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* [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver
@ 2020-07-17  1:33 Laurent Pinchart
  2020-07-17  1:33 ` [PATCH v7 1/5] dt: bindings: dma: xilinx: dpdma: DT bindings for Xilinx DPDMA Laurent Pinchart
                   ` (5 more replies)
  0 siblings, 6 replies; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-17  1:33 UTC (permalink / raw)
  To: dmaengine
  Cc: Michal Simek, Hyun Kwon, Tejas Upadhyay, Satish Kumar Nagireddy,
	Vinod Koul, Peter Ujfalusi

Hello,

This patch series adds a new driver for the DPDMA engine found in the
Xilinx ZynqMP.

The previous version can be found at [1]. All review comments have been
taken into account. The main changes are in the DPDMA driver, with
cleanups in the debugfs support, and handling of the !LOAD_EOT case when
preparing transactions.

The driver has been successfully tested with the ZynqMP DisplayPort
subsystem DRM driver.

As I would like to merge both this series and the DRM driver that
depends on it for v5.9 (if still possible), I have based those patches
on top of v5.8-rc1. There's unfortunately a conflict with the DMA engine
next branch, which is easy to resolve.

Vinod, if you're fine with the series, I can propose two ways forward:

- You can apply the patches on top of v5.8-rc1, push that to a base
  branch, merge it into the dmaengine -next branch, and push the base
  branch to a public git tree to let me base the DRM driver on it.

- I can perform that work if you give me a Reviewed-by tag for the
  series (at for patches 2/5 to 4/5), providing you with two signed
  tags, one for the base branch and one for the merged branch. You could
  then just pull the merged branch (please make sure not to rebase it or
  otherwise modify it in that case).

What's your preference ?

[1] https://lore.kernel.org/dmaengine/20200708201906.4546-1-laurent.pinchart@ideasonboard.com/

Hyun Kwon (1):
  dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver

Laurent Pinchart (4):
  dt: bindings: dma: xilinx: dpdma: DT bindings for Xilinx DPDMA
  dmaengine: Add support for repeating transactions
  dmaengine: xilinx: dpdma: Add debugfs support
  arm64: dts: zynqmp: Add DPDMA node

 .../dma/xilinx/xlnx,zynqmp-dpdma.yaml         |   68 +
 Documentation/driver-api/dmaengine/client.rst |    4 +-
 .../driver-api/dmaengine/provider.rst         |   49 +
 MAINTAINERS                                   |    9 +
 .../arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi |    4 +
 arch/arm64/boot/dts/xilinx/zynqmp.dtsi        |   10 +
 drivers/dma/Kconfig                           |   10 +
 drivers/dma/xilinx/Makefile                   |    1 +
 drivers/dma/xilinx/xilinx_dpdma.c             | 1771 +++++++++++++++++
 include/dt-bindings/dma/xlnx-zynqmp-dpdma.h   |   16 +
 include/linux/dmaengine.h                     |   17 +
 11 files changed, 1958 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
 create mode 100644 drivers/dma/xilinx/xilinx_dpdma.c
 create mode 100644 include/dt-bindings/dma/xlnx-zynqmp-dpdma.h

-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v7 1/5] dt: bindings: dma: xilinx: dpdma: DT bindings for Xilinx DPDMA
  2020-07-17  1:33 [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Laurent Pinchart
@ 2020-07-17  1:33 ` Laurent Pinchart
  2020-07-17  1:33 ` [PATCH v7 2/5] dmaengine: Add support for repeating transactions Laurent Pinchart
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-17  1:33 UTC (permalink / raw)
  To: dmaengine
  Cc: Michal Simek, Hyun Kwon, Tejas Upadhyay, Satish Kumar Nagireddy,
	Vinod Koul, Peter Ujfalusi

The ZynqMP includes the DisplayPort subsystem with its own DMA engine
called DPDMA. The DPDMA IP comes with 6 individual channels
(4 for display, 2 for audio). This documentation describes DT bindings
of DPDMA.

Signed-off-by: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
Changes since v2:

- Fix id URL
- Fix path to dma-controller.yaml
- Update license to GPL-2.0-only OR BSD-2-Clause

Changes since v1:

- Convert the DT bindings to YAML
- Drop the DT child nodes
---
 .../dma/xilinx/xlnx,zynqmp-dpdma.yaml         | 68 +++++++++++++++++++
 MAINTAINERS                                   |  8 +++
 include/dt-bindings/dma/xlnx-zynqmp-dpdma.h   | 16 +++++
 3 files changed, 92 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
 create mode 100644 include/dt-bindings/dma/xlnx-zynqmp-dpdma.h

diff --git a/Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml b/Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
new file mode 100644
index 000000000000..5de510f8c88c
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/xilinx/xlnx,zynqmp-dpdma.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xilinx ZynqMP DisplayPort DMA Controller Device Tree Bindings
+
+description: |
+  These bindings describe the DMA engine included in the Xilinx ZynqMP
+  DisplayPort Subsystem. The DMA engine supports up to 6 DMA channels (3
+  channels for a video stream, 1 channel for a graphics stream, and 2 channels
+  for an audio stream).
+
+maintainers:
+  - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+
+allOf:
+  - $ref: "../dma-controller.yaml#"
+
+properties:
+  "#dma-cells":
+    const: 1
+    description: |
+      The cell is the DMA channel ID (see dt-bindings/dma/xlnx-zynqmp-dpdma.h
+      for a list of channel IDs).
+
+  compatible:
+    const: xlnx,zynqmp-dpdma
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    description: The AXI clock
+    maxItems: 1
+
+  clock-names:
+    const: axi_clk
+
+required:
+  - "#dma-cells"
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    dma: dma-controller@fd4c0000 {
+      compatible = "xlnx,zynqmp-dpdma";
+      reg = <0x0 0xfd4c0000 0x0 0x1000>;
+      interrupts = <GIC_SPI 122 IRQ_TYPE_LEVEL_HIGH>;
+      interrupt-parent = <&gic>;
+      clocks = <&dpdma_clk>;
+      clock-names = "axi_clk";
+      #dma-cells = <1>;
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 68f21d46614c..fa52d4f9f8c8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18852,6 +18852,14 @@ F:	Documentation/devicetree/bindings/media/xilinx/
 F:	drivers/media/platform/xilinx/
 F:	include/uapi/linux/xilinx-v4l2-controls.h
 
+XILINX ZYNQMP DPDMA DRIVER
+M:	Hyun Kwon <hyun.kwon@xilinx.com>
+M:	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+L:	dmaengine@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
+F:	include/dt-bindings/dma/xlnx-zynqmp-dpdma.h
+
 XILLYBUS DRIVER
 M:	Eli Billauer <eli.billauer@gmail.com>
 L:	linux-kernel@vger.kernel.org
diff --git a/include/dt-bindings/dma/xlnx-zynqmp-dpdma.h b/include/dt-bindings/dma/xlnx-zynqmp-dpdma.h
new file mode 100644
index 000000000000..3719cda5679d
--- /dev/null
+++ b/include/dt-bindings/dma/xlnx-zynqmp-dpdma.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
+/*
+ * Copyright 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+#ifndef __DT_BINDINGS_DMA_XLNX_ZYNQMP_DPDMA_H__
+#define __DT_BINDINGS_DMA_XLNX_ZYNQMP_DPDMA_H__
+
+#define ZYNQMP_DPDMA_VIDEO0		0
+#define ZYNQMP_DPDMA_VIDEO1		1
+#define ZYNQMP_DPDMA_VIDEO2		2
+#define ZYNQMP_DPDMA_GRAPHICS		3
+#define ZYNQMP_DPDMA_AUDIO0		4
+#define ZYNQMP_DPDMA_AUDIO1		5
+
+#endif /* __DT_BINDINGS_DMA_XLNX_ZYNQMP_DPDMA_H__ */
-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v7 2/5] dmaengine: Add support for repeating transactions
  2020-07-17  1:33 [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Laurent Pinchart
  2020-07-17  1:33 ` [PATCH v7 1/5] dt: bindings: dma: xilinx: dpdma: DT bindings for Xilinx DPDMA Laurent Pinchart
@ 2020-07-17  1:33 ` Laurent Pinchart
  2020-07-17  1:33 ` [PATCH v7 3/5] dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver Laurent Pinchart
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-17  1:33 UTC (permalink / raw)
  To: dmaengine
  Cc: Michal Simek, Hyun Kwon, Tejas Upadhyay, Satish Kumar Nagireddy,
	Vinod Koul, Peter Ujfalusi

DMA engines used with displays perform 2D interleaved transfers to read
framebuffers from memory and feed the data to the display engine. As the
same framebuffer can be displayed for multiple frames, the DMA
transactions need to be repeated until a new framebuffer replaces the
current one. This feature is implemented natively by some DMA engines
that have the ability to repeat transactions and switch to a new
transaction at the end of a transfer without any race condition or frame
loss.

This patch implements support for this feature in the DMA engine API. A
new DMA_PREP_REPEAT transaction flag allows DMA clients to instruct the
DMA channel to repeat the transaction automatically until one or more
new transactions are issued on the channel (or until all active DMA
transfers are explicitly terminated with the dmaengine_terminate_*()
functions). A new DMA_REPEAT transaction type is also added for DMA
engine drivers to report their support of the DMA_PREP_REPEAT flag.

A new DMA_PREP_LOAD_EOT transaction flag is also introduced (with a
corresponding DMA_LOAD_EOT capability bit), as requested during the
review of v4. The flag instructs the DMA channel that the transaction
being queued should replace the active repeated transaction when the
latter terminates (at End Of Transaction). Not setting the flag will
result in the active repeated transaction to continue being repeated,
and the new transaction being silently ignored.

The DMA_PREP_REPEAT flag is currently supported for interleaved
transactions only. Its usage can easily be extended to cover more
transaction types simply by adding an appropriate check in the
corresponding dmaengine_prep_*() function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
Changes since v5:

- Document the API in Documentation/driver-api/dmaengine/
- Small improvements to documentation in header file

Changes since v4:

- Add DMA_LOAD_EOT and DMA_PREP_LOAD_EOT flags
---
 Documentation/driver-api/dmaengine/client.rst |  4 +-
 .../driver-api/dmaengine/provider.rst         | 49 +++++++++++++++++++
 include/linux/dmaengine.h                     | 17 +++++++
 3 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst
index 2104830a99ae..41938aa2bdeb 100644
--- a/Documentation/driver-api/dmaengine/client.rst
+++ b/Documentation/driver-api/dmaengine/client.rst
@@ -86,7 +86,9 @@ The details of these operations are:
   - interleaved_dma: This is common to Slave as well as M2M clients. For slave
     address of devices' fifo could be already known to the driver.
     Various types of operations could be expressed by setting
-    appropriate values to the 'dma_interleaved_template' members.
+    appropriate values to the 'dma_interleaved_template' members. Cyclic
+    interleaved DMA transfers are also possible if supported by the channel by
+    setting the DMA_PREP_REPEAT transfer flag.
 
   A non-NULL return of this transfer API represents a "descriptor" for
   the given transaction.
diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst
index 56e5833e8a07..f896acccdfee 100644
--- a/Documentation/driver-api/dmaengine/provider.rst
+++ b/Documentation/driver-api/dmaengine/provider.rst
@@ -239,6 +239,27 @@ Currently, the types available are:
     want to transfer a portion of uncompressed data directly to the
     display to print it
 
+- DMA_REPEAT
+
+  - The device supports repeated transfers. A repeated transfer, indicated by
+    the DMA_PREP_REPEAT transfer flag, is similar to a cyclic transfer in that
+    it gets automatically repeated when it ends, but can additionally be
+    replaced by the client.
+
+  - This feature is limited to interleaved transfers, this flag should thus not
+    be set if the DMA_INTERLEAVE flag isn't set. This limitation is based on
+    the current needs of DMA clients, support for additional transfer types
+    should be added in the future if and when the need arises.
+
+- DMA_LOAD_EOT
+
+  - The device supports replacing repeated transfers at end of transfer (EOT)
+    by queuing a new transfer with the DMA_PREP_LOAD_EOT flag set.
+
+  - Support for replacing a currently running transfer at another point (such
+    as end of burst instead of end of transfer) will be added in the future
+    based on DMA clients needs, if and when the need arises.
+
 These various types will also affect how the source and destination
 addresses change over time.
 
@@ -531,6 +552,34 @@ DMA_CTRL_REUSE
     writes for which the descriptor should be in different format from
     normal data descriptors.
 
+- DMA_PREP_REPEAT
+
+  - If set, the transfer will be automatically repeated when it ends until a
+    new transfer is queued on the same channel with the DMA_PREP_LOAD_EOT flag.
+    If the next transfer to be queued on the channel does not have the
+    DMA_PREP_LOAD_EOT flag set, the current transfer will be repeated until the
+    client terminates all transfers.
+
+  - This flag is only supported if the channel reports the DMA_REPEAT
+    capability.
+
+- DMA_PREP_LOAD_EOT
+
+  - If set, the transfer will replace the transfer currently being executed at
+    the end of the transfer.
+
+  - This is the default behaviour for non-repeated transfers, specifying
+    DMA_PREP_LOAD_EOT for non-repeated transfers will thus make no difference.
+
+  - When using repeated transfers, DMA clients will usually need to set the
+    DMA_PREP_LOAD_EOT flag on all transfers, otherwise the channel will keep
+    repeating the last repeated transfer and ignore the new transfers being
+    queued. Failure to set DMA_PREP_LOAD_EOT will appear as if the channel was
+    stuck on the previous transfer.
+
+  - This flag is only supported if the channel reports the DMA_LOAD_EOT
+    capability.
+
 General Design Notes
 ====================
 
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index e1c03339918f..328e3aca7f51 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -61,6 +61,8 @@ enum dma_transaction_type {
 	DMA_SLAVE,
 	DMA_CYCLIC,
 	DMA_INTERLEAVE,
+	DMA_REPEAT,
+	DMA_LOAD_EOT,
 /* last transaction type for creation of the capabilities mask */
 	DMA_TX_TYPE_END,
 };
@@ -176,6 +178,16 @@ struct dma_interleaved_template {
  * @DMA_PREP_CMD: tell the driver that the data passed to DMA API is command
  *  data and the descriptor should be in different format from normal
  *  data descriptors.
+ * @DMA_PREP_REPEAT: tell the driver that the transaction shall be automatically
+ *  repeated when it ends until a transaction is issued on the same channel
+ *  with the DMA_PREP_LOAD_EOT flag set. This flag is only applicable to
+ *  interleaved transactions and is ignored for all other transaction types.
+ * @DMA_PREP_LOAD_EOT: tell the driver that the transaction shall replace any
+ *  active repeated (as indicated by DMA_PREP_REPEAT) transaction when the
+ *  repeated transaction ends. Not setting this flag when the previously queued
+ *  transaction is marked with DMA_PREP_REPEAT will cause the new transaction
+ *  to never be processed and stay in the issued queue forever. The flag is
+ *  ignored if the previous transaction is not a repeated transaction.
  */
 enum dma_ctrl_flags {
 	DMA_PREP_INTERRUPT = (1 << 0),
@@ -186,6 +198,8 @@ enum dma_ctrl_flags {
 	DMA_PREP_FENCE = (1 << 5),
 	DMA_CTRL_REUSE = (1 << 6),
 	DMA_PREP_CMD = (1 << 7),
+	DMA_PREP_REPEAT = (1 << 8),
+	DMA_PREP_LOAD_EOT = (1 << 9),
 };
 
 /**
@@ -980,6 +994,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma(
 {
 	if (!chan || !chan->device || !chan->device->device_prep_interleaved_dma)
 		return NULL;
+	if (flags & DMA_PREP_REPEAT &&
+	    !test_bit(DMA_REPEAT, chan->device->cap_mask.bits))
+		return NULL;
 
 	return chan->device->device_prep_interleaved_dma(chan, xt, flags);
 }
-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v7 3/5] dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver
  2020-07-17  1:33 [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Laurent Pinchart
  2020-07-17  1:33 ` [PATCH v7 1/5] dt: bindings: dma: xilinx: dpdma: DT bindings for Xilinx DPDMA Laurent Pinchart
  2020-07-17  1:33 ` [PATCH v7 2/5] dmaengine: Add support for repeating transactions Laurent Pinchart
@ 2020-07-17  1:33 ` Laurent Pinchart
  2020-07-17  1:33 ` [PATCH v7 4/5] dmaengine: xilinx: dpdma: Add debugfs support Laurent Pinchart
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-17  1:33 UTC (permalink / raw)
  To: dmaengine
  Cc: Michal Simek, Hyun Kwon, Tejas Upadhyay, Satish Kumar Nagireddy,
	Vinod Koul, Peter Ujfalusi

From: Hyun Kwon <hyun.kwon@xilinx.com>

The ZynqMP DisplayPort subsystem includes a DMA engine called DPDMA with
6 DMa channels (4 for display and 2 for audio). This driver exposes the
DPDMA through the dmaengine API, to be used by audio (ALSA) and display
(DRM) drivers for the DisplayPort subsystem.

Signed-off-by: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: Tejas Upadhyay <tejasu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v6:

- Reject transactions without DMA_PREP_LOAD_EOT

Changes since v5:

- Update copyright year
- Use GFP_NOWAIT to allocate descriptor
- Drop check of deprecated direction parameter in channel configuration
- Don't reject channel configuration if the channel is busy

Changes since v4:

- Support DMA_PREP_LOAD_EOT, ignoring any transaction that doesn't have
  the flag set, as requested in the review of v4

Changes since v3:

- Fix uninitialized variable in xilinx_dpdma_config()
- Free pending and active descriptors upon termination
- Switch to DMA_PREP_REPEAT

Changes since v2:

- Switch to virt-dma
- Support interleaved cyclic transfers and nothing else
- Fix terminate_all behaviour (don't wait)
- Fix bug in extended address handling for hw desc
- Clean up video group handling
- Update driver name
- Use macros for bitfields
- Remove unneeded header
- Coding style and typo fixes

Changes since v1:

- Remove unneeded #include
- Drop enum xilinx_dpdma_chan_id
- Update compatible string
- Drop DT subnodes
- Replace XILINX_DPDMA_NUM_CHAN with ARRAY_SIZE(xdev->chan)
- Disable IRQ at remove() time
- Use devm_platform_ioremap_resource()
- Don't inline functions manually
- Add section headers
- Merge DMA engine implementation in their wrappers
- Rename xilinx_dpdma_sw_desc::phys to dma_addr
- Use GENMASK()
- Use FIELD_PREP/FIELD_GET
- Fix MSB handling in xilinx_dpdma_sw_desc_addr_64()
- Fix logic in xilinx_dpdma_chan_prep_slave_sg()
- Document why xilinx_dpdma_config() doesn't need to check most
  parameters
- Remove debugfs support
- Rechedule errored descriptor
- Align the line size with 128bit
- SPDX header formatting
---
 MAINTAINERS                       |    1 +
 drivers/dma/Kconfig               |   10 +
 drivers/dma/xilinx/Makefile       |    1 +
 drivers/dma/xilinx/xilinx_dpdma.c | 1533 +++++++++++++++++++++++++++++
 4 files changed, 1545 insertions(+)
 create mode 100644 drivers/dma/xilinx/xilinx_dpdma.c

diff --git a/MAINTAINERS b/MAINTAINERS
index fa52d4f9f8c8..6c20a6d338f0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18858,6 +18858,7 @@ M:	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 L:	dmaengine@vger.kernel.org
 S:	Supported
 F:	Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
+F:	drivers/dma/xilinx/xilinx_dpdma.c
 F:	include/dt-bindings/dma/xlnx-zynqmp-dpdma.h
 
 XILLYBUS DRIVER
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index de41d7928bff..668e9636c547 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -707,6 +707,16 @@ config XILINX_ZYNQMP_DMA
 	help
 	  Enable support for Xilinx ZynqMP DMA controller.
 
+config XILINX_ZYNQMP_DPDMA
+	tristate "Xilinx DPDMA Engine"
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for Xilinx ZynqMP DisplayPort DMA. Choose this option
+	  if you have a Xilinx ZynqMP SoC with a DisplayPort subsystem. The
+	  driver provides the dmaengine required by the DisplayPort subsystem
+	  display driver.
+
 config ZX_DMA
 	tristate "ZTE ZX DMA support"
 	depends on ARCH_ZX || COMPILE_TEST
diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile
index e921de575b55..767bb45f641f 100644
--- a/drivers/dma/xilinx/Makefile
+++ b/drivers/dma/xilinx/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_XILINX_DMA) += xilinx_dma.o
 obj-$(CONFIG_XILINX_ZYNQMP_DMA) += zynqmp_dma.o
+obj-$(CONFIG_XILINX_ZYNQMP_DPDMA) += xilinx_dpdma.o
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c
new file mode 100644
index 000000000000..af88a6762ef4
--- /dev/null
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -0,0 +1,1533 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx ZynqMP DPDMA Engine driver
+ *
+ * Copyright (C) 2015 - 2020 Xilinx, Inc.
+ *
+ * Author: Hyun Woo Kwon <hyun.kwon@xilinx.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+
+#include <dt-bindings/dma/xlnx-zynqmp-dpdma.h>
+
+#include "../dmaengine.h"
+#include "../virt-dma.h"
+
+/* DPDMA registers */
+#define XILINX_DPDMA_ERR_CTRL				0x000
+#define XILINX_DPDMA_ISR				0x004
+#define XILINX_DPDMA_IMR				0x008
+#define XILINX_DPDMA_IEN				0x00c
+#define XILINX_DPDMA_IDS				0x010
+#define XILINX_DPDMA_INTR_DESC_DONE(n)			BIT((n) + 0)
+#define XILINX_DPDMA_INTR_DESC_DONE_MASK		GENMASK(5, 0)
+#define XILINX_DPDMA_INTR_NO_OSTAND(n)			BIT((n) + 6)
+#define XILINX_DPDMA_INTR_NO_OSTAND_MASK		GENMASK(11, 6)
+#define XILINX_DPDMA_INTR_AXI_ERR(n)			BIT((n) + 12)
+#define XILINX_DPDMA_INTR_AXI_ERR_MASK			GENMASK(17, 12)
+#define XILINX_DPDMA_INTR_DESC_ERR(n)			BIT((n) + 16)
+#define XILINX_DPDMA_INTR_DESC_ERR_MASK			GENMASK(23, 18)
+#define XILINX_DPDMA_INTR_WR_CMD_FIFO_FULL		BIT(24)
+#define XILINX_DPDMA_INTR_WR_DATA_FIFO_FULL		BIT(25)
+#define XILINX_DPDMA_INTR_AXI_4K_CROSS			BIT(26)
+#define XILINX_DPDMA_INTR_VSYNC				BIT(27)
+#define XILINX_DPDMA_INTR_CHAN_ERR_MASK			0x00041000
+#define XILINX_DPDMA_INTR_CHAN_ERR			0x00fff000
+#define XILINX_DPDMA_INTR_GLOBAL_ERR			0x07000000
+#define XILINX_DPDMA_INTR_ERR_ALL			0x07fff000
+#define XILINX_DPDMA_INTR_CHAN_MASK			0x00041041
+#define XILINX_DPDMA_INTR_GLOBAL_MASK			0x0f000000
+#define XILINX_DPDMA_INTR_ALL				0x0fffffff
+#define XILINX_DPDMA_EISR				0x014
+#define XILINX_DPDMA_EIMR				0x018
+#define XILINX_DPDMA_EIEN				0x01c
+#define XILINX_DPDMA_EIDS				0x020
+#define XILINX_DPDMA_EINTR_INV_APB			BIT(0)
+#define XILINX_DPDMA_EINTR_RD_AXI_ERR(n)		BIT((n) + 1)
+#define XILINX_DPDMA_EINTR_RD_AXI_ERR_MASK		GENMASK(6, 1)
+#define XILINX_DPDMA_EINTR_PRE_ERR(n)			BIT((n) + 7)
+#define XILINX_DPDMA_EINTR_PRE_ERR_MASK			GENMASK(12, 7)
+#define XILINX_DPDMA_EINTR_CRC_ERR(n)			BIT((n) + 13)
+#define XILINX_DPDMA_EINTR_CRC_ERR_MASK			GENMASK(18, 13)
+#define XILINX_DPDMA_EINTR_WR_AXI_ERR(n)		BIT((n) + 19)
+#define XILINX_DPDMA_EINTR_WR_AXI_ERR_MASK		GENMASK(24, 19)
+#define XILINX_DPDMA_EINTR_DESC_DONE_ERR(n)		BIT((n) + 25)
+#define XILINX_DPDMA_EINTR_DESC_DONE_ERR_MASK		GENMASK(30, 25)
+#define XILINX_DPDMA_EINTR_RD_CMD_FIFO_FULL		BIT(32)
+#define XILINX_DPDMA_EINTR_CHAN_ERR_MASK		0x02082082
+#define XILINX_DPDMA_EINTR_CHAN_ERR			0x7ffffffe
+#define XILINX_DPDMA_EINTR_GLOBAL_ERR			0x80000001
+#define XILINX_DPDMA_EINTR_ALL				0xffffffff
+#define XILINX_DPDMA_CNTL				0x100
+#define XILINX_DPDMA_GBL				0x104
+#define XILINX_DPDMA_GBL_TRIG_MASK(n)			((n) << 0)
+#define XILINX_DPDMA_GBL_RETRIG_MASK(n)			((n) << 6)
+#define XILINX_DPDMA_ALC0_CNTL				0x108
+#define XILINX_DPDMA_ALC0_STATUS			0x10c
+#define XILINX_DPDMA_ALC0_MAX				0x110
+#define XILINX_DPDMA_ALC0_MIN				0x114
+#define XILINX_DPDMA_ALC0_ACC				0x118
+#define XILINX_DPDMA_ALC0_ACC_TRAN			0x11c
+#define XILINX_DPDMA_ALC1_CNTL				0x120
+#define XILINX_DPDMA_ALC1_STATUS			0x124
+#define XILINX_DPDMA_ALC1_MAX				0x128
+#define XILINX_DPDMA_ALC1_MIN				0x12c
+#define XILINX_DPDMA_ALC1_ACC				0x130
+#define XILINX_DPDMA_ALC1_ACC_TRAN			0x134
+
+/* Channel register */
+#define XILINX_DPDMA_CH_BASE				0x200
+#define XILINX_DPDMA_CH_OFFSET				0x100
+#define XILINX_DPDMA_CH_DESC_START_ADDRE		0x000
+#define XILINX_DPDMA_CH_DESC_START_ADDRE_MASK		GENMASK(15, 0)
+#define XILINX_DPDMA_CH_DESC_START_ADDR			0x004
+#define XILINX_DPDMA_CH_DESC_NEXT_ADDRE			0x008
+#define XILINX_DPDMA_CH_DESC_NEXT_ADDR			0x00c
+#define XILINX_DPDMA_CH_PYLD_CUR_ADDRE			0x010
+#define XILINX_DPDMA_CH_PYLD_CUR_ADDR			0x014
+#define XILINX_DPDMA_CH_CNTL				0x018
+#define XILINX_DPDMA_CH_CNTL_ENABLE			BIT(0)
+#define XILINX_DPDMA_CH_CNTL_PAUSE			BIT(1)
+#define XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK		GENMASK(5, 2)
+#define XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK		GENMASK(9, 6)
+#define XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK		GENMASK(13, 10)
+#define XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS		11
+#define XILINX_DPDMA_CH_STATUS				0x01c
+#define XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK		GENMASK(24, 21)
+#define XILINX_DPDMA_CH_VDO				0x020
+#define XILINX_DPDMA_CH_PYLD_SZ				0x024
+#define XILINX_DPDMA_CH_DESC_ID				0x028
+
+/* DPDMA descriptor fields */
+#define XILINX_DPDMA_DESC_CONTROL_PREEMBLE		0xa5
+#define XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR		BIT(8)
+#define XILINX_DPDMA_DESC_CONTROL_DESC_UPDATE		BIT(9)
+#define XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE		BIT(10)
+#define XILINX_DPDMA_DESC_CONTROL_FRAG_MODE		BIT(18)
+#define XILINX_DPDMA_DESC_CONTROL_LAST			BIT(19)
+#define XILINX_DPDMA_DESC_CONTROL_ENABLE_CRC		BIT(20)
+#define XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME		BIT(21)
+#define XILINX_DPDMA_DESC_ID_MASK			GENMASK(15, 0)
+#define XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK	GENMASK(17, 0)
+#define XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK	GENMASK(31, 18)
+#define XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK	GENMASK(15, 0)
+#define XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK	GENMASK(31, 16)
+
+#define XILINX_DPDMA_ALIGN_BYTES			256
+#define XILINX_DPDMA_LINESIZE_ALIGN_BITS		128
+
+#define XILINX_DPDMA_NUM_CHAN				6
+
+struct xilinx_dpdma_chan;
+
+/**
+ * struct xilinx_dpdma_hw_desc - DPDMA hardware descriptor
+ * @control: control configuration field
+ * @desc_id: descriptor ID
+ * @xfer_size: transfer size
+ * @hsize_stride: horizontal size and stride
+ * @timestamp_lsb: LSB of time stamp
+ * @timestamp_msb: MSB of time stamp
+ * @addr_ext: upper 16 bit of 48 bit address (next_desc and src_addr)
+ * @next_desc: next descriptor 32 bit address
+ * @src_addr: payload source address (1st page, 32 LSB)
+ * @addr_ext_23: payload source address (3nd and 3rd pages, 16 LSBs)
+ * @addr_ext_45: payload source address (4th and 5th pages, 16 LSBs)
+ * @src_addr2: payload source address (2nd page, 32 LSB)
+ * @src_addr3: payload source address (3rd page, 32 LSB)
+ * @src_addr4: payload source address (4th page, 32 LSB)
+ * @src_addr5: payload source address (5th page, 32 LSB)
+ * @crc: descriptor CRC
+ */
+struct xilinx_dpdma_hw_desc {
+	u32 control;
+	u32 desc_id;
+	u32 xfer_size;
+	u32 hsize_stride;
+	u32 timestamp_lsb;
+	u32 timestamp_msb;
+	u32 addr_ext;
+	u32 next_desc;
+	u32 src_addr;
+	u32 addr_ext_23;
+	u32 addr_ext_45;
+	u32 src_addr2;
+	u32 src_addr3;
+	u32 src_addr4;
+	u32 src_addr5;
+	u32 crc;
+} __aligned(XILINX_DPDMA_ALIGN_BYTES);
+
+/**
+ * struct xilinx_dpdma_sw_desc - DPDMA software descriptor
+ * @hw: DPDMA hardware descriptor
+ * @node: list node for software descriptors
+ * @dma_addr: DMA address of the software descriptor
+ */
+struct xilinx_dpdma_sw_desc {
+	struct xilinx_dpdma_hw_desc hw;
+	struct list_head node;
+	dma_addr_t dma_addr;
+};
+
+/**
+ * struct xilinx_dpdma_tx_desc - DPDMA transaction descriptor
+ * @vdesc: virtual DMA descriptor
+ * @chan: DMA channel
+ * @descriptors: list of software descriptors
+ * @error: an error has been detected with this descriptor
+ */
+struct xilinx_dpdma_tx_desc {
+	struct virt_dma_desc vdesc;
+	struct xilinx_dpdma_chan *chan;
+	struct list_head descriptors;
+	bool error;
+};
+
+#define to_dpdma_tx_desc(_desc) \
+	container_of(_desc, struct xilinx_dpdma_tx_desc, vdesc)
+
+/**
+ * struct xilinx_dpdma_chan - DPDMA channel
+ * @vchan: virtual DMA channel
+ * @reg: register base address
+ * @id: channel ID
+ * @wait_to_stop: queue to wait for outstanding transacitons before stopping
+ * @running: true if the channel is running
+ * @first_frame: flag for the first frame of stream
+ * @video_group: flag if multi-channel operation is needed for video channels
+ * @lock: lock to access struct xilinx_dpdma_chan
+ * @desc_pool: descriptor allocation pool
+ * @err_task: error IRQ bottom half handler
+ * @desc.pending: Descriptor schedule to the hardware, pending execution
+ * @desc.active: Descriptor being executed by the hardware
+ * @xdev: DPDMA device
+ */
+struct xilinx_dpdma_chan {
+	struct virt_dma_chan vchan;
+	void __iomem *reg;
+	unsigned int id;
+
+	wait_queue_head_t wait_to_stop;
+	bool running;
+	bool first_frame;
+	bool video_group;
+
+	spinlock_t lock; /* lock to access struct xilinx_dpdma_chan */
+	struct dma_pool *desc_pool;
+	struct tasklet_struct err_task;
+
+	struct {
+		struct xilinx_dpdma_tx_desc *pending;
+		struct xilinx_dpdma_tx_desc *active;
+	} desc;
+
+	struct xilinx_dpdma_device *xdev;
+};
+
+#define to_xilinx_chan(_chan) \
+	container_of(_chan, struct xilinx_dpdma_chan, vchan.chan)
+
+/**
+ * struct xilinx_dpdma_device - DPDMA device
+ * @common: generic dma device structure
+ * @reg: register base address
+ * @dev: generic device structure
+ * @irq: the interrupt number
+ * @axi_clk: axi clock
+ * @chan: DPDMA channels
+ * @ext_addr: flag for 64 bit system (48 bit addressing)
+ */
+struct xilinx_dpdma_device {
+	struct dma_device common;
+	void __iomem *reg;
+	struct device *dev;
+	int irq;
+
+	struct clk *axi_clk;
+	struct xilinx_dpdma_chan *chan[XILINX_DPDMA_NUM_CHAN];
+
+	bool ext_addr;
+};
+
+/* -----------------------------------------------------------------------------
+ * I/O Accessors
+ */
+
+static inline u32 dpdma_read(void __iomem *base, u32 offset)
+{
+	return ioread32(base + offset);
+}
+
+static inline void dpdma_write(void __iomem *base, u32 offset, u32 val)
+{
+	iowrite32(val, base + offset);
+}
+
+static inline void dpdma_clr(void __iomem *base, u32 offset, u32 clr)
+{
+	dpdma_write(base, offset, dpdma_read(base, offset) & ~clr);
+}
+
+static inline void dpdma_set(void __iomem *base, u32 offset, u32 set)
+{
+	dpdma_write(base, offset, dpdma_read(base, offset) | set);
+}
+
+/* -----------------------------------------------------------------------------
+ * Descriptor Operations
+ */
+
+/**
+ * xilinx_dpdma_sw_desc_set_dma_addrs - Set DMA addresses in the descriptor
+ * @sw_desc: The software descriptor in which to set DMA addresses
+ * @prev: The previous descriptor
+ * @dma_addr: array of dma addresses
+ * @num_src_addr: number of addresses in @dma_addr
+ *
+ * Set all the DMA addresses in the hardware descriptor corresponding to @dev
+ * from @dma_addr. If a previous descriptor is specified in @prev, its next
+ * descriptor DMA address is set to the DMA address of @sw_desc. @prev may be
+ * identical to @sw_desc for cyclic transfers.
+ */
+static void xilinx_dpdma_sw_desc_set_dma_addrs(struct xilinx_dpdma_device *xdev,
+					       struct xilinx_dpdma_sw_desc *sw_desc,
+					       struct xilinx_dpdma_sw_desc *prev,
+					       dma_addr_t dma_addr[],
+					       unsigned int num_src_addr)
+{
+	struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
+	unsigned int i;
+
+	hw_desc->src_addr = lower_32_bits(dma_addr[0]);
+	if (xdev->ext_addr)
+		hw_desc->addr_ext |=
+			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK,
+				   upper_32_bits(dma_addr[0]));
+
+	for (i = 1; i < num_src_addr; i++) {
+		u32 *addr = &hw_desc->src_addr2;
+
+		addr[i-1] = lower_32_bits(dma_addr[i]);
+
+		if (xdev->ext_addr) {
+			u32 *addr_ext = &hw_desc->addr_ext_23;
+			u32 addr_msb;
+
+			addr_msb = upper_32_bits(dma_addr[i]) & GENMASK(15, 0);
+			addr_msb <<= 16 * ((i - 1) % 2);
+			addr_ext[(i - 1) / 2] |= addr_msb;
+		}
+	}
+
+	if (!prev)
+		return;
+
+	prev->hw.next_desc = lower_32_bits(sw_desc->dma_addr);
+	if (xdev->ext_addr)
+		prev->hw.addr_ext |=
+			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK,
+				   upper_32_bits(sw_desc->dma_addr));
+}
+
+/**
+ * xilinx_dpdma_chan_alloc_sw_desc - Allocate a software descriptor
+ * @chan: DPDMA channel
+ *
+ * Allocate a software descriptor from the channel's descriptor pool.
+ *
+ * Return: a software descriptor or NULL.
+ */
+static struct xilinx_dpdma_sw_desc *
+xilinx_dpdma_chan_alloc_sw_desc(struct xilinx_dpdma_chan *chan)
+{
+	struct xilinx_dpdma_sw_desc *sw_desc;
+	dma_addr_t dma_addr;
+
+	sw_desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &dma_addr);
+	if (!sw_desc)
+		return NULL;
+
+	sw_desc->dma_addr = dma_addr;
+
+	return sw_desc;
+}
+
+/**
+ * xilinx_dpdma_chan_free_sw_desc - Free a software descriptor
+ * @chan: DPDMA channel
+ * @sw_desc: software descriptor to free
+ *
+ * Free a software descriptor from the channel's descriptor pool.
+ */
+static void
+xilinx_dpdma_chan_free_sw_desc(struct xilinx_dpdma_chan *chan,
+			       struct xilinx_dpdma_sw_desc *sw_desc)
+{
+	dma_pool_free(chan->desc_pool, sw_desc, sw_desc->dma_addr);
+}
+
+/**
+ * xilinx_dpdma_chan_dump_tx_desc - Dump a tx descriptor
+ * @chan: DPDMA channel
+ * @tx_desc: tx descriptor to dump
+ *
+ * Dump contents of a tx descriptor
+ */
+static void xilinx_dpdma_chan_dump_tx_desc(struct xilinx_dpdma_chan *chan,
+					   struct xilinx_dpdma_tx_desc *tx_desc)
+{
+	struct xilinx_dpdma_sw_desc *sw_desc;
+	struct device *dev = chan->xdev->dev;
+	unsigned int i = 0;
+
+	dev_dbg(dev, "------- TX descriptor dump start -------\n");
+	dev_dbg(dev, "------- channel ID = %d -------\n", chan->id);
+
+	list_for_each_entry(sw_desc, &tx_desc->descriptors, node) {
+		struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
+
+		dev_dbg(dev, "------- HW descriptor %d -------\n", i++);
+		dev_dbg(dev, "descriptor DMA addr: %pad\n", &sw_desc->dma_addr);
+		dev_dbg(dev, "control: 0x%08x\n", hw_desc->control);
+		dev_dbg(dev, "desc_id: 0x%08x\n", hw_desc->desc_id);
+		dev_dbg(dev, "xfer_size: 0x%08x\n", hw_desc->xfer_size);
+		dev_dbg(dev, "hsize_stride: 0x%08x\n", hw_desc->hsize_stride);
+		dev_dbg(dev, "timestamp_lsb: 0x%08x\n", hw_desc->timestamp_lsb);
+		dev_dbg(dev, "timestamp_msb: 0x%08x\n", hw_desc->timestamp_msb);
+		dev_dbg(dev, "addr_ext: 0x%08x\n", hw_desc->addr_ext);
+		dev_dbg(dev, "next_desc: 0x%08x\n", hw_desc->next_desc);
+		dev_dbg(dev, "src_addr: 0x%08x\n", hw_desc->src_addr);
+		dev_dbg(dev, "addr_ext_23: 0x%08x\n", hw_desc->addr_ext_23);
+		dev_dbg(dev, "addr_ext_45: 0x%08x\n", hw_desc->addr_ext_45);
+		dev_dbg(dev, "src_addr2: 0x%08x\n", hw_desc->src_addr2);
+		dev_dbg(dev, "src_addr3: 0x%08x\n", hw_desc->src_addr3);
+		dev_dbg(dev, "src_addr4: 0x%08x\n", hw_desc->src_addr4);
+		dev_dbg(dev, "src_addr5: 0x%08x\n", hw_desc->src_addr5);
+		dev_dbg(dev, "crc: 0x%08x\n", hw_desc->crc);
+	}
+
+	dev_dbg(dev, "------- TX descriptor dump end -------\n");
+}
+
+/**
+ * xilinx_dpdma_chan_alloc_tx_desc - Allocate a transaction descriptor
+ * @chan: DPDMA channel
+ *
+ * Allocate a tx descriptor.
+ *
+ * Return: a tx descriptor or NULL.
+ */
+static struct xilinx_dpdma_tx_desc *
+xilinx_dpdma_chan_alloc_tx_desc(struct xilinx_dpdma_chan *chan)
+{
+	struct xilinx_dpdma_tx_desc *tx_desc;
+
+	tx_desc = kzalloc(sizeof(*tx_desc), GFP_NOWAIT);
+	if (!tx_desc)
+		return NULL;
+
+	INIT_LIST_HEAD(&tx_desc->descriptors);
+	tx_desc->chan = chan;
+	tx_desc->error = false;
+
+	return tx_desc;
+}
+
+/**
+ * xilinx_dpdma_chan_free_tx_desc - Free a virtual DMA descriptor
+ * @vdesc: virtual DMA descriptor
+ *
+ * Free the virtual DMA descriptor @vdesc including its software descriptors.
+ */
+static void xilinx_dpdma_chan_free_tx_desc(struct virt_dma_desc *vdesc)
+{
+	struct xilinx_dpdma_sw_desc *sw_desc, *next;
+	struct xilinx_dpdma_tx_desc *desc;
+
+	if (!vdesc)
+		return;
+
+	desc = to_dpdma_tx_desc(vdesc);
+
+	list_for_each_entry_safe(sw_desc, next, &desc->descriptors, node) {
+		list_del(&sw_desc->node);
+		xilinx_dpdma_chan_free_sw_desc(desc->chan, sw_desc);
+	}
+
+	kfree(desc);
+}
+
+/**
+ * xilinx_dpdma_chan_prep_interleaved_dma - Prepare an interleaved dma
+ *					    descriptor
+ * @chan: DPDMA channel
+ * @xt: dma interleaved template
+ *
+ * Prepare a tx descriptor including internal software/hardware descriptors
+ * based on @xt.
+ *
+ * Return: A DPDMA TX descriptor on success, or NULL.
+ */
+static struct xilinx_dpdma_tx_desc *
+xilinx_dpdma_chan_prep_interleaved_dma(struct xilinx_dpdma_chan *chan,
+				       struct dma_interleaved_template *xt)
+{
+	struct xilinx_dpdma_tx_desc *tx_desc;
+	struct xilinx_dpdma_sw_desc *sw_desc;
+	struct xilinx_dpdma_hw_desc *hw_desc;
+	size_t hsize = xt->sgl[0].size;
+	size_t stride = hsize + xt->sgl[0].icg;
+
+	if (!IS_ALIGNED(xt->src_start, XILINX_DPDMA_ALIGN_BYTES)) {
+		dev_err(chan->xdev->dev, "buffer should be aligned at %d B\n",
+			XILINX_DPDMA_ALIGN_BYTES);
+		return NULL;
+	}
+
+	tx_desc = xilinx_dpdma_chan_alloc_tx_desc(chan);
+	if (!tx_desc)
+		return NULL;
+
+	sw_desc = xilinx_dpdma_chan_alloc_sw_desc(chan);
+	if (!sw_desc) {
+		xilinx_dpdma_chan_free_tx_desc(&tx_desc->vdesc);
+		return NULL;
+	}
+
+	xilinx_dpdma_sw_desc_set_dma_addrs(chan->xdev, sw_desc, sw_desc,
+					   &xt->src_start, 1);
+
+	hw_desc = &sw_desc->hw;
+	hsize = ALIGN(hsize, XILINX_DPDMA_LINESIZE_ALIGN_BITS / 8);
+	hw_desc->xfer_size = hsize * xt->numf;
+	hw_desc->hsize_stride =
+		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK, hsize) |
+		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK,
+			   stride / 16);
+	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_PREEMBLE;
+	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR;
+	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE;
+	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME;
+
+	list_add_tail(&sw_desc->node, &tx_desc->descriptors);
+
+	return tx_desc;
+}
+
+/* -----------------------------------------------------------------------------
+ * DPDMA Channel Operations
+ */
+
+/**
+ * xilinx_dpdma_chan_enable - Enable the channel
+ * @chan: DPDMA channel
+ *
+ * Enable the channel and its interrupts. Set the QoS values for video class.
+ */
+static void xilinx_dpdma_chan_enable(struct xilinx_dpdma_chan *chan)
+{
+	u32 reg;
+
+	reg = (XILINX_DPDMA_INTR_CHAN_MASK << chan->id)
+	    | XILINX_DPDMA_INTR_GLOBAL_MASK;
+	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
+	reg = (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id)
+	    | XILINX_DPDMA_INTR_GLOBAL_ERR;
+	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
+
+	reg = XILINX_DPDMA_CH_CNTL_ENABLE
+	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK,
+			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
+	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK,
+			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
+	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK,
+			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS);
+	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, reg);
+}
+
+/**
+ * xilinx_dpdma_chan_disable - Disable the channel
+ * @chan: DPDMA channel
+ *
+ * Disable the channel and its interrupts.
+ */
+static void xilinx_dpdma_chan_disable(struct xilinx_dpdma_chan *chan)
+{
+	u32 reg;
+
+	reg = XILINX_DPDMA_INTR_CHAN_MASK << chan->id;
+	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
+	reg = XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id;
+	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
+
+	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_ENABLE);
+}
+
+/**
+ * xilinx_dpdma_chan_pause - Pause the channel
+ * @chan: DPDMA channel
+ *
+ * Pause the channel.
+ */
+static void xilinx_dpdma_chan_pause(struct xilinx_dpdma_chan *chan)
+{
+	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
+}
+
+/**
+ * xilinx_dpdma_chan_unpause - Unpause the channel
+ * @chan: DPDMA channel
+ *
+ * Unpause the channel.
+ */
+static void xilinx_dpdma_chan_unpause(struct xilinx_dpdma_chan *chan)
+{
+	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
+}
+
+static u32 xilinx_dpdma_chan_video_group_ready(struct xilinx_dpdma_chan *chan)
+{
+	struct xilinx_dpdma_device *xdev = chan->xdev;
+	u32 channels = 0;
+	unsigned int i;
+
+	for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
+		if (xdev->chan[i]->video_group && !xdev->chan[i]->running)
+			return 0;
+
+		if (xdev->chan[i]->video_group)
+			channels |= BIT(i);
+	}
+
+	return channels;
+}
+
+/**
+ * xilinx_dpdma_chan_queue_transfer - Queue the next transfer
+ * @chan: DPDMA channel
+ *
+ * Queue the next descriptor, if any, to the hardware. If the channel is
+ * stopped, start it first. Otherwise retrigger it with the next descriptor.
+ */
+static void xilinx_dpdma_chan_queue_transfer(struct xilinx_dpdma_chan *chan)
+{
+	struct xilinx_dpdma_device *xdev = chan->xdev;
+	struct xilinx_dpdma_sw_desc *sw_desc;
+	struct xilinx_dpdma_tx_desc *desc;
+	struct virt_dma_desc *vdesc;
+	u32 reg, channels;
+
+	lockdep_assert_held(&chan->lock);
+
+	if (chan->desc.pending)
+		return;
+
+	if (!chan->running) {
+		xilinx_dpdma_chan_unpause(chan);
+		xilinx_dpdma_chan_enable(chan);
+		chan->first_frame = true;
+		chan->running = true;
+	}
+
+	if (chan->video_group)
+		channels = xilinx_dpdma_chan_video_group_ready(chan);
+	else
+		channels = BIT(chan->id);
+
+	if (!channels)
+		return;
+
+	vdesc = vchan_next_desc(&chan->vchan);
+	if (!vdesc)
+		return;
+
+	desc = to_dpdma_tx_desc(vdesc);
+	chan->desc.pending = desc;
+	list_del(&desc->vdesc.node);
+
+	/*
+	 * Assign the cookie to descriptors in this transaction. Only 16 bit
+	 * will be used, but it should be enough.
+	 */
+	list_for_each_entry(sw_desc, &desc->descriptors, node)
+		sw_desc->hw.desc_id = desc->vdesc.tx.cookie;
+
+	sw_desc = list_first_entry(&desc->descriptors,
+				   struct xilinx_dpdma_sw_desc, node);
+	dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR,
+		    lower_32_bits(sw_desc->dma_addr));
+	if (xdev->ext_addr)
+		dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE,
+			    FIELD_PREP(XILINX_DPDMA_CH_DESC_START_ADDRE_MASK,
+				       upper_32_bits(sw_desc->dma_addr)));
+
+	if (chan->first_frame)
+		reg = XILINX_DPDMA_GBL_TRIG_MASK(channels);
+	else
+		reg = XILINX_DPDMA_GBL_RETRIG_MASK(channels);
+
+	chan->first_frame = false;
+
+	dpdma_write(xdev->reg, XILINX_DPDMA_GBL, reg);
+}
+
+/**
+ * xilinx_dpdma_chan_ostand - Number of outstanding transactions
+ * @chan: DPDMA channel
+ *
+ * Read and return the number of outstanding transactions from register.
+ *
+ * Return: Number of outstanding transactions from the status register.
+ */
+static u32 xilinx_dpdma_chan_ostand(struct xilinx_dpdma_chan *chan)
+{
+	return FIELD_GET(XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK,
+			 dpdma_read(chan->reg, XILINX_DPDMA_CH_STATUS));
+}
+
+/**
+ * xilinx_dpdma_chan_no_ostand - Notify no outstanding transaction event
+ * @chan: DPDMA channel
+ *
+ * Notify waiters for no outstanding event, so waiters can stop the channel
+ * safely. This function is supposed to be called when 'no outstanding'
+ * interrupt is generated. The 'no outstanding' interrupt is disabled and
+ * should be re-enabled when this event is handled. If the channel status
+ * register still shows some number of outstanding transactions, the interrupt
+ * remains enabled.
+ *
+ * Return: 0 on success. On failure, -EWOULDBLOCK if there's still outstanding
+ * transaction(s).
+ */
+static int xilinx_dpdma_chan_notify_no_ostand(struct xilinx_dpdma_chan *chan)
+{
+	u32 cnt;
+
+	cnt = xilinx_dpdma_chan_ostand(chan);
+	if (cnt) {
+		dev_dbg(chan->xdev->dev, "%d outstanding transactions\n", cnt);
+		return -EWOULDBLOCK;
+	}
+
+	/* Disable 'no outstanding' interrupt */
+	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IDS,
+		    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
+	wake_up(&chan->wait_to_stop);
+
+	return 0;
+}
+
+/**
+ * xilinx_dpdma_chan_wait_no_ostand - Wait for the no outstanding irq
+ * @chan: DPDMA channel
+ *
+ * Wait for the no outstanding transaction interrupt. This functions can sleep
+ * for 50ms.
+ *
+ * Return: 0 on success. On failure, -ETIMEOUT for time out, or the error code
+ * from wait_event_interruptible_timeout().
+ */
+static int xilinx_dpdma_chan_wait_no_ostand(struct xilinx_dpdma_chan *chan)
+{
+	int ret;
+
+	/* Wait for a no outstanding transaction interrupt upto 50msec */
+	ret = wait_event_interruptible_timeout(chan->wait_to_stop,
+					       !xilinx_dpdma_chan_ostand(chan),
+					       msecs_to_jiffies(50));
+	if (ret > 0) {
+		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
+			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
+		return 0;
+	}
+
+	dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
+		xilinx_dpdma_chan_ostand(chan));
+
+	if (ret == 0)
+		return -ETIMEDOUT;
+
+	return ret;
+}
+
+/**
+ * xilinx_dpdma_chan_poll_no_ostand - Poll the outstanding transaction status
+ * @chan: DPDMA channel
+ *
+ * Poll the outstanding transaction status, and return when there's no
+ * outstanding transaction. This functions can be used in the interrupt context
+ * or where the atomicity is required. Calling thread may wait more than 50ms.
+ *
+ * Return: 0 on success, or -ETIMEDOUT.
+ */
+static int xilinx_dpdma_chan_poll_no_ostand(struct xilinx_dpdma_chan *chan)
+{
+	u32 cnt, loop = 50000;
+
+	/* Poll at least for 50ms (20 fps). */
+	do {
+		cnt = xilinx_dpdma_chan_ostand(chan);
+		udelay(1);
+	} while (loop-- > 0 && cnt);
+
+	if (loop) {
+		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
+			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
+		return 0;
+	}
+
+	dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
+		xilinx_dpdma_chan_ostand(chan));
+
+	return -ETIMEDOUT;
+}
+
+/**
+ * xilinx_dpdma_chan_stop - Stop the channel
+ * @chan: DPDMA channel
+ *
+ * Stop a previously paused channel by first waiting for completion of all
+ * outstanding transaction and then disabling the channel.
+ *
+ * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
+ */
+static int xilinx_dpdma_chan_stop(struct xilinx_dpdma_chan *chan)
+{
+	unsigned long flags;
+	int ret;
+
+	ret = xilinx_dpdma_chan_wait_no_ostand(chan);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&chan->lock, flags);
+	xilinx_dpdma_chan_disable(chan);
+	chan->running = false;
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	return 0;
+}
+
+/**
+ * xilinx_dpdma_chan_done_irq - Handle hardware descriptor completion
+ * @chan: DPDMA channel
+ *
+ * Handle completion of the currently active descriptor (@chan->desc.active). As
+ * we currently support cyclic transfers only, this just invokes the cyclic
+ * callback. The descriptor will be completed at the VSYNC interrupt when a new
+ * descriptor replaces it.
+ */
+static void xilinx_dpdma_chan_done_irq(struct xilinx_dpdma_chan *chan)
+{
+	struct xilinx_dpdma_tx_desc *active = chan->desc.active;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	if (active)
+		vchan_cyclic_callback(&active->vdesc);
+	else
+		dev_warn(chan->xdev->dev,
+			 "DONE IRQ with no active descriptor!\n");
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
+ * xilinx_dpdma_chan_vsync_irq - Handle hardware descriptor scheduling
+ * @chan: DPDMA channel
+ *
+ * At VSYNC the active descriptor may have been replaced by the pending
+ * descriptor. Detect this through the DESC_ID and perform appropriate
+ * bookkeeping.
+ */
+static void xilinx_dpdma_chan_vsync_irq(struct  xilinx_dpdma_chan *chan)
+{
+	struct xilinx_dpdma_tx_desc *pending;
+	struct xilinx_dpdma_sw_desc *sw_desc;
+	unsigned long flags;
+	u32 desc_id;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	pending = chan->desc.pending;
+	if (!chan->running || !pending)
+		goto out;
+
+	desc_id = dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_ID);
+
+	/* If the retrigger raced with vsync, retry at the next frame. */
+	sw_desc = list_first_entry(&pending->descriptors,
+				   struct xilinx_dpdma_sw_desc, node);
+	if (sw_desc->hw.desc_id != desc_id)
+		goto out;
+
+	/*
+	 * Complete the active descriptor, if any, promote the pending
+	 * descriptor to active, and queue the next transfer, if any.
+	 */
+	if (chan->desc.active)
+		vchan_cookie_complete(&chan->desc.active->vdesc);
+	chan->desc.active = pending;
+	chan->desc.pending = NULL;
+
+	xilinx_dpdma_chan_queue_transfer(chan);
+
+out:
+	spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
+ * xilinx_dpdma_chan_err - Detect any channel error
+ * @chan: DPDMA channel
+ * @isr: masked Interrupt Status Register
+ * @eisr: Error Interrupt Status Register
+ *
+ * Return: true if any channel error occurs, or false otherwise.
+ */
+static bool
+xilinx_dpdma_chan_err(struct xilinx_dpdma_chan *chan, u32 isr, u32 eisr)
+{
+	if (!chan)
+		return false;
+
+	if (chan->running &&
+	    ((isr & (XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id)) ||
+	    (eisr & (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id))))
+		return true;
+
+	return false;
+}
+
+/**
+ * xilinx_dpdma_chan_handle_err - DPDMA channel error handling
+ * @chan: DPDMA channel
+ *
+ * This function is called when any channel error or any global error occurs.
+ * The function disables the paused channel by errors and determines
+ * if the current active descriptor can be rescheduled depending on
+ * the descriptor status.
+ */
+static void xilinx_dpdma_chan_handle_err(struct xilinx_dpdma_chan *chan)
+{
+	struct xilinx_dpdma_device *xdev = chan->xdev;
+	struct xilinx_dpdma_tx_desc *active;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	dev_dbg(xdev->dev, "cur desc addr = 0x%04x%08x\n",
+		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE),
+		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR));
+	dev_dbg(xdev->dev, "cur payload addr = 0x%04x%08x\n",
+		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDRE),
+		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDR));
+
+	xilinx_dpdma_chan_disable(chan);
+	chan->running = false;
+
+	if (!chan->desc.active)
+		goto out_unlock;
+
+	active = chan->desc.active;
+	chan->desc.active = NULL;
+
+	xilinx_dpdma_chan_dump_tx_desc(chan, active);
+
+	if (active->error)
+		dev_dbg(xdev->dev, "repeated error on desc\n");
+
+	/* Reschedule if there's no new descriptor */
+	if (!chan->desc.pending &&
+	    list_empty(&chan->vchan.desc_issued)) {
+		active->error = true;
+		list_add_tail(&active->vdesc.node,
+			      &chan->vchan.desc_issued);
+	} else {
+		xilinx_dpdma_chan_free_tx_desc(&active->vdesc);
+	}
+
+out_unlock:
+	spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/* -----------------------------------------------------------------------------
+ * DMA Engine Operations
+ */
+
+static struct dma_async_tx_descriptor *
+xilinx_dpdma_prep_interleaved_dma(struct dma_chan *dchan,
+				  struct dma_interleaved_template *xt,
+				  unsigned long flags)
+{
+	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+	struct xilinx_dpdma_tx_desc *desc;
+
+	if (xt->dir != DMA_MEM_TO_DEV)
+		return NULL;
+
+	if (!xt->numf || !xt->sgl[0].size)
+		return NULL;
+
+	if (!(flags & DMA_PREP_REPEAT) || !(flags & DMA_PREP_LOAD_EOT))
+		return NULL;
+
+	desc = xilinx_dpdma_chan_prep_interleaved_dma(chan, xt);
+	if (!desc)
+		return NULL;
+
+	vchan_tx_prep(&chan->vchan, &desc->vdesc, flags | DMA_CTRL_ACK);
+
+	return &desc->vdesc.tx;
+}
+
+/**
+ * xilinx_dpdma_alloc_chan_resources - Allocate resources for the channel
+ * @dchan: DMA channel
+ *
+ * Allocate a descriptor pool for the channel.
+ *
+ * Return: 0 on success, or -ENOMEM if failed to allocate a pool.
+ */
+static int xilinx_dpdma_alloc_chan_resources(struct dma_chan *dchan)
+{
+	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+	size_t align = __alignof__(struct xilinx_dpdma_sw_desc);
+
+	chan->desc_pool = dma_pool_create(dev_name(chan->xdev->dev),
+					  chan->xdev->dev,
+					  sizeof(struct xilinx_dpdma_sw_desc),
+					  align, 0);
+	if (!chan->desc_pool) {
+		dev_err(chan->xdev->dev,
+			"failed to allocate a descriptor pool\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/**
+ * xilinx_dpdma_free_chan_resources - Free all resources for the channel
+ * @dchan: DMA channel
+ *
+ * Free resources associated with the virtual DMA channel, and destroy the
+ * descriptor pool.
+ */
+static void xilinx_dpdma_free_chan_resources(struct dma_chan *dchan)
+{
+	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+
+	vchan_free_chan_resources(&chan->vchan);
+
+	dma_pool_destroy(chan->desc_pool);
+	chan->desc_pool = NULL;
+}
+
+static void xilinx_dpdma_issue_pending(struct dma_chan *dchan)
+{
+	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->vchan.lock, flags);
+	if (vchan_issue_pending(&chan->vchan))
+		xilinx_dpdma_chan_queue_transfer(chan);
+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
+}
+
+static int xilinx_dpdma_config(struct dma_chan *dchan,
+			       struct dma_slave_config *config)
+{
+	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+	unsigned long flags;
+
+	/*
+	 * The destination address doesn't need to be specified as the DPDMA is
+	 * hardwired to the destination (the DP controller). The transfer
+	 * width, burst size and port window size are thus meaningless, they're
+	 * fixed both on the DPDMA side and on the DP controller side.
+	 */
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	/*
+	 * Abuse the slave_id to indicate that the channel is part of a video
+	 * group.
+	 */
+	if (chan->id >= ZYNQMP_DPDMA_VIDEO0 && chan->id <= ZYNQMP_DPDMA_VIDEO2)
+		chan->video_group = config->slave_id != 0;
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	return 0;
+}
+
+static int xilinx_dpdma_pause(struct dma_chan *dchan)
+{
+	xilinx_dpdma_chan_pause(to_xilinx_chan(dchan));
+
+	return 0;
+}
+
+static int xilinx_dpdma_resume(struct dma_chan *dchan)
+{
+	xilinx_dpdma_chan_unpause(to_xilinx_chan(dchan));
+
+	return 0;
+}
+
+/**
+ * xilinx_dpdma_terminate_all - Terminate the channel and descriptors
+ * @dchan: DMA channel
+ *
+ * Pause the channel without waiting for ongoing transfers to complete. Waiting
+ * for completion is performed by xilinx_dpdma_synchronize() that will disable
+ * the channel to complete the stop.
+ *
+ * All the descriptors associated with the channel that are guaranteed not to
+ * be touched by the hardware. The pending and active descriptor are not
+ * touched, and will be freed either upon completion, or by
+ * xilinx_dpdma_synchronize().
+ *
+ * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
+ */
+static int xilinx_dpdma_terminate_all(struct dma_chan *dchan)
+{
+	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+	struct xilinx_dpdma_device *xdev = chan->xdev;
+	LIST_HEAD(descriptors);
+	unsigned long flags;
+	unsigned int i;
+
+	/* Pause the channel (including the whole video group if applicable). */
+	if (chan->video_group) {
+		for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
+			if (xdev->chan[i]->video_group &&
+			    xdev->chan[i]->running) {
+				xilinx_dpdma_chan_pause(xdev->chan[i]);
+				xdev->chan[i]->video_group = false;
+			}
+		}
+	} else {
+		xilinx_dpdma_chan_pause(chan);
+	}
+
+	/* Gather all the descriptors we can free and free them. */
+	spin_lock_irqsave(&chan->vchan.lock, flags);
+	vchan_get_all_descriptors(&chan->vchan, &descriptors);
+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+	vchan_dma_desc_free_list(&chan->vchan, &descriptors);
+
+	return 0;
+}
+
+/**
+ * xilinx_dpdma_synchronize - Synchronize callback execution
+ * @dchan: DMA channel
+ *
+ * Synchronizing callback execution ensures that all previously issued
+ * transfers have completed and all associated callbacks have been called and
+ * have returned.
+ *
+ * This function waits for the DMA channel to stop. It assumes it has been
+ * paused by a previous call to dmaengine_terminate_async(), and that no new
+ * pending descriptors have been issued with dma_async_issue_pending(). The
+ * behaviour is undefined otherwise.
+ */
+static void xilinx_dpdma_synchronize(struct dma_chan *dchan)
+{
+	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
+	unsigned long flags;
+
+	xilinx_dpdma_chan_stop(chan);
+
+	spin_lock_irqsave(&chan->vchan.lock, flags);
+	if (chan->desc.pending) {
+		vchan_terminate_vdesc(&chan->desc.pending->vdesc);
+		chan->desc.pending = NULL;
+	}
+	if (chan->desc.active) {
+		vchan_terminate_vdesc(&chan->desc.active->vdesc);
+		chan->desc.active = NULL;
+	}
+	spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+	vchan_synchronize(&chan->vchan);
+}
+
+/* -----------------------------------------------------------------------------
+ * Interrupt and Tasklet Handling
+ */
+
+/**
+ * xilinx_dpdma_err - Detect any global error
+ * @isr: Interrupt Status Register
+ * @eisr: Error Interrupt Status Register
+ *
+ * Return: True if any global error occurs, or false otherwise.
+ */
+static bool xilinx_dpdma_err(u32 isr, u32 eisr)
+{
+	if (isr & XILINX_DPDMA_INTR_GLOBAL_ERR ||
+	    eisr & XILINX_DPDMA_EINTR_GLOBAL_ERR)
+		return true;
+
+	return false;
+}
+
+/**
+ * xilinx_dpdma_handle_err_irq - Handle DPDMA error interrupt
+ * @xdev: DPDMA device
+ * @isr: masked Interrupt Status Register
+ * @eisr: Error Interrupt Status Register
+ *
+ * Handle if any error occurs based on @isr and @eisr. This function disables
+ * corresponding error interrupts, and those should be re-enabled once handling
+ * is done.
+ */
+static void xilinx_dpdma_handle_err_irq(struct xilinx_dpdma_device *xdev,
+					u32 isr, u32 eisr)
+{
+	bool err = xilinx_dpdma_err(isr, eisr);
+	unsigned int i;
+
+	dev_dbg_ratelimited(xdev->dev,
+			    "error irq: isr = 0x%08x, eisr = 0x%08x\n",
+			    isr, eisr);
+
+	/* Disable channel error interrupts until errors are handled. */
+	dpdma_write(xdev->reg, XILINX_DPDMA_IDS,
+		    isr & ~XILINX_DPDMA_INTR_GLOBAL_ERR);
+	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS,
+		    eisr & ~XILINX_DPDMA_EINTR_GLOBAL_ERR);
+
+	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
+		if (err || xilinx_dpdma_chan_err(xdev->chan[i], isr, eisr))
+			tasklet_schedule(&xdev->chan[i]->err_task);
+}
+
+/**
+ * xilinx_dpdma_enable_irq - Enable interrupts
+ * @xdev: DPDMA device
+ *
+ * Enable interrupts.
+ */
+static void xilinx_dpdma_enable_irq(struct xilinx_dpdma_device *xdev)
+{
+	dpdma_write(xdev->reg, XILINX_DPDMA_IEN, XILINX_DPDMA_INTR_ALL);
+	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN, XILINX_DPDMA_EINTR_ALL);
+}
+
+/**
+ * xilinx_dpdma_disable_irq - Disable interrupts
+ * @xdev: DPDMA device
+ *
+ * Disable interrupts.
+ */
+static void xilinx_dpdma_disable_irq(struct xilinx_dpdma_device *xdev)
+{
+	dpdma_write(xdev->reg, XILINX_DPDMA_IDS, XILINX_DPDMA_INTR_ERR_ALL);
+	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS, XILINX_DPDMA_EINTR_ALL);
+}
+
+/**
+ * xilinx_dpdma_chan_err_task - Per channel tasklet for error handling
+ * @data: tasklet data to be casted to DPDMA channel structure
+ *
+ * Per channel error handling tasklet. This function waits for the outstanding
+ * transaction to complete and triggers error handling. After error handling,
+ * re-enable channel error interrupts, and restart the channel if needed.
+ */
+static void xilinx_dpdma_chan_err_task(unsigned long data)
+{
+	struct xilinx_dpdma_chan *chan = (struct xilinx_dpdma_chan *)data;
+	struct xilinx_dpdma_device *xdev = chan->xdev;
+	unsigned long flags;
+
+	/* Proceed error handling even when polling fails. */
+	xilinx_dpdma_chan_poll_no_ostand(chan);
+
+	xilinx_dpdma_chan_handle_err(chan);
+
+	dpdma_write(xdev->reg, XILINX_DPDMA_IEN,
+		    XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id);
+	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN,
+		    XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id);
+
+	spin_lock_irqsave(&chan->lock, flags);
+	xilinx_dpdma_chan_queue_transfer(chan);
+	spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+static irqreturn_t xilinx_dpdma_irq_handler(int irq, void *data)
+{
+	struct xilinx_dpdma_device *xdev = data;
+	unsigned long mask;
+	unsigned int i;
+	u32 status;
+	u32 error;
+
+	status = dpdma_read(xdev->reg, XILINX_DPDMA_ISR);
+	error = dpdma_read(xdev->reg, XILINX_DPDMA_EISR);
+	if (!status && !error)
+		return IRQ_NONE;
+
+	dpdma_write(xdev->reg, XILINX_DPDMA_ISR, status);
+	dpdma_write(xdev->reg, XILINX_DPDMA_EISR, error);
+
+	if (status & XILINX_DPDMA_INTR_VSYNC) {
+		/*
+		 * There's a single VSYNC interrupt that needs to be processed
+		 * by each running channel to update the active descriptor.
+		 */
+		for (i = 0; i < ARRAY_SIZE(xdev->chan); i++) {
+			struct xilinx_dpdma_chan *chan = xdev->chan[i];
+
+			if (chan)
+				xilinx_dpdma_chan_vsync_irq(chan);
+		}
+	}
+
+	mask = FIELD_GET(XILINX_DPDMA_INTR_DESC_DONE_MASK, status);
+	if (mask) {
+		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
+			xilinx_dpdma_chan_done_irq(xdev->chan[i]);
+	}
+
+	mask = FIELD_GET(XILINX_DPDMA_INTR_NO_OSTAND_MASK, status);
+	if (mask) {
+		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
+			xilinx_dpdma_chan_notify_no_ostand(xdev->chan[i]);
+	}
+
+	mask = status & XILINX_DPDMA_INTR_ERR_ALL;
+	if (mask || error)
+		xilinx_dpdma_handle_err_irq(xdev, mask, error);
+
+	return IRQ_HANDLED;
+}
+
+/* -----------------------------------------------------------------------------
+ * Initialization & Cleanup
+ */
+
+static int xilinx_dpdma_chan_init(struct xilinx_dpdma_device *xdev,
+				  unsigned int chan_id)
+{
+	struct xilinx_dpdma_chan *chan;
+
+	chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
+	if (!chan)
+		return -ENOMEM;
+
+	chan->id = chan_id;
+	chan->reg = xdev->reg + XILINX_DPDMA_CH_BASE
+		  + XILINX_DPDMA_CH_OFFSET * chan->id;
+	chan->running = false;
+	chan->xdev = xdev;
+
+	spin_lock_init(&chan->lock);
+	init_waitqueue_head(&chan->wait_to_stop);
+
+	tasklet_init(&chan->err_task, xilinx_dpdma_chan_err_task,
+		     (unsigned long)chan);
+
+	chan->vchan.desc_free = xilinx_dpdma_chan_free_tx_desc;
+	vchan_init(&chan->vchan, &xdev->common);
+
+	xdev->chan[chan->id] = chan;
+
+	return 0;
+}
+
+static void xilinx_dpdma_chan_remove(struct xilinx_dpdma_chan *chan)
+{
+	if (!chan)
+		return;
+
+	tasklet_kill(&chan->err_task);
+	list_del(&chan->vchan.chan.device_node);
+}
+
+static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
+					    struct of_dma *ofdma)
+{
+	struct xilinx_dpdma_device *xdev = ofdma->of_dma_data;
+	uint32_t chan_id = dma_spec->args[0];
+
+	if (chan_id >= ARRAY_SIZE(xdev->chan))
+		return NULL;
+
+	if (!xdev->chan[chan_id])
+		return NULL;
+
+	return dma_get_slave_channel(&xdev->chan[chan_id]->vchan.chan);
+}
+
+static int xilinx_dpdma_probe(struct platform_device *pdev)
+{
+	struct xilinx_dpdma_device *xdev;
+	struct dma_device *ddev;
+	unsigned int i;
+	int ret;
+
+	xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
+	if (!xdev)
+		return -ENOMEM;
+
+	xdev->dev = &pdev->dev;
+	xdev->ext_addr = sizeof(dma_addr_t) > 4;
+
+	INIT_LIST_HEAD(&xdev->common.channels);
+
+	platform_set_drvdata(pdev, xdev);
+
+	xdev->axi_clk = devm_clk_get(xdev->dev, "axi_clk");
+	if (IS_ERR(xdev->axi_clk))
+		return PTR_ERR(xdev->axi_clk);
+
+	xdev->reg = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(xdev->reg))
+		return PTR_ERR(xdev->reg);
+
+	xdev->irq = platform_get_irq(pdev, 0);
+	if (xdev->irq < 0) {
+		dev_err(xdev->dev, "failed to get platform irq\n");
+		return xdev->irq;
+	}
+
+	ret = request_irq(xdev->irq, xilinx_dpdma_irq_handler, IRQF_SHARED,
+			  dev_name(xdev->dev), xdev);
+	if (ret) {
+		dev_err(xdev->dev, "failed to request IRQ\n");
+		return ret;
+	}
+
+	ddev = &xdev->common;
+	ddev->dev = &pdev->dev;
+
+	dma_cap_set(DMA_SLAVE, ddev->cap_mask);
+	dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
+	dma_cap_set(DMA_INTERLEAVE, ddev->cap_mask);
+	dma_cap_set(DMA_REPEAT, ddev->cap_mask);
+	dma_cap_set(DMA_LOAD_EOT, ddev->cap_mask);
+	ddev->copy_align = fls(XILINX_DPDMA_ALIGN_BYTES - 1);
+
+	ddev->device_alloc_chan_resources = xilinx_dpdma_alloc_chan_resources;
+	ddev->device_free_chan_resources = xilinx_dpdma_free_chan_resources;
+	ddev->device_prep_interleaved_dma = xilinx_dpdma_prep_interleaved_dma;
+	/* TODO: Can we achieve better granularity ? */
+	ddev->device_tx_status = dma_cookie_status;
+	ddev->device_issue_pending = xilinx_dpdma_issue_pending;
+	ddev->device_config = xilinx_dpdma_config;
+	ddev->device_pause = xilinx_dpdma_pause;
+	ddev->device_resume = xilinx_dpdma_resume;
+	ddev->device_terminate_all = xilinx_dpdma_terminate_all;
+	ddev->device_synchronize = xilinx_dpdma_synchronize;
+	ddev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED);
+	ddev->directions = BIT(DMA_MEM_TO_DEV);
+	ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
+
+	for (i = 0; i < ARRAY_SIZE(xdev->chan); ++i) {
+		ret = xilinx_dpdma_chan_init(xdev, i);
+		if (ret < 0) {
+			dev_err(xdev->dev, "failed to initialize channel %u\n",
+				i);
+			goto error;
+		}
+	}
+
+	ret = clk_prepare_enable(xdev->axi_clk);
+	if (ret) {
+		dev_err(xdev->dev, "failed to enable the axi clock\n");
+		goto error;
+	}
+
+	ret = dma_async_device_register(ddev);
+	if (ret) {
+		dev_err(xdev->dev, "failed to register the dma device\n");
+		goto error_dma_async;
+	}
+
+	ret = of_dma_controller_register(xdev->dev->of_node,
+					 of_dma_xilinx_xlate, ddev);
+	if (ret) {
+		dev_err(xdev->dev, "failed to register DMA to DT DMA helper\n");
+		goto error_of_dma;
+	}
+
+	xilinx_dpdma_enable_irq(xdev);
+
+	dev_info(&pdev->dev, "Xilinx DPDMA engine is probed\n");
+
+	return 0;
+
+error_of_dma:
+	dma_async_device_unregister(ddev);
+error_dma_async:
+	clk_disable_unprepare(xdev->axi_clk);
+error:
+	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
+		xilinx_dpdma_chan_remove(xdev->chan[i]);
+
+	free_irq(xdev->irq, xdev);
+
+	return ret;
+}
+
+static int xilinx_dpdma_remove(struct platform_device *pdev)
+{
+	struct xilinx_dpdma_device *xdev = platform_get_drvdata(pdev);
+	unsigned int i;
+
+	/* Start by disabling the IRQ to avoid races during cleanup. */
+	free_irq(xdev->irq, xdev);
+
+	xilinx_dpdma_disable_irq(xdev);
+	of_dma_controller_free(pdev->dev.of_node);
+	dma_async_device_unregister(&xdev->common);
+	clk_disable_unprepare(xdev->axi_clk);
+
+	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
+		xilinx_dpdma_chan_remove(xdev->chan[i]);
+
+	return 0;
+}
+
+static const struct of_device_id xilinx_dpdma_of_match[] = {
+	{ .compatible = "xlnx,zynqmp-dpdma",},
+	{ /* end of table */ },
+};
+MODULE_DEVICE_TABLE(of, xilinx_dpdma_of_match);
+
+static struct platform_driver xilinx_dpdma_driver = {
+	.probe			= xilinx_dpdma_probe,
+	.remove			= xilinx_dpdma_remove,
+	.driver			= {
+		.name		= "xilinx-zynqmp-dpdma",
+		.of_match_table	= xilinx_dpdma_of_match,
+	},
+};
+
+module_platform_driver(xilinx_dpdma_driver);
+
+MODULE_AUTHOR("Xilinx, Inc.");
+MODULE_DESCRIPTION("Xilinx ZynqMP DPDMA driver");
+MODULE_LICENSE("GPL v2");
-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v7 4/5] dmaengine: xilinx: dpdma: Add debugfs support
  2020-07-17  1:33 [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Laurent Pinchart
                   ` (2 preceding siblings ...)
  2020-07-17  1:33 ` [PATCH v7 3/5] dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver Laurent Pinchart
@ 2020-07-17  1:33 ` Laurent Pinchart
  2020-07-17  6:05   ` Vinod Koul
  2020-07-17  1:33 ` [PATCH v7 5/5] arm64: dts: zynqmp: Add DPDMA node Laurent Pinchart
  2020-07-17  6:11 ` [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Vinod Koul
  5 siblings, 1 reply; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-17  1:33 UTC (permalink / raw)
  To: dmaengine
  Cc: Michal Simek, Hyun Kwon, Tejas Upadhyay, Satish Kumar Nagireddy,
	Vinod Koul, Peter Ujfalusi

Expose statistics to debugfs when available. This helps debugging issues
with the DPDMA driver.

Signed-off-by: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v6:

- Move debugfs node to the dmaengine directory
- Destroy debugfs directory upon removal

Changes since v3:

- Return -EFAULT instead of bytes remaining after copy_to_user()

Changes since v2:

- Refactor debugfs code
---
 drivers/dma/xilinx/xilinx_dpdma.c | 238 ++++++++++++++++++++++++++++++
 1 file changed, 238 insertions(+)

diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c
index af88a6762ef4..753c0c8c4833 100644
--- a/drivers/dma/xilinx/xilinx_dpdma.c
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -10,6 +10,7 @@
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/clk.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
 #include <linux/dmapool.h>
@@ -252,6 +253,7 @@ struct xilinx_dpdma_chan {
  * @axi_clk: axi clock
  * @chan: DPDMA channels
  * @ext_addr: flag for 64 bit system (48 bit addressing)
+ * @debugfs_dir: root debugfs directory for the device
  */
 struct xilinx_dpdma_device {
 	struct dma_device common;
@@ -263,8 +265,238 @@ struct xilinx_dpdma_device {
 	struct xilinx_dpdma_chan *chan[XILINX_DPDMA_NUM_CHAN];
 
 	bool ext_addr;
+
+	struct dentry *debugfs_dir;
 };
 
+/* -----------------------------------------------------------------------------
+ * DebugFS
+ */
+
+#ifdef CONFIG_DEBUG_FS
+
+#define XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE	32
+#define XILINX_DPDMA_DEBUGFS_UINT16_MAX_STR	"65535"
+
+/* Match xilinx_dpdma_testcases vs dpdma_debugfs_reqs[] entry */
+enum xilinx_dpdma_testcases {
+	DPDMA_TC_INTR_DONE,
+	DPDMA_TC_NONE
+};
+
+struct xilinx_dpdma_debugfs {
+	enum xilinx_dpdma_testcases testcase;
+	u16 xilinx_dpdma_irq_done_count;
+	unsigned int chan_id;
+};
+
+static struct xilinx_dpdma_debugfs dpdma_debugfs;
+struct xilinx_dpdma_debugfs_request {
+	const char *name;
+	enum xilinx_dpdma_testcases tc;
+	ssize_t (*read)(char *buf);
+	int (*write)(char *args);
+};
+
+static void xilinx_dpdma_debugfs_desc_done_irq(struct xilinx_dpdma_chan *chan)
+{
+	if (chan->id == dpdma_debugfs.chan_id)
+		dpdma_debugfs.xilinx_dpdma_irq_done_count++;
+}
+
+static ssize_t xilinx_dpdma_debugfs_desc_done_irq_read(char *buf)
+{
+	size_t out_str_len;
+
+	dpdma_debugfs.testcase = DPDMA_TC_NONE;
+
+	out_str_len = strlen(XILINX_DPDMA_DEBUGFS_UINT16_MAX_STR);
+	out_str_len = min_t(size_t, XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE,
+			    out_str_len);
+	snprintf(buf, out_str_len, "%d",
+		 dpdma_debugfs.xilinx_dpdma_irq_done_count);
+
+	return 0;
+}
+
+static int xilinx_dpdma_debugfs_desc_done_irq_write(char *args)
+{
+	char *arg;
+	int ret;
+	u32 id;
+
+	arg = strsep(&args, " ");
+	if (!arg || strncasecmp(arg, "start", 5))
+		return -EINVAL;
+
+	arg = strsep(&args, " ");
+	if (!arg)
+		return -EINVAL;
+
+	ret = kstrtou32(arg, 0, &id);
+	if (ret < 0)
+		return ret;
+
+	if (id < ZYNQMP_DPDMA_VIDEO0 || id > ZYNQMP_DPDMA_AUDIO1)
+		return -EINVAL;
+
+	dpdma_debugfs.testcase = DPDMA_TC_INTR_DONE;
+	dpdma_debugfs.xilinx_dpdma_irq_done_count = 0;
+	dpdma_debugfs.chan_id = id;
+
+	return 0;
+}
+
+/* Match xilinx_dpdma_testcases vs dpdma_debugfs_reqs[] entry */
+struct xilinx_dpdma_debugfs_request dpdma_debugfs_reqs[] = {
+	{
+		.name = "DESCRIPTOR_DONE_INTR",
+		.tc = DPDMA_TC_INTR_DONE,
+		.read = xilinx_dpdma_debugfs_desc_done_irq_read,
+		.write = xilinx_dpdma_debugfs_desc_done_irq_write,
+	},
+};
+
+static ssize_t xilinx_dpdma_debugfs_read(struct file *f, char __user *buf,
+					 size_t size, loff_t *pos)
+{
+	enum xilinx_dpdma_testcases testcase;
+	char *kern_buff;
+	int ret = 0;
+
+	if (*pos != 0 || size <= 0)
+		return -EINVAL;
+
+	kern_buff = kzalloc(XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE, GFP_KERNEL);
+	if (!kern_buff) {
+		dpdma_debugfs.testcase = DPDMA_TC_NONE;
+		return -ENOMEM;
+	}
+
+	testcase = READ_ONCE(dpdma_debugfs.testcase);
+	if (testcase != DPDMA_TC_NONE) {
+		ret = dpdma_debugfs_reqs[testcase].read(kern_buff);
+		if (ret < 0)
+			goto done;
+	} else {
+		strlcpy(kern_buff, "No testcase executed",
+			XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE);
+	}
+
+	size = min(size, strlen(kern_buff));
+	if (copy_to_user(buf, kern_buff, size))
+		ret = -EFAULT;
+
+done:
+	kfree(kern_buff);
+	if (ret)
+		return ret;
+
+	*pos = size + 1;
+	return size;
+}
+
+static ssize_t xilinx_dpdma_debugfs_write(struct file *f,
+					  const char __user *buf, size_t size,
+					  loff_t *pos)
+{
+	char *kern_buff, *kern_buff_start;
+	char *testcase;
+	unsigned int i;
+	int ret;
+
+	if (*pos != 0 || size <= 0)
+		return -EINVAL;
+
+	/* Supporting single instance of test as of now. */
+	if (dpdma_debugfs.testcase != DPDMA_TC_NONE)
+		return -EBUSY;
+
+	kern_buff = kzalloc(size, GFP_KERNEL);
+	if (!kern_buff)
+		return -ENOMEM;
+	kern_buff_start = kern_buff;
+
+	ret = strncpy_from_user(kern_buff, buf, size);
+	if (ret < 0)
+		goto done;
+
+	/* Read the testcase name from a user request. */
+	testcase = strsep(&kern_buff, " ");
+
+	for (i = 0; i < ARRAY_SIZE(dpdma_debugfs_reqs); i++) {
+		if (!strcasecmp(testcase, dpdma_debugfs_reqs[i].name))
+			break;
+	}
+
+	if (i == ARRAY_SIZE(dpdma_debugfs_reqs)) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	ret = dpdma_debugfs_reqs[i].write(kern_buff);
+	if (ret < 0)
+		goto done;
+
+	ret = size;
+
+done:
+	kfree(kern_buff_start);
+	return ret;
+}
+
+static const struct file_operations fops_xilinx_dpdma_dbgfs = {
+	.owner = THIS_MODULE,
+	.read = xilinx_dpdma_debugfs_read,
+	.write = xilinx_dpdma_debugfs_write,
+};
+
+static void xilinx_dpdma_debugfs_cleanup(struct xilinx_dpdma_device *xdev)
+{
+	debugfs_remove_recursive(xdev->debugfs_dir);
+	xdev->debugfs_dir = NULL;
+}
+
+static int xilinx_dpdma_debugfs_init(struct xilinx_dpdma_device *xdev)
+{
+	struct dentry *dent;
+
+	dpdma_debugfs.testcase = DPDMA_TC_NONE;
+
+	dent = debugfs_create_dir("dpdma", xdev->common.dbg_dev_root);
+	if (IS_ERR(dent)) {
+		dev_err(xdev->dev, "Failed to create debugfs directory\n");
+		return -ENODEV;
+	}
+
+	xdev->debugfs_dir = dent;
+
+	dent = debugfs_create_file("testcase", 0444, xdev->debugfs_dir, NULL,
+				   &fops_xilinx_dpdma_dbgfs);
+	if (IS_ERR(dent)) {
+		dev_err(xdev->dev, "Failed to cerate debugfs testcase file\n");
+		xilinx_dpdma_debugfs_cleanup(xdev);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+#else
+static void xilinx_dpdma_debugfs_cleanup(struct xilinx_dpdma_device *xdev)
+{
+}
+
+static int xilinx_dpdma_debugfs_init(struct xilinx_dpdma_device *xdev)
+{
+	return 0;
+}
+
+static void xilinx_dpdma_debugfs_desc_done_irq(struct xilinx_dpdma_chan *chan)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
 /* -----------------------------------------------------------------------------
  * I/O Accessors
  */
@@ -840,6 +1072,8 @@ static void xilinx_dpdma_chan_done_irq(struct xilinx_dpdma_chan *chan)
 
 	spin_lock_irqsave(&chan->lock, flags);
 
+	xilinx_dpdma_debugfs_desc_done_irq(chan);
+
 	if (active)
 		vchan_cyclic_callback(&active->vdesc);
 	else
@@ -1475,6 +1709,8 @@ static int xilinx_dpdma_probe(struct platform_device *pdev)
 
 	xilinx_dpdma_enable_irq(xdev);
 
+	xilinx_dpdma_debugfs_init(xdev);
+
 	dev_info(&pdev->dev, "Xilinx DPDMA engine is probed\n");
 
 	return 0;
@@ -1500,6 +1736,8 @@ static int xilinx_dpdma_remove(struct platform_device *pdev)
 	/* Start by disabling the IRQ to avoid races during cleanup. */
 	free_irq(xdev->irq, xdev);
 
+	xilinx_dpdma_debugfs_cleanup(xdev);
+
 	xilinx_dpdma_disable_irq(xdev);
 	of_dma_controller_free(pdev->dev.of_node);
 	dma_async_device_unregister(&xdev->common);
-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v7 5/5] arm64: dts: zynqmp: Add DPDMA node
  2020-07-17  1:33 [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Laurent Pinchart
                   ` (3 preceding siblings ...)
  2020-07-17  1:33 ` [PATCH v7 4/5] dmaengine: xilinx: dpdma: Add debugfs support Laurent Pinchart
@ 2020-07-17  1:33 ` Laurent Pinchart
  2020-07-17  6:11 ` [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Vinod Koul
  5 siblings, 0 replies; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-17  1:33 UTC (permalink / raw)
  To: dmaengine
  Cc: Michal Simek, Hyun Kwon, Tejas Upadhyay, Satish Kumar Nagireddy,
	Vinod Koul, Peter Ujfalusi

Add a DT node for the DisplayPort DMA engine (DPDMA).

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
---
 arch/arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi |  4 ++++
 arch/arm64/boot/dts/xilinx/zynqmp.dtsi         | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi b/arch/arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi
index 9868ca15dfc5..32c4914738d9 100644
--- a/arch/arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi
+++ b/arch/arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi
@@ -57,6 +57,10 @@ &cpu0 {
 	clocks = <&zynqmp_clk ACPU>;
 };
 
+&dpdma {
+	clocks = <&zynqmp_clk DPDMA_REF>;
+};
+
 &fpd_dma_chan1 {
 	clocks = <&zynqmp_clk GDMA_REF>, <&zynqmp_clk LPD_LSBUS>;
 };
diff --git a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
index 9174ddc76bdc..d2554640db57 100644
--- a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
+++ b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
@@ -250,6 +250,16 @@ pmu@9000 {
 			};
 		};
 
+		dpdma: dma-controller@fd4c0000 {
+			compatible = "xlnx,zynqmp-dpdma";
+			status = "disabled";
+			reg = <0x0 0xfd4c0000 0x0 0x1000>;
+			interrupts = <0 122 4>;
+			interrupt-parent = <&gic>;
+			clock-names = "axi_clk";
+			#dma-cells = <1>;
+		};
+
 		/* GDMA */
 		fpd_dma_chan1: dma@fd500000 {
 			status = "disabled";
-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v7 4/5] dmaengine: xilinx: dpdma: Add debugfs support
  2020-07-17  1:33 ` [PATCH v7 4/5] dmaengine: xilinx: dpdma: Add debugfs support Laurent Pinchart
@ 2020-07-17  6:05   ` Vinod Koul
  2020-07-18  0:23     ` Laurent Pinchart
  0 siblings, 1 reply; 10+ messages in thread
From: Vinod Koul @ 2020-07-17  6:05 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: dmaengine, Michal Simek, Hyun Kwon, Tejas Upadhyay,
	Satish Kumar Nagireddy, Peter Ujfalusi

On 17-07-20, 04:33, Laurent Pinchart wrote:

> +static void xilinx_dpdma_debugfs_cleanup(struct xilinx_dpdma_device *xdev)
> +{
> +	debugfs_remove_recursive(xdev->debugfs_dir);

you can skip this step as core will do so when you call
dma_async_device_unregister()

> +	xdev->debugfs_dir = NULL;
> +}
> +
> +static int xilinx_dpdma_debugfs_init(struct xilinx_dpdma_device *xdev)
> +{
> +	struct dentry *dent;
> +
> +	dpdma_debugfs.testcase = DPDMA_TC_NONE;
> +
> +	dent = debugfs_create_dir("dpdma", xdev->common.dbg_dev_root);
> +	if (IS_ERR(dent)) {
> +		dev_err(xdev->dev, "Failed to create debugfs directory\n");
> +		return -ENODEV;
> +	}

Do you really need another dir in your device root. You should already
have .../dmaengine/<dpdma-dev-name>/ adding dpdma dir seems overkill

-- 
~Vinod

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver
  2020-07-17  1:33 [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Laurent Pinchart
                   ` (4 preceding siblings ...)
  2020-07-17  1:33 ` [PATCH v7 5/5] arm64: dts: zynqmp: Add DPDMA node Laurent Pinchart
@ 2020-07-17  6:11 ` Vinod Koul
  2020-07-18  0:24   ` Laurent Pinchart
  5 siblings, 1 reply; 10+ messages in thread
From: Vinod Koul @ 2020-07-17  6:11 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: dmaengine, Michal Simek, Hyun Kwon, Tejas Upadhyay,
	Satish Kumar Nagireddy, Peter Ujfalusi

On 17-07-20, 04:33, Laurent Pinchart wrote:
> Hello,
> 
> This patch series adds a new driver for the DPDMA engine found in the
> Xilinx ZynqMP.
> 
> The previous version can be found at [1]. All review comments have been
> taken into account. The main changes are in the DPDMA driver, with
> cleanups in the debugfs support, and handling of the !LOAD_EOT case when
> preparing transactions.
> 
> The driver has been successfully tested with the ZynqMP DisplayPort
> subsystem DRM driver.
> 
> As I would like to merge both this series and the DRM driver that
> depends on it for v5.9 (if still possible), I have based those patches
> on top of v5.8-rc1. There's unfortunately a conflict with the DMA engine
> next branch, which is easy to resolve.
> 
> Vinod, if you're fine with the series, I can propose two ways forward:
> 
> - You can apply the patches on top of v5.8-rc1, push that to a base
>   branch, merge it into the dmaengine -next branch, and push the base
>   branch to a public git tree to let me base the DRM driver on it.

Applied 1-3 to dmaengine.git topic/xilinx, it should show up in -next
later in the day

Thanks
-- 
~Vinod

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v7 4/5] dmaengine: xilinx: dpdma: Add debugfs support
  2020-07-17  6:05   ` Vinod Koul
@ 2020-07-18  0:23     ` Laurent Pinchart
  0 siblings, 0 replies; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-18  0:23 UTC (permalink / raw)
  To: Vinod Koul
  Cc: dmaengine, Michal Simek, Hyun Kwon, Tejas Upadhyay,
	Satish Kumar Nagireddy, Peter Ujfalusi

Hi Vinod,

On Fri, Jul 17, 2020 at 11:35:15AM +0530, Vinod Koul wrote:
> On 17-07-20, 04:33, Laurent Pinchart wrote:
> 
> > +static void xilinx_dpdma_debugfs_cleanup(struct xilinx_dpdma_device *xdev)
> > +{
> > +	debugfs_remove_recursive(xdev->debugfs_dir);
> 
> you can skip this step as core will do so when you call
> dma_async_device_unregister()
> 
> > +	xdev->debugfs_dir = NULL;
> > +}
> > +
> > +static int xilinx_dpdma_debugfs_init(struct xilinx_dpdma_device *xdev)
> > +{
> > +	struct dentry *dent;
> > +
> > +	dpdma_debugfs.testcase = DPDMA_TC_NONE;
> > +
> > +	dent = debugfs_create_dir("dpdma", xdev->common.dbg_dev_root);
> > +	if (IS_ERR(dent)) {
> > +		dev_err(xdev->dev, "Failed to create debugfs directory\n");
> > +		return -ENODEV;
> > +	}
> 
> Do you really need another dir in your device root. You should already
> have .../dmaengine/<dpdma-dev-name>/ adding dpdma dir seems overkill

It's indeed overkill. I'll remove it. Thanks for catching the issue.

-- 
Regards,

Laurent Pinchart

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver
  2020-07-17  6:11 ` [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Vinod Koul
@ 2020-07-18  0:24   ` Laurent Pinchart
  0 siblings, 0 replies; 10+ messages in thread
From: Laurent Pinchart @ 2020-07-18  0:24 UTC (permalink / raw)
  To: Vinod Koul
  Cc: dmaengine, Michal Simek, Hyun Kwon, Tejas Upadhyay,
	Satish Kumar Nagireddy, Peter Ujfalusi

Hi Vinod,

On Fri, Jul 17, 2020 at 11:41:20AM +0530, Vinod Koul wrote:
> On 17-07-20, 04:33, Laurent Pinchart wrote:
> > Hello,
> > 
> > This patch series adds a new driver for the DPDMA engine found in the
> > Xilinx ZynqMP.
> > 
> > The previous version can be found at [1]. All review comments have been
> > taken into account. The main changes are in the DPDMA driver, with
> > cleanups in the debugfs support, and handling of the !LOAD_EOT case when
> > preparing transactions.
> > 
> > The driver has been successfully tested with the ZynqMP DisplayPort
> > subsystem DRM driver.
> > 
> > As I would like to merge both this series and the DRM driver that
> > depends on it for v5.9 (if still possible), I have based those patches
> > on top of v5.8-rc1. There's unfortunately a conflict with the DMA engine
> > next branch, which is easy to resolve.
> > 
> > Vinod, if you're fine with the series, I can propose two ways forward:
> > 
> > - You can apply the patches on top of v5.8-rc1, push that to a base
> >   branch, merge it into the dmaengine -next branch, and push the base
> >   branch to a public git tree to let me base the DRM driver on it.
> 
> Applied 1-3 to dmaengine.git topic/xilinx, it should show up in -next
> later in the day

Thank you!

-- 
Regards,

Laurent Pinchart

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, back to index

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-17  1:33 [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Laurent Pinchart
2020-07-17  1:33 ` [PATCH v7 1/5] dt: bindings: dma: xilinx: dpdma: DT bindings for Xilinx DPDMA Laurent Pinchart
2020-07-17  1:33 ` [PATCH v7 2/5] dmaengine: Add support for repeating transactions Laurent Pinchart
2020-07-17  1:33 ` [PATCH v7 3/5] dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver Laurent Pinchart
2020-07-17  1:33 ` [PATCH v7 4/5] dmaengine: xilinx: dpdma: Add debugfs support Laurent Pinchart
2020-07-17  6:05   ` Vinod Koul
2020-07-18  0:23     ` Laurent Pinchart
2020-07-17  1:33 ` [PATCH v7 5/5] arm64: dts: zynqmp: Add DPDMA node Laurent Pinchart
2020-07-17  6:11 ` [PATCH v7 0/5] dma: Add Xilinx ZynqMP DPDMA driver Vinod Koul
2020-07-18  0:24   ` Laurent Pinchart

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