_err(uaudio_qdev->dev, "unable to find the va %lu\n", va);
+		return;
+	}
+done:
+	*curr_iova_size += size;
+	dev_dbg(uaudio_qdev->dev, "curr_iova_size %zu\n", *curr_iova_size);
+}
+
+/**
+ * uaudio_iommu_unmap() - unmaps iommu memory for adsp
+ * @mtype: ring type
+ * @va: virtual address to unmap
+ * @iova_size: region size
+ * @mapped_iova_size: mapped region size
+ *
+ * Unmaps the memory region that was previously assigned to the adsp.
+ *
+ */
+static void uaudio_iommu_unmap(enum mem_type mtype, unsigned long va,
+	size_t iova_size, size_t mapped_iova_size)
+{
+	size_t umap_size;
+	bool unmap = true;
+
+	if (!va || !iova_size)
+		return;
+
+	switch (mtype) {
+	case MEM_EVENT_RING:
+		if (uaudio_qdev->er_mapped)
+			uaudio_qdev->er_mapped = false;
+		else
+			unmap = false;
+		break;
+
+	case MEM_XFER_RING:
+		uaudio_put_iova(va, iova_size, &uaudio_qdev->xfer_ring_list,
+		&uaudio_qdev->xfer_ring_iova_size);
+		break;
+	case MEM_XFER_BUF:
+		uaudio_put_iova(va, iova_size, &uaudio_qdev->xfer_buf_list,
+		&uaudio_qdev->xfer_buf_iova_size);
+		break;
+	default:
+		dev_err(uaudio_qdev->dev, "unknown mem type %d\n", mtype);
+		unmap = false;
+	}
+
+	if (!unmap || !mapped_iova_size)
+		return;
+
+	dev_dbg(uaudio_qdev->dev, "type %d: unmap iova 0x%08lx size %zu\n",
+		mtype, va, mapped_iova_size);
+
+	umap_size = iommu_unmap(uaudio_qdev->domain, va, mapped_iova_size);
+	if (umap_size != mapped_iova_size)
+		dev_err(uaudio_qdev->dev,
+			"unmapped size %zu for iova 0x%08lx of mapped size %zu\n",
+			umap_size, va, mapped_iova_size);
+}
+
+/**
+ * uaudio_iommu_map() - maps iommu memory for adsp
+ * @mtype: ring type
+ * @dma_coherent: dma coherent
+ * @pa: physical address for ring/buffer
+ * @size: size of memory region
+ * @sgt: sg table for memory region
+ *
+ * Maps the XHCI related resources to a memory region that is assigned to be
+ * used by the adsp.  This will be mapped to the domain, which is created by
+ * the ASoC USB backend driver.
+ *
+ */
+static unsigned long uaudio_iommu_map(enum mem_type mtype, bool dma_coherent,
+		phys_addr_t pa, size_t size, struct sg_table *sgt)
+{
+	unsigned long va_sg, va = 0;
+	bool map = true;
+	int i, ret;
+	size_t sg_len, total_len = 0;
+	struct scatterlist *sg;
+	phys_addr_t pa_sg;
+	int prot = IOMMU_READ | IOMMU_WRITE;
+
+	if (dma_coherent)
+		prot |= IOMMU_CACHE;
+
+	switch (mtype) {
+	case MEM_EVENT_RING:
+		va = IOVA_BASE;
+		/* er already mapped */
+		if (uaudio_qdev->er_mapped)
+			map = false;
+		break;
+	case MEM_XFER_RING:
+		va = uaudio_get_iova(&uaudio_qdev->curr_xfer_ring_iova,
+		&uaudio_qdev->xfer_ring_iova_size, &uaudio_qdev->xfer_ring_list,
+		size);
+		break;
+	case MEM_XFER_BUF:
+		va = uaudio_get_iova(&uaudio_qdev->curr_xfer_buf_iova,
+		&uaudio_qdev->xfer_buf_iova_size, &uaudio_qdev->xfer_buf_list,
+		size);
+		break;
+	default:
+		dev_err(uaudio_qdev->dev, "unknown mem type %d\n", mtype);
+	}
+
+	if (!va || !map)
+		goto done;
+
+	if (!sgt)
+		goto skip_sgt_map;
+
+	va_sg = va;
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		sg_len = PAGE_ALIGN(sg->offset + sg->length);
+		pa_sg = page_to_phys(sg_page(sg));
+		ret = iommu_map(uaudio_qdev->domain, va_sg, pa_sg, sg_len,
+				prot, GFP_KERNEL);
+		if (ret) {
+			dev_err(uaudio_qdev->dev, "mapping failed ret%d\n", ret);
+			dev_err(uaudio_qdev->dev,
+				"type:%d, pa:%pa iova:0x%08lx sg_len:%zu\n",
+				mtype, &pa_sg, va_sg, sg_len);
+			uaudio_iommu_unmap(MEM_XFER_BUF, va, size, total_len);
+			va = 0;
+			goto done;
+		}
+		dev_dbg(uaudio_qdev->dev,
+			"type:%d map pa:%pa to iova:0x%08lx len:%zu offset:%u\n",
+			mtype, &pa_sg, va_sg, sg_len, sg->offset);
+		va_sg += sg_len;
+		total_len += sg_len;
+	}
+
+	if (size != total_len) {
+		dev_err(uaudio_qdev->dev, "iova size %zu != mapped iova size %zu\n",
+			size, total_len);
+		uaudio_iommu_unmap(MEM_XFER_BUF, va, size, total_len);
+		va = 0;
+	}
+	return va;
+
+skip_sgt_map:
+	dev_dbg(uaudio_qdev->dev, "type:%d map pa:%pa to iova:0x%08lx size:%zu\n",
+		mtype, &pa, va, size);
+
+	ret = iommu_map(uaudio_qdev->domain, va, pa, size, prot, GFP_KERNEL);
+	if (ret)
+		dev_err(uaudio_qdev->dev,
+			"failed to map pa:%pa iova:0x%lx type:%d ret:%d\n",
+			&pa, va, mtype, ret);
+done:
+	return va;
+}
+
+/* looks up alias, if any, for controller DT node and returns the index */
+static int usb_get_controller_id(struct usb_device *udev)
+{
+	if (udev->bus->sysdev && udev->bus->sysdev->of_node)
+		return of_alias_get_id(udev->bus->sysdev->of_node, "usb");
+
+	return -ENODEV;
+}
+
+/**
+ * uaudio_dev_intf_cleanup() - cleanup transfer resources
+ * @udev: usb device
+ * @info: usb offloading interface
+ *
+ * Cleans up the transfer ring related resources which are assigned per
+ * endpoint from XHCI.  This is invoked when the USB endpoints are no
+ * longer in use by the adsp.
+ *
+ */
+static void uaudio_dev_intf_cleanup(struct usb_device *udev,
+	struct intf_info *info)
+{
+	uaudio_iommu_unmap(MEM_XFER_RING, info->data_xfer_ring_va,
+		info->data_xfer_ring_size, info->data_xfer_ring_size);
+	info->data_xfer_ring_va = 0;
+	info->data_xfer_ring_size = 0;
+
+	uaudio_iommu_unmap(MEM_XFER_RING, info->sync_xfer_ring_va,
+		info->sync_xfer_ring_size, info->sync_xfer_ring_size);
+	info->sync_xfer_ring_va = 0;
+	info->sync_xfer_ring_size = 0;
+
+	uaudio_iommu_unmap(MEM_XFER_BUF, info->xfer_buf_va,
+		info->xfer_buf_size, info->xfer_buf_size);
+	info->xfer_buf_va = 0;
+
+	usb_free_coherent(udev, info->xfer_buf_size,
+		info->xfer_buf, info->xfer_buf_pa);
+	info->xfer_buf_size = 0;
+	info->xfer_buf = NULL;
+	info->xfer_buf_pa = 0;
+
+	info->in_use = false;
+}
+
+/**
+ * uaudio_event_ring_cleanup_free() - cleanup secondary event ring
+ * @dev: usb offload device
+ *
+ * Cleans up the secondary event ring that was requested.  This will
+ * occur when the adsp is no longer transferring data on the USB bus
+ * across all endpoints.
+ *
+ */
+static void uaudio_event_ring_cleanup_free(struct uaudio_dev *dev)
+{
+	clear_bit(dev->chip->card->number, &uaudio_qdev->card_slot);
+	/* all audio devices are disconnected */
+	if (!uaudio_qdev->card_slot) {
+		uaudio_iommu_unmap(MEM_EVENT_RING, IOVA_BASE, PAGE_SIZE,
+			PAGE_SIZE);
+		xhci_sideband_remove_interrupter(uadev[dev->chip->card->number].sb);
+	}
+}
+
+static void uaudio_dev_cleanup(struct uaudio_dev *dev)
+{
+	int if_idx;
+
+	if (!dev->udev)
+		return;
+
+	/* free xfer buffer and unmap xfer ring and buf per interface */
+	for (if_idx = 0; if_idx < dev->num_intf; if_idx++) {
+		if (!dev->info[if_idx].in_use)
+			continue;
+		uaudio_dev_intf_cleanup(dev->udev, &dev->info[if_idx]);
+		dev_dbg(uaudio_qdev->dev, "release resources: intf# %d card# %d\n",
+			dev->info[if_idx].intf_num, dev->chip->card->number);
+	}
+
+	dev->num_intf = 0;
+
+	/* free interface info */
+	kfree(dev->info);
+	dev->info = NULL;
+	uaudio_event_ring_cleanup_free(dev);
+	dev->udev = NULL;
+}
+
+/**
+ * disable_audio_stream() - disable usb snd endpoints
+ * @subs: usb substream
+ *
+ * Closes the USB SND endpoints associated with the current audio stream
+ * used.  This will decrement the USB SND endpoint opened reference count.
+ *
+ */
+static void disable_audio_stream(struct snd_usb_substream *subs)
+{
+	struct snd_usb_audio *chip = subs->stream->chip;
+
+	snd_usb_hw_free(subs);
+	snd_usb_autosuspend(chip);
+}
+
+/* QMI service disconnect handlers */
+static void qmi_disconnect_work(struct work_struct *w)
+{
+	struct intf_info *info;
+	int idx, if_idx;
+	struct snd_usb_substream *subs;
+	struct snd_usb_audio *chip;
+
+	mutex_lock(&qdev_mutex);
+	/* find all active intf for set alt 0 and cleanup usb audio dev */
+	for (idx = 0; idx < SNDRV_CARDS; idx++) {
+		if (!atomic_read(&uadev[idx].in_use))
+			continue;
+
+		chip = uadev[idx].chip;
+		for (if_idx = 0; if_idx < uadev[idx].num_intf; if_idx++) {
+			if (!uadev[idx].info || !uadev[idx].info[if_idx].in_use)
+				continue;
+			info = &uadev[idx].info[if_idx];
+			subs = find_substream(info->pcm_card_num,
+						info->pcm_dev_num,
+						info->direction);
+			if (!subs || !chip || atomic_read(&chip->shutdown)) {
+				dev_err(&subs->dev->dev,
+					"no sub for c#%u dev#%u dir%u\n",
+					info->pcm_card_num,
+					info->pcm_dev_num,
+					info->direction);
+				continue;
+			}
+			disable_audio_stream(subs);
+		}
+		atomic_set(&uadev[idx].in_use, 0);
+		mutex_lock(&chip->mutex);
+		uaudio_dev_cleanup(&uadev[idx]);
+		mutex_unlock(&chip->mutex);
+	}
+	mutex_unlock(&qdev_mutex);
+}
+
+/**
+ * qmi_bye_cb() - qmi bye message callback
+ * @handle: QMI handle
+ * @node: id of the dying node
+ *
+ * This callback is invoked when the QMI bye control message is received
+ * from the QMI client.  Handle the message accordingly by ensuring that
+ * the USB offload path is disabled and cleaned up.  At this point, ADSP
+ * is not utilizing the USB bus.
+ *
+ */
+static void qmi_bye_cb(struct qmi_handle *handle, unsigned int node)
+{
+	struct uaudio_qmi_svc *svc = uaudio_svc;
+
+	if (svc->uaudio_svc_hdl != handle)
+		return;
+
+	if (svc->client_connected && svc->client_sq.sq_node == node) {
+		queue_work(svc->uaudio_wq, &svc->qmi_disconnect_work);
+		svc->client_sq.sq_node = 0;
+		svc->client_sq.sq_port = 0;
+		svc->client_sq.sq_family = 0;
+		svc->client_connected = false;
+	}
+}
+
+/**
+ * qmi_svc_disconnect_cb() - qmi client disconnected
+ * @handle: QMI handle
+ * @node: id of the dying node
+ * @port: port of the dying client
+ *
+ * Invoked when the remote QMI client is disconnected.  Handle this event
+ * the same way as when the QMI bye message is received.  This will ensure
+ * the USB offloading path is disabled and cleaned up.
+ *
+ */
+static void qmi_svc_disconnect_cb(struct qmi_handle *handle,
+				  unsigned int node, unsigned int port)
+{
+	struct uaudio_qmi_svc *svc;
+
+	if (uaudio_svc == NULL)
+		return;
+
+	svc = uaudio_svc;
+	if (svc->uaudio_svc_hdl != handle)
+		return;
+
+	if (svc->client_connected && svc->client_sq.sq_node == node &&
+			svc->client_sq.sq_port == port) {
+		queue_work(svc->uaudio_wq, &svc->qmi_disconnect_work);
+		svc->client_sq.sq_node = 0;
+		svc->client_sq.sq_port = 0;
+		svc->client_sq.sq_family = 0;
+		svc->client_connected = false;
+	}
+}
+
+/* QMI client callback handlers from QMI interface */
+static struct qmi_ops uaudio_svc_ops_options = {
+	.bye = qmi_bye_cb,
+	.del_client = qmi_svc_disconnect_cb,
+};
+
+/* kref release callback when all streams are disabled */
+static void uaudio_dev_release(struct kref *kref)
+{
+	struct uaudio_dev *dev = container_of(kref, struct uaudio_dev, kref);
+
+	uaudio_event_ring_cleanup_free(dev);
+	atomic_set(&dev->in_use, 0);
+	wake_up(&dev->disconnect_wq);
+}
+
+/**
+ * enable_audio_stream() - enable usb snd endpoints
+ * @subs: usb substream
+ * @pcm_format: pcm format requested
+ * @channels: number of channels
+ * @cur_rate: sample rate
+ * @datainterval: interval
+ *
+ * Opens all USB SND endpoints used for the data interface.  This will increment
+ * the USB SND endpoint's opened count.  Requests to keep the interface resumed
+ * until the audio stream is stopped.  Will issue the USB set interface control
+ * message to enable the data interface.
+ *
+ */
+static int enable_audio_stream(struct snd_usb_substream *subs,
+				snd_pcm_format_t pcm_format,
+				unsigned int channels, unsigned int cur_rate,
+				int datainterval)
+{
+	struct snd_usb_audio *chip = subs->stream->chip;
+	struct snd_pcm_hw_params params;
+	struct snd_mask *m;
+	struct snd_interval *i;
+	int ret;
+
+	_snd_pcm_hw_params_any(&params);
+
+	m = hw_param_mask(&params, SNDRV_PCM_HW_PARAM_FORMAT);
+	snd_mask_leave(m, pcm_format);
+
+	i = hw_param_interval(&params, SNDRV_PCM_HW_PARAM_CHANNELS);
+	snd_interval_setinteger(i);
+	i->min = i->max = channels;
+
+	i = hw_param_interval(&params, SNDRV_PCM_HW_PARAM_RATE);
+	snd_interval_setinteger(i);
+	i->min = i->max = cur_rate;
+
+	pm_runtime_barrier(&chip->intf[0]->dev);
+	snd_usb_autoresume(chip);
+
+	ret = snd_usb_hw_params(subs, &params);
+	if (ret < 0)
+		goto put_suspend;
+
+	if (!atomic_read(&chip->shutdown)) {
+		ret = snd_usb_lock_shutdown(chip);
+		if (ret < 0)
+			goto detach_ep;
+
+		if (subs->sync_endpoint) {
+			ret = snd_usb_endpoint_prepare(chip, subs->sync_endpoint);
+			if (ret < 0)
+				goto unlock;
+		}
+
+		ret = snd_usb_endpoint_prepare(chip, subs->data_endpoint);
+		if (ret < 0)
+			goto unlock;
+
+		snd_usb_unlock_shutdown(chip);
+
+		dev_dbg(uaudio_qdev->dev,
+			"selected %s iface:%d altsetting:%d datainterval:%dus\n",
+			subs->direction ? "capture" : "playback",
+			subs->cur_audiofmt->iface, subs->cur_audiofmt->altsetting,
+			(1 << subs->cur_audiofmt->datainterval) *
+			(subs->dev->speed >= USB_SPEED_HIGH ?
+			BUS_INTERVAL_HIGHSPEED_AND_ABOVE :
+			BUS_INTERVAL_FULL_SPEED));
+	}
+
+	return 0;
+
+unlock:
+	snd_usb_unlock_shutdown(chip);
+
+detach_ep:
+	snd_usb_hw_free(subs);
+
+put_suspend:
+	snd_usb_autosuspend(chip);
+
+	return ret;
+}
+
+/* returns usb hcd sysdev */
+static struct device *usb_get_usb_backend(struct usb_device *udev)
+{
+	if (udev->bus->sysdev && udev->bus->sysdev->of_node)
+		return udev->bus->sysdev;
+
+	return NULL;
+}
+
+/**
+ * prepare_qmi_response() - prepare stream enable response
+ * @subs: usb substream
+ * @req_msg: QMI request message
+ * @resp: QMI response buffer
+ * @info_idx: usb interface array index
+ *
+ * Prepares the QMI response for a USB QMI stream enable request.  Will parse
+ * out the parameters within the stream enable request, in order to match
+ * requested audio profile to the ones exposed by the USB device connected.
+ *
+ * In addition, will fetch the XHCI transfer resources needed for the handoff to
+ * happen.  This includes, transfer ring and buffer addresses and secondary event
+ * ring address.  These parameters will be communicated as part of the USB QMI
+ * stream enable response.
+ *
+ */
+static int prepare_qmi_response(struct snd_usb_substream *subs,
+		struct qmi_uaudio_stream_req_msg_v01 *req_msg,
+		struct qmi_uaudio_stream_resp_msg_v01 *resp, int info_idx)
+{
+	struct usb_interface *iface;
+	struct usb_host_interface *alts;
+	struct usb_interface_descriptor *altsd;
+	struct usb_interface_assoc_descriptor *assoc;
+	struct usb_host_endpoint *ep;
+	struct uac_format_type_i_continuous_descriptor *fmt;
+	struct uac_format_type_i_discrete_descriptor *fmt_v1;
+	struct uac_format_type_i_ext_descriptor *fmt_v2;
+	struct uac1_as_header_descriptor *as;
+	struct q6usb_offload *data;
+	int ret;
+	int protocol, card_num, pcm_dev_num;
+	void *hdr_ptr;
+	u8 *xfer_buf;
+	unsigned int data_ep_pipe = 0, sync_ep_pipe = 0;
+	u32 len, mult, remainder, xfer_buf_len;
+	unsigned long va, tr_data_va = 0, tr_sync_va = 0;
+	phys_addr_t xhci_pa, xfer_buf_pa, tr_data_pa = 0, tr_sync_pa = 0;
+	struct sg_table *sgt;
+	struct sg_table xfer_buf_sgt;
+	struct page *pg;
+	bool dma_coherent;
+
+	iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
+	if (!iface) {
+		dev_err(uaudio_qdev->dev, "interface # %d does not exist\n",
+			subs->cur_audiofmt->iface);
+		ret = -ENODEV;
+		goto err;
+	}
+
+	assoc = iface->intf_assoc;
+	pcm_dev_num = (req_msg->usb_token & QMI_STREAM_REQ_DEV_NUM_MASK) >> 8;
+	xfer_buf_len = req_msg->xfer_buff_size;
+	card_num = uaudio_qdev->last_card_num;
+
+	alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
+	altsd = get_iface_desc(alts);
+	protocol = altsd->bInterfaceProtocol;
+
+	/* get format type */
+	if (protocol != UAC_VERSION_3) {
+		fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
+				UAC_FORMAT_TYPE);
+		if (!fmt) {
+			dev_err(uaudio_qdev->dev,
+				"%u:%d : no UAC_FORMAT_TYPE desc\n",
+				subs->cur_audiofmt->iface,
+				subs->cur_audiofmt->altset_idx);
+			ret = -ENODEV;
+			goto err;
+		}
+	}
+
+	if (!uadev[card_num].ctrl_intf) {
+		dev_err(uaudio_qdev->dev, "audio ctrl intf info not cached\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	if (protocol != UAC_VERSION_3) {
+		hdr_ptr = snd_usb_find_csint_desc(uadev[card_num].ctrl_intf->extra,
+				uadev[card_num].ctrl_intf->extralen, NULL,
+				UAC_HEADER);
+		if (!hdr_ptr) {
+			dev_err(uaudio_qdev->dev, "no UAC_HEADER desc\n");
+			ret = -ENODEV;
+			goto err;
+		}
+	}
+
+	if (protocol == UAC_VERSION_1) {
+		struct uac1_ac_header_descriptor *uac1_hdr = hdr_ptr;
+
+		as = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
+			UAC_AS_GENERAL);
+		if (!as) {
+			dev_err(uaudio_qdev->dev,
+				"%u:%d : no UAC_AS_GENERAL desc\n",
+				subs->cur_audiofmt->iface,
+				subs->cur_audiofmt->altset_idx);
+			ret = -ENODEV;
+			goto err;
+		}
+		resp->data_path_delay = as->bDelay;
+		resp->data_path_delay_valid = 1;
+		fmt_v1 = (struct uac_format_type_i_discrete_descriptor *)fmt;
+		resp->usb_audio_subslot_size = fmt_v1->bSubframeSize;
+		resp->usb_audio_subslot_size_valid = 1;
+
+		resp->usb_audio_spec_revision = le16_to_cpu(uac1_hdr->bcdADC);
+		resp->usb_audio_spec_revision_valid = 1;
+	} else if (protocol == UAC_VERSION_2) {
+		struct uac2_ac_header_descriptor *uac2_hdr = hdr_ptr;
+
+		fmt_v2 = (struct uac_format_type_i_ext_descriptor *)fmt;
+		resp->usb_audio_subslot_size = fmt_v2->bSubslotSize;
+		resp->usb_audio_subslot_size_valid = 1;
+
+		resp->usb_audio_spec_revision = le16_to_cpu(uac2_hdr->bcdADC);
+		resp->usb_audio_spec_revision_valid = 1;
+	} else if (protocol == UAC_VERSION_3) {
+		if (assoc->bFunctionSubClass ==
+					UAC3_FUNCTION_SUBCLASS_FULL_ADC_3_0) {
+			dev_err(uaudio_qdev->dev, "full adc is not supported\n");
+			ret = -EINVAL;
+		}
+
+		switch (le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize)) {
+		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
+		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
+		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
+		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16: {
+			resp->usb_audio_subslot_size = 0x2;
+			break;
+		}
+
+		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
+		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
+		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
+		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24: {
+			resp->usb_audio_subslot_size = 0x3;
+			break;
+		}
+
+		default:
+			dev_err(uaudio_qdev->dev,
+				"%d: %u: Invalid wMaxPacketSize\n",
+				subs->cur_audiofmt->iface,
+				subs->cur_audiofmt->altset_idx);
+			ret = -EINVAL;
+			goto err;
+		}
+		resp->usb_audio_subslot_size_valid = 1;
+	} else {
+		dev_err(uaudio_qdev->dev, "unknown protocol version %x\n",
+			protocol);
+		ret = -ENODEV;
+		goto err;
+	}
+
+	resp->slot_id = subs->dev->slot_id;
+	resp->slot_id_valid = 1;
+
+	memcpy(&resp->std_as_opr_intf_desc, &alts->desc, sizeof(alts->desc));
+	resp->std_as_opr_intf_desc_valid = 1;
+
+	ep = usb_pipe_endpoint(subs->dev, subs->data_endpoint->pipe);
+	if (!ep) {
+		dev_err(uaudio_qdev->dev, "data ep # %d context is null\n",
+			subs->data_endpoint->ep_num);
+		ret = -ENODEV;
+		goto err;
+	}
+	data_ep_pipe = subs->data_endpoint->pipe;
+	memcpy(&resp->std_as_data_ep_desc, &ep->desc, sizeof(ep->desc));
+	resp->std_as_data_ep_desc_valid = 1;
+
+	ret = xhci_sideband_add_endpoint(uadev[card_num].sb, ep);
+	if (ret < 0) {
+		dev_err(uaudio_qdev->dev, "failed to add data ep to sideband\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	sgt = xhci_sideband_get_endpoint_buffer(uadev[card_num].sb, ep);
+	if (!sgt) {
+		dev_err(uaudio_qdev->dev, "failed to get data ep ring address\n");
+		ret = -ENODEV;
+		goto drop_data_ep;
+	}
+
+	pg = sg_page(sgt->sgl);
+	tr_data_pa = page_to_phys(pg);
+	resp->xhci_mem_info.tr_data.pa = sg_dma_address(sgt->sgl);
+	sg_free_table(sgt);
+
+	if (subs->sync_endpoint) {
+		ep = usb_pipe_endpoint(subs->dev, subs->sync_endpoint->pipe);
+		if (!ep) {
+			dev_err(uaudio_qdev->dev, "implicit fb on data ep\n");
+			goto skip_sync_ep;
+		}
+		sync_ep_pipe = subs->sync_endpoint->pipe;
+		memcpy(&resp->std_as_sync_ep_desc, &ep->desc, sizeof(ep->desc));
+		resp->std_as_sync_ep_desc_valid = 1;
+
+		ret = xhci_sideband_add_endpoint(uadev[card_num].sb, ep);
+		if (ret < 0) {
+			dev_err(uaudio_qdev->dev,
+				"failed to add sync ep to sideband\n");
+			ret = -ENODEV;
+			goto drop_data_ep;
+		}
+
+		sgt = xhci_sideband_get_endpoint_buffer(uadev[card_num].sb, ep);
+		if (!sgt) {
+			dev_err(uaudio_qdev->dev, "failed to get sync ep ring address\n");
+			ret = -ENODEV;
+			goto drop_sync_ep;
+		}
+
+		pg = sg_page(sgt->sgl);
+		tr_sync_pa = page_to_phys(pg);
+		resp->xhci_mem_info.tr_sync.pa = sg_dma_address(sgt->sgl);
+		sg_free_table(sgt);
+	}
+
+skip_sync_ep:
+	data = snd_soc_usb_find_priv_data(usb_get_usb_backend(subs->dev));
+	if (!data)
+		goto drop_sync_ep;
+
+	uaudio_qdev->domain = data->domain;
+	uaudio_qdev->sid = data->sid;
+	uaudio_qdev->intr_num = data->intr_num;
+	uaudio_qdev->dev = data->dev;
+
+	resp->interrupter_num_valid = 1;
+	resp->controller_num_valid = 0;
+	ret = usb_get_controller_id(subs->dev);
+	if (ret >= 0) {
+		resp->controller_num = ret;
+		resp->controller_num_valid = 1;
+	}
+	/* map xhci data structures PA memory to iova */
+	dma_coherent = dev_is_dma_coherent(subs->dev->bus->sysdev);
+
+	/* event ring */
+	ret = xhci_sideband_create_interrupter(uadev[card_num].sb, uaudio_qdev->intr_num);
+	if (ret < 0) {
+		dev_err(uaudio_qdev->dev, "failed to fetch interrupter\n");
+		ret = -ENODEV;
+		goto drop_sync_ep;
+	}
+
+	sgt = xhci_sideband_get_event_buffer(uadev[card_num].sb);
+	if (!sgt) {
+		dev_err(uaudio_qdev->dev, "failed to get event ring address\n");
+		ret = -ENODEV;
+		goto free_sec_ring;
+	}
+
+	xhci_pa = page_to_phys(sg_page(sgt->sgl));
+	resp->xhci_mem_info.evt_ring.pa = sg_dma_address(sgt->sgl);
+	sg_free_table(sgt);
+	if (!xhci_pa) {
+		dev_err(uaudio_qdev->dev,
+			"failed to get sec event ring address\n");
+		ret = -ENODEV;
+		goto free_sec_ring;
+	}
+
+	resp->interrupter_num = xhci_sideband_interrupter_id(uadev[card_num].sb);
+
+	va = uaudio_iommu_map(MEM_EVENT_RING, dma_coherent, xhci_pa, PAGE_SIZE,
+			NULL);
+	if (!va) {
+		ret = -ENOMEM;
+		goto free_sec_ring;
+	}
+
+	resp->xhci_mem_info.evt_ring.va = PREPEND_SID_TO_IOVA(va,
+						uaudio_qdev->sid);
+	resp->xhci_mem_info.evt_ring.size = PAGE_SIZE;
+	uaudio_qdev->er_mapped = true;
+
+	resp->speed_info = get_speed_info(subs->dev->speed);
+	if (resp->speed_info == USB_QMI_DEVICE_SPEED_INVALID_V01) {
+		ret = -ENODEV;
+		goto unmap_er;
+	}
+
+	resp->speed_info_valid = 1;
+
+	/* data transfer ring */
+	va = uaudio_iommu_map(MEM_XFER_RING, dma_coherent, tr_data_pa,
+			PAGE_SIZE, NULL);
+	if (!va) {
+		ret = -ENOMEM;
+		goto unmap_er;
+	}
+
+	tr_data_va = va;
+	resp->xhci_mem_info.tr_data.va = PREPEND_SID_TO_IOVA(va,
+						uaudio_qdev->sid);
+	resp->xhci_mem_info.tr_data.size = PAGE_SIZE;
+
+	/* sync transfer ring */
+	if (!resp->xhci_mem_info.tr_sync.pa)
+		goto skip_sync;
+
+	xhci_pa = resp->xhci_mem_info.tr_sync.pa;
+	va = uaudio_iommu_map(MEM_XFER_RING, dma_coherent, tr_sync_pa,
+			PAGE_SIZE, NULL);
+	if (!va) {
+		ret = -ENOMEM;
+		goto unmap_data;
+	}
+
+	tr_sync_va = va;
+	resp->xhci_mem_info.tr_sync.va = PREPEND_SID_TO_IOVA(va,
+						uaudio_qdev->sid);
+	resp->xhci_mem_info.tr_sync.size = PAGE_SIZE;
+
+skip_sync:
+	/* xfer buffer, multiple of 4K only */
+	if (!xfer_buf_len)
+		xfer_buf_len = PAGE_SIZE;
+
+	mult = xfer_buf_len / PAGE_SIZE;
+	remainder = xfer_buf_len % PAGE_SIZE;
+	len = mult * PAGE_SIZE;
+	len += remainder ? PAGE_SIZE : 0;
+
+	if (len > MAX_XFER_BUFF_LEN) {
+		dev_err(uaudio_qdev->dev,
+			"req buf len %d > max buf len %lu, setting %lu\n",
+			len, MAX_XFER_BUFF_LEN, MAX_XFER_BUFF_LEN);
+		len = MAX_XFER_BUFF_LEN;
+	}
+
+	xfer_buf = usb_alloc_coherent(subs->dev, len, GFP_KERNEL, &xfer_buf_pa);
+	if (!xfer_buf) {
+		ret = -ENOMEM;
+		goto unmap_sync;
+	}
+
+	dma_get_sgtable(subs->dev->bus->sysdev, &xfer_buf_sgt, xfer_buf, xfer_buf_pa,
+			len);
+	va = uaudio_iommu_map(MEM_XFER_BUF, dma_coherent, xfer_buf_pa, len,
+			&xfer_buf_sgt);
+	if (!va) {
+		ret = -ENOMEM;
+		goto unmap_sync;
+	}
+
+	resp->xhci_mem_info.xfer_buff.pa = xfer_buf_pa;
+	resp->xhci_mem_info.xfer_buff.size = len;
+
+	resp->xhci_mem_info.xfer_buff.va = PREPEND_SID_TO_IOVA(va,
+						uaudio_qdev->sid);
+
+	resp->xhci_mem_info_valid = 1;
+
+	sg_free_table(&xfer_buf_sgt);
+
+	if (!atomic_read(&uadev[card_num].in_use)) {
+		kref_init(&uadev[card_num].kref);
+		init_waitqueue_head(&uadev[card_num].disconnect_wq);
+		uadev[card_num].num_intf =
+			subs->dev->config->desc.bNumInterfaces;
+		uadev[card_num].info = kcalloc(uadev[card_num].num_intf,
+			sizeof(struct intf_info), GFP_KERNEL);
+		if (!uadev[card_num].info) {
+			ret = -ENOMEM;
+			goto unmap_sync;
+		}
+		uadev[card_num].udev = subs->dev;
+		atomic_set(&uadev[card_num].in_use, 1);
+	} else {
+		kref_get(&uadev[card_num].kref);
+	}
+
+	uadev[card_num].usb_core_id = resp->controller_num;
+
+	/* cache intf specific info to use it for unmap and free xfer buf */
+	uadev[card_num].info[info_idx].data_xfer_ring_va = tr_data_va;
+	uadev[card_num].info[info_idx].data_xfer_ring_size = PAGE_SIZE;
+	uadev[card_num].info[info_idx].sync_xfer_ring_va = tr_sync_va;
+	uadev[card_num].info[info_idx].sync_xfer_ring_size = PAGE_SIZE;
+	uadev[card_num].info[info_idx].xfer_buf_va = va;
+	uadev[card_num].info[info_idx].xfer_buf_pa = xfer_buf_pa;
+	uadev[card_num].info[info_idx].xfer_buf_size = len;
+	uadev[card_num].info[info_idx].data_ep_pipe = data_ep_pipe;
+	uadev[card_num].info[info_idx].sync_ep_pipe = sync_ep_pipe;
+	uadev[card_num].info[info_idx].xfer_buf = xfer_buf;
+	uadev[card_num].info[info_idx].pcm_card_num = card_num;
+	uadev[card_num].info[info_idx].pcm_dev_num = pcm_dev_num;
+	uadev[card_num].info[info_idx].direction = subs->direction;
+	uadev[card_num].info[info_idx].intf_num = subs->cur_audiofmt->iface;
+	uadev[card_num].info[info_idx].in_use = true;
+
+	set_bit(card_num, &uaudio_qdev->card_slot);
+
+	return 0;
+
+unmap_sync:
+	usb_free_coherent(subs->dev, len, xfer_buf, xfer_buf_pa);
+	uaudio_iommu_unmap(MEM_XFER_RING, tr_sync_va, PAGE_SIZE, PAGE_SIZE);
+unmap_data:
+	uaudio_iommu_unmap(MEM_XFER_RING, tr_data_va, PAGE_SIZE, PAGE_SIZE);
+unmap_er:
+	uaudio_iommu_unmap(MEM_EVENT_RING, IOVA_BASE, PAGE_SIZE, PAGE_SIZE);
+free_sec_ring:
+	xhci_sideband_remove_interrupter(uadev[card_num].sb);
+drop_sync_ep:
+	if (subs->sync_endpoint)
+		xhci_sideband_remove_endpoint(uadev[card_num].sb,
+			usb_pipe_endpoint(subs->dev, subs->sync_endpoint->pipe));
+drop_data_ep:
+	xhci_sideband_remove_endpoint(uadev[card_num].sb,
+			usb_pipe_endpoint(subs->dev, subs->data_endpoint->pipe));
+
+err:
+	return ret;
+}
+
+/**
+ * handle_uaudio_stream_req() - handle stream enable/disable request
+ * @handle: QMI client handle
+ * @sq: qrtr socket
+ * @txn: QMI transaction context
+ * @decoded_msg: decoded QMI message
+ *
+ * Main handler for the QMI stream enable/disable requests.  This executes the
+ * corresponding enable/disable stream apis, respectively.
+ *
+ */
+static void handle_uaudio_stream_req(struct qmi_handle *handle,
+			struct sockaddr_qrtr *sq,
+			struct qmi_txn *txn,
+			const void *decoded_msg)
+{
+	struct qmi_uaudio_stream_req_msg_v01 *req_msg;
+	struct qmi_uaudio_stream_resp_msg_v01 resp = {{0}, 0};
+	struct snd_usb_substream *subs;
+	struct snd_usb_audio *chip = NULL;
+	struct uaudio_qmi_svc *svc = uaudio_svc;
+	struct intf_info *info;
+	struct usb_host_endpoint *ep;
+	u8 pcm_card_num, pcm_dev_num, direction;
+	int info_idx = -EINVAL, datainterval = -EINVAL, ret = 0;
+
+	if (!svc->client_connected) {
+		svc->client_sq = *sq;
+		svc->client_connected = true;
+	}
+
+	mutex_lock(&qdev_mutex);
+	req_msg = (struct qmi_uaudio_stream_req_msg_v01 *)decoded_msg;
+	if (!req_msg->audio_format_valid || !req_msg->bit_rate_valid ||
+	    !req_msg->number_of_ch_valid || !req_msg->xfer_buff_size_valid) {
+		ret = -EINVAL;
+		goto response;
+	}
+
+	if (!uaudio_qdev) {
+		ret = -EINVAL;
+		goto response;
+	}
+
+	direction = (req_msg->usb_token & QMI_STREAM_REQ_DIRECTION);
+	pcm_dev_num = (req_msg->usb_token & QMI_STREAM_REQ_DEV_NUM_MASK) >> 8;
+	pcm_card_num = req_msg->enable ? uaudio_qdev->last_card_num :
+				ffs(uaudio_qdev->card_slot) - 1;
+	if (pcm_card_num >= SNDRV_CARDS) {
+		ret = -EINVAL;
+		goto response;
+	}
+
+	if (req_msg->audio_format > USB_QMI_PCM_FORMAT_U32_BE) {
+		ret = -EINVAL;
+		goto response;
+	}
+
+	subs = find_substream(pcm_card_num, pcm_dev_num, direction);
+	chip = uadev[pcm_card_num].chip;
+	if (!subs || !chip || atomic_read(&chip->shutdown)) {
+		ret = -ENODEV;
+		goto response;
+	}
+
+	info_idx = info_idx_from_ifnum(pcm_card_num, subs->cur_audiofmt ?
+			subs->cur_audiofmt->iface : -1, req_msg->enable);
+	if (atomic_read(&chip->shutdown) || !subs->stream || !subs->stream->pcm
+			|| !subs->stream->chip) {
+		ret = -ENODEV;
+		goto response;
+	}
+
+	if (req_msg->enable) {
+		if (info_idx < 0 || chip->system_suspend) {
+			ret = -EBUSY;
+			goto response;
+		}
+	}
+
+	if (req_msg->service_interval_valid) {
+		ret = get_data_interval_from_si(subs,
+						req_msg->service_interval);
+		if (ret == -EINVAL)
+			goto response;
+
+		datainterval = ret;
+	}
+
+	uadev[pcm_card_num].ctrl_intf = chip->ctrl_intf;
+
+	if (req_msg->enable) {
+		ret = enable_audio_stream(subs,
+				map_pcm_format(req_msg->audio_format),
+				req_msg->number_of_ch, req_msg->bit_rate,
+				datainterval);
+
+		if (!ret)
+			ret = prepare_qmi_response(subs, req_msg, &resp,
+					info_idx);
+	} else {
+		info = &uadev[pcm_card_num].info[info_idx];
+		if (info->data_ep_pipe) {
+			ep = usb_pipe_endpoint(uadev[pcm_card_num].udev,
+						info->data_ep_pipe);
+			if (ep)
+				xhci_sideband_stop_endpoint(uadev[pcm_card_num].sb,
+						ep);
+			xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb, ep);
+			info->data_ep_pipe = 0;
+		}
+
+		if (info->sync_ep_pipe) {
+			ep = usb_pipe_endpoint(uadev[pcm_card_num].udev,
+						info->sync_ep_pipe);
+			if (ep)
+				xhci_sideband_stop_endpoint(uadev[pcm_card_num].sb,
+						ep);
+			xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb, ep);
+			info->sync_ep_pipe = 0;
+		}
+
+		disable_audio_stream(subs);
+	}
+
+response:
+	if (!req_msg->enable && ret != -EINVAL && ret != -ENODEV) {
+		mutex_lock(&chip->mutex);
+		if (info_idx >= 0) {
+			info = &uadev[pcm_card_num].info[info_idx];
+			uaudio_dev_intf_cleanup(
+					uadev[pcm_card_num].udev,
+					info);
+		}
+		if (atomic_read(&uadev[pcm_card_num].in_use))
+			kref_put(&uadev[pcm_card_num].kref,
+					uaudio_dev_release);
+		mutex_unlock(&chip->mutex);
+	}
+	mutex_unlock(&qdev_mutex);
+
+	resp.usb_token = req_msg->usb_token;
+	resp.usb_token_valid = 1;
+	resp.internal_status = ret;
+	resp.internal_status_valid = 1;
+	resp.status = ret ? USB_QMI_STREAM_REQ_FAILURE_V01 : ret;
+	resp.status_valid = 1;
+	ret = qmi_send_response(svc->uaudio_svc_hdl, sq, txn,
+			QMI_UAUDIO_STREAM_RESP_V01,
+			QMI_UAUDIO_STREAM_RESP_MSG_V01_MAX_MSG_LEN,
+			qmi_uaudio_stream_resp_msg_v01_ei, &resp);
+}
+
+static struct qmi_msg_handler uaudio_stream_req_handlers = {
+	.type = QMI_REQUEST,
+	.msg_id = QMI_UAUDIO_STREAM_REQ_V01,
+	.ei = qmi_uaudio_stream_req_msg_v01_ei,
+	.decoded_size = QMI_UAUDIO_STREAM_REQ_MSG_V01_MAX_MSG_LEN,
+	.fn = handle_uaudio_stream_req,
+};
+
+/**
+ * qc_usb_audio_offload_init_qmi_dev() - initializes qmi dev
+ *
+ * Initializes the USB qdev, which is used to carry information pertaining to
+ * the offloading resources.  This device is freed only when there are no longer
+ * any offloading candidates. (i.e, when all audio devices are disconnected)
+ *
+ */
+static int qc_usb_audio_offload_init_qmi_dev(struct usb_device *udev)
+{
+	uaudio_qdev = kzalloc(sizeof(struct uaudio_qmi_dev),
+		GFP_KERNEL);
+	if (!uaudio_qdev)
+		return -ENOMEM;
+
+	/* initialize xfer ring and xfer buf iova list */
+	INIT_LIST_HEAD(&uaudio_qdev->xfer_ring_list);
+	uaudio_qdev->curr_xfer_ring_iova = IOVA_XFER_RING_BASE;
+	uaudio_qdev->xfer_ring_iova_size =
+			IOVA_XFER_RING_MAX - IOVA_XFER_RING_BASE;
+
+	INIT_LIST_HEAD(&uaudio_qdev->xfer_buf_list);
+	uaudio_qdev->curr_xfer_buf_iova = IOVA_XFER_BUF_BASE;
+	uaudio_qdev->xfer_buf_iova_size =
+		IOVA_XFER_BUF_MAX - IOVA_XFER_BUF_BASE;
+
+	return 0;
+}
+
+/**
+ * qc_usb_audio_offload_probe() - platform op connect handler
+ * @chip: USB SND device
+ *
+ * Platform connect handler when a USB SND device is detected. Will
+ * notify SOC USB about the connection to enable the USB ASoC backend
+ * and populate internal USB chip array.
+ *
+ */
+static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)
+{
+	struct usb_device *udev = chip->dev;
+	struct xhci_sideband *sb;
+	struct snd_soc_usb_device *sdev;
+
+	/*
+	 * If there is no priv_data, the connected device is on a USB bus
+	 * that doesn't support offloading.  Avoid populating entries for
+	 * this device.
+	 */
+	if (!snd_soc_usb_find_priv_data(usb_get_usb_backend(udev)))
+		return;
+
+	mutex_lock(&chip->mutex);
+	if (!uadev[chip->card->number].chip) {
+		sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
+		if (!sdev)
+			goto exit;
+
+		sb = xhci_sideband_register(udev);
+		if (!sb)
+			goto free_sdev;
+	} else {
+		sb = uadev[chip->card->number].sb;
+		sdev = uadev[chip->card->number].sdev;
+	}
+
+	mutex_lock(&qdev_mutex);
+	if (!uaudio_qdev)
+		qc_usb_audio_offload_init_qmi_dev(udev);
+
+	atomic_inc(&uaudio_qdev->qdev_in_use);
+	mutex_unlock(&qdev_mutex);
+
+	uadev[chip->card->number].sb = sb;
+	uadev[chip->card->number].chip = chip;
+
+	sdev->card_idx = chip->card->number;
+	sdev->chip_idx = chip->index;
+	uadev[chip->card->number].sdev = sdev;
+
+	uaudio_qdev->last_card_num = chip->card->number;
+	snd_soc_usb_connect(usb_get_usb_backend(udev), sdev);
+	mutex_unlock(&chip->mutex);
+
+	return;
+
+free_sdev:
+	kfree(sdev);
+exit:
+	mutex_unlock(&chip->mutex);
+}
+
+/**
+ * qc_usb_audio_cleanup_qmi_dev() - release qmi device
+ *
+ * Frees the USB qdev.  Only occurs when there are no longer any potential
+ * devices that can utilize USB audio offloading.
+ *
+ */
+static void qc_usb_audio_cleanup_qmi_dev(void)
+{
+	kfree(uaudio_qdev);
+	uaudio_qdev = NULL;
+}
+
+/**
+ * qc_usb_audio_offload_disconnect() - platform op disconnect handler
+ * @chip: USB SND device
+ *
+ * Platform disconnect handler.  Will ensure that any pending stream is
+ * halted by issuing a QMI disconnect indication packet to the adsp.
+ *
+ */
+static void qc_usb_audio_offload_disconnect(struct snd_usb_audio *chip)
+{
+	struct qmi_uaudio_stream_ind_msg_v01 disconnect_ind = {0};
+	struct uaudio_qmi_svc *svc = uaudio_svc;
+	struct uaudio_dev *dev;
+	int card_num;
+	int ret;
+
+	if (!chip)
+		return;
+
+	card_num = chip->card->number;
+	if (card_num >= SNDRV_CARDS)
+		return;
+
+	mutex_lock(&qdev_mutex);
+	mutex_lock(&chip->mutex);
+	dev = &uadev[card_num];
+
+	/* Device has already been cleaned up, or never populated */
+	if (!dev->chip) {
+		mutex_unlock(&qdev_mutex);
+		mutex_unlock(&chip->mutex);
+		return;
+	}
+
+	/* clean up */
+	if (!dev->udev)
+		goto done;
+
+	if (atomic_read(&dev->in_use)) {
+		mutex_unlock(&chip->mutex);
+		mutex_unlock(&qdev_mutex);
+		dev_dbg(uaudio_qdev->dev, "sending qmi indication disconnect\n");
+		disconnect_ind.dev_event = USB_QMI_DEV_DISCONNECT_V01;
+		disconnect_ind.slot_id = dev->udev->slot_id;
+		disconnect_ind.controller_num = dev->usb_core_id;
+		disconnect_ind.controller_num_valid = 1;
+		ret = qmi_send_indication(svc->uaudio_svc_hdl, &svc->client_sq,
+				QMI_UAUDIO_STREAM_IND_V01,
+				QMI_UAUDIO_STREAM_IND_MSG_V01_MAX_MSG_LEN,
+				qmi_uaudio_stream_ind_msg_v01_ei,
+				&disconnect_ind);
+		if (ret < 0)
+			dev_err(uaudio_qdev->dev,
+				"qmi send failed with err: %d\n", ret);
+
+		ret = wait_event_interruptible_timeout(dev->disconnect_wq,
+				!atomic_read(&dev->in_use),
+				msecs_to_jiffies(DEV_RELEASE_WAIT_TIMEOUT));
+		if (!ret) {
+			dev_err(uaudio_qdev->dev,
+				"timeout while waiting for dev_release\n");
+			atomic_set(&dev->in_use, 0);
+		} else if (ret < 0) {
+			dev_err(uaudio_qdev->dev, "failed with ret %d\n", ret);
+			atomic_set(&dev->in_use, 0);
+		}
+		mutex_lock(&qdev_mutex);
+		mutex_lock(&chip->mutex);
+	}
+
+	uaudio_dev_cleanup(dev);
+done:
+	snd_soc_usb_disconnect(usb_get_usb_backend(chip->dev), dev->sdev);
+
+	/*
+	 * If num_interfaces == 1, the last USB SND interface is being removed.
+	 * This is to accommodate for devices w/ multiple UAC functions.
+	 */
+	if (chip->num_interfaces == 1) {
+		xhci_sideband_unregister(dev->sb);
+		dev->chip = NULL;
+		kfree(dev->sdev);
+		dev->sdev = NULL;
+	}
+	mutex_unlock(&chip->mutex);
+
+	atomic_dec(&uaudio_qdev->qdev_in_use);
+	if (!atomic_read(&uaudio_qdev->qdev_in_use)) {
+		snd_soc_usb_disconnect(usb_get_usb_backend(udev));
+		qc_usb_audio_cleanup_qmi_dev();
+	}
+	mutex_unlock(&qdev_mutex);
+}
+
+/**
+ * qc_usb_audio_offload_suspend() - USB offload PM suspend handler
+ * @intf: USB interface
+ * @message: suspend type
+ *
+ * PM suspend handler to ensure that the USB offloading driver is able to stop
+ * any pending traffic, so that the bus can be suspended.
+ *
+ */
+static void qc_usb_audio_offload_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct snd_usb_audio *chip = usb_get_intfdata(intf);
+	struct qmi_uaudio_stream_ind_msg_v01 disconnect_ind = {0};
+	struct uaudio_qmi_svc *svc = uaudio_svc;
+	struct uaudio_dev *dev;
+	int card_num;
+	int ret;
+
+	if (!chip)
+		return;
+
+	card_num = chip->card->number;
+	if (card_num >= SNDRV_CARDS)
+		return;
+
+
+	mutex_lock(&chip->mutex);
+	dev = &uadev[card_num];
+
+	if (atomic_read(&dev->in_use)) {
+		mutex_unlock(&chip->mutex);
+		dev_dbg(uaudio_qdev->dev, "sending qmi indication suspend\n");
+		disconnect_ind.dev_event = USB_QMI_DEV_DISCONNECT_V01;
+		disconnect_ind.slot_id = dev->udev->slot_id;
+		disconnect_ind.controller_num = dev->usb_core_id;
+		disconnect_ind.controller_num_valid = 1;
+		ret = qmi_send_indication(svc->uaudio_svc_hdl, &svc->client_sq,
+				QMI_UAUDIO_STREAM_IND_V01,
+				QMI_UAUDIO_STREAM_IND_MSG_V01_MAX_MSG_LEN,
+				qmi_uaudio_stream_ind_msg_v01_ei,
+				&disconnect_ind);
+		if (ret < 0)
+			dev_err(uaudio_qdev->dev,
+				"qmi send failed with err: %d\n", ret);
+
+		ret = wait_event_interruptible_timeout(dev->disconnect_wq,
+				!atomic_read(&dev->in_use),
+				msecs_to_jiffies(DEV_RELEASE_WAIT_TIMEOUT));
+		if (!ret) {
+			dev_err(uaudio_qdev->dev,
+				"timeout while waiting for dev_release\n");
+			atomic_set(&dev->in_use, 0);
+		} else if (ret < 0) {
+			dev_err(uaudio_qdev->dev, "failed with ret %d\n", ret);
+			atomic_set(&dev->in_use, 0);
+		}
+		mutex_lock(&chip->mutex);
+	}
+	mutex_unlock(&chip->mutex);
+}
+
+static struct snd_usb_platform_ops offload_ops = {
+	.connect_cb = qc_usb_audio_offload_probe,
+	.disconnect_cb = qc_usb_audio_offload_disconnect,
+	.suspend_cb = qc_usb_audio_offload_suspend,
+};
+
+static int __init qc_usb_audio_offload_init(void)
+{
+	struct uaudio_qmi_svc *svc;
+	int ret;
+
+	svc = kzalloc(sizeof(struct uaudio_qmi_svc), GFP_KERNEL);
+	if (!svc)
+		return -ENOMEM;
+
+	svc->uaudio_wq = create_singlethread_workqueue("uaudio_svc");
+	if (!svc->uaudio_wq) {
+		ret = -ENOMEM;
+		goto free_svc;
+	}
+
+	svc->uaudio_svc_hdl = kzalloc(sizeof(struct qmi_handle), GFP_KERNEL);
+	if (!svc->uaudio_svc_hdl) {
+		ret = -ENOMEM;
+		goto free_wq;
+	}
+
+	ret = qmi_handle_init(svc->uaudio_svc_hdl,
+				QMI_UAUDIO_STREAM_REQ_MSG_V01_MAX_MSG_LEN,
+				&uaudio_svc_ops_options,
+				&uaudio_stream_req_handlers);
+	ret = qmi_add_server(svc->uaudio_svc_hdl, UAUDIO_STREAM_SERVICE_ID_V01,
+					UAUDIO_STREAM_SERVICE_VERS_V01, 0);
+
+	INIT_WORK(&svc->qmi_disconnect_work, qmi_disconnect_work);
+	uaudio_svc = svc;
+
+	ret = snd_usb_register_platform_ops(&offload_ops);
+	if (ret < 0)
+		goto release_qmi;
+
+	return 0;
+
+release_qmi:
+	qmi_handle_release(svc->uaudio_svc_hdl);
+free_wq:
+	destroy_workqueue(svc->uaudio_wq);
+free_svc:
+	kfree(svc);
+
+	return ret;
+}
+
+static void __exit qc_usb_audio_offload_exit(void)
+{
+	struct uaudio_qmi_svc *svc = uaudio_svc;
+	int idx;
+
+	/*
+	 * Remove all connected devices after unregistering ops, to ensure
+	 * that no further connect events will occur.  The disconnect routine
+	 * will issue the QMI disconnect indication, which results in the
+	 * external DSP to stop issuing transfers.
+	 */
+	snd_usb_unregister_platform_ops();
+	for (idx = 0; idx < SNDRV_CARDS; idx++)
+		qc_usb_audio_offload_disconnect(uadev[idx].chip);
+
+	qmi_handle_release(svc->uaudio_svc_hdl);
+	flush_workqueue(svc->uaudio_wq);
+	destroy_workqueue(svc->uaudio_wq);
+	kfree(svc);
+	uaudio_svc = NULL;
+}
+
+module_init(qc_usb_audio_offload_init);
+module_exit(qc_usb_audio_offload_exit);
+
+MODULE_DESCRIPTION("QC USB Audio Offloading");
+MODULE_LICENSE("GPL");

[PATCH v9 20/34] ALSA: usb-audio: Check for support for requested audio format

[Wesley Cheng]

Allow for checks on a specific USB audio device to see if a requested PCM
format is supported.  This is needed for support for when playback is
initiated by the ASoC USB backend path.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/card.c | 40 ++++++++++++++++++++++++++++++++++++++++
 sound/usb/card.h | 11 +++++++++++
 2 files changed, 51 insertions(+)

diff --git a/sound/usb/card.c b/sound/usb/card.c
index c0b312e264bf..88f431917c15 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -162,6 +162,46 @@ int snd_usb_unregister_platform_ops(void)
 }
 EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
 
+/*
+ * Checks to see if requested audio profile, i.e sample rate, # of
+ * channels, etc... is supported by the substream associated to the
+ * USB audio device.
+ */
+struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
+			struct snd_pcm_hw_params *params, int direction)
+{
+	struct snd_usb_audio *chip;
+	struct snd_usb_substream *subs = NULL;
+	struct snd_usb_stream *as;
+	const struct audioformat *fmt;
+
+	/*
+	 * Register mutex is held when populating and clearing usb_chip
+	 * array.
+	 */
+	mutex_lock(&register_mutex);
+	chip = usb_chip[card_idx];
+	if (!chip) {
+		mutex_unlock(&register_mutex);
+		return NULL;
+	}
+
+	if (enable[card_idx]) {
+		list_for_each_entry(as, &chip->pcm_list, list) {
+			subs = &as->substream[direction];
+			fmt = snd_usb_find_substream_format(subs, params);
+			if (fmt) {
+				mutex_unlock(&register_mutex);
+				return as;
+			}
+		}
+	}
+	mutex_unlock(&register_mutex);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(snd_usb_find_suppported_substream);
+
 /*
  * disconnect streams
  * called from usb_audio_disconnect()
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 2884912adc96..e26292363cf0 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -216,4 +216,15 @@ struct snd_usb_platform_ops {
 
 int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
 int snd_usb_unregister_platform_ops(void);
+
+#if IS_ENABLED(CONFIG_SND_USB_AUDIO)
+struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
+			struct snd_pcm_hw_params *params, int direction);
+#else
+static struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
+			struct snd_pcm_hw_params *params, int direction)
+{
+	return NULL;
+}
+#endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
 #endif /* __USBAUDIO_CARD_H */

[PATCH v9 21/34] ASoC: usb: Add PCM format check API for USB backend

[Wesley Cheng]

Introduce a check for if a particular PCM format is supported by the USB
audio device connected.  If the USB audio device does not have an audio
profile which can support the requested format, then notify the USB
backend.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 include/sound/soc-usb.h |  3 +++
 sound/soc/soc-usb.c     | 13 +++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
index 58c686f4f7ba..c6ddc055c4cd 100644
--- a/include/sound/soc-usb.h
+++ b/include/sound/soc-usb.h
@@ -37,6 +37,9 @@ struct snd_soc_usb {
 	void *priv_data;
 };
 
+int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
+			int direction);
+
 int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
 int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
 void *snd_soc_usb_find_priv_data(struct device *usbdev);
diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
index 73b1bcc3b506..7407678a993e 100644
--- a/sound/soc/soc-usb.c
+++ b/sound/soc/soc-usb.c
@@ -63,6 +63,19 @@ void *snd_soc_usb_find_priv_data(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(snd_soc_usb_find_priv_data);
 
+int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
+			int direction)
+{
+	struct snd_usb_stream *as;
+
+	as = snd_usb_find_suppported_substream(card_idx, params, direction);
+	if (!as)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_usb_find_format);
+
 /**
  * snd_soc_usb_add_port() - Add a USB backend port
  * @dev: USB backend device

[PATCH v9 22/34] ASoC: qcom: qdsp6: Ensure PCM format is supported by USB audio device

[Wesley Cheng]

Check for if the PCM format is supported during the hw_params callback.  If
the profile is not supported then the userspace ALSA entity will receive an
error, and can take further action.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6usb.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
index dd664ad41668..329a7d4a3c01 100644
--- a/sound/soc/qcom/qdsp6/q6usb.c
+++ b/sound/soc/qcom/qdsp6/q6usb.c
@@ -44,7 +44,10 @@ static int q6usb_hw_params(struct snd_pcm_substream *substream,
 			   struct snd_pcm_hw_params *params,
 			   struct snd_soc_dai *dai)
 {
-	return 0;
+	struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
+	int direction = substream->stream;
+
+	return snd_soc_usb_find_format(data->active_idx, params, direction);
 }
 
 static const struct snd_soc_dai_ops q6usb_ops = {

[PATCH v9 23/34] ALSA: usb-audio: Prevent starting of audio stream if in use

[Wesley Cheng]

With USB audio offloading, an audio session is started from the ASoC
platform sound card and PCM devices.  Likewise, the USB SND path is still
readily available for use, in case the non-offload path is desired.  In
order to prevent the two entities from attempting to use the USB bus,
introduce a flag that determines when either paths are in use.

If a PCM device is already in use, the check will return an error to
userspace notifying that the stream is currently busy.  This ensures that
only one path is using the USB substream.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/card.h                  |  1 +
 sound/usb/pcm.c                   | 19 +++++++++++++++++--
 sound/usb/qcom/qc_audio_offload.c | 15 ++++++++++++++-
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/sound/usb/card.h b/sound/usb/card.h
index e26292363cf0..01f7e10f30f4 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -164,6 +164,7 @@ struct snd_usb_substream {
 	unsigned int pkt_offset_adj;	/* Bytes to drop from beginning of packets (for non-compliant devices) */
 	unsigned int stream_offset_adj;	/* Bytes to drop from beginning of stream (for non-compliant devices) */
 
+	unsigned int opened:1;		/* pcm device opened */
 	unsigned int running: 1;	/* running status */
 	unsigned int period_elapsed_pending;	/* delay period handling */
 
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 3adb09ce1702..c2cb52cd5d23 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -1241,8 +1241,15 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_usb_substream *subs = &as->substream[direction];
+	struct snd_usb_audio *chip = subs->stream->chip;
 	int ret;
 
+	mutex_lock(&chip->mutex);
+	if (subs->opened) {
+		mutex_unlock(&chip->mutex);
+		return -EBUSY;
+	}
+
 	runtime->hw = snd_usb_hardware;
 	/* need an explicit sync to catch applptr update in low-latency mode */
 	if (direction == SNDRV_PCM_STREAM_PLAYBACK &&
@@ -1259,13 +1266,17 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
 
 	ret = setup_hw_info(runtime, subs);
 	if (ret < 0)
-		return ret;
+		goto out;
 	ret = snd_usb_autoresume(subs->stream->chip);
 	if (ret < 0)
-		return ret;
+		goto out;
 	ret = snd_media_stream_init(subs, as->pcm, direction);
 	if (ret < 0)
 		snd_usb_autosuspend(subs->stream->chip);
+	subs->opened = 1;
+out:
+	mutex_unlock(&chip->mutex);
+
 	return ret;
 }
 
@@ -1274,6 +1285,7 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
 	int direction = substream->stream;
 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
 	struct snd_usb_substream *subs = &as->substream[direction];
+	struct snd_usb_audio *chip = subs->stream->chip;
 	int ret;
 
 	snd_media_stop_pipeline(subs);
@@ -1287,6 +1299,9 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
 
 	subs->pcm_substream = NULL;
 	snd_usb_autosuspend(subs->stream->chip);
+	mutex_lock(&chip->mutex);
+	subs->opened = 0;
+	mutex_unlock(&chip->mutex);
 
 	return 0;
 }
diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
index 320ce3a6688f..bd6b84f72c74 100644
--- a/sound/usb/qcom/qc_audio_offload.c
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -1413,12 +1413,17 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
 		goto response;
 	}
 
+	mutex_lock(&chip->mutex);
 	if (req_msg->enable) {
-		if (info_idx < 0 || chip->system_suspend) {
+		if (info_idx < 0 || chip->system_suspend || subs->opened) {
 			ret = -EBUSY;
+			mutex_unlock(&chip->mutex);
+
 			goto response;
 		}
+		subs->opened = 1;
 	}
+	mutex_unlock(&chip->mutex);
 
 	if (req_msg->service_interval_valid) {
 		ret = get_data_interval_from_si(subs,
@@ -1440,6 +1445,11 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
 		if (!ret)
 			ret = prepare_qmi_response(subs, req_msg, &resp,
 					info_idx);
+		if (ret < 0) {
+			mutex_lock(&chip->mutex);
+			subs->opened = 0;
+			mutex_unlock(&chip->mutex);
+		}
 	} else {
 		info = &uadev[pcm_card_num].info[info_idx];
 		if (info->data_ep_pipe) {
@@ -1463,6 +1473,9 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
 		}
 
 		disable_audio_stream(subs);
+		mutex_lock(&chip->mutex);
+		subs->opened = 0;
+		mutex_unlock(&chip->mutex);
 	}
 
 response:

[PATCH v9 24/34] ASoC: dt-bindings: Add Q6USB backend

[Wesley Cheng]

Add a dt-binding to describe the definition of enabling the Q6 USB backend
device for audio offloading.  The node carries information, which is passed
along to the QC USB SND class driver counterpart.  These parameters will be
utilized during QMI stream enable requests.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 .../devicetree/bindings/sound/qcom,q6usb.yaml | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/sound/qcom,q6usb.yaml

diff --git a/Documentation/devicetree/bindings/sound/qcom,q6usb.yaml b/Documentation/devicetree/bindings/sound/qcom,q6usb.yaml
new file mode 100644
index 000000000000..37161d2aa96e
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/qcom,q6usb.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/qcom,q6usb.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm ASoC DPCM USB backend DAI
+
+maintainers:
+  - Wesley Cheng <quic_wcheng@quicinc.com>
+
+description:
+  The USB port is a supported AFE path on the Q6 DSP.  This ASoC DPCM
+  backend DAI will communicate the required settings to initialize the
+  XHCI host controller properly for enabling the offloaded audio stream.
+  Parameters defined under this node will carry settings, which will be
+  passed along during the QMI stream enable request and configuration of
+  the XHCI host controller.
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    enum:
+      - qcom,q6usb
+
+  iommus:
+    maxItems: 1
+
+  "#sound-dai-cells":
+    const: 1
+
+  qcom,usb-audio-intr-idx:
+    description:
+      Desired XHCI interrupter number to use.  Depending on the audio DSP
+      on the platform, it will operate on a specific XHCI interrupter.
+    $ref: /schemas/types.yaml#/definitions/uint16
+    maximum: 8
+
+required:
+  - compatible
+  - "#sound-dai-cells"
+  - qcom,usb-audio-intr-idx
+
+additionalProperties: false
+
+examples:
+  - |
+    dais {
+      compatible = "qcom,q6usb";
+      #sound-dai-cells = <1>;
+      iommus = <&apps_smmu 0x180f 0x0>;
+      qcom,usb-audio-intr-idx = /bits/ 16 <2>;
+    };

[PATCH v9 25/34] ASoC: dt-bindings: Update example for enabling USB offload on SM8250

[Wesley Cheng]

Add an example on enabling of USB offload for the Q6DSP.  The routing can
be done by the mixer, which can pass the multimedia stream to the USB
backend.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 .../devicetree/bindings/sound/qcom,sm8250.yaml    | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml b/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml
index 262de7a60a73..13145e010ddf 100644
--- a/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml
+++ b/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml
@@ -220,6 +220,21 @@ examples:
                 sound-dai = <&vamacro 0>;
             };
         };
+
+        usb-dai-link {
+            link-name = "USB Playback";
+            cpu {
+                sound-dai = <&q6afedai USB_RX>;
+            };
+
+            codec {
+                sound-dai = <&usbdai USB_RX>;
+            };
+
+            platform {
+                sound-dai = <&q6routing>;
+            };
+        };
     };
 
   - |

[PATCH v9 26/34] ASoC: qcom: qdsp6: q6afe: Split USB AFE dev_token param into separate API

[Wesley Cheng]

The Q6USB backend can carry information about the available USB SND cards
and PCM devices discovered on the USB bus.  The dev_token field is used by
the audio DSP to notify the USB offload driver of which card and PCM index
to enable playback on.  Separate this into a dedicated API, so the USB
backend can set the dev_token accordingly.  The audio DSP does not utilize
this information until the AFE port start command is sent, which is done
during the PCM prepare phase.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6afe.c | 49 +++++++++++++++++++++++++-----------
 sound/soc/qcom/qdsp6/q6afe.h |  1 +
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6afe.c b/sound/soc/qcom/qdsp6/q6afe.c
index 72c4e6fe20c4..f09a756246f8 100644
--- a/sound/soc/qcom/qdsp6/q6afe.c
+++ b/sound/soc/qcom/qdsp6/q6afe.c
@@ -1394,10 +1394,42 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port,
 }
 EXPORT_SYMBOL_GPL(q6afe_tdm_port_prepare);
 
-static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
+/**
+ * afe_port_send_usb_dev_param() - Send USB dev token
+ *
+ * @port: Instance of afe port
+ * @cardidx: USB SND card index to reference
+ * @pcmidx: USB SND PCM device index to reference
+ *
+ * The USB dev token carries information about which USB SND card instance and
+ * PCM device to execute the offload on.  This information is carried through
+ * to the stream enable QMI request, which is handled by the offload class
+ * driver.  The information is parsed to determine which USB device to query
+ * the required resources for.
+ */
+int afe_port_send_usb_dev_param(struct q6afe_port *port, int cardidx, int pcmidx)
 {
-	union afe_port_config *pcfg = &port->port_cfg;
 	struct afe_param_id_usb_audio_dev_params usb_dev;
+	int ret;
+
+	memset(&usb_dev, 0, sizeof(usb_dev));
+
+	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
+	usb_dev.dev_token = (cardidx << 16) | (pcmidx << 8);
+	ret = q6afe_port_set_param_v2(port, &usb_dev,
+				AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
+				AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
+	if (ret)
+		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
+			__func__, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(afe_port_send_usb_dev_param);
+
+static int afe_port_send_usb_params(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
+{
+	union afe_port_config *pcfg = &port->port_cfg;
 	struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
 	struct afe_param_id_usb_audio_svc_interval svc_int;
 	int ret = 0;
@@ -1408,20 +1440,9 @@ static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb
 		goto exit;
 	}
 
-	memset(&usb_dev, 0, sizeof(usb_dev));
 	memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
 	memset(&svc_int, 0, sizeof(svc_int));
 
-	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
-	ret = q6afe_port_set_param_v2(port, &usb_dev,
-				      AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
-				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
-	if (ret) {
-		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
-			__func__, ret);
-		goto exit;
-	}
-
 	lpcm_fmt.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
 	lpcm_fmt.endian = pcfg->usb_cfg.endian;
 	ret = q6afe_port_set_param_v2(port, &lpcm_fmt,
@@ -1463,7 +1484,7 @@ void q6afe_usb_port_prepare(struct q6afe_port *port,
 	pcfg->usb_cfg.num_channels = cfg->num_channels;
 	pcfg->usb_cfg.bit_width = cfg->bit_width;
 
-	afe_port_send_usb_dev_param(port, cfg);
+	afe_port_send_usb_params(port, cfg);
 }
 EXPORT_SYMBOL_GPL(q6afe_usb_port_prepare);
 
diff --git a/sound/soc/qcom/qdsp6/q6afe.h b/sound/soc/qcom/qdsp6/q6afe.h
index ef47b4ae9e27..2ce5ba9dba69 100644
--- a/sound/soc/qcom/qdsp6/q6afe.h
+++ b/sound/soc/qcom/qdsp6/q6afe.h
@@ -263,6 +263,7 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port, struct q6afe_tdm_cfg *cfg);
 void q6afe_cdc_dma_port_prepare(struct q6afe_port *port,
 				struct q6afe_cdc_dma_cfg *cfg);
 
+int afe_port_send_usb_dev_param(struct q6afe_port *port, int cardidx, int pcmidx);
 int q6afe_port_set_sysclk(struct q6afe_port *port, int clk_id,
 			  int clk_src, int clk_root,
 			  unsigned int freq, int dir);

[PATCH v9 27/34] ALSA: usb-audio: qcom: Populate PCM and USB chip information

[Wesley Cheng]

Currently, only the index to the USB SND card array is passed to the USB
backend.  Pass through more information, specifically the USB SND card
number and the number of PCM devices available.  This allows for the DPCM
backend to determine what USB resources are available during situations,
such as USB audio offloading.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/qcom/qc_audio_offload.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
index bd6b84f72c74..ae74098b41f5 100644
--- a/sound/usb/qcom/qc_audio_offload.c
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -173,6 +173,21 @@ enum usb_qmi_audio_format {
 	USB_QMI_PCM_FORMAT_U32_BE,
 };
 
+static int usb_qmi_get_pcm_num(struct snd_usb_audio *chip, int direction)
+{
+	struct snd_usb_substream *subs = NULL;
+	struct snd_usb_stream *as;
+	int count = 0;
+
+	list_for_each_entry(as, &chip->pcm_list, list) {
+		subs = &as->substream[direction];
+		if (subs->ep_num)
+			count++;
+	}
+
+	return count;
+}
+
 static enum usb_qmi_audio_device_speed_enum_v01
 get_speed_info(enum usb_device_speed udev_speed)
 {
@@ -1592,6 +1607,8 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)
 
 	sdev->card_idx = chip->card->number;
 	sdev->chip_idx = chip->index;
+	sdev->num_playback = usb_qmi_get_pcm_num(chip, 0);
+	sdev->num_capture = usb_qmi_get_pcm_num(chip, 1);
 	uadev[chip->card->number].sdev = sdev;
 
 	uaudio_qdev->last_card_num = chip->card->number;
@@ -1706,10 +1723,8 @@ static void qc_usb_audio_offload_disconnect(struct snd_usb_audio *chip)
 	mutex_unlock(&chip->mutex);
 
 	atomic_dec(&uaudio_qdev->qdev_in_use);
-	if (!atomic_read(&uaudio_qdev->qdev_in_use)) {
-		snd_soc_usb_disconnect(usb_get_usb_backend(udev));
+	if (!atomic_read(&uaudio_qdev->qdev_in_use))
 		qc_usb_audio_cleanup_qmi_dev();
-	}
 	mutex_unlock(&qdev_mutex);
 }
 

[PATCH v9 28/34] ASoC: qcom: qdsp6: Add support to track available USB PCM devices

[Wesley Cheng]

The USB backend should know about which sound resources are being shared
between the ASoC and USB SND paths.  This can be utilized to properly
select and maintain the offloading devices.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6usb.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
index 329a7d4a3c01..d697cbe7f184 100644
--- a/sound/soc/qcom/qdsp6/q6usb.c
+++ b/sound/soc/qcom/qdsp6/q6usb.c
@@ -25,10 +25,18 @@
 
 #define SID_MASK	0xF
 
+struct q6usb_status {
+	unsigned int num_pcm;
+	unsigned int chip_index;
+	unsigned int pcm_index;
+};
+
 struct q6usb_port_data {
 	struct q6afe_usb_cfg usb_cfg;
 	struct snd_soc_usb *usb;
 	struct q6usb_offload priv;
+	unsigned long available_card_slot;
+	struct q6usb_status status[SNDRV_CARDS];
 	int active_idx;
 };
 
@@ -110,6 +118,14 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
 	if (connected) {
 		/* We only track the latest USB headset plugged in */
 		data->active_idx = sdev->card_idx;
+
+		set_bit(sdev->card_idx, &data->available_card_slot);
+		data->status[sdev->card_idx].num_pcm = sdev->num_playback;
+		data->status[sdev->card_idx].chip_index = sdev->chip_idx;
+	} else {
+		clear_bit(sdev->card_idx, &data->available_card_slot);
+		data->status[sdev->card_idx].num_pcm = 0;
+		data->status[sdev->card_idx].chip_index = 0;
 	}
 
 	return 0;

[PATCH v9 29/34] ASoC: qcom: qdsp6: Add SND kcontrol to select offload device

[Wesley Cheng]

Expose a kcontrol on the platform sound card, which will allow for
userspace to determine which USB card number and PCM device to offload.
This allows for userspace to potentially tag an alternate path for a
specific USB SND card and PCM device.  Previously, control was absent, and
the offload path would be enabled on the last USB SND device which was
connected.  This logic will continue to be applicable if no mixer input is
received for specific device selection.

An example to configure the offload device using tinymix:
tinymix -D 0 set 'Q6USB offload SND device select' 1 0

The above will set the Q6AFE device token to choose offload on card#1 and
pcm#0.  Device selection is made possible by setting the Q6AFE device
token.  The audio DSP utilizes this parameter, and will pass this field
back to the USB offload driver within the QMI stream requests.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6usb.c | 125 ++++++++++++++++++++++++++++++++++-
 1 file changed, 122 insertions(+), 3 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
index d697cbe7f184..a95276b7d91d 100644
--- a/sound/soc/qcom/qdsp6/q6usb.c
+++ b/sound/soc/qcom/qdsp6/q6usb.c
@@ -14,6 +14,7 @@
 #include <linux/dma-map-ops.h>
 
 #include <sound/pcm.h>
+#include <sound/control.h>
 #include <sound/soc.h>
 #include <sound/soc-usb.h>
 #include <sound/pcm_params.h>
@@ -35,9 +36,12 @@ struct q6usb_port_data {
 	struct q6afe_usb_cfg usb_cfg;
 	struct snd_soc_usb *usb;
 	struct q6usb_offload priv;
+	struct mutex mutex;
 	unsigned long available_card_slot;
 	struct q6usb_status status[SNDRV_CARDS];
-	int active_idx;
+	bool idx_valid;
+	int sel_card_idx;
+	int sel_pcm_idx;
 };
 
 static const struct snd_soc_dapm_widget q6usb_dai_widgets[] = {
@@ -53,9 +57,34 @@ static int q6usb_hw_params(struct snd_pcm_substream *substream,
 			   struct snd_soc_dai *dai)
 {
 	struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
+	struct q6afe_port *q6usb_afe;
 	int direction = substream->stream;
+	int chip_idx;
+	int ret;
+
+	mutex_lock(&data->mutex);
+	chip_idx = data->status[data->sel_card_idx].chip_index;
+
+	ret = snd_soc_usb_find_format(chip_idx, params, direction);
+	if (ret < 0)
+		goto out;
+
+	q6usb_afe = q6afe_port_get_from_id(cpu_dai->dev, USB_RX);
+	if (IS_ERR(q6usb_afe))
+		goto out;
 
-	return snd_soc_usb_find_format(data->active_idx, params, direction);
+	ret = afe_port_send_usb_dev_param(q6usb_afe, data->sel_card_idx,
+						data->sel_pcm_idx);
+	if (ret < 0)
+		goto out;
+
+	data->status[data->sel_card_idx].pcm_index = data->sel_pcm_idx;
+out:
+	mutex_unlock(&data->mutex);
+
+	return ret;
 }
 
 static const struct snd_soc_dai_ops q6usb_ops = {
@@ -86,6 +115,89 @@ static struct snd_soc_dai_driver q6usb_be_dais[] = {
 	},
 };
 
+static int q6usb_get_offload_dev(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
+	int pcm_idx;
+	int card_idx;
+
+	mutex_lock(&data->mutex);
+	if (!data->idx_valid) {
+		card_idx = -1;
+		pcm_idx = -1;
+	} else {
+		card_idx = data->sel_card_idx;
+		pcm_idx = data->sel_pcm_idx;
+	}
+
+	ucontrol->value.integer.value[0] = card_idx;
+	ucontrol->value.integer.value[1] = pcm_idx;
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+static int q6usb_put_offload_dev(struct snd_kcontrol *kcontrol,
+			      struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
+	int changed = 0;
+	int pcmidx;
+	int cardidx;
+
+	cardidx = ucontrol->value.integer.value[0];
+	pcmidx = ucontrol->value.integer.value[1];
+
+	mutex_lock(&data->mutex);
+	if ((cardidx >= 0 && test_bit(cardidx, &data->available_card_slot))) {
+		data->sel_card_idx = cardidx;
+		changed = 1;
+	}
+
+	if ((pcmidx >= 0 && pcmidx < data->status[cardidx].num_pcm)) {
+		data->sel_pcm_idx = pcmidx;
+		data->idx_valid = true;
+		changed = 1;
+	}
+	mutex_unlock(&data->mutex);
+
+	return changed;
+}
+
+static int q6usb_offload_dev_info(struct snd_kcontrol *kcontrol,
+			      struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 2;
+	uinfo->value.integer.min = -1;
+	uinfo->value.integer.max = SNDRV_CARDS;
+
+	return 0;
+}
+
+static const struct snd_kcontrol_new q6usb_offload_dev_ctrl = {
+	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+	.name = "Q6USB offload SND device select",
+	.info = q6usb_offload_dev_info,
+	.get = q6usb_get_offload_dev,
+	.put = q6usb_put_offload_dev,
+};
+
+/* Build a mixer control for a UAC connector control (jack-detect) */
+static void q6usb_connector_control_init(struct snd_soc_component *component)
+{
+	int ret;
+
+	ret = snd_ctl_add(component->card->snd_card,
+				snd_ctl_new1(&q6usb_offload_dev_ctrl, component));
+	if (ret < 0)
+		return;
+}
+
 static int q6usb_audio_ports_of_xlate_dai_name(struct snd_soc_component *component,
 					const struct of_phandle_args *args,
 					const char **dai_name)
@@ -115,9 +227,11 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
 
 	data = dev_get_drvdata(usb->component->dev);
 
+	mutex_lock(&data->mutex);
 	if (connected) {
 		/* We only track the latest USB headset plugged in */
-		data->active_idx = sdev->card_idx;
+		if (!data->idx_valid || data->sel_card_idx < 0)
+			data->sel_card_idx = sdev->card_idx;
 
 		set_bit(sdev->card_idx, &data->available_card_slot);
 		data->status[sdev->card_idx].num_pcm = sdev->num_playback;
@@ -127,6 +241,7 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
 		data->status[sdev->card_idx].num_pcm = 0;
 		data->status[sdev->card_idx].chip_index = 0;
 	}
+	mutex_unlock(&data->mutex);
 
 	return 0;
 }
@@ -135,6 +250,8 @@ static int q6usb_component_probe(struct snd_soc_component *component)
 {
 	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
 
+	q6usb_connector_control_init(component);
+
 	data->usb = snd_soc_usb_add_port(component->dev, &data->priv, q6usb_alsa_connection_cb);
 	if (IS_ERR(data->usb)) {
 		dev_err(component->dev, "failed to add usb port\n");
@@ -189,6 +306,8 @@ static int q6usb_dai_dev_probe(struct platform_device *pdev)
 
 	data->priv.domain = iommu_get_domain_for_dev(&pdev->dev);
 
+	mutex_init(&data->mutex);
+
 	data->priv.dev = dev;
 	dev_set_drvdata(dev, data);
 

[PATCH v9 30/34] ASoC: qcom: qdsp6: Add SND kcontrol for fetching offload status

[Wesley Cheng]

Add a kcontrol to the platform sound card to fetch the current offload
status.  This can allow for userspace to ensure/check which USB SND
resources are actually busy versus having to attempt opening the USB SND
devices, which will result in an error if offloading is active.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6usb.c | 104 ++++++++++++++++++++++++++++++++++-
 1 file changed, 101 insertions(+), 3 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
index a95276b7d91d..d2f60ce66cf3 100644
--- a/sound/soc/qcom/qdsp6/q6usb.c
+++ b/sound/soc/qcom/qdsp6/q6usb.c
@@ -30,6 +30,8 @@ struct q6usb_status {
 	unsigned int num_pcm;
 	unsigned int chip_index;
 	unsigned int pcm_index;
+	bool prepared;
+	bool running;
 };
 
 struct q6usb_port_data {
@@ -52,6 +54,17 @@ static const struct snd_soc_dapm_route q6usb_dapm_routes[] = {
 	{"USB Playback", NULL, "USB_RX_BE"},
 };
 
+static int q6usb_find_running(struct q6usb_port_data *data)
+{
+	int i;
+
+	for (i = 0; i < SNDRV_CARDS; i++) {
+		if (data->status[i].running)
+			return i;
+	}
+	return -ENODEV;
+}
+
 static int q6usb_hw_params(struct snd_pcm_substream *substream,
 			   struct snd_pcm_hw_params *params,
 			   struct snd_soc_dai *dai)
@@ -81,14 +94,40 @@ static int q6usb_hw_params(struct snd_pcm_substream *substream,
 		goto out;
 
 	data->status[data->sel_card_idx].pcm_index = data->sel_pcm_idx;
+	data->status[data->sel_card_idx].prepared = true;
 out:
 	mutex_unlock(&data->mutex);
 
 	return ret;
 }
 
+static int q6usb_prepare(struct snd_pcm_substream *substream,
+		struct snd_soc_dai *dai)
+{
+	struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
+
+	mutex_lock(&data->mutex);
+	data->status[data->sel_card_idx].running = true;
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+static void q6usb_shutdown(struct snd_pcm_substream *substream,
+				struct snd_soc_dai *dai)
+{
+	struct q6usb_port_data *data = dev_get_drvdata(dai->dev);
+
+	mutex_lock(&data->mutex);
+	data->status[data->sel_card_idx].running = false;
+	data->status[data->sel_card_idx].prepared = false;
+	mutex_unlock(&data->mutex);
+}
+
 static const struct snd_soc_dai_ops q6usb_ops = {
 	.hw_params = q6usb_hw_params,
+	.prepare = q6usb_prepare,
+	.shutdown = q6usb_shutdown,
 };
 
 static struct snd_soc_dai_driver q6usb_be_dais[] = {
@@ -148,10 +187,15 @@ static int q6usb_put_offload_dev(struct snd_kcontrol *kcontrol,
 	int pcmidx;
 	int cardidx;
 
+	mutex_lock(&data->mutex);
+
+	/* Don't allow changes to the offloading devices if session is busy */
+	if (data->sel_card_idx >= 0 && data->status[data->sel_card_idx].prepared)
+		goto out;
+
 	cardidx = ucontrol->value.integer.value[0];
 	pcmidx = ucontrol->value.integer.value[1];
 
-	mutex_lock(&data->mutex);
 	if ((cardidx >= 0 && test_bit(cardidx, &data->available_card_slot))) {
 		data->sel_card_idx = cardidx;
 		changed = 1;
@@ -162,6 +206,8 @@ static int q6usb_put_offload_dev(struct snd_kcontrol *kcontrol,
 		data->idx_valid = true;
 		changed = 1;
 	}
+
+out:
 	mutex_unlock(&data->mutex);
 
 	return changed;
@@ -187,11 +233,59 @@ static const struct snd_kcontrol_new q6usb_offload_dev_ctrl = {
 	.put = q6usb_put_offload_dev,
 };
 
+static int q6usb_mixer_get_offload_status(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
+	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
+	int running;
+	int card_idx;
+	int pcm_idx;
+
+	running = q6usb_find_running(data);
+	if (running < 0) {
+		card_idx = -1;
+		pcm_idx = -1;
+	} else {
+		card_idx = running;
+		pcm_idx = data->status[running].pcm_index;
+	}
+
+	ucontrol->value.integer.value[0] = card_idx;
+	ucontrol->value.integer.value[1] = pcm_idx;
+	return 0;
+}
+
+static int q6usb_offload_ctl_info(struct snd_kcontrol *kcontrol,
+			      struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 2;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = SNDRV_CARDS;
+
+	return 0;
+}
+
+static const struct snd_kcontrol_new q6usb_offload_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_CARD,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ,
+	.name = "Q6USB offload status",
+	.info = q6usb_offload_ctl_info,
+	.get = q6usb_mixer_get_offload_status,
+	.put = NULL,
+};
+
 /* Build a mixer control for a UAC connector control (jack-detect) */
 static void q6usb_connector_control_init(struct snd_soc_component *component)
 {
 	int ret;
 
+	ret = snd_ctl_add(component->card->snd_card,
+				snd_ctl_new1(&q6usb_offload_control, component));
+	if (ret < 0)
+		return;
+
 	ret = snd_ctl_add(component->card->snd_card,
 				snd_ctl_new1(&q6usb_offload_dev_ctrl, component));
 	if (ret < 0)
@@ -229,8 +323,12 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
 
 	mutex_lock(&data->mutex);
 	if (connected) {
-		/* We only track the latest USB headset plugged in */
-		if (!data->idx_valid || data->sel_card_idx < 0)
+		/*
+		 * Update the latest USB headset plugged in, if session is
+		 * idle.
+		 */
+		if ((!data->idx_valid || data->sel_card_idx < 0) &&
+			!data->status[data->sel_card_idx].prepared)
 			data->sel_card_idx = sdev->card_idx;
 
 		set_bit(sdev->card_idx, &data->available_card_slot);

[PATCH v9 31/34] ASoC: qcom: qdsp6: Add headphone jack for offload connection status

[Wesley Cheng]

The headphone jack framework has a well defined infrastructure for
notifying userspace entities through input devices.  Expose a jack device
that carries information about if an offload capable device is connected.
Applications can further identify specific offloading information through
other SND kcontrols.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/qcom/qdsp6/q6usb.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
index d2f60ce66cf3..9fa6c4016222 100644
--- a/sound/soc/qcom/qdsp6/q6usb.c
+++ b/sound/soc/qcom/qdsp6/q6usb.c
@@ -20,6 +20,7 @@
 #include <sound/pcm_params.h>
 #include <sound/asound.h>
 #include <sound/q6usboffload.h>
+#include <sound/jack.h>
 
 #include "q6dsp-lpass-ports.h"
 #include "q6afe.h"
@@ -37,6 +38,7 @@ struct q6usb_status {
 struct q6usb_port_data {
 	struct q6afe_usb_cfg usb_cfg;
 	struct snd_soc_usb *usb;
+	struct snd_soc_jack hs_jack;
 	struct q6usb_offload priv;
 	struct mutex mutex;
 	unsigned long available_card_slot;
@@ -279,6 +281,7 @@ static const struct snd_kcontrol_new q6usb_offload_control = {
 /* Build a mixer control for a UAC connector control (jack-detect) */
 static void q6usb_connector_control_init(struct snd_soc_component *component)
 {
+	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
 	int ret;
 
 	ret = snd_ctl_add(component->card->snd_card,
@@ -290,6 +293,11 @@ static void q6usb_connector_control_init(struct snd_soc_component *component)
 				snd_ctl_new1(&q6usb_offload_dev_ctrl, component));
 	if (ret < 0)
 		return;
+
+	ret = snd_soc_card_jack_new(component->card, "USB offload",
+					SND_JACK_HEADSET, &data->hs_jack);
+	if (ret)
+		return;
 }
 
 static int q6usb_audio_ports_of_xlate_dai_name(struct snd_soc_component *component,
@@ -323,6 +331,9 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
 
 	mutex_lock(&data->mutex);
 	if (connected) {
+		if (!data->available_card_slot)
+			snd_jack_report(data->hs_jack.jack, 1);
+
 		/*
 		 * Update the latest USB headset plugged in, if session is
 		 * idle.
@@ -338,6 +349,9 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
 		clear_bit(sdev->card_idx, &data->available_card_slot);
 		data->status[sdev->card_idx].num_pcm = 0;
 		data->status[sdev->card_idx].chip_index = 0;
+
+		if (!data->available_card_slot)
+			snd_jack_report(data->hs_jack.jack, 0);
 	}
 	mutex_unlock(&data->mutex);
 

[PATCH v9 32/34] ALSA: usb-audio: qcom: Use card and PCM index from QMI request

[Wesley Cheng]

Utilize the card and PCM index coming from the USB QMI stream request.
This field follows what is set by the ASoC USB backend, and could
potentially carry information about a specific device selected through the
ASoC USB backend.  The backend also has information about the last USB
sound device plugged in, so it can choose to select the last device plugged
in, accordingly.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/qcom/qc_audio_offload.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
index ae74098b41f5..675dac4c2179 100644
--- a/sound/usb/qcom/qc_audio_offload.c
+++ b/sound/usb/qcom/qc_audio_offload.c
@@ -107,8 +107,6 @@ struct uaudio_qmi_dev {
 	bool er_mapped;
 	/* reference count to number of possible consumers */
 	atomic_t qdev_in_use;
-	/* idx to last udev card number plugged in */
-	unsigned int last_card_num;
 };
 
 struct uaudio_dev {
@@ -981,7 +979,7 @@ static int prepare_qmi_response(struct snd_usb_substream *subs,
 	assoc = iface->intf_assoc;
 	pcm_dev_num = (req_msg->usb_token & QMI_STREAM_REQ_DEV_NUM_MASK) >> 8;
 	xfer_buf_len = req_msg->xfer_buff_size;
-	card_num = uaudio_qdev->last_card_num;
+	card_num = (req_msg->usb_token & QMI_STREAM_REQ_CARD_NUM_MASK) >> 16;
 
 	alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
 	altsd = get_iface_desc(alts);
@@ -1401,8 +1399,7 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
 
 	direction = (req_msg->usb_token & QMI_STREAM_REQ_DIRECTION);
 	pcm_dev_num = (req_msg->usb_token & QMI_STREAM_REQ_DEV_NUM_MASK) >> 8;
-	pcm_card_num = req_msg->enable ? uaudio_qdev->last_card_num :
-				ffs(uaudio_qdev->card_slot) - 1;
+	pcm_card_num = (req_msg->usb_token & QMI_STREAM_REQ_CARD_NUM_MASK) >> 16;
 	if (pcm_card_num >= SNDRV_CARDS) {
 		ret = -EINVAL;
 		goto response;
@@ -1611,7 +1608,6 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)
 	sdev->num_capture = usb_qmi_get_pcm_num(chip, 1);
 	uadev[chip->card->number].sdev = sdev;
 
-	uaudio_qdev->last_card_num = chip->card->number;
 	snd_soc_usb_connect(usb_get_usb_backend(udev), sdev);
 	mutex_unlock(&chip->mutex);
 

[PATCH v9 33/34] ALSA: usb-audio: Allow for rediscovery of connected USB SND devices

[Wesley Cheng]

In case of notifying SND platform drivers of connection events, some of
these use cases, such as offloading, require an ASoC USB backend device to
be initialized before the events can be handled.  If the USB backend device
has not yet been probed, this leads to missing initial USB audio device
connection events.

Expose an API that traverses the usb_chip array for connected devices, and
to call the respective connection callback registered to the SND platform
driver.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/usb/card.c | 19 +++++++++++++++++++
 sound/usb/card.h |  2 ++
 2 files changed, 21 insertions(+)

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 88f431917c15..7d3f470754ca 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -202,6 +202,25 @@ struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
 }
 EXPORT_SYMBOL_GPL(snd_usb_find_suppported_substream);
 
+/*
+ * in case the platform driver was not ready at the time of USB SND
+ * device connect, expose an API to discover all connected USB devices
+ * so it can populate any dependent resources/structures.
+ */
+void snd_usb_rediscover_devices(void)
+{
+	int i;
+
+	mutex_lock(&register_mutex);
+	for (i = 0; i < SNDRV_CARDS; i++) {
+		if (usb_chip[i])
+			if (platform_ops && platform_ops->connect_cb)
+				platform_ops->connect_cb(usb_chip[i]);
+	}
+	mutex_unlock(&register_mutex);
+}
+EXPORT_SYMBOL_GPL(snd_usb_rediscover_devices);
+
 /*
  * disconnect streams
  * called from usb_audio_disconnect()
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 01f7e10f30f4..c0aeda17ed69 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -221,11 +221,13 @@ int snd_usb_unregister_platform_ops(void);
 #if IS_ENABLED(CONFIG_SND_USB_AUDIO)
 struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
 			struct snd_pcm_hw_params *params, int direction);
+void snd_usb_rediscover_devices(void);
 #else
 static struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
 			struct snd_pcm_hw_params *params, int direction)
 {
 	return NULL;
 }
+static void snd_usb_rediscover_devices(void) { }
 #endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
 #endif /* __USBAUDIO_CARD_H */

[PATCH v9 34/34] ASoC: usb: Rediscover USB SND devices on USB port add

[Wesley Cheng]

In case the USB backend device has not been initialized/probed, USB SND
device connections can still occur.  When the USB backend is eventually
made available, previous USB SND device connections are not communicated to
the USB backend.  Call snd_usb_rediscover_devices() to generate the connect
callbacks for all USB SND devices connected.  This will allow for the USB
backend to be updated with the current set of devices available.

The chip array entries are all populated and removed while under the
register_mutex, so going over potential race conditions:

Thread#1:
  q6usb_component_probe()
    --> snd_soc_usb_add_port()
      --> snd_usb_rediscover_devices()
        --> mutex_lock(register_mutex)

Thread#2
  --> usb_audio_disconnect()
    --> mutex_lock(register_mutex)

So either thread#1 or thread#2 will complete first.  If

Thread#1 completes before thread#2:
  SOC USB will notify DPCM backend of the device connection.  Shortly
  after, once thread#2 runs, we will get a disconnect event for the
  connected device.

Thread#2 completes before thread#1:
  Then during snd_usb_rediscover_devices() it won't notify of any
  connection for that particular chip index.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 sound/soc/soc-usb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
index 7407678a993e..60aafbe87c36 100644
--- a/sound/soc/soc-usb.c
+++ b/sound/soc/soc-usb.c
@@ -104,6 +104,8 @@ struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
 	list_add_tail(&usb->list, &usb_ctx_list);
 	mutex_unlock(&ctx_mutex);
 
+	snd_usb_rediscover_devices();
+
 	return usb;
 }
 EXPORT_SYMBOL_GPL(snd_soc_usb_add_port);

Re: [PATCH v9 00/34] Introduce QC USB SND audio offloading support

[Pierre-Louis Bossart]

It's been a very long time since I reviewed earlier versions, and I am
still lost on terminology and concepts. The explanations below should
really be added as a .rst file in Documentation for reference, not just
as a cover letter.

> Several Qualcomm based chipsets can support USB audio offloading to a
> dedicated audio DSP, which can take over issuing transfers to the USB
> host controller.  The intention is to reduce the load on the main
> processors in the SoC, and allow them to be placed into lower power modes.
> There are several parts to this design:
>   1. Adding ASoC binding layer
>   2. Create a USB backend for Q6DSP

"backend" is a loaded terms for ASoC. Can you clarify which part of the
ascii art below is a 'backend'?

>   3. Introduce XHCI interrupter support
>   4. Create vendor ops for the USB SND driver
> 
>       USB                          |            ASoC
> --------------------------------------------------------------------
>                                    |  _________________________
>                                    | |sm8250 platform card     |
>                                    | |_________________________|
>                                    |         |           |
>                                    |      ___V____   ____V____
>                                    |     |Q6USB   | |Q6AFE    |  
>                                    |     |"codec" | |"cpu"    |
>                                    |     |________| |_________|
>                                    |         ^  ^        ^
>                                    |         |  |________|
>                                    |      ___V____    |
>                                    |     |SOC-USB |   |
>    ________       ________               |        |   |
>   |USB SND |<--->|QC offld|<------------>|________|   |
>   |(card.c)|     |        |<----------                |
>   |________|     |________|___     | |                |
>       ^               ^       |    | |    ____________V_________
>       |               |       |    | |   |APR/GLINK             |
>    __ V_______________V_____  |    | |   |______________________|
>   |USB SND (endpoint.c)     | |    | |              ^
>   |_________________________| |    | |              |
>               ^               |    | |   ___________V___________
>               |               |    | |->|audio DSP              |
>    ___________V_____________  |    |    |_______________________|
>   |XHCI HCD                 |<-    |
>   |_________________________|      |
> 
> 
> Adding ASoC binding layer:
> soc-usb: Intention is to treat a USB port similar to a headphone jack.

What is a 'port'? USB refers to "interfaces" and "endpoints". Is a
"port" a 1:1 mapping to "endpoint"?

Below I read "AFE port" so not sure what concepts refer to what.

> The port is always present on the device, but cable/pin status can be
> enabled/disabled.  Expose mechanisms for USB backend ASoC drivers to
> communicate with USB SND.
> 
> Create a USB backend for Q6DSP:
> q6usb: Basic backend driver that will be responsible for maintaining the

The asciiart above suggests that q6usb exposes a codec DAI - but the
backend dailink is created by the platform card?

> resources needed to initiate a playback stream using the Q6DSP.  Will

is capture supported? there's explicit references to "num_capture" in
following patches.

> be the entity that checks to make sure the connected USB audio device
> supports the requested PCM format.  If it does not, the PCM open call will
> fail, and userpsace ALSA can take action accordingly.
> 
> Introduce XHCI interrupter support:
> XHCI HCD supports multiple interrupters, which allows for events to be routed
> to different event rings.  This is determined by "Interrupter Target" field
> specified in Section "6.4.1.1 Normal TRB" of the XHCI specification.
> 
> Events in the offloading case will be routed to an event ring that is assigned
> to the audio DSP.
> 
> Create vendor ops for the USB SND driver:
> qc_audio_offload: This particular driver has several components associated
> with it:
> - QMI stream request handler
> - XHCI interrupter and resource management
> - audio DSP memory management
> 
> When the audio DSP wants to enable a playback stream, the request is first
> received by the ASoC platform sound card.  Depending on the selected route,
> ASoC will bring up the individual DAIs in the path.  The Q6USB backend DAI
> will send an AFE port start command (with enabling the USB playback path), and
> the audio DSP will handle the request accordingly.

what about capture, e.g. for a headset?

> Part of the AFE USB port start handling will have an exchange of control
> messages using the QMI protocol.  The qc_audio_offload driver will populate the
> buffer information:
> - Event ring base address
> - EP transfer ring base address
> 
> and pass it along to the audio DSP.  All endpoint management will now be handed
> over to the DSP, and the main processor is not involved in transfers.
> 
> Overall, implementing this feature will still expose separate sound card and PCM
> devices for both the platorm card and USB audio device:

typo: platform

>  0 [SM8250MTPWCD938]: sm8250 - SM8250-MTP-WCD9380-WSA8810-VA-D
>                       SM8250-MTP-WCD9380-WSA8810-VA-DMIC

How do you plan on exposing the USB PCM device?

The lines above are really cryptic, and with no USB reference in any of
the short/long card names it's not obvious that this card is different
from the no-offload case, is it?

>  1 [Audio          ]: USB-Audio - USB Audio
>                       Generic USB Audio at usb-xhci-hcd.1.auto-1.4, high speed

likewise some sort of qualifier would be useful to show that card 0 and
card 1 can target the same USB endpoints.

> This is to ensure that userspace ALSA entities can decide which route to take
> when executing the audio playback.  In the above, if card#1 is selected, then
> USB audio data will take the legacy path over the USB PCM drivers, etc...
> 
> This feature was validated using:
> - tinymix: set/enable the multimedia path to route to USB backend
> - tinyplay: issue playback on platform card

Re: [PATCH v9 09/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

[Pierre-Louis Bossart]

On 10/17/23 15:00, Wesley Cheng wrote:
> The QC ADSP is able to support USB playback endpoints, so that the main

playback only?

> application processor can be placed into lower CPU power modes.  This adds
> the required AFE port configurations and port start command to start an
> audio session.
> 
> Specifically, the QC ADSP can support all potential endpoints that are
> exposed by the audio data interface.  This includes, feedback endpoints
> (both implicit and explicit) as well as the isochronous (data) endpoints.

implicit feedback means support for capture. This is confusing...

> +static int q6usb_hw_params(struct snd_pcm_substream *substream,
> +			   struct snd_pcm_hw_params *params,
> +			   struct snd_soc_dai *dai)
> +{
> +	struct q6afe_dai_data *dai_data = dev_get_drvdata(dai->dev);
> +	int channels = params_channels(params);
> +	int rate = params_rate(params);
> +	struct q6afe_usb_cfg *usb = &dai_data->port_config[dai->id].usb_audio;
> +
> +	usb->sample_rate = rate;
> +	usb->num_channels = channels;
> +
> +	switch (params_format(params)) {
> +	case SNDRV_PCM_FORMAT_U16_LE:
> +	case SNDRV_PCM_FORMAT_S16_LE:
> +	case SNDRV_PCM_FORMAT_SPECIAL:

what does FORMAT_SPECIAL mean? the only other reference I see to this is
related to SLIMbus, not sure how this is related?

> +		usb->bit_width = 16;
> +		break;
> +	case SNDRV_PCM_FORMAT_S24_LE:
> +	case SNDRV_PCM_FORMAT_S24_3LE:
> +		usb->bit_width = 24;
> +		break;
> +	case SNDRV_PCM_FORMAT_S32_LE:
> +		usb->bit_width = 32;
> +		break;
> +	default:
> +		dev_err(dai->dev, "%s: invalid format %d\n",
> +			__func__, params_format(params));
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}

> @@ -617,6 +655,9 @@ static const struct snd_soc_dapm_route q6afe_dapm_routes[] = {
>  	{"TX_CODEC_DMA_TX_5", NULL, "TX_CODEC_DMA_TX_5 Capture"},
>  	{"RX_CODEC_DMA_RX_6 Playback", NULL, "RX_CODEC_DMA_RX_6"},
>  	{"RX_CODEC_DMA_RX_7 Playback", NULL, "RX_CODEC_DMA_RX_7"},
> +
> +	/* USB playback AFE port receives data for playback, hence use the RX port */
> +	{"USB Playback", NULL, "USB_RX"},

Capture for implicit feedback?

>  };
>  
>  static int msm_dai_q6_dai_probe(struct snd_soc_dai *dai)
> @@ -644,6 +685,18 @@ static int msm_dai_q6_dai_remove(struct snd_soc_dai *dai)
>  	return 0;
>  }
>  
> +static const struct snd_soc_dai_ops q6usb_ops = {
> +	.probe		= msm_dai_q6_dai_probe,
> +	.prepare	= q6afe_dai_prepare,
> +	.hw_params	= q6usb_hw_params,

this is rather confusing with two different layers used for hw_params
and prepare? Additional comments or explanations wouldn't hurt.

> +	.shutdown	= q6afe_dai_shutdown,
> +	/*
> +	 * Startup callback not needed, as AFE port start command passes the PCM
> +	 * parameters within the AFE command, which is provided by the PCM core
> +	 * during the prepare() stage.

This doesn't really explain why you need a shutdown?


> + * struct afe_param_id_usb_audio_dev_latency_mode
> + * @cfg_minor_version: Minor version used for tracking USB audio device
> + * configuration.
> + * Supported values:
> + *     AFE_API_MINOR_VERSION_USB_AUDIO_LATENCY_MODE
> + * @mode: latency mode for the USB audio device

what are the different latency modes? and is this related to the latency
reporting that was added in the USB2 audio class IIRC?

> +static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
> +{
> +	union afe_port_config *pcfg = &port->port_cfg;
> +	struct afe_param_id_usb_audio_dev_params usb_dev;
> +	struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
> +	struct afe_param_id_usb_audio_svc_interval svc_int;
> +	int ret = 0;

useless init overridden...
> +
> +	if (!pcfg) {
> +		dev_err(port->afe->dev, "%s: Error, no configuration data\n", __func__);
> +		ret = -EINVAL;
> +		goto exit;
> +	}
> +
> +	memset(&usb_dev, 0, sizeof(usb_dev));
> +	memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
> +	memset(&svc_int, 0, sizeof(svc_int));
> +
> +	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> +	ret = q6afe_port_set_param_v2(port, &usb_dev,

.... here

> +				      AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
> +				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
> +	if (ret) {
> +		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
> +			__func__, ret);
> +		goto exit;
> +	}
> +
> +	lpcm_fmt.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> +	lpcm_fmt.endian = pcfg->usb_cfg.endian;
> +	ret = q6afe_port_set_param_v2(port, &lpcm_fmt,
> +				      AFE_PARAM_ID_USB_AUDIO_DEV_LPCM_FMT,
> +				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(lpcm_fmt));
> +	if (ret) {
> +		dev_err(port->afe->dev, "%s: AFE device param cmd LPCM_FMT failed %d\n",
> +			__func__, ret);
> +		goto exit;
> +	}
> +
> +	svc_int.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> +	svc_int.svc_interval = pcfg->usb_cfg.service_interval;
> +	ret = q6afe_port_set_param_v2(port, &svc_int,
> +				      AFE_PARAM_ID_USB_AUDIO_SVC_INTERVAL,
> +				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(svc_int));
> +	if (ret)
> +		dev_err(port->afe->dev, "%s: AFE device param cmd svc_interval failed %d\n",
> +			__func__, ret);
> +
> +exit:
> +	return ret;
> +}

> -#define AFE_PORT_MAX		129
> +#define AFE_PORT_MAX		137

does this mean 8 ports are reserved for USB?

Or is this 137 just a random index coming from the AFE design?

Re: [PATCH v9 11/34] ASoC: qcom: qdsp6: Add USB backend ASoC driver for Q6

[Pierre-Louis Bossart]

> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/device.h>

alphabetical order?

> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/iommu.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dma-map-ops.h>
> +
> +#include <sound/pcm.h>
> +#include <sound/soc.h>
> +#include <sound/soc-usb.h>
> +#include <sound/pcm_params.h>
> +#include <sound/asound.h>
> +#include <sound/q6usboffload.h>
> +
> +#include "q6dsp-lpass-ports.h"
> +#include "q6afe.h"
> +
> +#define SID_MASK	0xF

Prefix? e.g. Q6_USB_SID_MASK?

> +
> +struct q6usb_port_data {
> +	struct q6afe_usb_cfg usb_cfg;
> +	struct snd_soc_usb *usb;
> +	struct q6usb_offload priv;
> +	int active_idx;

index of what?

> +};
> +
> +static const struct snd_soc_dapm_widget q6usb_dai_widgets[] = {
> +	SND_SOC_DAPM_HP("USB_RX_BE", NULL),
> +};
> +
> +static const struct snd_soc_dapm_route q6usb_dapm_routes[] = {
> +	{"USB Playback", NULL, "USB_RX_BE"},
> +};
> +
> +static int q6usb_hw_params(struct snd_pcm_substream *substream,
> +			   struct snd_pcm_hw_params *params,
> +			   struct snd_soc_dai *dai)
> +{
> +	return 0;
> +}
> +
> +static const struct snd_soc_dai_ops q6usb_ops = {
> +	.hw_params = q6usb_hw_params,
> +};
> +
> +static struct snd_soc_dai_driver q6usb_be_dais[] = {
> +	{
> +		.playback = {
> +			.stream_name = "USB BE RX",
> +			.rates = SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |
> +				SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 |
> +				SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
> +				SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000 |
> +				SNDRV_PCM_RATE_192000,
> +			.formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
> +				SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_U16_BE |
> +				SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE |
> +				SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_U24_BE,
> +			.channels_min = 1,
> +			.channels_max = 2,
> +			.rate_max =     192000,
> +			.rate_min =	8000,
> +		},
> +		.id = USB_RX,
> +		.name = "USB_RX_BE",
> +		.ops = &q6usb_ops,
> +	},
> +};

This is a bit confusing.

In patch 9/34 you have a

static struct snd_soc_dai_driver q6dsp_audio_fe_dais[] = {

but this was not described anywhere in your cover letter.

or maybe this referred to the 'Q6AFE "cpu"', in which case you have
inconsistent naming between q6dsp and q6afe?

> +
> +static int q6usb_audio_ports_of_xlate_dai_name(struct snd_soc_component *component,
> +					const struct of_phandle_args *args,
> +					const char **dai_name)
> +{
> +	int id = args->args[0];
> +	int ret = -EINVAL;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(q6usb_be_dais); i++) {
> +		if (q6usb_be_dais[i].id == id) {
> +			*dai_name = q6usb_be_dais[i].name;
> +			ret = 0;
> +			break;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
> +			struct snd_soc_usb_device *sdev, bool connected)
> +{
> +	struct q6usb_port_data *data;
> +
> +	if (!usb->component)
> +		return -ENODEV;
> +
> +	data = dev_get_drvdata(usb->component->dev);
> +
> +	if (connected) {
> +		/* We only track the latest USB headset plugged in */
> +		data->active_idx = sdev->card_idx;
> +	}
> +
> +	return 0;
> +}
> +
> +static int q6usb_component_probe(struct snd_soc_component *component)
> +{
> +	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
> +
> +	data->usb = snd_soc_usb_add_port(component->dev, &data->priv, q6usb_alsa_connection_cb);

There is a conceptual problem here wrt. resource allocation.

snd_soc_usb_add_port() uses devm_kzalloc().

This cannot be used in a component probe, this has to be used in a real
driver probe.

> +	if (IS_ERR(data->usb)) {
> +		dev_err(component->dev, "failed to add usb port\n");
> +		return -ENODEV;
> +	}
> +
> +	data->usb->component = component;
> +
> +	return 0;
> +}
> +
> +static void q6usb_component_remove(struct snd_soc_component *component)
> +{
> +	snd_soc_usb_remove_port(component->dev);

and here as well, this should free the "struct snd_soc_usb *usb"
allocated in the probe. relying on devm_ is not quite right. Or if you
use devm_, you have to call it from the platform driver .probe.

> +static struct platform_driver q6usb_dai_platform_driver = {
> +	.driver = {
> +		.name = "q6usb-dai",
> +		.of_match_table = of_match_ptr(q6usb_dai_device_id),
> +	},
> +	.probe = q6usb_dai_dev_probe,
> +	/*
> +	 * Remove not required as resources are cleaned up as part of
> +	 * component removal.  Others are device managed resources.
> +	 */
> +};
> +module_platform_driver(q6usb_dai_platform_driver);
> +
> +MODULE_DESCRIPTION("Q6 USB backend dai driver");
> +MODULE_LICENSE("GPL");

Re: [PATCH v9 07/34] ASoC: Add SOC USB APIs for adding an USB backend

[Pierre-Louis Bossart]

On 10/17/23 15:00, Wesley Cheng wrote:
> Some platforms may have support for offloading USB audio devices to a
> dedicated audio DSP.  Introduce a set of APIs that allow for management of
> USB sound card and PCM devices enumerated by the USB SND class driver.
> This allows for the ASoC components to be aware of what USB devices are

USB devices or USB endpoints? or both?

> available for offloading.

> +/**
> + * struct snd_soc_usb_device
> + * @card_idx - sound card index associated with USB device
> + * @chip_idx - USB sound chip array index
> + * @num_playback - number of playback streams
> + * @num_capture - number of capture streams

presumably excluding explicit feedback streams?

> + **/
> +struct snd_soc_usb_device {
> +	int card_idx;
> +	int chip_idx;
> +	int num_playback;
> +	int num_capture;
> +};
> +
> +/**
> + * struct snd_soc_usb
> + * @list - list head for SND SOC struct list
> + * @dev - USB backend device reference
> + * @component - reference to ASoC component
> + * @connection_status_cb - callback to notify connection events
> + * @priv_data - driver data
> + **/
> +struct snd_soc_usb {
> +	struct list_head list;
> +	struct device *dev;

usbdev for consistency with the API below?

> +	struct snd_soc_component *component;

could you use component only and infer the device from component->dev?

> +	int (*connection_status_cb)(struct snd_soc_usb *usb,
> +			struct snd_soc_usb_device *sdev, bool connected);
> +	void *priv_data;
> +};
> +
> +int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
> +int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
> +void *snd_soc_usb_get_priv_data(struct device *usbdev);
> +
> +struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,

struct device *usbdev for consistency ?

> +			int (*connection_cb)(struct snd_soc_usb *usb,
> +			struct snd_soc_usb_device *sdev, bool connected));
> +int snd_soc_usb_remove_port(struct device *dev);

struct device *usbdev for consistency ?


> +struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
> +			int (*connection_cb)(struct snd_soc_usb *usb,
> +			struct snd_soc_usb_device *sdev, bool connected))> +{
> +	struct snd_soc_usb *usb;
> +
> +	usb = devm_kzalloc(dev, sizeof(*usb), GFP_KERNEL);
> +	if (!usb)
> +		return ERR_PTR(-ENOMEM);
> +
> +	usb->connection_status_cb = connection_cb;
> +	usb->dev = dev;
> +	usb->priv_data = priv;
> +
> +	mutex_lock(&ctx_mutex);
> +	list_add_tail(&usb->list, &usb_ctx_list);
> +	mutex_unlock(&ctx_mutex);
> +
> +	return usb;
> +}
> +EXPORT_SYMBOL_GPL(snd_soc_usb_add_port);
> +
> +/**
> + * snd_soc_usb_remove_port() - Remove a USB backend port
> + * @dev: USB backend device
> + *
> + * Remove a USB backend device from USB SND SOC.  Memory is freed when USB
> + * backend is removed.

when the USB backend driver is unbound?

> + *
> + */
> +int snd_soc_usb_remove_port(struct device *dev)
> +{
> +	struct snd_soc_usb *ctx, *tmp;
> +
> +	mutex_lock(&ctx_mutex);
> +	list_for_each_entry_safe(ctx, tmp, &usb_ctx_list, list) {
> +		if (ctx->dev == dev) {
> +			list_del(&ctx->list);
> +			break;
> +		}
> +	}
> +	mutex_unlock(&ctx_mutex);
> +
> +	return 0;

can this return void to align with the current trend?

> +}
> +EXPORT_SYMBOL_GPL(snd_soc_usb_remove_port);
> +
> +/**
> + * snd_soc_usb_connect() - Notification of USB device connection
> + * @usbdev: USB bus device
> + * @card_idx: USB SND card instance
> + *
> + * Notify of a new USB SND device connection.  The card_idx can be used to
> + * handle how the DPCM backend selects, which device to enable USB offloading
> + * on.

card_idx is not used below, and I don't see how this relates to a
notification?

> + *
> + */
> +int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev)
> +{
> +	struct snd_soc_usb *ctx;
> +	struct device_node *node;
> +
> +	if (!usbdev)
> +		return -ENODEV;
> +
> +	node = snd_soc_find_phandle(usbdev);
> +	if (IS_ERR(node))
> +		return -ENODEV;
> +
> +	ctx = snd_soc_find_usb_ctx(node);
> +	of_node_put(node);
> +	if (!ctx)
> +		return -ENODEV;
> +
> +	if (ctx->connection_status_cb)
> +		ctx->connection_status_cb(ctx, sdev, true);
> +
> +	return 0;
> +}

Re: [PATCH v9 20/34] ALSA: usb-audio: Check for support for requested audio format

[Pierre-Louis Bossart]

On 10/17/23 15:00, Wesley Cheng wrote:
> Allow for checks on a specific USB audio device to see if a requested PCM
> format is supported.  This is needed for support for when playback is

This is needed for support when playback is

> initiated by the ASoC USB backend path.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/usb/card.c | 40 ++++++++++++++++++++++++++++++++++++++++
>  sound/usb/card.h | 11 +++++++++++
>  2 files changed, 51 insertions(+)
> 
> diff --git a/sound/usb/card.c b/sound/usb/card.c
> index c0b312e264bf..88f431917c15 100644
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -162,6 +162,46 @@ int snd_usb_unregister_platform_ops(void)
>  }
>  EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
>  
> +/*
> + * Checks to see if requested audio profile, i.e sample rate, # of
> + * channels, etc... is supported by the substream associated to the
> + * USB audio device.
> + */
> +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
> +			struct snd_pcm_hw_params *params, int direction)
> +{
> +	struct snd_usb_audio *chip;
> +	struct snd_usb_substream *subs = NULL;

useless init?

> +	struct snd_usb_stream *as;
> +	const struct audioformat *fmt;
> +
> +	/*
> +	 * Register mutex is held when populating and clearing usb_chip
> +	 * array.
> +	 */
> +	mutex_lock(&register_mutex);
> +	chip = usb_chip[card_idx];
> +	if (!chip) {
> +		mutex_unlock(&register_mutex);
> +		return NULL;
> +	}
> +
> +	if (enable[card_idx]) {
> +		list_for_each_entry(as, &chip->pcm_list, list) {
> +			subs = &as->substream[direction];
> +			fmt = snd_usb_find_substream_format(subs, params);
> +			if (fmt) {
> +				mutex_unlock(&register_mutex);
> +				return as;
> +			}
> +		}
> +	}
> +	mutex_unlock(&register_mutex);
> +
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(snd_usb_find_suppported_substream);
> +
>  /*
>   * disconnect streams
>   * called from usb_audio_disconnect()
> diff --git a/sound/usb/card.h b/sound/usb/card.h
> index 2884912adc96..e26292363cf0 100644
> --- a/sound/usb/card.h
> +++ b/sound/usb/card.h
> @@ -216,4 +216,15 @@ struct snd_usb_platform_ops {
>  
>  int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops);
>  int snd_usb_unregister_platform_ops(void);
> +
> +#if IS_ENABLED(CONFIG_SND_USB_AUDIO)
> +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
> +			struct snd_pcm_hw_params *params, int direction);
> +#else
> +static struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
> +			struct snd_pcm_hw_params *params, int direction)
> +{
> +	return NULL;
> +}
> +#endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
>  #endif /* __USBAUDIO_CARD_H */

Re: [PATCH v9 21/34] ASoC: usb: Add PCM format check API for USB backend

[Pierre-Louis Bossart]

On 10/17/23 15:00, Wesley Cheng wrote:
> Introduce a check for if a particular PCM format is supported by the USB

Introduce a helper to check if a ...

> audio device connected.  If the USB audio device does not have an audio
> profile which can support the requested format, then notify the USB
> backend.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  include/sound/soc-usb.h |  3 +++
>  sound/soc/soc-usb.c     | 13 +++++++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
> index 58c686f4f7ba..c6ddc055c4cd 100644
> --- a/include/sound/soc-usb.h
> +++ b/include/sound/soc-usb.h
> @@ -37,6 +37,9 @@ struct snd_soc_usb {
>  	void *priv_data;
>  };
>  
> +int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
> +			int direction);
> +
>  int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
>  int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
>  void *snd_soc_usb_find_priv_data(struct device *usbdev);
> diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
> index 73b1bcc3b506..7407678a993e 100644
> --- a/sound/soc/soc-usb.c
> +++ b/sound/soc/soc-usb.c
> @@ -63,6 +63,19 @@ void *snd_soc_usb_find_priv_data(struct device *dev)
>  }
>  EXPORT_SYMBOL_GPL(snd_soc_usb_find_priv_data);
>  
> +int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
> +			int direction)
> +{
> +	struct snd_usb_stream *as;
> +
> +	as = snd_usb_find_suppported_substream(card_idx, params, direction);
> +	if (!as)
> +		return -EOPNOTSUPP;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(snd_soc_usb_find_format);

Is this the right way to check for formats?

formats are defined within the scope of an endpoint, and those endpoints
are themselves defined within the scope of an interface?

I don't see a notion of endpoint here. Does this assume all endpoints
are valid, or maybe the existence of a single endpoint in a device?

Confused.

Re: [PATCH v9 23/34] ALSA: usb-audio: Prevent starting of audio stream if in use

[Pierre-Louis Bossart]

On 10/17/23 15:00, Wesley Cheng wrote:
> With USB audio offloading, an audio session is started from the ASoC
> platform sound card and PCM devices.  Likewise, the USB SND path is still
> readily available for use, in case the non-offload path is desired.  In
> order to prevent the two entities from attempting to use the USB bus,
> introduce a flag that determines when either paths are in use.
> 
> If a PCM device is already in use, the check will return an error to
> userspace notifying that the stream is currently busy.  This ensures that
> only one path is using the USB substream.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/usb/card.h                  |  1 +
>  sound/usb/pcm.c                   | 19 +++++++++++++++++--
>  sound/usb/qcom/qc_audio_offload.c | 15 ++++++++++++++-

should this be split in a generic part and a more specific qcom patch?

>  3 files changed, 32 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/usb/card.h b/sound/usb/card.h
> index e26292363cf0..01f7e10f30f4 100644
> --- a/sound/usb/card.h
> +++ b/sound/usb/card.h
> @@ -164,6 +164,7 @@ struct snd_usb_substream {
>  	unsigned int pkt_offset_adj;	/* Bytes to drop from beginning of packets (for non-compliant devices) */
>  	unsigned int stream_offset_adj;	/* Bytes to drop from beginning of stream (for non-compliant devices) */
>  
> +	unsigned int opened:1;		/* pcm device opened */
>  	unsigned int running: 1;	/* running status */
>  	unsigned int period_elapsed_pending;	/* delay period handling */
>  
> diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
> index 3adb09ce1702..c2cb52cd5d23 100644
> --- a/sound/usb/pcm.c
> +++ b/sound/usb/pcm.c
> @@ -1241,8 +1241,15 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
>  	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
>  	struct snd_pcm_runtime *runtime = substream->runtime;
>  	struct snd_usb_substream *subs = &as->substream[direction];
> +	struct snd_usb_audio *chip = subs->stream->chip;
>  	int ret;
>  
> +	mutex_lock(&chip->mutex);
> +	if (subs->opened) {
> +		mutex_unlock(&chip->mutex);
> +		return -EBUSY;
> +	}
> +
>  	runtime->hw = snd_usb_hardware;
>  	/* need an explicit sync to catch applptr update in low-latency mode */
>  	if (direction == SNDRV_PCM_STREAM_PLAYBACK &&
> @@ -1259,13 +1266,17 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
>  
>  	ret = setup_hw_info(runtime, subs);
>  	if (ret < 0)
> -		return ret;
> +		goto out;
>  	ret = snd_usb_autoresume(subs->stream->chip);
>  	if (ret < 0)
> -		return ret;
> +		goto out;
>  	ret = snd_media_stream_init(subs, as->pcm, direction);
>  	if (ret < 0)
>  		snd_usb_autosuspend(subs->stream->chip);
> +	subs->opened = 1;
> +out:
> +	mutex_unlock(&chip->mutex);
> +
>  	return ret;
>  }
>  
> @@ -1274,6 +1285,7 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
>  	int direction = substream->stream;
>  	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
>  	struct snd_usb_substream *subs = &as->substream[direction];
> +	struct snd_usb_audio *chip = subs->stream->chip;
>  	int ret;
>  
>  	snd_media_stop_pipeline(subs);
> @@ -1287,6 +1299,9 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
>  
>  	subs->pcm_substream = NULL;
>  	snd_usb_autosuspend(subs->stream->chip);
> +	mutex_lock(&chip->mutex);
> +	subs->opened = 0;
> +	mutex_unlock(&chip->mutex);
>  
>  	return 0;
>  }
> diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
> index 320ce3a6688f..bd6b84f72c74 100644
> --- a/sound/usb/qcom/qc_audio_offload.c
> +++ b/sound/usb/qcom/qc_audio_offload.c
> @@ -1413,12 +1413,17 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
>  		goto response;
>  	}
>  
> +	mutex_lock(&chip->mutex);
>  	if (req_msg->enable) {
> -		if (info_idx < 0 || chip->system_suspend) {
> +		if (info_idx < 0 || chip->system_suspend || subs->opened) {
>  			ret = -EBUSY;
> +			mutex_unlock(&chip->mutex);
> +
>  			goto response;
>  		}
> +		subs->opened = 1;
>  	}
> +	mutex_unlock(&chip->mutex);
>  
>  	if (req_msg->service_interval_valid) {
>  		ret = get_data_interval_from_si(subs,
> @@ -1440,6 +1445,11 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
>  		if (!ret)
>  			ret = prepare_qmi_response(subs, req_msg, &resp,
>  					info_idx);
> +		if (ret < 0) {
> +			mutex_lock(&chip->mutex);
> +			subs->opened = 0;
> +			mutex_unlock(&chip->mutex);
> +		}
>  	} else {
>  		info = &uadev[pcm_card_num].info[info_idx];
>  		if (info->data_ep_pipe) {
> @@ -1463,6 +1473,9 @@ static void handle_uaudio_stream_req(struct qmi_handle *handle,
>  		}
>  
>  		disable_audio_stream(subs);
> +		mutex_lock(&chip->mutex);
> +		subs->opened = 0;
> +		mutex_unlock(&chip->mutex);
>  	}
>  
>  response:

Re: [PATCH v9 26/34] ASoC: qcom: qdsp6: q6afe: Split USB AFE dev_token param into separate API

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> The Q6USB backend can carry information about the available USB SND cards
> and PCM devices discovered on the USB bus.  The dev_token field is used by
> the audio DSP to notify the USB offload driver of which card and PCM index
> to enable playback on.  Separate this into a dedicated API, so the USB
> backend can set the dev_token accordingly.  The audio DSP does not utilize
> this information until the AFE port start command is sent, which is done
> during the PCM prepare phase.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/soc/qcom/qdsp6/q6afe.c | 49 +++++++++++++++++++++++++-----------
>  sound/soc/qcom/qdsp6/q6afe.h |  1 +
>  2 files changed, 36 insertions(+), 14 deletions(-)
> 
> diff --git a/sound/soc/qcom/qdsp6/q6afe.c b/sound/soc/qcom/qdsp6/q6afe.c
> index 72c4e6fe20c4..f09a756246f8 100644
> --- a/sound/soc/qcom/qdsp6/q6afe.c
> +++ b/sound/soc/qcom/qdsp6/q6afe.c
> @@ -1394,10 +1394,42 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port,
>  }
>  EXPORT_SYMBOL_GPL(q6afe_tdm_port_prepare);
>  
> -static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
> +/**
> + * afe_port_send_usb_dev_param() - Send USB dev token
> + *
> + * @port: Instance of afe port
> + * @cardidx: USB SND card index to reference
> + * @pcmidx: USB SND PCM device index to reference
> + *
> + * The USB dev token carries information about which USB SND card instance and
> + * PCM device to execute the offload on.  This information is carried through
> + * to the stream enable QMI request, which is handled by the offload class
> + * driver.  The information is parsed to determine which USB device to query
> + * the required resources for.
> + */
> +int afe_port_send_usb_dev_param(struct q6afe_port *port, int cardidx, int pcmidx)
>  {
> -	union afe_port_config *pcfg = &port->port_cfg;
>  	struct afe_param_id_usb_audio_dev_params usb_dev;
> +	int ret;
> +
> +	memset(&usb_dev, 0, sizeof(usb_dev));
> +
> +	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> +	usb_dev.dev_token = (cardidx << 16) | (pcmidx << 8);
> +	ret = q6afe_port_set_param_v2(port, &usb_dev,
> +				AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
> +				AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
> +	if (ret)
> +		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
> +			__func__, ret);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(afe_port_send_usb_dev_param);
> +
> +static int afe_port_send_usb_params(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
> +{
> +	union afe_port_config *pcfg = &port->port_cfg;
>  	struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
>  	struct afe_param_id_usb_audio_svc_interval svc_int;
>  	int ret = 0;
> @@ -1408,20 +1440,9 @@ static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb
>  		goto exit;
>  	}
>  
> -	memset(&usb_dev, 0, sizeof(usb_dev));
>  	memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
>  	memset(&svc_int, 0, sizeof(svc_int));
>  
> -	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
> -	ret = q6afe_port_set_param_v2(port, &usb_dev,
> -				      AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
> -				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
> -	if (ret) {
> -		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
> -			__func__, ret);
> -		goto exit;
> -	}
> -

this feels like a questionable patch split. Why not introduce the new
helper earlier and avoid adding code then modifying the same code?

>  	lpcm_fmt.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
>  	lpcm_fmt.endian = pcfg->usb_cfg.endian;
>  	ret = q6afe_port_set_param_v2(port, &lpcm_fmt,
> @@ -1463,7 +1484,7 @@ void q6afe_usb_port_prepare(struct q6afe_port *port,
>  	pcfg->usb_cfg.num_channels = cfg->num_channels;
>  	pcfg->usb_cfg.bit_width = cfg->bit_width;
>  
> -	afe_port_send_usb_dev_param(port, cfg);
> +	afe_port_send_usb_params(port, cfg);
>  }
>  EXPORT_SYMBOL_GPL(q6afe_usb_port_prepare);
>  
> diff --git a/sound/soc/qcom/qdsp6/q6afe.h b/sound/soc/qcom/qdsp6/q6afe.h
> index ef47b4ae9e27..2ce5ba9dba69 100644
> --- a/sound/soc/qcom/qdsp6/q6afe.h
> +++ b/sound/soc/qcom/qdsp6/q6afe.h
> @@ -263,6 +263,7 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port, struct q6afe_tdm_cfg *cfg);
>  void q6afe_cdc_dma_port_prepare(struct q6afe_port *port,
>  				struct q6afe_cdc_dma_cfg *cfg);
>  
> +int afe_port_send_usb_dev_param(struct q6afe_port *port, int cardidx, int pcmidx);
>  int q6afe_port_set_sysclk(struct q6afe_port *port, int clk_id,
>  			  int clk_src, int clk_root,
>  			  unsigned int freq, int dir);

Re: [PATCH v9 27/34] ALSA: usb-audio: qcom: Populate PCM and USB chip information

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> Currently, only the index to the USB SND card array is passed to the USB
> backend.  Pass through more information, specifically the USB SND card
> number and the number of PCM devices available.  This allows for the DPCM
> backend to determine what USB resources are available during situations,
> such as USB audio offloading.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/usb/qcom/qc_audio_offload.c | 21 ++++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
> index bd6b84f72c74..ae74098b41f5 100644
> --- a/sound/usb/qcom/qc_audio_offload.c
> +++ b/sound/usb/qcom/qc_audio_offload.c
> @@ -173,6 +173,21 @@ enum usb_qmi_audio_format {
>  	USB_QMI_PCM_FORMAT_U32_BE,
>  };
>  
> +static int usb_qmi_get_pcm_num(struct snd_usb_audio *chip, int direction)
> +{
> +	struct snd_usb_substream *subs = NULL;
> +	struct snd_usb_stream *as;
> +	int count = 0;
> +
> +	list_for_each_entry(as, &chip->pcm_list, list) {
> +		subs = &as->substream[direction];
> +		if (subs->ep_num)
> +			count++;
> +	}
> +
> +	return count;
> +}
> +
>  static enum usb_qmi_audio_device_speed_enum_v01
>  get_speed_info(enum usb_device_speed udev_speed)
>  {
> @@ -1592,6 +1607,8 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)
>  
>  	sdev->card_idx = chip->card->number;
>  	sdev->chip_idx = chip->index;
> +	sdev->num_playback = usb_qmi_get_pcm_num(chip, 0);
> +	sdev->num_capture = usb_qmi_get_pcm_num(chip, 1);
>  	uadev[chip->card->number].sdev = sdev;
>  
>  	uaudio_qdev->last_card_num = chip->card->number;
> @@ -1706,10 +1723,8 @@ static void qc_usb_audio_offload_disconnect(struct snd_usb_audio *chip)
>  	mutex_unlock(&chip->mutex);
>  
>  	atomic_dec(&uaudio_qdev->qdev_in_use);
> -	if (!atomic_read(&uaudio_qdev->qdev_in_use)) {
> -		snd_soc_usb_disconnect(usb_get_usb_backend(udev));

this also feels like a patch split issue, removing this
snd_soc_usb_disconnect() has nothing to do with the "populate PCM and
USB chip information" ?

> +	if (!atomic_read(&uaudio_qdev->qdev_in_use))
>  		qc_usb_audio_cleanup_qmi_dev();
> -	}
>  	mutex_unlock(&qdev_mutex);
>  }
>  

Re: [PATCH v9 28/34] ASoC: qcom: qdsp6: Add support to track available USB PCM devices

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> The USB backend should know about which sound resources are being shared
> between the ASoC and USB SND paths.  This can be utilized to properly
> select and maintain the offloading devices.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/soc/qcom/qdsp6/q6usb.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
> index 329a7d4a3c01..d697cbe7f184 100644
> --- a/sound/soc/qcom/qdsp6/q6usb.c
> +++ b/sound/soc/qcom/qdsp6/q6usb.c
> @@ -25,10 +25,18 @@
>  
>  #define SID_MASK	0xF
>  
> +struct q6usb_status {
> +	unsigned int num_pcm;

how would one know which ones are capture and which ones are playback?

This really looks like a playback-only assumption, despite earlier
mentions of capture supported.

> +	unsigned int chip_index;
> +	unsigned int pcm_index;
> +};
> +
>  struct q6usb_port_data {
>  	struct q6afe_usb_cfg usb_cfg;
>  	struct snd_soc_usb *usb;
>  	struct q6usb_offload priv;
> +	unsigned long available_card_slot;
> +	struct q6usb_status status[SNDRV_CARDS];
>  	int active_idx;
>  };
>  
> @@ -110,6 +118,14 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
>  	if (connected) {
>  		/* We only track the latest USB headset plugged in */
>  		data->active_idx = sdev->card_idx;
> +
> +		set_bit(sdev->card_idx, &data->available_card_slot);
> +		data->status[sdev->card_idx].num_pcm = sdev->num_playback;

there you go...

> +		data->status[sdev->card_idx].chip_index = sdev->chip_idx;
> +	} else {
> +		clear_bit(sdev->card_idx, &data->available_card_slot);
> +		data->status[sdev->card_idx].num_pcm = 0;
> +		data->status[sdev->card_idx].chip_index = 0;
>  	}
>  
>  	return 0;

Re: [PATCH v9 29/34] ASoC: qcom: qdsp6: Add SND kcontrol to select offload device

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> Expose a kcontrol on the platform sound card, which will allow for
> userspace to determine which USB card number and PCM device to offload.
> This allows for userspace to potentially tag an alternate path for a
> specific USB SND card and PCM device.  Previously, control was absent, and
> the offload path would be enabled on the last USB SND device which was
> connected.  This logic will continue to be applicable if no mixer input is
> received for specific device selection.
> 
> An example to configure the offload device using tinymix:
> tinymix -D 0 set 'Q6USB offload SND device select' 1 0
> 
> The above will set the Q6AFE device token to choose offload on card#1 and
> pcm#0.  Device selection is made possible by setting the Q6AFE device
> token.  The audio DSP utilizes this parameter, and will pass this field
> back to the USB offload driver within the QMI stream requests.

This still begs the question on how userspace would figure what the
card1 is and which endpoint is used when PCM0 is opened?

Ideally userpace would not have to know anything about "Q6USB".
Presumably when other vendors expose their USB offload solution, we
would want a generic control name, no?

Jaroslav should chime in on this one :-)


> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/soc/qcom/qdsp6/q6usb.c | 125 ++++++++++++++++++++++++++++++++++-
>  1 file changed, 122 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
> index d697cbe7f184..a95276b7d91d 100644
> --- a/sound/soc/qcom/qdsp6/q6usb.c
> +++ b/sound/soc/qcom/qdsp6/q6usb.c
> @@ -14,6 +14,7 @@
>  #include <linux/dma-map-ops.h>
>  
>  #include <sound/pcm.h>
> +#include <sound/control.h>
>  #include <sound/soc.h>
>  #include <sound/soc-usb.h>
>  #include <sound/pcm_params.h>
> @@ -35,9 +36,12 @@ struct q6usb_port_data {
>  	struct q6afe_usb_cfg usb_cfg;
>  	struct snd_soc_usb *usb;
>  	struct q6usb_offload priv;
> +	struct mutex mutex;

missing comment on what this protects. "mutex" is really a poor
choice/name if I am honest.

>  	unsigned long available_card_slot;
>  	struct q6usb_status status[SNDRV_CARDS];
> -	int active_idx;
> +	bool idx_valid;
> +	int sel_card_idx;
> +	int sel_pcm_idx;
>  };

> +/* Build a mixer control for a UAC connector control (jack-detect) */
> +static void q6usb_connector_control_init(struct snd_soc_component *component)
> +{
> +	int ret;
> +
> +	ret = snd_ctl_add(component->card->snd_card,
> +				snd_ctl_new1(&q6usb_offload_dev_ctrl, component));
> +	if (ret < 0)
> +		return;

that error handling does not seem terribly useful...

> +}
> +
>  static int q6usb_audio_ports_of_xlate_dai_name(struct snd_soc_component *component,
>  					const struct of_phandle_args *args,
>  					const char **dai_name)
> @@ -115,9 +227,11 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
>  
>  	data = dev_get_drvdata(usb->component->dev);
>  
> +	mutex_lock(&data->mutex);
>  	if (connected) {
>  		/* We only track the latest USB headset plugged in */
> -		data->active_idx = sdev->card_idx;
> +		if (!data->idx_valid || data->sel_card_idx < 0)
> +			data->sel_card_idx = sdev->card_idx;
>  
>  		set_bit(sdev->card_idx, &data->available_card_slot);
>  		data->status[sdev->card_idx].num_pcm = sdev->num_playback;
> @@ -127,6 +241,7 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
>  		data->status[sdev->card_idx].num_pcm = 0;
>  		data->status[sdev->card_idx].chip_index = 0;
>  	}
> +	mutex_unlock(&data->mutex);
>  
>  	return 0;
>  }
> @@ -135,6 +250,8 @@ static int q6usb_component_probe(struct snd_soc_component *component)
>  {
>  	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
>  
> +	q6usb_connector_control_init(component);
> +
>  	data->usb = snd_soc_usb_add_port(component->dev, &data->priv, q6usb_alsa_connection_cb);
>  	if (IS_ERR(data->usb)) {
>  		dev_err(component->dev, "failed to add usb port\n");
> @@ -189,6 +306,8 @@ static int q6usb_dai_dev_probe(struct platform_device *pdev)
>  
>  	data->priv.domain = iommu_get_domain_for_dev(&pdev->dev);
>  
> +	mutex_init(&data->mutex);
> +
>  	data->priv.dev = dev;
>  	dev_set_drvdata(dev, data);
>  

Re: [PATCH v9 30/34] ASoC: qcom: qdsp6: Add SND kcontrol for fetching offload status

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> Add a kcontrol to the platform sound card to fetch the current offload
> status.  This can allow for userspace to ensure/check which USB SND
> resources are actually busy versus having to attempt opening the USB SND
> devices, which will result in an error if offloading is active.

I think I mentioned this a while back, but why not add the status in the
USB card itself? That's a generic component that all userspace agent
could query. Having a QCOM-specific control doesn't make the life of
userspace easier IMHO.

Re: [PATCH v9 31/34] ASoC: qcom: qdsp6: Add headphone jack for offload connection status

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> The headphone jack framework has a well defined infrastructure for
> notifying userspace entities through input devices.  Expose a jack device
> that carries information about if an offload capable device is connected.
> Applications can further identify specific offloading information through
> other SND kcontrols.

maybe I am mistaken but if you expose a jack, is there not a need to
implement a .set_jack callback in the component driver?

>  static void q6usb_connector_control_init(struct snd_soc_component *component)
>  {
> +	struct q6usb_port_data *data = dev_get_drvdata(component->dev);
>  	int ret;
>  
>  	ret = snd_ctl_add(component->card->snd_card,
> @@ -290,6 +293,11 @@ static void q6usb_connector_control_init(struct snd_soc_component *component)
>  				snd_ctl_new1(&q6usb_offload_dev_ctrl, component));
>  	if (ret < 0)
>  		return;
> +
> +	ret = snd_soc_card_jack_new(component->card, "USB offload",
> +					SND_JACK_HEADSET, &data->hs_jack);
> +	if (ret)
> +		return;

Also if you report a jack then usually there's a difference between
SND_JACK_HEADPHONE and SND_JACK_HEADSET - where the latter case hints at
capture support.

Clearly you don't have capture support for now, so should this be
SND_JACK_HEADPHONE ?

I must say I still don't get how this entire patchset would be used, for
playback userspace *may* use offload but for any sort of voice call then
userspace *shall* rely on the legacy USB card. Is this not a
show-stopper for CRAS or PipeWire?

Re: [PATCH v9 33/34] ALSA: usb-audio: Allow for rediscovery of connected USB SND devices

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> In case of notifying SND platform drivers of connection events, some of
> these use cases, such as offloading, require an ASoC USB backend device to
> be initialized before the events can be handled.  If the USB backend device
> has not yet been probed, this leads to missing initial USB audio device
> connection events.
> 
> Expose an API that traverses the usb_chip array for connected devices, and
> to call the respective connection callback registered to the SND platform
> driver.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  sound/usb/card.c | 19 +++++++++++++++++++
>  sound/usb/card.h |  2 ++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/sound/usb/card.c b/sound/usb/card.c
> index 88f431917c15..7d3f470754ca 100644
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -202,6 +202,25 @@ struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
>  }
>  EXPORT_SYMBOL_GPL(snd_usb_find_suppported_substream);
>  
> +/*
> + * in case the platform driver was not ready at the time of USB SND
> + * device connect, expose an API to discover all connected USB devices
> + * so it can populate any dependent resources/structures.

it's really unclear how the "platform driver was not ready at the time
of USB SND device connect" condition can be detected. It's my
understanding that we should never assume any specific order or timing
on platform driver probes. And things should also work if a driver is
unbound.

> + */
> +void snd_usb_rediscover_devices(void)
> +{
> +	int i;
> +
> +	mutex_lock(&register_mutex);
> +	for (i = 0; i < SNDRV_CARDS; i++) {
> +		if (usb_chip[i])
> +			if (platform_ops && platform_ops->connect_cb)
> +				platform_ops->connect_cb(usb_chip[i]);
> +	}
> +	mutex_unlock(&register_mutex);
> +}
> +EXPORT_SYMBOL_GPL(snd_usb_rediscover_devices);
> +
>  /*
>   * disconnect streams
>   * called from usb_audio_disconnect()
> diff --git a/sound/usb/card.h b/sound/usb/card.h
> index 01f7e10f30f4..c0aeda17ed69 100644
> --- a/sound/usb/card.h
> +++ b/sound/usb/card.h
> @@ -221,11 +221,13 @@ int snd_usb_unregister_platform_ops(void);
>  #if IS_ENABLED(CONFIG_SND_USB_AUDIO)
>  struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
>  			struct snd_pcm_hw_params *params, int direction);
> +void snd_usb_rediscover_devices(void);
>  #else
>  static struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
>  			struct snd_pcm_hw_params *params, int direction)
>  {
>  	return NULL;
>  }
> +static void snd_usb_rediscover_devices(void) { }
>  #endif /* IS_ENABLED(CONFIG_SND_USB_AUDIO) */
>  #endif /* __USBAUDIO_CARD_H */

Re: [PATCH v9 34/34] ASoC: usb: Rediscover USB SND devices on USB port add

[Pierre-Louis Bossart]

On 10/17/23 15:01, Wesley Cheng wrote:
> In case the USB backend device has not been initialized/probed, USB SND
> device connections can still occur.  When the USB backend is eventually
> made available, previous USB SND device connections are not communicated to
> the USB backend.  Call snd_usb_rediscover_devices() to generate the connect
> callbacks for all USB SND devices connected.  This will allow for the USB
> backend to be updated with the current set of devices available.
> 
> The chip array entries are all populated and removed while under the
> register_mutex, so going over potential race conditions:
> 
> Thread#1:
>   q6usb_component_probe()
>     --> snd_soc_usb_add_port()
>       --> snd_usb_rediscover_devices()
>         --> mutex_lock(register_mutex)
> 
> Thread#2
>   --> usb_audio_disconnect()
>     --> mutex_lock(register_mutex)
> 
> So either thread#1 or thread#2 will complete first.  If
> 
> Thread#1 completes before thread#2:
>   SOC USB will notify DPCM backend of the device connection.  Shortly
>   after, once thread#2 runs, we will get a disconnect event for the
>   connected device.
> 
> Thread#2 completes before thread#1:
>   Then during snd_usb_rediscover_devices() it won't notify of any
>   connection for that particular chip index.
Looks like you are assuming the regular USB audio stuff is probed first?

What if it's not the case? Have you tested with a manual 'blacklist' and
"modprobe" sequence long after all the DSP stuff is initialized?

It really reminds me of audio+display issues, and the same opens apply IMHO.

Re: [PATCH v9 19/34] ALSA: usb-audio: qcom: Introduce QC USB SND offloading support

[Pierre-Louis Bossart]

> +config SND_USB_AUDIO_QMI
> +	tristate "Qualcomm Audio Offload driver"
> +	depends on QCOM_QMI_HELPERS && SND_USB_AUDIO && USB_XHCI_SIDEBAND
> +	select SND_PCM

This select is not needed:

config SND_USB_AUDIO
	tristate "USB Audio/MIDI driver"
	select SND_HWDEP
	select SND_RAWMIDI
	select SND_PCM


> +#include <linux/ctype.h>
> +#include <linux/moduleparam.h>
> +#include <linux/module.h>
> +#include <linux/usb.h>
> +#include <linux/init.h>

alphabetical order?

> +#include <linux/usb/hcd.h>
> +#include <linux/usb/xhci-sideband.h>
> +#include <linux/usb/quirks.h>
> +#include <linux/usb/audio.h>
> +#include <linux/usb/audio-v2.h>
> +#include <linux/usb/audio-v3.h>
> +#include <linux/soc/qcom/qmi.h>
> +#include <linux/iommu.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dma-map-ops.h>
> +#include <sound/q6usboffload.h>
> +
> +#include <sound/control.h>
> +#include <sound/core.h>
> +#include <sound/info.h>
> +#include <sound/pcm.h>
> +#include <sound/pcm_params.h>
> +#include <sound/initval.h>
> +
> +#include <sound/soc.h>
> +#include <sound/soc-usb.h>
> +#include "../usbaudio.h"
> +#include "../card.h"
> +#include "../endpoint.h"
> +#include "../helper.h"
> +#include "../pcm.h"
> +#include "../format.h"
> +#include "../power.h"
> +#include "usb_audio_qmi_v01.h"
> +
> +/* Stream disable request timeout during USB device disconnect */
> +#define DEV_RELEASE_WAIT_TIMEOUT 10000 /* in ms */

DEV_RELEASE_WAIT_TIMEOUT_MS?

why 10s btw?

> +
> +/* Data interval calculation parameters */
> +#define BUS_INTERVAL_FULL_SPEED 1000 /* in us */
> +#define BUS_INTERVAL_HIGHSPEED_AND_ABOVE 125 /* in us */
> +#define MAX_BINTERVAL_ISOC_EP 16
> +
> +#define QMI_STREAM_REQ_CARD_NUM_MASK 0xffff0000
> +#define QMI_STREAM_REQ_DEV_NUM_MASK 0xff00
> +#define QMI_STREAM_REQ_DIRECTION 0xff
> +
> +/* iommu resource parameters and management */
> +#define PREPEND_SID_TO_IOVA(iova, sid) ((u64)(((u64)(iova)) | \
> +					(((u64)sid) << 32)))
> +#define IOVA_BASE 0x1000
> +#define IOVA_XFER_RING_BASE (IOVA_BASE + PAGE_SIZE * (SNDRV_CARDS + 1))
> +#define IOVA_XFER_BUF_BASE (IOVA_XFER_RING_BASE + PAGE_SIZE * SNDRV_CARDS * 32)
> +#define IOVA_XFER_RING_MAX (IOVA_XFER_BUF_BASE - PAGE_SIZE)
> +#define IOVA_XFER_BUF_MAX (0xfffff000 - PAGE_SIZE)
> +
> +#define MAX_XFER_BUFF_LEN (24 * PAGE_SIZE)
> +
> +struct iova_info {
> +	struct list_head list;
> +	unsigned long start_iova;
> +	size_t size;
> +	bool in_use;
> +};
> +
> +struct intf_info {
> +	unsigned long data_xfer_ring_va;
> +	size_t data_xfer_ring_size;
> +	unsigned long sync_xfer_ring_va;
> +	size_t sync_xfer_ring_size;
> +	unsigned long xfer_buf_va;
> +	size_t xfer_buf_size;
> +	phys_addr_t xfer_buf_pa;
> +	unsigned int data_ep_pipe;
> +	unsigned int sync_ep_pipe;
> +	u8 *xfer_buf;
> +	u8 intf_num;
> +	u8 pcm_card_num;
> +	u8 pcm_dev_num;
> +	u8 direction;
> +	bool in_use;
> +};
> +
> +struct uaudio_qmi_dev {
> +	struct device *dev;
> +	u32 sid;
> +	u32 intr_num;
> +	struct xhci_ring *sec_ring;
> +	struct iommu_domain *domain;
> +
> +	/* list to keep track of available iova */
> +	struct list_head xfer_ring_list;
> +	size_t xfer_ring_iova_size;
> +	unsigned long curr_xfer_ring_iova;
> +	struct list_head xfer_buf_list;
> +	size_t xfer_buf_iova_size;
> +	unsigned long curr_xfer_buf_iova;
> +
> +	/* bit fields representing pcm card enabled */
> +	unsigned long card_slot;
> +	/* indicate event ring mapped or not */
> +	bool er_mapped;
> +	/* reference count to number of possible consumers */
> +	atomic_t qdev_in_use;
> +	/* idx to last udev card number plugged in */
> +	unsigned int last_card_num;
> +};
> +
> +struct uaudio_dev {
> +	struct usb_device *udev;
> +	/* audio control interface */
> +	struct usb_host_interface *ctrl_intf;
> +	unsigned int usb_core_id;
> +	atomic_t in_use;
> +	struct kref kref;
> +	wait_queue_head_t disconnect_wq;
> +
> +	/* interface specific */
> +	int num_intf;
> +	struct intf_info *info;
> +	struct snd_usb_audio *chip;
> +
> +	/* xhci sideband */
> +	struct xhci_sideband *sb;
> +
> +	/* SoC USB device */
> +	struct snd_soc_usb_device *sdev;
> +};

these structures feel like a set of kitchen sinks... Or a possible
copy-paste, I don't know how one would add all these pointers on their own?

Do you really need all this? Is there not a way to use existing
substructures?


> +static int get_data_interval_from_si(struct snd_usb_substream *subs,
> +	u32 service_interval)
> +{
> +	unsigned int bus_intval, bus_intval_mult, binterval;
> +
> +	if (subs->dev->speed >= USB_SPEED_HIGH)
> +		bus_intval = BUS_INTERVAL_HIGHSPEED_AND_ABOVE;
> +	else
> +		bus_intval = BUS_INTERVAL_FULL_SPEED;
> +
> +	if (service_interval % bus_intval)
> +		return -EINVAL;
> +
> +	bus_intval_mult = service_interval / bus_intval;
> +	binterval = ffs(bus_intval_mult);
> +	if (!binterval || binterval > MAX_BINTERVAL_ISOC_EP)
> +		return -EINVAL;
> +
> +	/* check if another bit is set then bail out */
> +	bus_intval_mult = bus_intval_mult >> binterval;
> +	if (bus_intval_mult)
> +		return -EINVAL;
> +
> +	return (binterval - 1);
> +}

This also feels like a generic helper. I don't see what's Qualcomm
specific here?


> +static unsigned long uaudio_iommu_map(enum mem_type mtype, bool dma_coherent,
> +		phys_addr_t pa, size_t size, struct sg_table *sgt)
> +{
> +	unsigned long va_sg, va = 0;
> +	bool map = true;
> +	int i, ret;
> +	size_t sg_len, total_len = 0;
> +	struct scatterlist *sg;
> +	phys_addr_t pa_sg;
> +	int prot = IOMMU_READ | IOMMU_WRITE;

reverse x-mas tree style?

> +
> +	if (dma_coherent)
> +		prot |= IOMMU_CACHE;
> +
> +	switch (mtype) {
> +	case MEM_EVENT_RING:
> +		va = IOVA_BASE;
> +		/* er already mapped */
> +		if (uaudio_qdev->er_mapped)
> +			map = false;
> +		break;
> +	case MEM_XFER_RING:
> +		va = uaudio_get_iova(&uaudio_qdev->curr_xfer_ring_iova,
> +		&uaudio_qdev->xfer_ring_iova_size, &uaudio_qdev->xfer_ring_list,
> +		size);
> +		break;
> +	case MEM_XFER_BUF:
> +		va = uaudio_get_iova(&uaudio_qdev->curr_xfer_buf_iova,
> +		&uaudio_qdev->xfer_buf_iova_size, &uaudio_qdev->xfer_buf_list,
> +		size);
> +		break;
> +	default:
> +		dev_err(uaudio_qdev->dev, "unknown mem type %d\n", mtype);
> +	}
> +
> +	if (!va || !map)
> +		goto done;
> +
> +	if (!sgt)
> +		goto skip_sgt_map;
> +
> +	va_sg = va;
> +	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
> +		sg_len = PAGE_ALIGN(sg->offset + sg->length);
> +		pa_sg = page_to_phys(sg_page(sg));
> +		ret = iommu_map(uaudio_qdev->domain, va_sg, pa_sg, sg_len,
> +				prot, GFP_KERNEL);
> +		if (ret) {
> +			dev_err(uaudio_qdev->dev, "mapping failed ret%d\n", ret);
> +			dev_err(uaudio_qdev->dev,
> +				"type:%d, pa:%pa iova:0x%08lx sg_len:%zu\n",
> +				mtype, &pa_sg, va_sg, sg_len);
> +			uaudio_iommu_unmap(MEM_XFER_BUF, va, size, total_len);
> +			va = 0;

so it's an error but the function returns 0?

> +			goto done;
> +		}
> +		dev_dbg(uaudio_qdev->dev,
> +			"type:%d map pa:%pa to iova:0x%08lx len:%zu offset:%u\n",
> +			mtype, &pa_sg, va_sg, sg_len, sg->offset);
> +		va_sg += sg_len;
> +		total_len += sg_len;
> +	}
> +
> +	if (size != total_len) {
> +		dev_err(uaudio_qdev->dev, "iova size %zu != mapped iova size %zu\n",
> +			size, total_len);
> +		uaudio_iommu_unmap(MEM_XFER_BUF, va, size, total_len);
> +		va = 0;
> +	}
> +	return va;
> +
> +skip_sgt_map:
> +	dev_dbg(uaudio_qdev->dev, "type:%d map pa:%pa to iova:0x%08lx size:%zu\n",
> +		mtype, &pa, va, size);
> +
> +	ret = iommu_map(uaudio_qdev->domain, va, pa, size, prot, GFP_KERNEL);
> +	if (ret)
> +		dev_err(uaudio_qdev->dev,
> +			"failed to map pa:%pa iova:0x%lx type:%d ret:%d\n",
> +			&pa, va, mtype, ret);
> +done:
> +	return va;
> +}
> +
> +/* looks up alias, if any, for controller DT node and returns the index */
> +static int usb_get_controller_id(struct usb_device *udev)
> +{
> +	if (udev->bus->sysdev && udev->bus->sysdev->of_node)
> +		return of_alias_get_id(udev->bus->sysdev->of_node, "usb");
> +
> +	return -ENODEV;
> +}
> +
> +/**
> + * uaudio_dev_intf_cleanup() - cleanup transfer resources
> + * @udev: usb device
> + * @info: usb offloading interface
> + *
> + * Cleans up the transfer ring related resources which are assigned per
> + * endpoint from XHCI.  This is invoked when the USB endpoints are no
> + * longer in use by the adsp.
> + *
> + */
> +static void uaudio_dev_intf_cleanup(struct usb_device *udev,
> +	struct intf_info *info)
> +{
> +	uaudio_iommu_unmap(MEM_XFER_RING, info->data_xfer_ring_va,
> +		info->data_xfer_ring_size, info->data_xfer_ring_size);
> +	info->data_xfer_ring_va = 0;
> +	info->data_xfer_ring_size = 0;
> +
> +	uaudio_iommu_unmap(MEM_XFER_RING, info->sync_xfer_ring_va,
> +		info->sync_xfer_ring_size, info->sync_xfer_ring_size);
> +	info->sync_xfer_ring_va = 0;
> +	info->sync_xfer_ring_size = 0;
> +
> +	uaudio_iommu_unmap(MEM_XFER_BUF, info->xfer_buf_va,
> +		info->xfer_buf_size, info->xfer_buf_size);
> +	info->xfer_buf_va = 0;
> +
> +	usb_free_coherent(udev, info->xfer_buf_size,
> +		info->xfer_buf, info->xfer_buf_pa);
> +	info->xfer_buf_size = 0;
> +	info->xfer_buf = NULL;
> +	info->xfer_buf_pa = 0;
> +
> +	info->in_use = false;
> +}
> +
> +/**
> + * uaudio_event_ring_cleanup_free() - cleanup secondary event ring
> + * @dev: usb offload device
> + *
> + * Cleans up the secondary event ring that was requested.  This will
> + * occur when the adsp is no longer transferring data on the USB bus
> + * across all endpoints.
> + *
> + */
> +static void uaudio_event_ring_cleanup_free(struct uaudio_dev *dev)
> +{
> +	clear_bit(dev->chip->card->number, &uaudio_qdev->card_slot);
> +	/* all audio devices are disconnected */
> +	if (!uaudio_qdev->card_slot) {
> +		uaudio_iommu_unmap(MEM_EVENT_RING, IOVA_BASE, PAGE_SIZE,
> +			PAGE_SIZE);
> +		xhci_sideband_remove_interrupter(uadev[dev->chip->card->number].sb);
> +	}
> +}
> +
> +static void uaudio_dev_cleanup(struct uaudio_dev *dev)

there should be a comment that this assumes a mutex is locked in the caller.

> +{
> +	int if_idx;
> +
> +	if (!dev->udev)
> +		return;
> +
> +	/* free xfer buffer and unmap xfer ring and buf per interface */
> +	for (if_idx = 0; if_idx < dev->num_intf; if_idx++) {
> +		if (!dev->info[if_idx].in_use)
> +			continue;
> +		uaudio_dev_intf_cleanup(dev->udev, &dev->info[if_idx]);
> +		dev_dbg(uaudio_qdev->dev, "release resources: intf# %d card# %d\n",
> +			dev->info[if_idx].intf_num, dev->chip->card->number);
> +	}
> +
> +	dev->num_intf = 0;
> +
> +	/* free interface info */
> +	kfree(dev->info);
> +	dev->info = NULL;
> +	uaudio_event_ring_cleanup_free(dev);
> +	dev->udev = NULL;
> +}
> +
> +/**
> + * disable_audio_stream() - disable usb snd endpoints
> + * @subs: usb substream
> + *
> + * Closes the USB SND endpoints associated with the current audio stream
> + * used.  This will decrement the USB SND endpoint opened reference count.
> + *
> + */
> +static void disable_audio_stream(struct snd_usb_substream *subs)
> +{
> +	struct snd_usb_audio *chip = subs->stream->chip;
> +
> +	snd_usb_hw_free(subs);
> +	snd_usb_autosuspend(chip);
> +}
> +
> +/* QMI service disconnect handlers */
> +static void qmi_disconnect_work(struct work_struct *w)
> +{
> +	struct intf_info *info;
> +	int idx, if_idx;
> +	struct snd_usb_substream *subs;
> +	struct snd_usb_audio *chip;
> +
> +	mutex_lock(&qdev_mutex);
> +	/* find all active intf for set alt 0 and cleanup usb audio dev */
> +	for (idx = 0; idx < SNDRV_CARDS; idx++) {
> +		if (!atomic_read(&uadev[idx].in_use))
> +			continue;
> +
> +		chip = uadev[idx].chip;
> +		for (if_idx = 0; if_idx < uadev[idx].num_intf; if_idx++) {
> +			if (!uadev[idx].info || !uadev[idx].info[if_idx].in_use)
> +				continue;
> +			info = &uadev[idx].info[if_idx];
> +			subs = find_substream(info->pcm_card_num,
> +						info->pcm_dev_num,
> +						info->direction);
> +			if (!subs || !chip || atomic_read(&chip->shutdown)) {
> +				dev_err(&subs->dev->dev,
> +					"no sub for c#%u dev#%u dir%u\n",
> +					info->pcm_card_num,
> +					info->pcm_dev_num,
> +					info->direction);
> +				continue;
> +			}
> +			disable_audio_stream(subs);
> +		}
> +		atomic_set(&uadev[idx].in_use, 0);
> +		mutex_lock(&chip->mutex);
> +		uaudio_dev_cleanup(&uadev[idx]);
> +		mutex_unlock(&chip->mutex);
> +	}
> +	mutex_unlock(&qdev_mutex);
> +}
> +
> +/**
> + * qmi_bye_cb() - qmi bye message callback
> + * @handle: QMI handle
> + * @node: id of the dying node
> + *
> + * This callback is invoked when the QMI bye control message is received
> + * from the QMI client.  Handle the message accordingly by ensuring that
> + * the USB offload path is disabled and cleaned up.  At this point, ADSP
> + * is not utilizing the USB bus.
> + *
> + */
> +static void qmi_bye_cb(struct qmi_handle *handle, unsigned int node)
> +{
> +	struct uaudio_qmi_svc *svc = uaudio_svc;
> +
> +	if (svc->uaudio_svc_hdl != handle)
> +		return;
> +
> +	if (svc->client_connected && svc->client_sq.sq_node == node) {
> +		queue_work(svc->uaudio_wq, &svc->qmi_disconnect_work);
> +		svc->client_sq.sq_node = 0;
> +		svc->client_sq.sq_port = 0;
> +		svc->client_sq.sq_family = 0;
> +		svc->client_connected = false;
> +	}
> +}
> +
> +/**
> + * qmi_svc_disconnect_cb() - qmi client disconnected
> + * @handle: QMI handle
> + * @node: id of the dying node
> + * @port: port of the dying client
> + *
> + * Invoked when the remote QMI client is disconnected.  Handle this event
> + * the same way as when the QMI bye message is received.  This will ensure
> + * the USB offloading path is disabled and cleaned up.
> + *
> + */
> +static void qmi_svc_disconnect_cb(struct qmi_handle *handle,
> +				  unsigned int node, unsigned int port)
> +{
> +	struct uaudio_qmi_svc *svc;
> +
> +	if (uaudio_svc == NULL)
> +		return;
> +
> +	svc = uaudio_svc;
> +	if (svc->uaudio_svc_hdl != handle)
> +		return;
> +
> +	if (svc->client_connected && svc->client_sq.sq_node == node &&
> +			svc->client_sq.sq_port == port) {
> +		queue_work(svc->uaudio_wq, &svc->qmi_disconnect_work);
> +		svc->client_sq.sq_node = 0;
> +		svc->client_sq.sq_port = 0;
> +		svc->client_sq.sq_family = 0;
> +		svc->client_connected = false;

this feels racy, shouldn't all these reset values be set in the work
function?

> +	}
> +}
> +
> +/* QMI client callback handlers from QMI interface */
> +static struct qmi_ops uaudio_svc_ops_options = {
> +	.bye = qmi_bye_cb,
> +	.del_client = qmi_svc_disconnect_cb,
> +};
> +
> +/* kref release callback when all streams are disabled */
> +static void uaudio_dev_release(struct kref *kref)
> +{
> +	struct uaudio_dev *dev = container_of(kref, struct uaudio_dev, kref);
> +
> +	uaudio_event_ring_cleanup_free(dev);
> +	atomic_set(&dev->in_use, 0);
> +	wake_up(&dev->disconnect_wq);
> +}
> +
> +/**
> + * enable_audio_stream() - enable usb snd endpoints
> + * @subs: usb substream
> + * @pcm_format: pcm format requested
> + * @channels: number of channels
> + * @cur_rate: sample rate
> + * @datainterval: interval
> + *
> + * Opens all USB SND endpoints used for the data interface.  This will increment
> + * the USB SND endpoint's opened count.  Requests to keep the interface resumed
> + * until the audio stream is stopped.  Will issue the USB set interface control
> + * message to enable the data interface.
> + *
> + */
> +static int enable_audio_stream(struct snd_usb_substream *subs,
> +				snd_pcm_format_t pcm_format,
> +				unsigned int channels, unsigned int cur_rate,
> +				int datainterval)
> +{
> +	struct snd_usb_audio *chip = subs->stream->chip;
> +	struct snd_pcm_hw_params params;
> +	struct snd_mask *m;
> +	struct snd_interval *i;
> +	int ret;
> +
> +	_snd_pcm_hw_params_any(&params);
> +
> +	m = hw_param_mask(&params, SNDRV_PCM_HW_PARAM_FORMAT);
> +	snd_mask_leave(m, pcm_format);
> +
> +	i = hw_param_interval(&params, SNDRV_PCM_HW_PARAM_CHANNELS);
> +	snd_interval_setinteger(i);
> +	i->min = i->max = channels;
> +
> +	i = hw_param_interval(&params, SNDRV_PCM_HW_PARAM_RATE);
> +	snd_interval_setinteger(i);
> +	i->min = i->max = cur_rate;
> +
> +	pm_runtime_barrier(&chip->intf[0]->dev);
> +	snd_usb_autoresume(chip);
> +
> +	ret = snd_usb_hw_params(subs, &params);
> +	if (ret < 0)
> +		goto put_suspend;
> +
> +	if (!atomic_read(&chip->shutdown)) {
> +		ret = snd_usb_lock_shutdown(chip);
> +		if (ret < 0)
> +			goto detach_ep;
> +
> +		if (subs->sync_endpoint) {
> +			ret = snd_usb_endpoint_prepare(chip, subs->sync_endpoint);
> +			if (ret < 0)
> +				goto unlock;
> +		}
> +
> +		ret = snd_usb_endpoint_prepare(chip, subs->data_endpoint);
> +		if (ret < 0)
> +			goto unlock;
> +
> +		snd_usb_unlock_shutdown(chip);
> +
> +		dev_dbg(uaudio_qdev->dev,
> +			"selected %s iface:%d altsetting:%d datainterval:%dus\n",
> +			subs->direction ? "capture" : "playback",
> +			subs->cur_audiofmt->iface, subs->cur_audiofmt->altsetting,
> +			(1 << subs->cur_audiofmt->datainterval) *
> +			(subs->dev->speed >= USB_SPEED_HIGH ?
> +			BUS_INTERVAL_HIGHSPEED_AND_ABOVE :
> +			BUS_INTERVAL_FULL_SPEED));
> +	}
> +
> +	return 0;
> +
> +unlock:
> +	snd_usb_unlock_shutdown(chip);
> +
> +detach_ep:
> +	snd_usb_hw_free(subs);
> +
> +put_suspend:
> +	snd_usb_autosuspend(chip);
> +
> +	return ret;
> +}
> +
> +/* returns usb hcd sysdev */
> +static struct device *usb_get_usb_backend(struct usb_device *udev)
> +{
> +	if (udev->bus->sysdev && udev->bus->sysdev->of_node)
> +		return udev->bus->sysdev;
> +
> +	return NULL;
> +}
> +
> +/**
> + * prepare_qmi_response() - prepare stream enable response
> + * @subs: usb substream
> + * @req_msg: QMI request message
> + * @resp: QMI response buffer
> + * @info_idx: usb interface array index
> + *
> + * Prepares the QMI response for a USB QMI stream enable request.  Will parse
> + * out the parameters within the stream enable request, in order to match
> + * requested audio profile to the ones exposed by the USB device connected.
> + *
> + * In addition, will fetch the XHCI transfer resources needed for the handoff to
> + * happen.  This includes, transfer ring and buffer addresses and secondary event
> + * ring address.  These parameters will be communicated as part of the USB QMI
> + * stream enable response.
> + *
> + */
> +static int prepare_qmi_response(struct snd_usb_substream *subs,
> +		struct qmi_uaudio_stream_req_msg_v01 *req_msg,
> +		struct qmi_uaudio_stream_resp_msg_v01 *resp, int info_idx)
> +{
> +	struct usb_interface *iface;
> +	struct usb_host_interface *alts;
> +	struct usb_interface_descriptor *altsd;
> +	struct usb_interface_assoc_descriptor *assoc;
> +	struct usb_host_endpoint *ep;
> +	struct uac_format_type_i_continuous_descriptor *fmt;
> +	struct uac_format_type_i_discrete_descriptor *fmt_v1;
> +	struct uac_format_type_i_ext_descriptor *fmt_v2;
> +	struct uac1_as_header_descriptor *as;
> +	struct q6usb_offload *data;
> +	int ret;
> +	int protocol, card_num, pcm_dev_num;
> +	void *hdr_ptr;
> +	u8 *xfer_buf;
> +	unsigned int data_ep_pipe = 0, sync_ep_pipe = 0;
> +	u32 len, mult, remainder, xfer_buf_len;
> +	unsigned long va, tr_data_va = 0, tr_sync_va = 0;
> +	phys_addr_t xhci_pa, xfer_buf_pa, tr_data_pa = 0, tr_sync_pa = 0;
> +	struct sg_table *sgt;
> +	struct sg_table xfer_buf_sgt;
> +	struct page *pg;
> +	bool dma_coherent;

consider simplifying or splitting in different functions? you have 20
lines and probably 30-odd variables. This is a bit beyond what reviewers
can handle...
> +
> +	iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
> +	if (!iface) {
> +		dev_err(uaudio_qdev->dev, "interface # %d does not exist\n",
> +			subs->cur_audiofmt->iface);
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +
> +	assoc = iface->intf_assoc;
> +	pcm_dev_num = (req_msg->usb_token & QMI_STREAM_REQ_DEV_NUM_MASK) >> 8;
> +	xfer_buf_len = req_msg->xfer_buff_size;
> +	card_num = uaudio_qdev->last_card_num;
> +
> +	alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
> +	altsd = get_iface_desc(alts);
> +	protocol = altsd->bInterfaceProtocol;
> +
> +	/* get format type */
> +	if (protocol != UAC_VERSION_3) {
> +		fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
> +				UAC_FORMAT_TYPE);
> +		if (!fmt) {
> +			dev_err(uaudio_qdev->dev,
> +				"%u:%d : no UAC_FORMAT_TYPE desc\n",
> +				subs->cur_audiofmt->iface,
> +				subs->cur_audiofmt->altset_idx);
> +			ret = -ENODEV;
> +			goto err;
> +		}
> +	}
> +
> +	if (!uadev[card_num].ctrl_intf) {
> +		dev_err(uaudio_qdev->dev, "audio ctrl intf info not cached\n");
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +
> +	if (protocol != UAC_VERSION_3) {
> +		hdr_ptr = snd_usb_find_csint_desc(uadev[card_num].ctrl_intf->extra,
> +				uadev[card_num].ctrl_intf->extralen, NULL,
> +				UAC_HEADER);
> +		if (!hdr_ptr) {
> +			dev_err(uaudio_qdev->dev, "no UAC_HEADER desc\n");
> +			ret = -ENODEV;
> +			goto err;
> +		}
> +	}
> +
> +	if (protocol == UAC_VERSION_1) {
> +		struct uac1_ac_header_descriptor *uac1_hdr = hdr_ptr;
> +
> +		as = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
> +			UAC_AS_GENERAL);
> +		if (!as) {
> +			dev_err(uaudio_qdev->dev,
> +				"%u:%d : no UAC_AS_GENERAL desc\n",
> +				subs->cur_audiofmt->iface,
> +				subs->cur_audiofmt->altset_idx);
> +			ret = -ENODEV;
> +			goto err;
> +		}
> +		resp->data_path_delay = as->bDelay;
> +		resp->data_path_delay_valid = 1;
> +		fmt_v1 = (struct uac_format_type_i_discrete_descriptor *)fmt;
> +		resp->usb_audio_subslot_size = fmt_v1->bSubframeSize;
> +		resp->usb_audio_subslot_size_valid = 1;
> +
> +		resp->usb_audio_spec_revision = le16_to_cpu(uac1_hdr->bcdADC);
> +		resp->usb_audio_spec_revision_valid = 1;
> +	} else if (protocol == UAC_VERSION_2) {
> +		struct uac2_ac_header_descriptor *uac2_hdr = hdr_ptr;
> +
> +		fmt_v2 = (struct uac_format_type_i_ext_descriptor *)fmt;
> +		resp->usb_audio_subslot_size = fmt_v2->bSubslotSize;
> +		resp->usb_audio_subslot_size_valid = 1;
> +
> +		resp->usb_audio_spec_revision = le16_to_cpu(uac2_hdr->bcdADC);
> +		resp->usb_audio_spec_revision_valid = 1;
> +	} else if (protocol == UAC_VERSION_3) {
> +		if (assoc->bFunctionSubClass ==
> +					UAC3_FUNCTION_SUBCLASS_FULL_ADC_3_0) {
> +			dev_err(uaudio_qdev->dev, "full adc is not supported\n");
> +			ret = -EINVAL;
> +		}
> +
> +		switch (le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize)) {
> +		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
> +		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
> +		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
> +		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16: {
> +			resp->usb_audio_subslot_size = 0x2;
> +			break;
> +		}
> +
> +		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
> +		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
> +		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
> +		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24: {
> +			resp->usb_audio_subslot_size = 0x3;
> +			break;
> +		}
> +
> +		default:
> +			dev_err(uaudio_qdev->dev,
> +				"%d: %u: Invalid wMaxPacketSize\n",
> +				subs->cur_audiofmt->iface,
> +				subs->cur_audiofmt->altset_idx);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +		resp->usb_audio_subslot_size_valid = 1;
> +	} else {
> +		dev_err(uaudio_qdev->dev, "unknown protocol version %x\n",
> +			protocol);
> +		ret = -ENODEV;
> +		goto err;
> +	}

these 100-odd lines look like duplicated code. Why would we redo the
parsing of UAC3 stuff in a QCOM-specific driver?

> +
> +	resp->slot_id = subs->dev->slot_id;
> +	resp->slot_id_valid = 1;
> +
> +	memcpy(&resp->std_as_opr_intf_desc, &alts->desc, sizeof(alts->desc));
> +	resp->std_as_opr_intf_desc_valid = 1;
> +
> +	ep = usb_pipe_endpoint(subs->dev, subs->data_endpoint->pipe);
> +	if (!ep) {
> +		dev_err(uaudio_qdev->dev, "data ep # %d context is null\n",
> +			subs->data_endpoint->ep_num);
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +	data_ep_pipe = subs->data_endpoint->pipe;
> +	memcpy(&resp->std_as_data_ep_desc, &ep->desc, sizeof(ep->desc));
> +	resp->std_as_data_ep_desc_valid = 1;
> +
> +	ret = xhci_sideband_add_endpoint(uadev[card_num].sb, ep);
> +	if (ret < 0) {
> +		dev_err(uaudio_qdev->dev, "failed to add data ep to sideband\n");
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +
> +	sgt = xhci_sideband_get_endpoint_buffer(uadev[card_num].sb, ep);
> +	if (!sgt) {
> +		dev_err(uaudio_qdev->dev, "failed to get data ep ring address\n");
> +		ret = -ENODEV;
> +		goto drop_data_ep;
> +	}
> +
> +	pg = sg_page(sgt->sgl);
> +	tr_data_pa = page_to_phys(pg);
> +	resp->xhci_mem_info.tr_data.pa = sg_dma_address(sgt->sgl);
> +	sg_free_table(sgt);
> +
> +	if (subs->sync_endpoint) {
> +		ep = usb_pipe_endpoint(subs->dev, subs->sync_endpoint->pipe);
> +		if (!ep) {
> +			dev_err(uaudio_qdev->dev, "implicit fb on data ep\n");
> +			goto skip_sync_ep;
> +		}
> +		sync_ep_pipe = subs->sync_endpoint->pipe;
> +		memcpy(&resp->std_as_sync_ep_desc, &ep->desc, sizeof(ep->desc));
> +		resp->std_as_sync_ep_desc_valid = 1;
> +
> +		ret = xhci_sideband_add_endpoint(uadev[card_num].sb, ep);
> +		if (ret < 0) {
> +			dev_err(uaudio_qdev->dev,
> +				"failed to add sync ep to sideband\n");
> +			ret = -ENODEV;
> +			goto drop_data_ep;
> +		}
> +
> +		sgt = xhci_sideband_get_endpoint_buffer(uadev[card_num].sb, ep);
> +		if (!sgt) {
> +			dev_err(uaudio_qdev->dev, "failed to get sync ep ring address\n");
> +			ret = -ENODEV;
> +			goto drop_sync_ep;
> +		}
> +
> +		pg = sg_page(sgt->sgl);
> +		tr_sync_pa = page_to_phys(pg);
> +		resp->xhci_mem_info.tr_sync.pa = sg_dma_address(sgt->sgl);
> +		sg_free_table(sgt);
> +	}
> +
> +skip_sync_ep:
> +	data = snd_soc_usb_find_priv_data(usb_get_usb_backend(subs->dev));
> +	if (!data)
> +		goto drop_sync_ep;
> +
> +	uaudio_qdev->domain = data->domain;
> +	uaudio_qdev->sid = data->sid;
> +	uaudio_qdev->intr_num = data->intr_num;
> +	uaudio_qdev->dev = data->dev;
> +
> +	resp->interrupter_num_valid = 1;
> +	resp->controller_num_valid = 0;
> +	ret = usb_get_controller_id(subs->dev);
> +	if (ret >= 0) {
> +		resp->controller_num = ret;
> +		resp->controller_num_valid = 1;
> +	}
> +	/* map xhci data structures PA memory to iova */
> +	dma_coherent = dev_is_dma_coherent(subs->dev->bus->sysdev);
> +
> +	/* event ring */
> +	ret = xhci_sideband_create_interrupter(uadev[card_num].sb, uaudio_qdev->intr_num);
> +	if (ret < 0) {
> +		dev_err(uaudio_qdev->dev, "failed to fetch interrupter\n");
> +		ret = -ENODEV;
> +		goto drop_sync_ep;
> +	}
> +
> +	sgt = xhci_sideband_get_event_buffer(uadev[card_num].sb);
> +	if (!sgt) {
> +		dev_err(uaudio_qdev->dev, "failed to get event ring address\n");
> +		ret = -ENODEV;
> +		goto free_sec_ring;
> +	}
> +
> +	xhci_pa = page_to_phys(sg_page(sgt->sgl));
> +	resp->xhci_mem_info.evt_ring.pa = sg_dma_address(sgt->sgl);
> +	sg_free_table(sgt);
> +	if (!xhci_pa) {
> +		dev_err(uaudio_qdev->dev,
> +			"failed to get sec event ring address\n");
> +		ret = -ENODEV;
> +		goto free_sec_ring;
> +	}
> +
> +	resp->interrupter_num = xhci_sideband_interrupter_id(uadev[card_num].sb);
> +
> +	va = uaudio_iommu_map(MEM_EVENT_RING, dma_coherent, xhci_pa, PAGE_SIZE,
> +			NULL);
> +	if (!va) {
> +		ret = -ENOMEM;
> +		goto free_sec_ring;
> +	}
> +
> +	resp->xhci_mem_info.evt_ring.va = PREPEND_SID_TO_IOVA(va,
> +						uaudio_qdev->sid);
> +	resp->xhci_mem_info.evt_ring.size = PAGE_SIZE;
> +	uaudio_qdev->er_mapped = true;
> +
> +	resp->speed_info = get_speed_info(subs->dev->speed);
> +	if (resp->speed_info == USB_QMI_DEVICE_SPEED_INVALID_V01) {
> +		ret = -ENODEV;
> +		goto unmap_er;
> +	}
> +
> +	resp->speed_info_valid = 1;
> +
> +	/* data transfer ring */
> +	va = uaudio_iommu_map(MEM_XFER_RING, dma_coherent, tr_data_pa,
> +			PAGE_SIZE, NULL);
> +	if (!va) {
> +		ret = -ENOMEM;
> +		goto unmap_er;
> +	}
> +
> +	tr_data_va = va;
> +	resp->xhci_mem_info.tr_data.va = PREPEND_SID_TO_IOVA(va,
> +						uaudio_qdev->sid);
> +	resp->xhci_mem_info.tr_data.size = PAGE_SIZE;
> +
> +	/* sync transfer ring */
> +	if (!resp->xhci_mem_info.tr_sync.pa)
> +		goto skip_sync;
> +
> +	xhci_pa = resp->xhci_mem_info.tr_sync.pa;
> +	va = uaudio_iommu_map(MEM_XFER_RING, dma_coherent, tr_sync_pa,
> +			PAGE_SIZE, NULL);
> +	if (!va) {
> +		ret = -ENOMEM;
> +		goto unmap_data;
> +	}
> +
> +	tr_sync_va = va;
> +	resp->xhci_mem_info.tr_sync.va = PREPEND_SID_TO_IOVA(va,
> +						uaudio_qdev->sid);
> +	resp->xhci_mem_info.tr_sync.size = PAGE_SIZE;
> +
> +skip_sync:
> +	/* xfer buffer, multiple of 4K only */
> +	if (!xfer_buf_len)
> +		xfer_buf_len = PAGE_SIZE;
> +
> +	mult = xfer_buf_len / PAGE_SIZE;
> +	remainder = xfer_buf_len % PAGE_SIZE;
> +	len = mult * PAGE_SIZE;
> +	len += remainder ? PAGE_SIZE : 0;
> +
> +	if (len > MAX_XFER_BUFF_LEN) {
> +		dev_err(uaudio_qdev->dev,
> +			"req buf len %d > max buf len %lu, setting %lu\n",
> +			len, MAX_XFER_BUFF_LEN, MAX_XFER_BUFF_LEN);
> +		len = MAX_XFER_BUFF_LEN;
> +	}
> +
> +	xfer_buf = usb_alloc_coherent(subs->dev, len, GFP_KERNEL, &xfer_buf_pa);
> +	if (!xfer_buf) {
> +		ret = -ENOMEM;
> +		goto unmap_sync;
> +	}
> +
> +	dma_get_sgtable(subs->dev->bus->sysdev, &xfer_buf_sgt, xfer_buf, xfer_buf_pa,
> +			len);
> +	va = uaudio_iommu_map(MEM_XFER_BUF, dma_coherent, xfer_buf_pa, len,
> +			&xfer_buf_sgt);
> +	if (!va) {
> +		ret = -ENOMEM;
> +		goto unmap_sync;
> +	}
> +
> +	resp->xhci_mem_info.xfer_buff.pa = xfer_buf_pa;
> +	resp->xhci_mem_info.xfer_buff.size = len;
> +
> +	resp->xhci_mem_info.xfer_buff.va = PREPEND_SID_TO_IOVA(va,
> +						uaudio_qdev->sid);
> +
> +	resp->xhci_mem_info_valid = 1;
> +
> +	sg_free_table(&xfer_buf_sgt);
> +
> +	if (!atomic_read(&uadev[card_num].in_use)) {
> +		kref_init(&uadev[card_num].kref);
> +		init_waitqueue_head(&uadev[card_num].disconnect_wq);
> +		uadev[card_num].num_intf =
> +			subs->dev->config->desc.bNumInterfaces;
> +		uadev[card_num].info = kcalloc(uadev[card_num].num_intf,
> +			sizeof(struct intf_info), GFP_KERNEL);
> +		if (!uadev[card_num].info) {
> +			ret = -ENOMEM;
> +			goto unmap_sync;
> +		}
> +		uadev[card_num].udev = subs->dev;
> +		atomic_set(&uadev[card_num].in_use, 1);
> +	} else {
> +		kref_get(&uadev[card_num].kref);
> +	}
> +
> +	uadev[card_num].usb_core_id = resp->controller_num;
> +
> +	/* cache intf specific info to use it for unmap and free xfer buf */
> +	uadev[card_num].info[info_idx].data_xfer_ring_va = tr_data_va;
> +	uadev[card_num].info[info_idx].data_xfer_ring_size = PAGE_SIZE;
> +	uadev[card_num].info[info_idx].sync_xfer_ring_va = tr_sync_va;
> +	uadev[card_num].info[info_idx].sync_xfer_ring_size = PAGE_SIZE;
> +	uadev[card_num].info[info_idx].xfer_buf_va = va;
> +	uadev[card_num].info[info_idx].xfer_buf_pa = xfer_buf_pa;
> +	uadev[card_num].info[info_idx].xfer_buf_size = len;
> +	uadev[card_num].info[info_idx].data_ep_pipe = data_ep_pipe;
> +	uadev[card_num].info[info_idx].sync_ep_pipe = sync_ep_pipe;
> +	uadev[card_num].info[info_idx].xfer_buf = xfer_buf;
> +	uadev[card_num].info[info_idx].pcm_card_num = card_num;
> +	uadev[card_num].info[info_idx].pcm_dev_num = pcm_dev_num;
> +	uadev[card_num].info[info_idx].direction = subs->direction;
> +	uadev[card_num].info[info_idx].intf_num = subs->cur_audiofmt->iface;
> +	uadev[card_num].info[info_idx].in_use = true;
> +
> +	set_bit(card_num, &uaudio_qdev->card_slot);
> +
> +	return 0;
> +
> +unmap_sync:
> +	usb_free_coherent(subs->dev, len, xfer_buf, xfer_buf_pa);
> +	uaudio_iommu_unmap(MEM_XFER_RING, tr_sync_va, PAGE_SIZE, PAGE_SIZE);
> +unmap_data:
> +	uaudio_iommu_unmap(MEM_XFER_RING, tr_data_va, PAGE_SIZE, PAGE_SIZE);
> +unmap_er:
> +	uaudio_iommu_unmap(MEM_EVENT_RING, IOVA_BASE, PAGE_SIZE, PAGE_SIZE);
> +free_sec_ring:
> +	xhci_sideband_remove_interrupter(uadev[card_num].sb);
> +drop_sync_ep:
> +	if (subs->sync_endpoint)
> +		xhci_sideband_remove_endpoint(uadev[card_num].sb,
> +			usb_pipe_endpoint(subs->dev, subs->sync_endpoint->pipe));
> +drop_data_ep:
> +	xhci_sideband_remove_endpoint(uadev[card_num].sb,
> +			usb_pipe_endpoint(subs->dev, subs->data_endpoint->pipe));
> +
> +err:
> +	return ret;
> +}

this is really the largest function I've seen in a while... Can this use
helpers or be more modular?

> +
> +/**
> + * handle_uaudio_stream_req() - handle stream enable/disable request
> + * @handle: QMI client handle
> + * @sq: qrtr socket
> + * @txn: QMI transaction context
> + * @decoded_msg: decoded QMI message
> + *
> + * Main handler for the QMI stream enable/disable requests.  This executes the
> + * corresponding enable/disable stream apis, respectively.
> + *
> + */
> +static void handle_uaudio_stream_req(struct qmi_handle *handle,
> +			struct sockaddr_qrtr *sq,
> +			struct qmi_txn *txn,
> +			const void *decoded_msg)
> +{
> +	struct qmi_uaudio_stream_req_msg_v01 *req_msg;
> +	struct qmi_uaudio_stream_resp_msg_v01 resp = {{0}, 0};
> +	struct snd_usb_substream *subs;
> +	struct snd_usb_audio *chip = NULL;
> +	struct uaudio_qmi_svc *svc = uaudio_svc;
> +	struct intf_info *info;
> +	struct usb_host_endpoint *ep;
> +	u8 pcm_card_num, pcm_dev_num, direction;
> +	int info_idx = -EINVAL, datainterval = -EINVAL, ret = 0;
> +
> +	if (!svc->client_connected) {
> +		svc->client_sq = *sq;
> +		svc->client_connected = true;
> +	}
> +
> +	mutex_lock(&qdev_mutex);
> +	req_msg = (struct qmi_uaudio_stream_req_msg_v01 *)decoded_msg;
> +	if (!req_msg->audio_format_valid || !req_msg->bit_rate_valid ||
> +	    !req_msg->number_of_ch_valid || !req_msg->xfer_buff_size_valid) {
> +		ret = -EINVAL;

this looks like copy pasted code, this function return void so all uses
of 'ret' are not so useful, are they?

> +		goto response;
> +	}
> +
> +	if (!uaudio_qdev) {
> +		ret = -EINVAL;
> +		goto response;
> +	}
> +
> +	direction = (req_msg->usb_token & QMI_STREAM_REQ_DIRECTION);
> +	pcm_dev_num = (req_msg->usb_token & QMI_STREAM_REQ_DEV_NUM_MASK) >> 8;
> +	pcm_card_num = req_msg->enable ? uaudio_qdev->last_card_num :
> +				ffs(uaudio_qdev->card_slot) - 1;
> +	if (pcm_card_num >= SNDRV_CARDS) {
> +		ret = -EINVAL;
> +		goto response;
> +	}
> +
> +	if (req_msg->audio_format > USB_QMI_PCM_FORMAT_U32_BE) {
> +		ret = -EINVAL;
> +		goto response;
> +	}
> +
> +	subs = find_substream(pcm_card_num, pcm_dev_num, direction);
> +	chip = uadev[pcm_card_num].chip;
> +	if (!subs || !chip || atomic_read(&chip->shutdown)) {
> +		ret = -ENODEV;
> +		goto response;
> +	}
> +
> +	info_idx = info_idx_from_ifnum(pcm_card_num, subs->cur_audiofmt ?
> +			subs->cur_audiofmt->iface : -1, req_msg->enable);
> +	if (atomic_read(&chip->shutdown) || !subs->stream || !subs->stream->pcm
> +			|| !subs->stream->chip) {
> +		ret = -ENODEV;
> +		goto response;
> +	}
> +
> +	if (req_msg->enable) {
> +		if (info_idx < 0 || chip->system_suspend) {
> +			ret = -EBUSY;
> +			goto response;
> +		}
> +	}
> +
> +	if (req_msg->service_interval_valid) {
> +		ret = get_data_interval_from_si(subs,
> +						req_msg->service_interval);
> +		if (ret == -EINVAL)
> +			goto response;
> +
> +		datainterval = ret;
> +	}
> +
> +	uadev[pcm_card_num].ctrl_intf = chip->ctrl_intf;
> +
> +	if (req_msg->enable) {
> +		ret = enable_audio_stream(subs,
> +				map_pcm_format(req_msg->audio_format),
> +				req_msg->number_of_ch, req_msg->bit_rate,
> +				datainterval);
> +
> +		if (!ret)
> +			ret = prepare_qmi_response(subs, req_msg, &resp,
> +					info_idx);
> +	} else {
> +		info = &uadev[pcm_card_num].info[info_idx];
> +		if (info->data_ep_pipe) {
> +			ep = usb_pipe_endpoint(uadev[pcm_card_num].udev,
> +						info->data_ep_pipe);
> +			if (ep)
> +				xhci_sideband_stop_endpoint(uadev[pcm_card_num].sb,
> +						ep);
> +			xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb, ep);
> +			info->data_ep_pipe = 0;
> +		}
> +
> +		if (info->sync_ep_pipe) {
> +			ep = usb_pipe_endpoint(uadev[pcm_card_num].udev,
> +						info->sync_ep_pipe);
> +			if (ep)
> +				xhci_sideband_stop_endpoint(uadev[pcm_card_num].sb,
> +						ep);
> +			xhci_sideband_remove_endpoint(uadev[pcm_card_num].sb, ep);
> +			info->sync_ep_pipe = 0;
> +		}
> +
> +		disable_audio_stream(subs);
> +	}
> +
> +response:
> +	if (!req_msg->enable && ret != -EINVAL && ret != -ENODEV) {
> +		mutex_lock(&chip->mutex);
> +		if (info_idx >= 0) {
> +			info = &uadev[pcm_card_num].info[info_idx];
> +			uaudio_dev_intf_cleanup(
> +					uadev[pcm_card_num].udev,
> +					info);
> +		}
> +		if (atomic_read(&uadev[pcm_card_num].in_use))
> +			kref_put(&uadev[pcm_card_num].kref,
> +					uaudio_dev_release);
> +		mutex_unlock(&chip->mutex);
> +	}
> +	mutex_unlock(&qdev_mutex);
> +
> +	resp.usb_token = req_msg->usb_token;
> +	resp.usb_token_valid = 1;
> +	resp.internal_status = ret;
> +	resp.internal_status_valid = 1;
> +	resp.status = ret ? USB_QMI_STREAM_REQ_FAILURE_V01 : ret;
> +	resp.status_valid = 1;
> +	ret = qmi_send_response(svc->uaudio_svc_hdl, sq, txn,
> +			QMI_UAUDIO_STREAM_RESP_V01,
> +			QMI_UAUDIO_STREAM_RESP_MSG_V01_MAX_MSG_LEN,
> +			qmi_uaudio_stream_resp_msg_v01_ei, &resp);

ret is not used?

> +}


I stopped here...

Re: [PATCH v9 00/34] Introduce QC USB SND audio offloading support

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 1:58 PM, Pierre-Louis Bossart wrote:
> It's been a very long time since I reviewed earlier versions, and I am
> still lost on terminology and concepts. The explanations below should
> really be added as a .rst file in Documentation for reference, not just
> as a cover letter.
> 

Thanks for the review!

Sure, maybe I can write a more comprehensive documentation that saves 
these details somewhere.  Will add a RST documentation for material 
where necessary.

>> Several Qualcomm based chipsets can support USB audio offloading to a
>> dedicated audio DSP, which can take over issuing transfers to the USB
>> host controller.  The intention is to reduce the load on the main
>> processors in the SoC, and allow them to be placed into lower power modes.
>> There are several parts to this design:
>>    1. Adding ASoC binding layer
>>    2. Create a USB backend for Q6DSP
> 
> "backend" is a loaded terms for ASoC. Can you clarify which part of the
> ascii art below is a 'backend'?
> 

This would be the Q6USB entity which is the DPCM backend for this 
particular audio path.

>>    3. Introduce XHCI interrupter support
>>    4. Create vendor ops for the USB SND driver
>>
>>        USB                          |            ASoC
>> --------------------------------------------------------------------
>>                                     |  _________________________
>>                                     | |sm8250 platform card     |
>>                                     | |_________________________|
>>                                     |         |           |
>>                                     |      ___V____   ____V____
>>                                     |     |Q6USB   | |Q6AFE    |
>>                                     |     |"codec" | |"cpu"    |
>>                                     |     |________| |_________|
>>                                     |         ^  ^        ^
>>                                     |         |  |________|
>>                                     |      ___V____    |
>>                                     |     |SOC-USB |   |
>>     ________       ________               |        |   |
>>    |USB SND |<--->|QC offld|<------------>|________|   |
>>    |(card.c)|     |        |<----------                |
>>    |________|     |________|___     | |                |
>>        ^               ^       |    | |    ____________V_________
>>        |               |       |    | |   |APR/GLINK             |
>>     __ V_______________V_____  |    | |   |______________________|
>>    |USB SND (endpoint.c)     | |    | |              ^
>>    |_________________________| |    | |              |
>>                ^               |    | |   ___________V___________
>>                |               |    | |->|audio DSP              |
>>     ___________V_____________  |    |    |_______________________|
>>    |XHCI HCD                 |<-    |
>>    |_________________________|      |
>>
>>
>> Adding ASoC binding layer:
>> soc-usb: Intention is to treat a USB port similar to a headphone jack.
> 
> What is a 'port'? USB refers to "interfaces" and "endpoints". Is a
> "port" a 1:1 mapping to "endpoint"?
> 
> Below I read "AFE port" so not sure what concepts refer to what.
> 

"Port" in this explanation refers to the USB port.  So the audio device 
connected.  You are right that a USB device can enumerate w/ multiple 
interfaces (ie UAC + HID + ...) so the closest relation to "port" is 
"interface."  It is not a 1:1 mapping w/ the number of endpoints exposed 
by a device.

"AFE port" is just something that has been termed from the audio DSP 
end, so that concept of port is not related to the port where USB 
devices are connected to.  This is something that is defined within the 
audio DSP.

>> The port is always present on the device, but cable/pin status can be
>> enabled/disabled.  Expose mechanisms for USB backend ASoC drivers to
>> communicate with USB SND.
>>
>> Create a USB backend for Q6DSP:
>> q6usb: Basic backend driver that will be responsible for maintaining the
> 
> The asciiart above suggests that q6usb exposes a codec DAI - but the
> backend dailink is created by the platform card?
> 

That is my understanding, at least.  The machine driver (sm8250.c) has 
an API that parses our DT node for the DAI relationships 
(qcom_snd_parse_of()), and seems to also create the dailinks.

>> resources needed to initiate a playback stream using the Q6DSP.  Will
> 
> is capture supported? there's explicit references to "num_capture" in
> following patches.
> 

We (QCOM) do not support capture at the moment, but the num_capture was 
added to the soc-usb driver, which is platform independent.  This is in 
case other vendors want to add this support, but have capture included 
as well.

>> be the entity that checks to make sure the connected USB audio device
>> supports the requested PCM format.  If it does not, the PCM open call will
>> fail, and userpsace ALSA can take action accordingly.
>>
>> Introduce XHCI interrupter support:
>> XHCI HCD supports multiple interrupters, which allows for events to be routed
>> to different event rings.  This is determined by "Interrupter Target" field
>> specified in Section "6.4.1.1 Normal TRB" of the XHCI specification.
>>
>> Events in the offloading case will be routed to an event ring that is assigned
>> to the audio DSP.
>>
>> Create vendor ops for the USB SND driver:
>> qc_audio_offload: This particular driver has several components associated
>> with it:
>> - QMI stream request handler
>> - XHCI interrupter and resource management
>> - audio DSP memory management
>>
>> When the audio DSP wants to enable a playback stream, the request is first
>> received by the ASoC platform sound card.  Depending on the selected route,
>> ASoC will bring up the individual DAIs in the path.  The Q6USB backend DAI
>> will send an AFE port start command (with enabling the USB playback path), and
>> the audio DSP will handle the request accordingly.
> 
> what about capture, e.g. for a headset?
> 

Not supported yet at the moment.

>> Part of the AFE USB port start handling will have an exchange of control
>> messages using the QMI protocol.  The qc_audio_offload driver will populate the
>> buffer information:
>> - Event ring base address
>> - EP transfer ring base address
>>
>> and pass it along to the audio DSP.  All endpoint management will now be handed
>> over to the DSP, and the main processor is not involved in transfers.
>>
>> Overall, implementing this feature will still expose separate sound card and PCM
>> devices for both the platorm card and USB audio device:
> 
> typo: platform
> 

Thanks, will fix this.

>>   0 [SM8250MTPWCD938]: sm8250 - SM8250-MTP-WCD9380-WSA8810-VA-D
>>                        SM8250-MTP-WCD9380-WSA8810-VA-DMIC
> 
> How do you plan on exposing the USB PCM device?
> 
> The lines above are really cryptic, and with no USB reference in any of
> the short/long card names it's not obvious that this card is different
> from the no-offload case, is it?
> 

In the end, since the offload case is handled by the audio DSP, it would 
have to go through the platform/machine sound card.  That is the sm8250 
device above.

>>   1 [Audio          ]: USB-Audio - USB Audio
>>                        Generic USB Audio at usb-xhci-hcd.1.auto-1.4, high speed
> 
> likewise some sort of qualifier would be useful to show that card 0 and
> card 1 can target the same USB endpoints.
> 

Do userspace entities look at this card string?  Assuming there is only 
one platform card, there are situations where maybe multiple USB audio 
devices are connected to the same USB root hub, so offloading can happen 
on any one of them (not at the same time).

Thanks
Wesley Cheng

Re: [PATCH v9 09/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 2:32 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:00, Wesley Cheng wrote:
>> The QC ADSP is able to support USB playback endpoints, so that the main
> 
> playback only?
> 

Correct, playback only at this time.

>> application processor can be placed into lower CPU power modes.  This adds
>> the required AFE port configurations and port start command to start an
>> audio session.
>>
>> Specifically, the QC ADSP can support all potential endpoints that are
>> exposed by the audio data interface.  This includes, feedback endpoints
>> (both implicit and explicit) as well as the isochronous (data) endpoints.
> 
> implicit feedback means support for capture. This is confusing...
> 

I mean, a USB device can expose a capture path, but as of now, we won't 
enable the offloading to the audio DSP for it.  However, if we're 
executing playback, and device does support implicit feedback, we will 
pass that along to the audio DSP to utilize.

>> +static int q6usb_hw_params(struct snd_pcm_substream *substream,
>> +			   struct snd_pcm_hw_params *params,
>> +			   struct snd_soc_dai *dai)
>> +{
>> +	struct q6afe_dai_data *dai_data = dev_get_drvdata(dai->dev);
>> +	int channels = params_channels(params);
>> +	int rate = params_rate(params);
>> +	struct q6afe_usb_cfg *usb = &dai_data->port_config[dai->id].usb_audio;
>> +
>> +	usb->sample_rate = rate;
>> +	usb->num_channels = channels;
>> +
>> +	switch (params_format(params)) {
>> +	case SNDRV_PCM_FORMAT_U16_LE:
>> +	case SNDRV_PCM_FORMAT_S16_LE:
>> +	case SNDRV_PCM_FORMAT_SPECIAL:
> 
> what does FORMAT_SPECIAL mean? the only other reference I see to this is
> related to SLIMbus, not sure how this is related?
> 

Thanks for catching this.  It shouldn't be included in this path.

>> +		usb->bit_width = 16;
>> +		break;
>> +	case SNDRV_PCM_FORMAT_S24_LE:
>> +	case SNDRV_PCM_FORMAT_S24_3LE:
>> +		usb->bit_width = 24;
>> +		break;
>> +	case SNDRV_PCM_FORMAT_S32_LE:
>> +		usb->bit_width = 32;
>> +		break;
>> +	default:
>> +		dev_err(dai->dev, "%s: invalid format %d\n",
>> +			__func__, params_format(params));
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
> 
>> @@ -617,6 +655,9 @@ static const struct snd_soc_dapm_route q6afe_dapm_routes[] = {
>>   	{"TX_CODEC_DMA_TX_5", NULL, "TX_CODEC_DMA_TX_5 Capture"},
>>   	{"RX_CODEC_DMA_RX_6 Playback", NULL, "RX_CODEC_DMA_RX_6"},
>>   	{"RX_CODEC_DMA_RX_7 Playback", NULL, "RX_CODEC_DMA_RX_7"},
>> +
>> +	/* USB playback AFE port receives data for playback, hence use the RX port */
>> +	{"USB Playback", NULL, "USB_RX"},
> 
> Capture for implicit feedback?
> 

Please refer to the above comment.

>>   };
>>   
>>   static int msm_dai_q6_dai_probe(struct snd_soc_dai *dai)
>> @@ -644,6 +685,18 @@ static int msm_dai_q6_dai_remove(struct snd_soc_dai *dai)
>>   	return 0;
>>   }
>>   
>> +static const struct snd_soc_dai_ops q6usb_ops = {
>> +	.probe		= msm_dai_q6_dai_probe,
>> +	.prepare	= q6afe_dai_prepare,
>> +	.hw_params	= q6usb_hw_params,
> 
> this is rather confusing with two different layers used for hw_params
> and prepare? Additional comments or explanations wouldn't hurt.
> 

I thought this was how the ASoC design was.  Each DAI defined for a 
particular path has it own set of callbacks implemented to bring up any 
required resources for that entity.  So in this case, it initializes the 
"cpu" DAI, which is the main component that handles communication with 
the audio DSP.

>> +	.shutdown	= q6afe_dai_shutdown,
>> +	/*
>> +	 * Startup callback not needed, as AFE port start command passes the PCM
>> +	 * parameters within the AFE command, which is provided by the PCM core
>> +	 * during the prepare() stage.
> 
> This doesn't really explain why you need a shutdown?
> 
> 

Sure, I'll add a comment.  shutdown() is needed to actually issue a AFE 
port stop command to stop pumping audio data on a particular AFE port. 
This occurs when userspace closes the PCM device for the platform sound 
card, and is triggered for all linked DAIs.

>> + * struct afe_param_id_usb_audio_dev_latency_mode
>> + * @cfg_minor_version: Minor version used for tracking USB audio device
>> + * configuration.
>> + * Supported values:
>> + *     AFE_API_MINOR_VERSION_USB_AUDIO_LATENCY_MODE
>> + * @mode: latency mode for the USB audio device
> 
> what are the different latency modes? and is this related to the latency
> reporting that was added in the USB2 audio class IIRC?
> 

Must've missed removing this part during one of the earlier revision 
cleanups I had done.  We aren't setting this parameter currently on the 
AFE side, and it isn't utilized either in the audio DSP, so I will 
remove this definition.

>> +static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
>> +{
>> +	union afe_port_config *pcfg = &port->port_cfg;
>> +	struct afe_param_id_usb_audio_dev_params usb_dev;
>> +	struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
>> +	struct afe_param_id_usb_audio_svc_interval svc_int;
>> +	int ret = 0;
> 
> useless init overridden...

Will fix this.

>> +
>> +	if (!pcfg) {
>> +		dev_err(port->afe->dev, "%s: Error, no configuration data\n", __func__);
>> +		ret = -EINVAL;
>> +		goto exit;
>> +	}
>> +
>> +	memset(&usb_dev, 0, sizeof(usb_dev));
>> +	memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
>> +	memset(&svc_int, 0, sizeof(svc_int));
>> +
>> +	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
>> +	ret = q6afe_port_set_param_v2(port, &usb_dev,
> 
> .... here
> 
>> +				      AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
>> +				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
>> +	if (ret) {
>> +		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
>> +			__func__, ret);
>> +		goto exit;
>> +	}
>> +
>> +	lpcm_fmt.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
>> +	lpcm_fmt.endian = pcfg->usb_cfg.endian;
>> +	ret = q6afe_port_set_param_v2(port, &lpcm_fmt,
>> +				      AFE_PARAM_ID_USB_AUDIO_DEV_LPCM_FMT,
>> +				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(lpcm_fmt));
>> +	if (ret) {
>> +		dev_err(port->afe->dev, "%s: AFE device param cmd LPCM_FMT failed %d\n",
>> +			__func__, ret);
>> +		goto exit;
>> +	}
>> +
>> +	svc_int.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
>> +	svc_int.svc_interval = pcfg->usb_cfg.service_interval;
>> +	ret = q6afe_port_set_param_v2(port, &svc_int,
>> +				      AFE_PARAM_ID_USB_AUDIO_SVC_INTERVAL,
>> +				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(svc_int));
>> +	if (ret)
>> +		dev_err(port->afe->dev, "%s: AFE device param cmd svc_interval failed %d\n",
>> +			__func__, ret);
>> +
>> +exit:
>> +	return ret;
>> +}
> 
>> -#define AFE_PORT_MAX		129
>> +#define AFE_PORT_MAX		137
> 
> does this mean 8 ports are reserved for USB?
> 
> Or is this 137 just a random index coming from the AFE design?
> 
> 

Its the latter.  Each port has a defined number/ID on the audio DSP AFE end.

Thanks
Wesley Cheng

Re: [PATCH v9 07/34] ASoC: Add SOC USB APIs for adding an USB backend

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 2:48 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:00, Wesley Cheng wrote:
>> Some platforms may have support for offloading USB audio devices to a
>> dedicated audio DSP.  Introduce a set of APIs that allow for management of
>> USB sound card and PCM devices enumerated by the USB SND class driver.
>> This allows for the ASoC components to be aware of what USB devices are
> 
> USB devices or USB endpoints? or both?
> 

USB devices.  At least in our case, which endpoints being used will be 
part of handling of the stream start QMI request coming from the audio 
DSP at a later stage.

>> available for offloading.
> 
>> +/**
>> + * struct snd_soc_usb_device
>> + * @card_idx - sound card index associated with USB device
>> + * @chip_idx - USB sound chip array index
>> + * @num_playback - number of playback streams
>> + * @num_capture - number of capture streams
> 
> presumably excluding explicit feedback streams?
> 

That's correct.  This doesn't include explicit streams.  This is going 
to be done during the stage mentioned above.  We find the alternate USB 
interface that supports the requested audio profile.  From there the USB 
SND already checks for if any feedback mechanism is used.

>> + **/
>> +struct snd_soc_usb_device {
>> +	int card_idx;
>> +	int chip_idx;
>> +	int num_playback;
>> +	int num_capture;
>> +};
>> +
>> +/**
>> + * struct snd_soc_usb
>> + * @list - list head for SND SOC struct list
>> + * @dev - USB backend device reference
>> + * @component - reference to ASoC component
>> + * @connection_status_cb - callback to notify connection events
>> + * @priv_data - driver data
>> + **/
>> +struct snd_soc_usb {
>> +	struct list_head list;
>> +	struct device *dev;
> 
> usbdev for consistency with the API below?
> 

This is not the usbdev, but the device reference to the DPCM backend DAI 
(q6usb)

>> +	struct snd_soc_component *component;
> 
> could you use component only and infer the device from component->dev?
> 

True, will look into that.

>> +	int (*connection_status_cb)(struct snd_soc_usb *usb,
>> +			struct snd_soc_usb_device *sdev, bool connected);
>> +	void *priv_data;
>> +};
>> +
>> +int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
>> +int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
>> +void *snd_soc_usb_get_priv_data(struct device *usbdev);
>> +
>> +struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
> 
> struct device *usbdev for consistency ?
> 
>> +			int (*connection_cb)(struct snd_soc_usb *usb,
>> +			struct snd_soc_usb_device *sdev, bool connected));
>> +int snd_soc_usb_remove_port(struct device *dev);
> 
> struct device *usbdev for consistency ?
> 
> 
>> +struct snd_soc_usb *snd_soc_usb_add_port(struct device *dev, void *priv,
>> +			int (*connection_cb)(struct snd_soc_usb *usb,
>> +			struct snd_soc_usb_device *sdev, bool connected))> +{
>> +	struct snd_soc_usb *usb;
>> +
>> +	usb = devm_kzalloc(dev, sizeof(*usb), GFP_KERNEL);
>> +	if (!usb)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	usb->connection_status_cb = connection_cb;
>> +	usb->dev = dev;
>> +	usb->priv_data = priv;
>> +
>> +	mutex_lock(&ctx_mutex);
>> +	list_add_tail(&usb->list, &usb_ctx_list);
>> +	mutex_unlock(&ctx_mutex);
>> +
>> +	return usb;
>> +}
>> +EXPORT_SYMBOL_GPL(snd_soc_usb_add_port);
>> +
>> +/**
>> + * snd_soc_usb_remove_port() - Remove a USB backend port
>> + * @dev: USB backend device
>> + *
>> + * Remove a USB backend device from USB SND SOC.  Memory is freed when USB
>> + * backend is removed.
> 
> when the USB backend driver is unbound?
> 

Will rename.

>> + *
>> + */
>> +int snd_soc_usb_remove_port(struct device *dev)
>> +{
>> +	struct snd_soc_usb *ctx, *tmp;
>> +
>> +	mutex_lock(&ctx_mutex);
>> +	list_for_each_entry_safe(ctx, tmp, &usb_ctx_list, list) {
>> +		if (ctx->dev == dev) {
>> +			list_del(&ctx->list);
>> +			break;
>> +		}
>> +	}
>> +	mutex_unlock(&ctx_mutex);
>> +
>> +	return 0;
> 
> can this return void to align with the current trend?
> 

Sure.

>> +}
>> +EXPORT_SYMBOL_GPL(snd_soc_usb_remove_port);
>> +
>> +/**
>> + * snd_soc_usb_connect() - Notification of USB device connection
>> + * @usbdev: USB bus device
>> + * @card_idx: USB SND card instance
>> + *
>> + * Notify of a new USB SND device connection.  The card_idx can be used to
>> + * handle how the DPCM backend selects, which device to enable USB offloading
>> + * on.
> 
> card_idx is not used below, and I don't see how this relates to a
> notification?
> 

Will fix this comment.

Thanks
Wesley Cheng

Re: [PATCH v9 09/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

[Pierre-Louis Bossart]

>>> Specifically, the QC ADSP can support all potential endpoints that are
>>> exposed by the audio data interface.  This includes, feedback endpoints
>>> (both implicit and explicit) as well as the isochronous (data)
>>> endpoints.
>>
>> implicit feedback means support for capture. This is confusing...
>>
> 
> I mean, a USB device can expose a capture path, but as of now, we won't
> enable the offloading to the audio DSP for it.  However, if we're
> executing playback, and device does support implicit feedback, we will
> pass that along to the audio DSP to utilize.

Not following. Implicit feedback means a capture stream *SHALL* be
started. Are you saying this capture stream is hidden and handled at the
DSP level only? If yes, what prevents you from exposing the capture
stream to userspace as well?

I must be missing something.

>>>   +static const struct snd_soc_dai_ops q6usb_ops = {
>>> +    .probe        = msm_dai_q6_dai_probe,
>>> +    .prepare    = q6afe_dai_prepare,
>>> +    .hw_params    = q6usb_hw_params,
>>
>> this is rather confusing with two different layers used for hw_params
>> and prepare? Additional comments or explanations wouldn't hurt.
>>
> 
> I thought this was how the ASoC design was.  Each DAI defined for a
> particular path has it own set of callbacks implemented to bring up any
> required resources for that entity.  So in this case, it initializes the
> "cpu" DAI, which is the main component that handles communication with
> the audio DSP.

Usually prepare and hw_params rely on the type of DAI callbacks, but
here you are mixing "q6afe" and "q6usb" which are shown in your Patch0
diagram as "cpu" and "codec" dais respectively. I don't think it's
correct to tie the two, it's a clear layering violation IMHO. The codec
dai .prepare should not invoke something that modifies the state of the
CPU dai, which should have its own .prepare callback.

Re: [PATCH v9 00/34] Introduce QC USB SND audio offloading support

[Pierre-Louis Bossart]

On 10/17/23 19:25, Wesley Cheng wrote:
> Hi Pierre,
> 
> On 10/17/2023 1:58 PM, Pierre-Louis Bossart wrote:
>> It's been a very long time since I reviewed earlier versions, and I am
>> still lost on terminology and concepts. The explanations below should
>> really be added as a .rst file in Documentation for reference, not just
>> as a cover letter.
>>
> 
> Thanks for the review!
> 
> Sure, maybe I can write a more comprehensive documentation that saves
> these details somewhere.  Will add a RST documentation for material
> where necessary.
> 
>>> Several Qualcomm based chipsets can support USB audio offloading to a
>>> dedicated audio DSP, which can take over issuing transfers to the USB
>>> host controller.  The intention is to reduce the load on the main
>>> processors in the SoC, and allow them to be placed into lower power
>>> modes.
>>> There are several parts to this design:
>>>    1. Adding ASoC binding layer
>>>    2. Create a USB backend for Q6DSP
>>
>> "backend" is a loaded terms for ASoC. Can you clarify which part of the
>> ascii art below is a 'backend'?
>>
> 
> This would be the Q6USB entity which is the DPCM backend for this
> particular audio path.

DPCM is about dailinks. Technically the q6usb entity is a codec dai
which is part of a DPCM backend dailink.
> 
>>>    3. Introduce XHCI interrupter support
>>>    4. Create vendor ops for the USB SND driver
>>>
>>>        USB                          |            ASoC
>>> --------------------------------------------------------------------
>>>                                     |  _________________________
>>>                                     | |sm8250 platform card     |
>>>                                     | |_________________________|
>>>                                     |         |           |
>>>                                     |      ___V____   ____V____
>>>                                     |     |Q6USB   | |Q6AFE    |
>>>                                     |     |"codec" | |"cpu"    |
>>>                                     |     |________| |_________|
>>>                                     |         ^  ^        ^
>>>                                     |         |  |________|
>>>                                     |      ___V____    |
>>>                                     |     |SOC-USB |   |
>>>     ________       ________               |        |   |
>>>    |USB SND |<--->|QC offld|<------------>|________|   |
>>>    |(card.c)|     |        |<----------                |
>>>    |________|     |________|___     | |                |
>>>        ^               ^       |    | |    ____________V_________
>>>        |               |       |    | |   |APR/GLINK             |
>>>     __ V_______________V_____  |    | |   |______________________|
>>>    |USB SND (endpoint.c)     | |    | |              ^
>>>    |_________________________| |    | |              |
>>>                ^               |    | |   ___________V___________
>>>                |               |    | |->|audio DSP              |
>>>     ___________V_____________  |    |    |_______________________|
>>>    |XHCI HCD                 |<-    |
>>>    |_________________________|      |
>>>
>>>
>>> Adding ASoC binding layer:
>>> soc-usb: Intention is to treat a USB port similar to a headphone jack.
>>
>> What is a 'port'? USB refers to "interfaces" and "endpoints". Is a
>> "port" a 1:1 mapping to "endpoint"?
>>
>> Below I read "AFE port" so not sure what concepts refer to what.
>>
> 
> "Port" in this explanation refers to the USB port.  So the audio device
> connected.  You are right that a USB device can enumerate w/ multiple
> interfaces (ie UAC + HID + ...) so the closest relation to "port" is
> "interface."  It is not a 1:1 mapping w/ the number of endpoints exposed
> by a device.
> 
> "AFE port" is just something that has been termed from the audio DSP
> end, so that concept of port is not related to the port where USB
> devices are connected to.  This is something that is defined within the
> audio DSP.

Wow. So there's a "USB port" and "AFE port". I would recommend avoiding
the same term for completely different concepts. Why not use "USB device"?

>>>   0 [SM8250MTPWCD938]: sm8250 - SM8250-MTP-WCD9380-WSA8810-VA-D
>>>                        SM8250-MTP-WCD9380-WSA8810-VA-DMIC
>>
>> How do you plan on exposing the USB PCM device?
>>
>> The lines above are really cryptic, and with no USB reference in any of
>> the short/long card names it's not obvious that this card is different
>> from the no-offload case, is it?
>>
> 
> In the end, since the offload case is handled by the audio DSP, it would
> have to go through the platform/machine sound card.  That is the sm8250
> device above.
> 
>>>   1 [Audio          ]: USB-Audio - USB Audio
>>>                        Generic USB Audio at usb-xhci-hcd.1.auto-1.4,
>>> high speed
>>
>> likewise some sort of qualifier would be useful to show that card 0 and
>> card 1 can target the same USB endpoints.
>>
> 
> Do userspace entities look at this card string?  Assuming there is only
> one platform card, there are situations where maybe multiple USB audio
> devices are connected to the same USB root hub, so offloading can happen
> on any one of them (not at the same time).

Jaroslav cares, as measured by the changes over the years to make the
card names more self-explanatory.

I really don't see anything in the SM8250MTPWCD938 card name that would
hint at the support of USB. If it's not in the card string, maybe this
can be added in the component string as well (amixer -Dhw:0 info). The
point is that userspace should not have to maintain an 'accept-list' of
card names but have the means to check the USB offload capability with a
vendor-neutral convention.

Re: [PATCH v9 09/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

[Wesley Cheng]

Hi Pierre,

On 10/18/2023 6:47 AM, Pierre-Louis Bossart wrote:
> 
>>>> Specifically, the QC ADSP can support all potential endpoints that are
>>>> exposed by the audio data interface.  This includes, feedback endpoints
>>>> (both implicit and explicit) as well as the isochronous (data)
>>>> endpoints.
>>>
>>> implicit feedback means support for capture. This is confusing...
>>>
>>
>> I mean, a USB device can expose a capture path, but as of now, we won't
>> enable the offloading to the audio DSP for it.  However, if we're
>> executing playback, and device does support implicit feedback, we will
>> pass that along to the audio DSP to utilize.
> 
> Not following. Implicit feedback means a capture stream *SHALL* be
> started. Are you saying this capture stream is hidden and handled at the
> DSP level only? If yes, what prevents you from exposing the capture
> stream to userspace as well?
> 
> I must be missing something.
> 

My understanding is that with implicit feedback endpoints, it allows for 
another data endpoint in the opposite direction to be utilized as a 
feedback endpoint (versus having to expose another EP, such as in the 
case of explicit feedback).  For example, if we are enabling the 
playback path (and the device does have a capture data ep) then the data 
ep used for the capture path can be used.

USB2.0 spec, section 5.12.4.3 (Implicit Feedback)
"
Two cases can arise:
• One or more asynchronous sink endpoints are accompanied by an 
asynchronous source endpoint. The
data rate on the source endpoint can be used as implicit feedback 
information to adjust the data rate on
the sink endpoint(s).
• One or more adaptive source endpoints are accompanied by an adaptive 
sink endpoint. The source
endpoint can adjust its data rate based on the data rate received by the 
sink endpoint.
"

The DSP will get this as part of the USB sync endpoint information which 
it will use to enable this EP.

>>>>    +static const struct snd_soc_dai_ops q6usb_ops = {
>>>> +    .probe        = msm_dai_q6_dai_probe,
>>>> +    .prepare    = q6afe_dai_prepare,
>>>> +    .hw_params    = q6usb_hw_params,
>>>
>>> this is rather confusing with two different layers used for hw_params
>>> and prepare? Additional comments or explanations wouldn't hurt.
>>>
>>
>> I thought this was how the ASoC design was.  Each DAI defined for a
>> particular path has it own set of callbacks implemented to bring up any
>> required resources for that entity.  So in this case, it initializes the
>> "cpu" DAI, which is the main component that handles communication with
>> the audio DSP.
> 
> Usually prepare and hw_params rely on the type of DAI callbacks, but
> here you are mixing "q6afe" and "q6usb" which are shown in your Patch0
> diagram as "cpu" and "codec" dais respectively. I don't think it's
> correct to tie the two, it's a clear layering violation IMHO. The codec
> dai .prepare should not invoke something that modifies the state of the
> CPU dai, which should have its own .prepare callback.

OK, I think I know where the misunderstanding is.  The API callback for 
hw_params() that is being registered here exists in q6afe, but with the 
q6usb prefix.  I will fix that in the next rev.

Thanks
Wesley Cheng

Re: [PATCH v9 00/34] Introduce QC USB SND audio offloading support

[Wesley Cheng]

Hi Pierre,

On 10/18/2023 6:54 AM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 19:25, Wesley Cheng wrote:
>> Hi Pierre,
>>
>> On 10/17/2023 1:58 PM, Pierre-Louis Bossart wrote:
>>> It's been a very long time since I reviewed earlier versions, and I am
>>> still lost on terminology and concepts. The explanations below should
>>> really be added as a .rst file in Documentation for reference, not just
>>> as a cover letter.
>>>
>>
>> Thanks for the review!
>>
>> Sure, maybe I can write a more comprehensive documentation that saves
>> these details somewhere.  Will add a RST documentation for material
>> where necessary.
>>
>>>> Several Qualcomm based chipsets can support USB audio offloading to a
>>>> dedicated audio DSP, which can take over issuing transfers to the USB
>>>> host controller.  The intention is to reduce the load on the main
>>>> processors in the SoC, and allow them to be placed into lower power
>>>> modes.
>>>> There are several parts to this design:
>>>>     1. Adding ASoC binding layer
>>>>     2. Create a USB backend for Q6DSP
>>>
>>> "backend" is a loaded terms for ASoC. Can you clarify which part of the
>>> ascii art below is a 'backend'?
>>>
>>
>> This would be the Q6USB entity which is the DPCM backend for this
>> particular audio path.
> 
> DPCM is about dailinks. Technically the q6usb entity is a codec dai
> which is part of a DPCM backend dailink.
>>
>>>>     3. Introduce XHCI interrupter support
>>>>     4. Create vendor ops for the USB SND driver
>>>>
>>>>         USB                          |            ASoC
>>>> --------------------------------------------------------------------
>>>>                                      |  _________________________
>>>>                                      | |sm8250 platform card     |
>>>>                                      | |_________________________|
>>>>                                      |         |           |
>>>>                                      |      ___V____   ____V____
>>>>                                      |     |Q6USB   | |Q6AFE    |
>>>>                                      |     |"codec" | |"cpu"    |
>>>>                                      |     |________| |_________|
>>>>                                      |         ^  ^        ^
>>>>                                      |         |  |________|
>>>>                                      |      ___V____    |
>>>>                                      |     |SOC-USB |   |
>>>>      ________       ________               |        |   |
>>>>     |USB SND |<--->|QC offld|<------------>|________|   |
>>>>     |(card.c)|     |        |<----------                |
>>>>     |________|     |________|___     | |                |
>>>>         ^               ^       |    | |    ____________V_________
>>>>         |               |       |    | |   |APR/GLINK             |
>>>>      __ V_______________V_____  |    | |   |______________________|
>>>>     |USB SND (endpoint.c)     | |    | |              ^
>>>>     |_________________________| |    | |              |
>>>>                 ^               |    | |   ___________V___________
>>>>                 |               |    | |->|audio DSP              |
>>>>      ___________V_____________  |    |    |_______________________|
>>>>     |XHCI HCD                 |<-    |
>>>>     |_________________________|      |
>>>>
>>>>
>>>> Adding ASoC binding layer:
>>>> soc-usb: Intention is to treat a USB port similar to a headphone jack.
>>>
>>> What is a 'port'? USB refers to "interfaces" and "endpoints". Is a
>>> "port" a 1:1 mapping to "endpoint"?
>>>
>>> Below I read "AFE port" so not sure what concepts refer to what.
>>>
>>
>> "Port" in this explanation refers to the USB port.  So the audio device
>> connected.  You are right that a USB device can enumerate w/ multiple
>> interfaces (ie UAC + HID + ...) so the closest relation to "port" is
>> "interface."  It is not a 1:1 mapping w/ the number of endpoints exposed
>> by a device.
>>
>> "AFE port" is just something that has been termed from the audio DSP
>> end, so that concept of port is not related to the port where USB
>> devices are connected to.  This is something that is defined within the
>> audio DSP.
> 
> Wow. So there's a "USB port" and "AFE port". I would recommend avoiding
> the same term for completely different concepts. Why not use "USB device"?
> 

I think maybe USB interface is probably the most acceptable, since even 
at the USB snd level, they work based on usb_interface, not on the udev 
(USB device) itself.

>>>>    0 [SM8250MTPWCD938]: sm8250 - SM8250-MTP-WCD9380-WSA8810-VA-D
>>>>                         SM8250-MTP-WCD9380-WSA8810-VA-DMIC
>>>
>>> How do you plan on exposing the USB PCM device?
>>>
>>> The lines above are really cryptic, and with no USB reference in any of
>>> the short/long card names it's not obvious that this card is different
>>> from the no-offload case, is it?
>>>
>>
>> In the end, since the offload case is handled by the audio DSP, it would
>> have to go through the platform/machine sound card.  That is the sm8250
>> device above.
>>
>>>>    1 [Audio          ]: USB-Audio - USB Audio
>>>>                         Generic USB Audio at usb-xhci-hcd.1.auto-1.4,
>>>> high speed
>>>
>>> likewise some sort of qualifier would be useful to show that card 0 and
>>> card 1 can target the same USB endpoints.
>>>
>>
>> Do userspace entities look at this card string?  Assuming there is only
>> one platform card, there are situations where maybe multiple USB audio
>> devices are connected to the same USB root hub, so offloading can happen
>> on any one of them (not at the same time).
> 
> Jaroslav cares, as measured by the changes over the years to make the
> card names more self-explanatory.
> 
> I really don't see anything in the SM8250MTPWCD938 card name that would
> hint at the support of USB. If it's not in the card string, maybe this
> can be added in the component string as well (amixer -Dhw:0 info). The
> point is that userspace should not have to maintain an 'accept-list' of
> card names but have the means to check the USB offload capability with a
> vendor-neutral convention.

I'll take a look at adding it into the components string.  At least in 
that case, we'd be able to dynamically modify to say if USB offload is 
supported or not based on the child entries/paths that are defined in 
the DT node.

Thanks
Wesley Cheng

Re: [PATCH v9 20/34] ALSA: usb-audio: Check for support for requested audio format

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:29 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:00, Wesley Cheng wrote:
>> Allow for checks on a specific USB audio device to see if a requested PCM
>> format is supported.  This is needed for support for when playback is
> 
> This is needed for support when playback is
> 

Will fix this typo

>> initiated by the ASoC USB backend path.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   sound/usb/card.c | 40 ++++++++++++++++++++++++++++++++++++++++
>>   sound/usb/card.h | 11 +++++++++++
>>   2 files changed, 51 insertions(+)
>>
>> diff --git a/sound/usb/card.c b/sound/usb/card.c
>> index c0b312e264bf..88f431917c15 100644
>> --- a/sound/usb/card.c
>> +++ b/sound/usb/card.c
>> @@ -162,6 +162,46 @@ int snd_usb_unregister_platform_ops(void)
>>   }
>>   EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
>>   
>> +/*
>> + * Checks to see if requested audio profile, i.e sample rate, # of
>> + * channels, etc... is supported by the substream associated to the
>> + * USB audio device.
>> + */
>> +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx,
>> +			struct snd_pcm_hw_params *params, int direction)
>> +{
>> +	struct snd_usb_audio *chip;
>> +	struct snd_usb_substream *subs = NULL;
> 
> useless init?
> 

Agreed.

Thanks
Wesley Cheng

Re: [PATCH v9 21/34] ASoC: usb: Add PCM format check API for USB backend

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:33 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:00, Wesley Cheng wrote:
>> Introduce a check for if a particular PCM format is supported by the USB
> 
> Introduce a helper to check if a ...
> 

Ack.

>> audio device connected.  If the USB audio device does not have an audio
>> profile which can support the requested format, then notify the USB
>> backend.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   include/sound/soc-usb.h |  3 +++
>>   sound/soc/soc-usb.c     | 13 +++++++++++++
>>   2 files changed, 16 insertions(+)
>>
>> diff --git a/include/sound/soc-usb.h b/include/sound/soc-usb.h
>> index 58c686f4f7ba..c6ddc055c4cd 100644
>> --- a/include/sound/soc-usb.h
>> +++ b/include/sound/soc-usb.h
>> @@ -37,6 +37,9 @@ struct snd_soc_usb {
>>   	void *priv_data;
>>   };
>>   
>> +int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
>> +			int direction);
>> +
>>   int snd_soc_usb_connect(struct device *usbdev, struct snd_soc_usb_device *sdev);
>>   int snd_soc_usb_disconnect(struct device *usbdev, struct snd_soc_usb_device *sdev);
>>   void *snd_soc_usb_find_priv_data(struct device *usbdev);
>> diff --git a/sound/soc/soc-usb.c b/sound/soc/soc-usb.c
>> index 73b1bcc3b506..7407678a993e 100644
>> --- a/sound/soc/soc-usb.c
>> +++ b/sound/soc/soc-usb.c
>> @@ -63,6 +63,19 @@ void *snd_soc_usb_find_priv_data(struct device *dev)
>>   }
>>   EXPORT_SYMBOL_GPL(snd_soc_usb_find_priv_data);
>>   
>> +int snd_soc_usb_find_format(int card_idx, struct snd_pcm_hw_params *params,
>> +			int direction)
>> +{
>> +	struct snd_usb_stream *as;
>> +
>> +	as = snd_usb_find_suppported_substream(card_idx, params, direction);
>> +	if (!as)
>> +		return -EOPNOTSUPP;
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(snd_soc_usb_find_format);
> 
> Is this the right way to check for formats?
> 
> formats are defined within the scope of an endpoint, and those endpoints
> are themselves defined within the scope of an interface?
> 
> I don't see a notion of endpoint here. Does this assume all endpoints
> are valid, or maybe the existence of a single endpoint in a device?
> 
> Confused.

At least in terms of USB and USB UAC, formats are defined within an 
audio streaming interface descriptor, which will include multiple (up to 
2) USB endpoints.  Those endpoints will be described w/ both an audio 
streaming endpoint descriptor as well as a standard USB endpoint 
descriptor.  The audio interface/format descriptors are the ones that 
carry the information about what formats are supported by the USB 
device.  So this API finds a possible USB AS streaming descriptor on the 
device that matches the requested one.  Endpoints will be opened 
subsequently when the audio stream is started, and an interface is 
enabled by sending a SET_INTERFACE control packet on the USB bus.

Thanks
Wesley Cheng

Re: [PATCH v9 23/34] ALSA: usb-audio: Prevent starting of audio stream if in use

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:37 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:00, Wesley Cheng wrote:
>> With USB audio offloading, an audio session is started from the ASoC
>> platform sound card and PCM devices.  Likewise, the USB SND path is still
>> readily available for use, in case the non-offload path is desired.  In
>> order to prevent the two entities from attempting to use the USB bus,
>> introduce a flag that determines when either paths are in use.
>>
>> If a PCM device is already in use, the check will return an error to
>> userspace notifying that the stream is currently busy.  This ensures that
>> only one path is using the USB substream.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   sound/usb/card.h                  |  1 +
>>   sound/usb/pcm.c                   | 19 +++++++++++++++++--
>>   sound/usb/qcom/qc_audio_offload.c | 15 ++++++++++++++-
> 
> should this be split in a generic part and a more specific qcom patch?
> 

Got it.

Thanks
Wesley Cheng

Re: [PATCH v9 26/34] ASoC: qcom: qdsp6: q6afe: Split USB AFE dev_token param into separate API

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:39 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:01, Wesley Cheng wrote:
>> The Q6USB backend can carry information about the available USB SND cards
>> and PCM devices discovered on the USB bus.  The dev_token field is used by
>> the audio DSP to notify the USB offload driver of which card and PCM index
>> to enable playback on.  Separate this into a dedicated API, so the USB
>> backend can set the dev_token accordingly.  The audio DSP does not utilize
>> this information until the AFE port start command is sent, which is done
>> during the PCM prepare phase.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   sound/soc/qcom/qdsp6/q6afe.c | 49 +++++++++++++++++++++++++-----------
>>   sound/soc/qcom/qdsp6/q6afe.h |  1 +
>>   2 files changed, 36 insertions(+), 14 deletions(-)
>>
>> diff --git a/sound/soc/qcom/qdsp6/q6afe.c b/sound/soc/qcom/qdsp6/q6afe.c
>> index 72c4e6fe20c4..f09a756246f8 100644
>> --- a/sound/soc/qcom/qdsp6/q6afe.c
>> +++ b/sound/soc/qcom/qdsp6/q6afe.c
>> @@ -1394,10 +1394,42 @@ void q6afe_tdm_port_prepare(struct q6afe_port *port,
>>   }
>>   EXPORT_SYMBOL_GPL(q6afe_tdm_port_prepare);
>>   
>> -static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
>> +/**
>> + * afe_port_send_usb_dev_param() - Send USB dev token
>> + *
>> + * @port: Instance of afe port
>> + * @cardidx: USB SND card index to reference
>> + * @pcmidx: USB SND PCM device index to reference
>> + *
>> + * The USB dev token carries information about which USB SND card instance and
>> + * PCM device to execute the offload on.  This information is carried through
>> + * to the stream enable QMI request, which is handled by the offload class
>> + * driver.  The information is parsed to determine which USB device to query
>> + * the required resources for.
>> + */
>> +int afe_port_send_usb_dev_param(struct q6afe_port *port, int cardidx, int pcmidx)
>>   {
>> -	union afe_port_config *pcfg = &port->port_cfg;
>>   	struct afe_param_id_usb_audio_dev_params usb_dev;
>> +	int ret;
>> +
>> +	memset(&usb_dev, 0, sizeof(usb_dev));
>> +
>> +	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
>> +	usb_dev.dev_token = (cardidx << 16) | (pcmidx << 8);
>> +	ret = q6afe_port_set_param_v2(port, &usb_dev,
>> +				AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
>> +				AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
>> +	if (ret)
>> +		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
>> +			__func__, ret);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(afe_port_send_usb_dev_param);
>> +
>> +static int afe_port_send_usb_params(struct q6afe_port *port, struct q6afe_usb_cfg *cfg)
>> +{
>> +	union afe_port_config *pcfg = &port->port_cfg;
>>   	struct afe_param_id_usb_audio_dev_lpcm_fmt lpcm_fmt;
>>   	struct afe_param_id_usb_audio_svc_interval svc_int;
>>   	int ret = 0;
>> @@ -1408,20 +1440,9 @@ static int afe_port_send_usb_dev_param(struct q6afe_port *port, struct q6afe_usb
>>   		goto exit;
>>   	}
>>   
>> -	memset(&usb_dev, 0, sizeof(usb_dev));
>>   	memset(&lpcm_fmt, 0, sizeof(lpcm_fmt));
>>   	memset(&svc_int, 0, sizeof(svc_int));
>>   
>> -	usb_dev.cfg_minor_version = AFE_API_MINOR_VERSION_USB_AUDIO_CONFIG;
>> -	ret = q6afe_port_set_param_v2(port, &usb_dev,
>> -				      AFE_PARAM_ID_USB_AUDIO_DEV_PARAMS,
>> -				      AFE_MODULE_AUDIO_DEV_INTERFACE, sizeof(usb_dev));
>> -	if (ret) {
>> -		dev_err(port->afe->dev, "%s: AFE device param cmd failed %d\n",
>> -			__func__, ret);
>> -		goto exit;
>> -	}
>> -
> 
> this feels like a questionable patch split. Why not introduce the new
> helper earlier and avoid adding code then modifying the same code?
> 

Let me see if I can squash this with the change that adds the USB AFE port.

Thanks
Wesley Cheng

Re: [PATCH v9 27/34] ALSA: usb-audio: qcom: Populate PCM and USB chip information

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:41 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:01, Wesley Cheng wrote:
>> Currently, only the index to the USB SND card array is passed to the USB
>> backend.  Pass through more information, specifically the USB SND card
>> number and the number of PCM devices available.  This allows for the DPCM
>> backend to determine what USB resources are available during situations,
>> such as USB audio offloading.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   sound/usb/qcom/qc_audio_offload.c | 21 ++++++++++++++++++---
>>   1 file changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/sound/usb/qcom/qc_audio_offload.c b/sound/usb/qcom/qc_audio_offload.c
>> index bd6b84f72c74..ae74098b41f5 100644
>> --- a/sound/usb/qcom/qc_audio_offload.c
>> +++ b/sound/usb/qcom/qc_audio_offload.c
>> @@ -173,6 +173,21 @@ enum usb_qmi_audio_format {
>>   	USB_QMI_PCM_FORMAT_U32_BE,
>>   };
>>   
>> +static int usb_qmi_get_pcm_num(struct snd_usb_audio *chip, int direction)
>> +{
>> +	struct snd_usb_substream *subs = NULL;
>> +	struct snd_usb_stream *as;
>> +	int count = 0;
>> +
>> +	list_for_each_entry(as, &chip->pcm_list, list) {
>> +		subs = &as->substream[direction];
>> +		if (subs->ep_num)
>> +			count++;
>> +	}
>> +
>> +	return count;
>> +}
>> +
>>   static enum usb_qmi_audio_device_speed_enum_v01
>>   get_speed_info(enum usb_device_speed udev_speed)
>>   {
>> @@ -1592,6 +1607,8 @@ static void qc_usb_audio_offload_probe(struct snd_usb_audio *chip)
>>   
>>   	sdev->card_idx = chip->card->number;
>>   	sdev->chip_idx = chip->index;
>> +	sdev->num_playback = usb_qmi_get_pcm_num(chip, 0);
>> +	sdev->num_capture = usb_qmi_get_pcm_num(chip, 1);
>>   	uadev[chip->card->number].sdev = sdev;
>>   
>>   	uaudio_qdev->last_card_num = chip->card->number;
>> @@ -1706,10 +1723,8 @@ static void qc_usb_audio_offload_disconnect(struct snd_usb_audio *chip)
>>   	mutex_unlock(&chip->mutex);
>>   
>>   	atomic_dec(&uaudio_qdev->qdev_in_use);
>> -	if (!atomic_read(&uaudio_qdev->qdev_in_use)) {
>> -		snd_soc_usb_disconnect(usb_get_usb_backend(udev));
> 
> this also feels like a patch split issue, removing this
> snd_soc_usb_disconnect() has nothing to do with the "populate PCM and
> USB chip information" ?
> 

Will fix this.

Thanks
Wesley Cheng

Re: [PATCH v9 09/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

[Pierre-Louis Bossart]

>>>>> Specifically, the QC ADSP can support all potential endpoints that are
>>>>> exposed by the audio data interface.  This includes, feedback
>>>>> endpoints
>>>>> (both implicit and explicit) as well as the isochronous (data)
>>>>> endpoints.
>>>>
>>>> implicit feedback means support for capture. This is confusing...
>>>>
>>>
>>> I mean, a USB device can expose a capture path, but as of now, we won't
>>> enable the offloading to the audio DSP for it.  However, if we're
>>> executing playback, and device does support implicit feedback, we will
>>> pass that along to the audio DSP to utilize.
>>
>> Not following. Implicit feedback means a capture stream *SHALL* be
>> started. Are you saying this capture stream is hidden and handled at the
>> DSP level only? If yes, what prevents you from exposing the capture
>> stream to userspace as well?
>>
>> I must be missing something.
>>
> 
> My understanding is that with implicit feedback endpoints, it allows for
> another data endpoint in the opposite direction to be utilized as a
> feedback endpoint (versus having to expose another EP, such as in the
> case of explicit feedback).  For example, if we are enabling the
> playback path (and the device does have a capture data ep) then the data
> ep used for the capture path can be used.

That's right, so all the plumbing is enabled for the capture path...
Making a decision to discard the data is very odd, all the work has
already been done at lower levels, so why not expose the captured data?

Re: [PATCH v9 28/34] ASoC: qcom: qdsp6: Add support to track available USB PCM devices

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:43 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:01, Wesley Cheng wrote:
>> The USB backend should know about which sound resources are being shared
>> between the ASoC and USB SND paths.  This can be utilized to properly
>> select and maintain the offloading devices.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   sound/soc/qcom/qdsp6/q6usb.c | 16 ++++++++++++++++
>>   1 file changed, 16 insertions(+)
>>
>> diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
>> index 329a7d4a3c01..d697cbe7f184 100644
>> --- a/sound/soc/qcom/qdsp6/q6usb.c
>> +++ b/sound/soc/qcom/qdsp6/q6usb.c
>> @@ -25,10 +25,18 @@
>>   
>>   #define SID_MASK	0xF
>>   
>> +struct q6usb_status {
>> +	unsigned int num_pcm;
> 
> how would one know which ones are capture and which ones are playback?
> 
> This really looks like a playback-only assumption, despite earlier
> mentions of capture supported.
> 

Yes, playback only, which is the reasoning for only having one parameter 
here.  I will rename it though to be clearer.

Thanks
Wesley Cheng

>> +	unsigned int chip_index;
>> +	unsigned int pcm_index;
>> +};
>> +
>>   struct q6usb_port_data {
>>   	struct q6afe_usb_cfg usb_cfg;
>>   	struct snd_soc_usb *usb;
>>   	struct q6usb_offload priv;
>> +	unsigned long available_card_slot;
>> +	struct q6usb_status status[SNDRV_CARDS];
>>   	int active_idx;
>>   };
>>   
>> @@ -110,6 +118,14 @@ static int q6usb_alsa_connection_cb(struct snd_soc_usb *usb,
>>   	if (connected) {
>>   		/* We only track the latest USB headset plugged in */
>>   		data->active_idx = sdev->card_idx;
>> +
>> +		set_bit(sdev->card_idx, &data->available_card_slot);
>> +		data->status[sdev->card_idx].num_pcm = sdev->num_playback;
> 
> there you go...
> 
>> +		data->status[sdev->card_idx].chip_index = sdev->chip_idx;
>> +	} else {
>> +		clear_bit(sdev->card_idx, &data->available_card_slot);
>> +		data->status[sdev->card_idx].num_pcm = 0;
>> +		data->status[sdev->card_idx].chip_index = 0;
>>   	}
>>   
>>   	return 0;

Re: [PATCH v9 29/34] ASoC: qcom: qdsp6: Add SND kcontrol to select offload device

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:50 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:01, Wesley Cheng wrote:
>> Expose a kcontrol on the platform sound card, which will allow for
>> userspace to determine which USB card number and PCM device to offload.
>> This allows for userspace to potentially tag an alternate path for a
>> specific USB SND card and PCM device.  Previously, control was absent, and
>> the offload path would be enabled on the last USB SND device which was
>> connected.  This logic will continue to be applicable if no mixer input is
>> received for specific device selection.
>>
>> An example to configure the offload device using tinymix:
>> tinymix -D 0 set 'Q6USB offload SND device select' 1 0
>>
>> The above will set the Q6AFE device token to choose offload on card#1 and
>> pcm#0.  Device selection is made possible by setting the Q6AFE device
>> token.  The audio DSP utilizes this parameter, and will pass this field
>> back to the USB offload driver within the QMI stream requests.
> 
> This still begs the question on how userspace would figure what the
> card1 is and which endpoint is used when PCM0 is opened?
> 

Assuming we have something maybe in the component string for card1, then 
maybe that will help in this case as you mentioned earlier.  Again, I 
think my understanding of "endpoint" here is referring to the USB 
endpoint.  However, that isn't normally how we should think about it. 
 From the USB sound perspective, it would be the USB interface that is 
selected, and the USB endpoints that that interface descriptor includes 
(up to 2 usb eps).

> Ideally userpace would not have to know anything about "Q6USB".
> Presumably when other vendors expose their USB offload solution, we
> would want a generic control name, no?
> 

Hmm...initially I was keeping the sound kcontrol implementation based on 
a vendor specific approach.  Although, it might be good to standardize 
it a bit.  I could see if we can add this to within soc-usb so whenever 
we just create a soc usb device, it would also create and initialize the 
kcontrols as well?

> Jaroslav should chime in on this one :-)
> 
> 
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>   sound/soc/qcom/qdsp6/q6usb.c | 125 ++++++++++++++++++++++++++++++++++-
>>   1 file changed, 122 insertions(+), 3 deletions(-)
>>
>> diff --git a/sound/soc/qcom/qdsp6/q6usb.c b/sound/soc/qcom/qdsp6/q6usb.c
>> index d697cbe7f184..a95276b7d91d 100644
>> --- a/sound/soc/qcom/qdsp6/q6usb.c
>> +++ b/sound/soc/qcom/qdsp6/q6usb.c
>> @@ -14,6 +14,7 @@
>>   #include <linux/dma-map-ops.h>
>>   
>>   #include <sound/pcm.h>
>> +#include <sound/control.h>
>>   #include <sound/soc.h>
>>   #include <sound/soc-usb.h>
>>   #include <sound/pcm_params.h>
>> @@ -35,9 +36,12 @@ struct q6usb_port_data {
>>   	struct q6afe_usb_cfg usb_cfg;
>>   	struct snd_soc_usb *usb;
>>   	struct q6usb_offload priv;
>> +	struct mutex mutex;
> 
> missing comment on what this protects. "mutex" is really a poor
> choice/name if I am honest.
> 
>>   	unsigned long available_card_slot;
>>   	struct q6usb_status status[SNDRV_CARDS];
>> -	int active_idx;
>> +	bool idx_valid;
>> +	int sel_card_idx;
>> +	int sel_pcm_idx;
>>   };
> 
>> +/* Build a mixer control for a UAC connector control (jack-detect) */
>> +static void q6usb_connector_control_init(struct snd_soc_component *component)
>> +{
>> +	int ret;
>> +
>> +	ret = snd_ctl_add(component->card->snd_card,
>> +				snd_ctl_new1(&q6usb_offload_dev_ctrl, component));
>> +	if (ret < 0)
>> +		return;
> 
> that error handling does not seem terribly useful...
> 

Based on your earlier comment, this might change :)

Thanks
Wesley Cheng

Re: [PATCH v9 30/34] ASoC: qcom: qdsp6: Add SND kcontrol for fetching offload status

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 3:53 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:01, Wesley Cheng wrote:
>> Add a kcontrol to the platform sound card to fetch the current offload
>> status.  This can allow for userspace to ensure/check which USB SND
>> resources are actually busy versus having to attempt opening the USB SND
>> devices, which will result in an error if offloading is active.
> 
> I think I mentioned this a while back, but why not add the status in the
> USB card itself? That's a generic component that all userspace agent
> could query. Having a QCOM-specific control doesn't make the life of
> userspace easier IMHO.
> 
> 

Will take a look at this based on the comments you had in the other 
kcontrol patch.  Seeing if we can move it to a more generic layer.

Thanks
Wesley Cheng

Re: [PATCH v9 09/34] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp

[Wesley Cheng]

Hi Pierre,

On 10/18/2023 6:00 PM, Pierre-Louis Bossart wrote:
> 
> 
>>>>>> Specifically, the QC ADSP can support all potential endpoints that are
>>>>>> exposed by the audio data interface.  This includes, feedback
>>>>>> endpoints
>>>>>> (both implicit and explicit) as well as the isochronous (data)
>>>>>> endpoints.
>>>>>
>>>>> implicit feedback means support for capture. This is confusing...
>>>>>
>>>>
>>>> I mean, a USB device can expose a capture path, but as of now, we won't
>>>> enable the offloading to the audio DSP for it.  However, if we're
>>>> executing playback, and device does support implicit feedback, we will
>>>> pass that along to the audio DSP to utilize.
>>>
>>> Not following. Implicit feedback means a capture stream *SHALL* be
>>> started. Are you saying this capture stream is hidden and handled at the
>>> DSP level only? If yes, what prevents you from exposing the capture
>>> stream to userspace as well?
>>>
>>> I must be missing something.
>>>
>>
>> My understanding is that with implicit feedback endpoints, it allows for
>> another data endpoint in the opposite direction to be utilized as a
>> feedback endpoint (versus having to expose another EP, such as in the
>> case of explicit feedback).  For example, if we are enabling the
>> playback path (and the device does have a capture data ep) then the data
>> ep used for the capture path can be used.
> 
> That's right, so all the plumbing is enabled for the capture path...
> Making a decision to discard the data is very odd, all the work has
> already been done at lower levels, so why not expose the captured data?
> 

So that would be at the USB level, but from the audio DSP end, there are 
still things that need to be enabled to route the data properly.  For 
feedback endpoints, the data we're actually sending won't involve the 
audio streaming side of things on the DSP.

Thanks
Wesley Cheng

Re: [PATCH v9 30/34] ASoC: qcom: qdsp6: Add SND kcontrol for fetching offload status

[Wesley Cheng]

Hi Pierre,

On 10/18/2023 6:41 PM, Wesley Cheng wrote:
> Hi Pierre,
> 
> On 10/17/2023 3:53 PM, Pierre-Louis Bossart wrote:
>>
>>
>> On 10/17/23 15:01, Wesley Cheng wrote:
>>> Add a kcontrol to the platform sound card to fetch the current offload
>>> status.  This can allow for userspace to ensure/check which USB SND
>>> resources are actually busy versus having to attempt opening the USB SND
>>> devices, which will result in an error if offloading is active.
>>
>> I think I mentioned this a while back, but why not add the status in the
>> USB card itself? That's a generic component that all userspace agent
>> could query. Having a QCOM-specific control doesn't make the life of
>> userspace easier IMHO.
>>
>>
> 
> Will take a look at this based on the comments you had in the other 
> kcontrol patch.  Seeing if we can move it to a more generic layer.
> 

I think it would make more sense to see if we can keep all the offload 
kcontrols under the sound card exposed by the platform.  Especially, if 
we are going to modify the components string of the card to signify that 
it supports USB offload.

Thanks
Wesley Cheng

Re: [PATCH v9 30/34] ASoC: qcom: qdsp6: Add SND kcontrol for fetching offload status

[Pierre-Louis Bossart]

>>>> Add a kcontrol to the platform sound card to fetch the current offload
>>>> status.  This can allow for userspace to ensure/check which USB SND
>>>> resources are actually busy versus having to attempt opening the USB
>>>> SND
>>>> devices, which will result in an error if offloading is active.
>>>
>>> I think I mentioned this a while back, but why not add the status in the
>>> USB card itself? That's a generic component that all userspace agent
>>> could query. Having a QCOM-specific control doesn't make the life of
>>> userspace easier IMHO.
>>>
>>>
>>
>> Will take a look at this based on the comments you had in the other
>> kcontrol patch.  Seeing if we can move it to a more generic layer.
>>
> 
> I think it would make more sense to see if we can keep all the offload
> kcontrols under the sound card exposed by the platform.  Especially, if
> we are going to modify the components string of the card to signify that
> it supports USB offload.

A two-way relationship would be ideal, i.e.
- the USB card has an indicator that it's currently bound with another
"platform" card that offers optimized offloaded capabilities.
- the platform card has a indicator that it exposes one or more PCM
devices routed to the USB card endpoint.

Android/HAL would typically start with the latter while other more
generic solutions would start from the former.

Re: [PATCH v9 34/34] ASoC: usb: Rediscover USB SND devices on USB port add

[Wesley Cheng]

Hi Pierre,

On 10/17/2023 4:11 PM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/17/23 15:01, Wesley Cheng wrote:
>> In case the USB backend device has not been initialized/probed, USB SND
>> device connections can still occur.  When the USB backend is eventually
>> made available, previous USB SND device connections are not communicated to
>> the USB backend.  Call snd_usb_rediscover_devices() to generate the connect
>> callbacks for all USB SND devices connected.  This will allow for the USB
>> backend to be updated with the current set of devices available.
>>
>> The chip array entries are all populated and removed while under the
>> register_mutex, so going over potential race conditions:
>>
>> Thread#1:
>>    q6usb_component_probe()
>>      --> snd_soc_usb_add_port()
>>        --> snd_usb_rediscover_devices()
>>          --> mutex_lock(register_mutex)
>>
>> Thread#2
>>    --> usb_audio_disconnect()
>>      --> mutex_lock(register_mutex)
>>
>> So either thread#1 or thread#2 will complete first.  If
>>
>> Thread#1 completes before thread#2:
>>    SOC USB will notify DPCM backend of the device connection.  Shortly
>>    after, once thread#2 runs, we will get a disconnect event for the
>>    connected device.
>>
>> Thread#2 completes before thread#1:
>>    Then during snd_usb_rediscover_devices() it won't notify of any
>>    connection for that particular chip index.
> Looks like you are assuming the regular USB audio stuff is probed first?
> 
> What if it's not the case? Have you tested with a manual 'blacklist' and
> "modprobe" sequence long after all the DSP stuff is initialized?
> 
> It really reminds me of audio+display issues, and the same opens apply IMHO.

Not necessarily...if the USB audio driver is not probed, then that is 
the same scenario as when there is no USB audio capable device plugged 
in, while the offload path is waiting for the connect event. I think 
this is the standard scenario.

In the situation where the platform sound card hasn't probed yet and USB 
audio devices are being identified, then that is basically the scenario 
that would be more of an issue, since its USB SND that notifies of the 
connection state (at the time of connect/disconnect).

I've tried with building these drivers as modules and probing them at 
different times/sequences, and I haven't seen an issue so far.

Thanks
Wesley Cheng

Re: [PATCH v9 34/34] ASoC: usb: Rediscover USB SND devices on USB port add

[Pierre-Louis Bossart]

On 10/23/23 16:54, Wesley Cheng wrote:
> Hi Pierre,
> 
> On 10/17/2023 4:11 PM, Pierre-Louis Bossart wrote:
>>
>>
>> On 10/17/23 15:01, Wesley Cheng wrote:
>>> In case the USB backend device has not been initialized/probed, USB SND
>>> device connections can still occur.  When the USB backend is eventually
>>> made available, previous USB SND device connections are not
>>> communicated to
>>> the USB backend.  Call snd_usb_rediscover_devices() to generate the
>>> connect
>>> callbacks for all USB SND devices connected.  This will allow for the
>>> USB
>>> backend to be updated with the current set of devices available.
>>>
>>> The chip array entries are all populated and removed while under the
>>> register_mutex, so going over potential race conditions:
>>>
>>> Thread#1:
>>>    q6usb_component_probe()
>>>      --> snd_soc_usb_add_port()
>>>        --> snd_usb_rediscover_devices()
>>>          --> mutex_lock(register_mutex)
>>>
>>> Thread#2
>>>    --> usb_audio_disconnect()
>>>      --> mutex_lock(register_mutex)
>>>
>>> So either thread#1 or thread#2 will complete first.  If
>>>
>>> Thread#1 completes before thread#2:
>>>    SOC USB will notify DPCM backend of the device connection.  Shortly
>>>    after, once thread#2 runs, we will get a disconnect event for the
>>>    connected device.
>>>
>>> Thread#2 completes before thread#1:
>>>    Then during snd_usb_rediscover_devices() it won't notify of any
>>>    connection for that particular chip index.
>> Looks like you are assuming the regular USB audio stuff is probed first?
>>
>> What if it's not the case? Have you tested with a manual 'blacklist' and
>> "modprobe" sequence long after all the DSP stuff is initialized?
>>
>> It really reminds me of audio+display issues, and the same opens apply
>> IMHO.
> 
> Not necessarily...if the USB audio driver is not probed, then that is
> the same scenario as when there is no USB audio capable device plugged
> in, while the offload path is waiting for the connect event. I think
> this is the standard scenario.
> 
> In the situation where the platform sound card hasn't probed yet and USB
> audio devices are being identified, then that is basically the scenario
> that would be more of an issue, since its USB SND that notifies of the
> connection state (at the time of connect/disconnect).

Not following if this scenario is covered?

> I've tried with building these drivers as modules and probing them at
> different times/sequences, and I haven't seen an issue so far.

The scenario I have in mind is this:

the platform driver is on the deny list, the USB driver detects a
device. When the platform driver probes at a later time (with a manual
modprobe to make delays really long), how would the notification be handled?

Between audio and display, we use the 'drm_audio_component' layer to
model these sort of run-time binding between independent driver stacks.
It's not used here but we need a moral equivalent, don't we?

It would really help if you documented a bit more the dependencies or
timing assumptions, to make sure we have a stable solution to build on.

Re: [PATCH v9 04/34] xhci: sideband: add initial api to register a sideband entity

[Albert Wang]

>+ * Returns the address of the endpoint buffer where xHC controller reads queued
>+ * transfer TRBs from. This is the starting address of the ringbuffer where the
>+ * sidband cliend should write TRBs to.

A typo here 'sideband cliend', it apparently should be 'sideband client'.


On Wed, Oct 18, 2023 at 4:03 AM Wesley Cheng <quic_wcheng@quicinc.com> wrote:
>
> From: Mathias Nyman <mathias.nyman@linux.intel.com>
>
> Introduce XHCI sideband, which manages the USB endpoints being requested by
> a client driver.  This is used for when client drivers are attempting to
> offload USB endpoints to another entity for handling USB transfers.  XHCI
> sideband will allow for drivers to fetch the required information about the
> transfer ring, so the user can submit transfers independently.  Expose the
> required APIs for drivers to register and request for a USB endpoint and to
> manage XHCI secondary interrupters.
>
> Multiple ring segment page linking and proper endpoint clean up added by
> Wesley Cheng to complete original concept code by Mathias Nyman.
>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> Co-developed-by: Wesley Cheng <quic_wcheng@quicinc.com>
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  drivers/usb/host/Kconfig          |   9 +
>  drivers/usb/host/Makefile         |   4 +
>  drivers/usb/host/xhci-sideband.c  | 371 ++++++++++++++++++++++++++++++
>  drivers/usb/host/xhci.h           |   4 +
>  include/linux/usb/xhci-sideband.h |  66 ++++++
>  5 files changed, 454 insertions(+)
>  create mode 100644 drivers/usb/host/xhci-sideband.c
>  create mode 100644 include/linux/usb/xhci-sideband.h
>
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index 4448d0ab06f0..923af11c1982 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -104,6 +104,15 @@ config USB_XHCI_RZV2M
>           Say 'Y' to enable the support for the xHCI host controller
>           found in Renesas RZ/V2M SoC.
>
> +config USB_XHCI_SIDEBAND
> +       bool "xHCI support for sideband"
> +       help
> +         Say 'Y' to enable the support for the xHCI sideband capability.
> +         provide a mechanism for a sideband datapath for payload associated
> +         with audio class endpoints. This allows for an audio DSP to use
> +         xHCI USB endpoints directly, allowing CPU to sleep while playing
> +         audio
> +
>  config USB_XHCI_TEGRA
>         tristate "xHCI support for NVIDIA Tegra SoCs"
>         depends on PHY_TEGRA_XUSB
> diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
> index be4e5245c52f..4df946c05ba0 100644
> --- a/drivers/usb/host/Makefile
> +++ b/drivers/usb/host/Makefile
> @@ -32,6 +32,10 @@ endif
>  xhci-rcar-hcd-y                                += xhci-rcar.o
>  xhci-rcar-hcd-$(CONFIG_USB_XHCI_RZV2M) += xhci-rzv2m.o
>
> +ifneq ($(CONFIG_USB_XHCI_SIDEBAND),)
> +       xhci-hcd-y              += xhci-sideband.o
> +endif
> +
>  obj-$(CONFIG_USB_PCI)  += pci-quirks.o
>
>  obj-$(CONFIG_USB_EHCI_HCD)     += ehci-hcd.o
> diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c
> new file mode 100644
> index 000000000000..cc4f90375e00
> --- /dev/null
> +++ b/drivers/usb/host/xhci-sideband.c
> @@ -0,0 +1,371 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * xHCI host controller sideband support
> + *
> + * Copyright (c) 2023, Intel Corporation.
> + *
> + * Author: Mathias Nyman
> + */
> +
> +#include <linux/usb/xhci-sideband.h>
> +#include <linux/dma-direct.h>
> +
> +#include "xhci.h"
> +
> +/* sideband internal helpers */
> +static struct sg_table *
> +xhci_ring_to_sgtable(struct xhci_sideband *sb, struct xhci_ring *ring)
> +{
> +       struct xhci_segment *seg;
> +       struct sg_table *sgt;
> +       unsigned int n_pages;
> +       struct page **pages;
> +       struct device *dev;
> +       size_t sz;
> +       int i;
> +
> +       dev = xhci_to_hcd(sb->xhci)->self.sysdev;
> +       sz = ring->num_segs * TRB_SEGMENT_SIZE;
> +       n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
> +       pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL);
> +       if (!pages)
> +               return NULL;
> +
> +       sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
> +       if (!sgt) {
> +               kvfree(pages);
> +               return NULL;
> +       }
> +
> +       seg = ring->first_seg;
> +       /*
> +        * Rings can potentially have multiple segments, create an array that
> +        * carries page references to allocated segments.  Utilize the
> +        * sg_alloc_table_from_pages() to create the sg table, and to ensure
> +        * that page links are created.
> +        */
> +       for (i = 0; i < ring->num_segs; i++) {
> +               dma_get_sgtable(dev, sgt, seg->trbs, seg->dma,
> +                                       TRB_SEGMENT_SIZE);
> +               pages[i] = sg_page(sgt->sgl);
> +               sg_free_table(sgt);
> +               seg = seg->next;
> +       }
> +
> +       if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) {
> +               kvfree(pages);
> +               kfree(sgt);
> +
> +               return NULL;
> +       }
> +       /*
> +        * Save first segment dma address to sg dma_address field for the sideband
> +        * client to have access to the IOVA of the ring.
> +        */
> +       sg_dma_address(sgt->sgl) = ring->first_seg->dma;
> +
> +       return sgt;
> +}
> +
> +static void
> +__xhci_sideband_remove_endpoint(struct xhci_sideband *sb, struct xhci_virt_ep *ep)
> +{
> +       /*
> +        * Issue a stop endpoint command when an endpoint is removed.
> +        * The stop ep cmd handler will handle the ring cleanup.
> +        */
> +       xhci_stop_endpoint_sync(sb->xhci, ep, 0, GFP_KERNEL);
> +
> +       ep->sideband = NULL;
> +       sb->eps[ep->ep_index] = NULL;
> +}
> +
> +/* sideband api functions */
> +
> +/**
> + * xhci_sideband_add_endpoint - add endpoint to sideband access list
> + * @sb: sideband instance for this usb device
> + * @host_ep: usb host endpoint
> + *
> + * Adds an endpoint to the list of sideband accessed endpoints for this usb
> + * device.
> + * After an endpoint is added the sideband client can get the endpoint transfer
> + * ring buffer by calling xhci_sideband_endpoint_buffer()
> + *
> + * Return: 0 on success, negative error otherwise.
> + */
> +int
> +xhci_sideband_add_endpoint(struct xhci_sideband *sb,
> +                          struct usb_host_endpoint *host_ep)
> +{
> +       struct xhci_virt_ep *ep;
> +       unsigned int ep_index;
> +
> +       ep_index = xhci_get_endpoint_index(&host_ep->desc);
> +       ep = &sb->vdev->eps[ep_index];
> +
> +       if (ep->ep_state & EP_HAS_STREAMS)
> +               return -EINVAL;
> +
> +       /*
> +        * Note, we don't know the DMA mask of the audio DSP device, if its
> +        * smaller than for xhci it won't be able to access the endpoint ring
> +        * buffer. This could be solved by not allowing the audio class driver
> +        * to add the endpoint the normal way, but instead offload it immediately,
> +        * and let this function add the endpoint and allocate the ring buffer
> +        * with the smallest common DMA mask
> +        */
> +
> +       if (sb->eps[ep_index] || ep->sideband)
> +               return -EBUSY;
> +
> +       ep->sideband = sb;
> +       sb->eps[ep_index] = ep;
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_add_endpoint);
> +
> +/**
> + * xhci_sideband_remove_endpoint - remove endpoint from sideband access list
> + * @sb: sideband instance for this usb device
> + * @host_ep: usb host endpoint
> + *
> + * Removes an endpoint from the list of sideband accessed endpoints for this usb
> + * device.
> + * sideband client should no longer touch the endpoint transfer buffer after
> + * calling this.
> + *
> + * Return: 0 on success, negative error otherwise.
> + */
> +int
> +xhci_sideband_remove_endpoint(struct xhci_sideband *sb,
> +                             struct usb_host_endpoint *host_ep)
> +{
> +       struct xhci_virt_ep *ep;
> +       unsigned int ep_index;
> +
> +       ep_index = xhci_get_endpoint_index(&host_ep->desc);
> +       ep = sb->eps[ep_index];
> +
> +       if (!ep || !ep->sideband)
> +               return -ENODEV;
> +
> +       __xhci_sideband_remove_endpoint(sb, ep);
> +       xhci_initialize_ring_info(ep->ring, 1);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_remove_endpoint);
> +
> +int
> +xhci_sideband_stop_endpoint(struct xhci_sideband *sb,
> +                           struct usb_host_endpoint *host_ep)
> +{
> +       struct xhci_virt_ep *ep;
> +       unsigned int ep_index;
> +
> +       ep_index = xhci_get_endpoint_index(&host_ep->desc);
> +       ep = sb->eps[ep_index];
> +
> +       if (!ep || ep->sideband != sb)
> +               return -EINVAL;
> +
> +       return xhci_stop_endpoint_sync(sb->xhci, ep, 0);
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_stop_endpoint);
> +
> +/**
> + * xhci_sideband_get_endpoint_buffer - gets the endpoint transfer buffer address
> + * @sb: sideband instance for this usb device
> + * @host_ep: usb host endpoint
> + *
> + * Returns the address of the endpoint buffer where xHC controller reads queued
> + * transfer TRBs from. This is the starting address of the ringbuffer where the
> + * sidband cliend should write TRBs to.
> + *
> + * Caller needs to free the returned sg_table
> + *
> + * Return: struct sg_table * if successful. NULL otherwise.
> + */
> +struct sg_table *
> +xhci_sideband_get_endpoint_buffer(struct xhci_sideband *sb,
> +                             struct usb_host_endpoint *host_ep)
> +{
> +       struct xhci_virt_ep *ep;
> +       unsigned int ep_index;
> +
> +       ep_index = xhci_get_endpoint_index(&host_ep->desc);
> +       ep = sb->eps[ep_index];
> +
> +       if (!ep)
> +               return NULL;
> +
> +       return xhci_ring_to_sgtable(sb, ep->ring);
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_get_endpoint_buffer);
> +
> +/**
> + * xhci_sideband_get_event_buffer - return the event buffer for this device
> + * @sb: sideband instance for this usb device
> + *
> + * If a secondary xhci interupter is set up for this usb device then this
> + * function returns the address of the event buffer where xHC writes
> + * the transfer completion events.
> + *
> + * Caller needs to free the returned sg_table
> + *
> + * Return: struct sg_table * if successful. NULL otherwise.
> + */
> +struct sg_table *
> +xhci_sideband_get_event_buffer(struct xhci_sideband *sb)
> +{
> +       if (!sb->ir)
> +               return NULL;
> +
> +       return xhci_ring_to_sgtable(sb, sb->ir->event_ring);
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_get_event_buffer);
> +
> +/**
> + * xhci_sideband_create_interrupter - creates a new interrupter for this sideband
> + * @sb: sideband instance for this usb device
> + *
> + * Sets up a xhci interrupter that can be used for this sideband accessed usb
> + * device. Transfer events for this device can be routed to this interrupters
> + * event ring by setting the 'Interrupter Target' field correctly when queueing
> + * the transfer TRBs.
> + * Once this interrupter is created the interrupter target ID can be obtained
> + * by calling xhci_sideband_interrupter_id()
> + *
> + * Returns 0 on success, negative error otherwise
> + */
> +int
> +xhci_sideband_create_interrupter(struct xhci_sideband *sb)
> +{
> +       if (sb->ir)
> +               return -EBUSY;
> +
> +       sb->ir = xhci_create_secondary_interrupter(xhci_to_hcd(sb->xhci));
> +       if (!sb->ir)
> +               return -ENOMEM;
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_create_interrupter);
> +
> +/**
> + * xhci_sideband_remove_interrupter - remove the interrupter from a sideband
> + * @sb: sideband instance for this usb device
> + *
> + * Removes a registered interrupt for a sideband.  This would allow for other
> + * sideband users to utilize this interrupter.
> + */
> +void
> +xhci_sideband_remove_interrupter(struct xhci_sideband *sb)
> +{
> +       if (!sb || !sb->ir)
> +               return;
> +
> +       xhci_remove_secondary_interrupter(xhci_to_hcd(sb->xhci), sb->ir);
> +
> +       sb->ir = NULL;
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_remove_interrupter);
> +
> +/**
> + * xhci_sideband_interrupter_id - return the interrupter target id
> + * @sb: sideband instance for this usb device
> + *
> + * If a secondary xhci interrupter is set up for this usb device then this
> + * function returns the ID used by the interrupter. The sideband client
> + * needs to write this ID to the 'Interrupter Target' field of the transfer TRBs
> + * it queues on the endpoints transfer ring to ensure transfer completion event
> + * are written by xHC to the correct interrupter event ring.
> + *
> + * Returns interrupter id on success, negative error othgerwise
> + */
> +int
> +xhci_sideband_interrupter_id(struct xhci_sideband *sb)
> +{
> +       if (!sb || !sb->ir)
> +               return -ENODEV;
> +
> +       return sb->ir->intr_num;
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_interrupter_id);
> +
> +/**
> + * xhci_sideband_register - register a sideband for a usb device
> + * @udev: usb device to be accessed via sideband
> + *
> + * Allows for clients to utilize XHCI interrupters and fetch transfer and event
> + * ring parameters for executing data transfers.
> + *
> + * Return: pointer to a new xhci_sideband instance if successful. NULL otherwise.
> + */
> +struct xhci_sideband *
> +xhci_sideband_register(struct usb_device *udev)
> +{
> +       struct usb_hcd *hcd = bus_to_hcd(udev->bus);
> +       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> +       struct xhci_virt_device *vdev;
> +       struct xhci_sideband *sb;
> +
> +       /* make sure the usb device is connected to a xhci controller */
> +       if (!udev->slot_id)
> +               return NULL;
> +
> +       sb = kzalloc_node(sizeof(*sb), GFP_KERNEL, dev_to_node(hcd->self.sysdev));
> +       if (!sb)
> +               return NULL;
> +
> +       /* check this device isn't already controlled via sideband */
> +       spin_lock_irq(&xhci->lock);
> +
> +       vdev = xhci->devs[udev->slot_id];
> +
> +       if (!vdev || vdev->sideband) {
> +               xhci_warn(xhci, "XHCI sideband for slot %d already in use\n",
> +                         udev->slot_id);
> +               spin_unlock_irq(&xhci->lock);
> +               kfree(sb);
> +               return NULL;
> +       }
> +
> +       sb->xhci = xhci;
> +       sb->vdev = vdev;
> +       vdev->sideband = sb;
> +
> +       spin_unlock_irq(&xhci->lock);
> +
> +       return sb;
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_register);
> +
> +/**
> + * xhci_sideband_unregister - unregister sideband access to a usb device
> + * @sb: sideband instance to be unregistered
> + *
> + * Unregisters sideband access to a usb device and frees the sideband
> + * instance.
> + * After this the endpoint and interrupter event buffers should no longer
> + * be accessed via sideband. The xhci driver can now take over handling
> + * the buffers.
> + */
> +void
> +xhci_sideband_unregister(struct xhci_sideband *sb)
> +{
> +       int i;
> +
> +       for (i = 0; i < EP_CTX_PER_DEV; i++)
> +               if (sb->eps[i])
> +                       __xhci_sideband_remove_endpoint(sb, sb->eps[i]);
> +
> +       xhci_sideband_remove_interrupter(sb);
> +
> +       sb->vdev->sideband = NULL;
> +       kfree(sb);
> +}
> +EXPORT_SYMBOL_GPL(xhci_sideband_unregister);
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 4b8caaed6f95..339d37c3a3d9 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -947,6 +947,8 @@ struct xhci_virt_ep {
>         int                     next_frame_id;
>         /* Use new Isoch TRB layout needed for extended TBC support */
>         bool                    use_extended_tbc;
> +       /* set if this endpoint is controlled via sideband access*/
> +       struct xhci_sideband                    *sideband;
>  };
>
>  enum xhci_overhead_type {
> @@ -1010,6 +1012,8 @@ struct xhci_virt_device {
>         u16                             current_mel;
>         /* Used for the debugfs interfaces. */
>         void                            *debugfs_private;
> +       /* set if this device is registered for sideband access */
> +       struct xhci_sideband                    *sideband;
>  };
>
>  /*
> diff --git a/include/linux/usb/xhci-sideband.h b/include/linux/usb/xhci-sideband.h
> new file mode 100644
> index 000000000000..c1457d1800f4
> --- /dev/null
> +++ b/include/linux/usb/xhci-sideband.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * xHCI host controller sideband support
> + *
> + * Copyright (c) 2023, Intel Corporation.
> + *
> + * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
> + */
> +
> +#ifndef __LINUX_XHCI_SIDEBAND_H
> +#define __LINUX_XHCI_SIDEBAND_H
> +
> +#include <linux/scatterlist.h>
> +#include <linux/usb.h>
> +
> +#define        EP_CTX_PER_DEV          31      /* FIMXME defined twice, from xhci.h */
> +
> +struct xhci_sideband;
> +
> +/**
> + * struct xhci_sideband - representation of a sideband accessed usb device.
> + * @xhci: The xhci host controller the usb device is connected to
> + * @vdev: the usb device accessed via sideband
> + * @eps: array of endpoints controlled via sideband
> + * @ir: event handling and buffer for sideband accessed device
> + *
> + * FIXME usb device accessed via sideband Keeping track of sideband accessed usb devices.
> + */
> +
> +struct xhci_sideband {
> +       struct xhci_hcd                 *xhci;
> +       struct xhci_virt_device         *vdev;
> +       struct xhci_virt_ep             *eps[EP_CTX_PER_DEV];
> +       struct xhci_interrupter         *ir;
> +};
> +
> +struct xhci_sideband *
> +xhci_sideband_register(struct usb_device *udev);
> +void
> +xhci_sideband_unregister(struct xhci_sideband *sb);
> +int
> +xhci_sideband_add_endpoint(struct xhci_sideband *sb,
> +                          struct usb_host_endpoint *host_ep);
> +int
> +xhci_sideband_remove_endpoint(struct xhci_sideband *sb,
> +                             struct usb_host_endpoint *host_ep);
> +int
> +xhci_sideband_stop_endpoint(struct xhci_sideband *sb,
> +                           struct usb_host_endpoint *host_ep);
> +struct sg_table *
> +xhci_sideband_get_endpoint_buffer(struct xhci_sideband *sb,
> +                                 struct usb_host_endpoint *host_ep);
> +struct sg_table *
> +xhci_sideband_get_event_buffer(struct xhci_sideband *sb);
> +
> +int
> +xhci_sideband_create_interrupter(struct xhci_sideband *sb);
> +
> +void
> +xhci_sideband_remove_interrupter(struct xhci_sideband *sb);
> +
> +int
> +xhci_sideband_interrupter_id(struct xhci_sideband *sb);
> +
> +#endif /* __LINUX_XHCI_SIDEBAND_H */
> +
>

Re: [PATCH v9 34/34] ASoC: usb: Rediscover USB SND devices on USB port add

[Wesley Cheng]

Hi Pierre,

On 10/24/2023 6:35 AM, Pierre-Louis Bossart wrote:
> 
> 
> On 10/23/23 16:54, Wesley Cheng wrote:
>> Hi Pierre,
>>
>> On 10/17/2023 4:11 PM, Pierre-Louis Bossart wrote:
>>>
>>>
>>> On 10/17/23 15:01, Wesley Cheng wrote:
>>>> In case the USB backend device has not been initialized/probed, USB SND
>>>> device connections can still occur.  When the USB backend is eventually
>>>> made available, previous USB SND device connections are not
>>>> communicated to
>>>> the USB backend.  Call snd_usb_rediscover_devices() to generate the
>>>> connect
>>>> callbacks for all USB SND devices connected.  This will allow for the
>>>> USB
>>>> backend to be updated with the current set of devices available.
>>>>
>>>> The chip array entries are all populated and removed while under the
>>>> register_mutex, so going over potential race conditions:
>>>>
>>>> Thread#1:
>>>>     q6usb_component_probe()
>>>>       --> snd_soc_usb_add_port()
>>>>         --> snd_usb_rediscover_devices()
>>>>           --> mutex_lock(register_mutex)
>>>>
>>>> Thread#2
>>>>     --> usb_audio_disconnect()
>>>>       --> mutex_lock(register_mutex)
>>>>
>>>> So either thread#1 or thread#2 will complete first.  If
>>>>
>>>> Thread#1 completes before thread#2:
>>>>     SOC USB will notify DPCM backend of the device connection.  Shortly
>>>>     after, once thread#2 runs, we will get a disconnect event for the
>>>>     connected device.
>>>>
>>>> Thread#2 completes before thread#1:
>>>>     Then during snd_usb_rediscover_devices() it won't notify of any
>>>>     connection for that particular chip index.
>>> Looks like you are assuming the regular USB audio stuff is probed first?
>>>
>>> What if it's not the case? Have you tested with a manual 'blacklist' and
>>> "modprobe" sequence long after all the DSP stuff is initialized?
>>>
>>> It really reminds me of audio+display issues, and the same opens apply
>>> IMHO.
>>
>> Not necessarily...if the USB audio driver is not probed, then that is
>> the same scenario as when there is no USB audio capable device plugged
>> in, while the offload path is waiting for the connect event. I think
>> this is the standard scenario.
>>
>> In the situation where the platform sound card hasn't probed yet and USB
>> audio devices are being identified, then that is basically the scenario
>> that would be more of an issue, since its USB SND that notifies of the
>> connection state (at the time of connect/disconnect).
> 
> Not following if this scenario is covered?
> 

Yes, this is covered.  For example, if there are already devices 
connected, but the platform sound card is still unbound.  Then this 
rediscover API will be called to traverse through the list of connected 
USB sound devices, so that the USB DPCM dai can know about their 
existence when it is probed.

>> I've tried with building these drivers as modules and probing them at
>> different times/sequences, and I haven't seen an issue so far.
> 
> The scenario I have in mind is this:
> 
> the platform driver is on the deny list, the USB driver detects a
> device. When the platform driver probes at a later time (with a manual
> modprobe to make delays really long), how would the notification be handled?
> 

So that is essentially the same scenario as when there is no USB device 
connected, ie no USB class driver is bounded to anything.  Since the 
notifications are all handled within USB SND (USB class driver) then if 
the module isn't loaded yet, no notification is sent to the DPCM USB 
backend.  Once you say...modprobe the USB SND driver, then the USB 
interface probe occurs, and that would issue the connect callback from 
the USB SND probe routine. (keep in mind these are not platform devices, 
we're working with devices under the usb bus)

> Between audio and display, we use the 'drm_audio_component' layer to
> model these sort of run-time binding between independent driver stacks.
> It's not used here but we need a moral equivalent, don't we?
> 
> It would really help if you documented a bit more the dependencies or
> timing assumptions, to make sure we have a stable solution to build on.
> 

I can add this to the RST that I'll make in detail, and add a summary 
here in the commit message.

Thanks
Wesley Cheng