[PATCH v3 0/5] firmware: ti_sci: Introduce system suspend support

[PATCH v3 0/5] firmware: ti_sci: Introduce system suspend support

[Georgi Vlaev]

This series introduces necessary ti_sci driver functionality in
preparation of supporting DeepSleep mode for suspend to mem on TI
K3 AM62x. This version is a fixup and rebase of the patch series by
Dave Gerlach [1]. It applies on top of v6.1-rc4.

Deep Sleep mode is described in section "5.2.4.4 DeepSleep" of the
AM62x Technical Reference Manual [2].

The kernel triggers entry to Deep Sleep mode through the mem suspend
transition with the following:

* Use a TF-A binary that supports PSCI_SYSTEM_SUSPEND call. This causes
  system to use PSCI system suspend as last step of mem sleep.

* The firmware requires that the OS sends a TISCI_MSG_PREPARE_SLEEP
  message in order to provide details about suspend, so we must add the
  ability to send this message. We also add TISCI_MSG_LPM_WAKE_REASON
  and TISCI_MSG_SET_IO_ISOLATION messages as part of a new PM ops. These
  messages are part of the TISCI PM Low Power Mode API [3]. (Patch 2)

* A memory address must be provided to the firmware using the above
  message, which is allocated and managed by dma_alloc_coherent()
  and friends. (Patch 3)

* System must load firmware to a specific location before Deep Sleep is
  entered, and this is accomplished using a memory region in device
  tree to indicate where this firmware should be loaded, and also a
  "firmware-name" property to indicate the name of the firmware
  to load. The ti_sci driver checks in its pm handler to see if
  the firmware has been loaded and if not, loads it. (Patch 4)

* Finally, the ti_sci driver must actually send TISCI_MSG_PREPARE_SLEEP
  message to firmware with the above information included, which it
  does during the driver suspend handler when PM_MEM_SUSPEND is the
  determined state being entered. (Patch 5)

This is tested on am625-sk using a limited dts with all devices disabled
apart from cpu0, main_uart0, i2c, rtc, mmc/sd, dmsc, and secure_proxy_main.

Testing this sequence requires K3 sdhci suspend/resume support [4],
enable the wkup_rtc in the am625-sk.dts, disable devices that don't
support system suspend/resume like OSPI and CPSW3G.

In can be tested on the following branch:
https://github.com/gvlaev/linux/tree/upstream-v6.2/lpm-ti-sci-v2

Changelog:
v3:
- Fix the compile warnings on 32-bit platforms reported by the kernel
  test robot in patches (3,5).
- Pick up Roger's "Tested-by" tags.

v2:
- Addressed comments received for v1 series [1].
- Updated v1 patch 5 to use pm notifier to avoid firmware loading
  issues.
- Dropped the reserved region requirement and allocate DMA memory
  instead. The reserved region binding patch is also removed.
- Introduce two more TISCI LPM messages that are supported in SysFW.
- Fixes in error handling.

[1] https://lore.kernel.org/lkml/20220421203659.27853-1-d-gerlach@ti.com
[2] https://www.ti.com/lit/pdf/spruiv7
[3] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html
[4] https://lore.kernel.org/lkml/20220408124338.27090-1-a-govindraju@ti.com

Georgi Vlaev (5):
  dt-bindings: ti, sci: Add lpm region and firmware-name
  firmware: ti_sci: Introduce Power Management Ops
  firmware: ti_sci: Allocate memory for the LPM modes
  firmware: ti_sci: Use dt provided fw name and address to load at
    suspend time
  firmware: ti_sci: Introduce prepare system suspend call

 .../bindings/arm/keystone/ti,sci.yaml         |  21 +-
 drivers/firmware/ti_sci.c                     | 356 ++++++++++++++++++
 drivers/firmware/ti_sci.h                     |  64 +++-
 include/linux/soc/ti/ti_sci_protocol.h        |  44 +++
 4 files changed, 480 insertions(+), 5 deletions(-)


base-commit: f0c4d9fc9cc9462659728d168387191387e903cc
-- 
2.30.2

[PATCH v3 1/5] dt-bindings: ti, sci: Add lpm region and firmware-name

[Georgi Vlaev]

From: Dave Gerlach <d-gerlach@ti.com>

Add documentation for the lpm region which tells the ti-sci driver where
to load the FS Stub low power mode firmware and also the firmware-name
which tells the driver which binary to load. Both of these are optional
for normal system operation but required to enabled suspend-to-mem usage
of Deep Sleep state.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Vibhore Vardhan <vibhore@ti.com>
Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
---
 .../bindings/arm/keystone/ti,sci.yaml         | 21 +++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml b/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
index 34f5f877d444..4c5213de24bc 100644
--- a/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
+++ b/Documentation/devicetree/bindings/arm/keystone/ti,sci.yaml
@@ -42,12 +42,19 @@ properties:
           - const: ti,am654-sci
 
   reg-names:
-    description: |
-      Specifies the debug messages memory mapped region that is optionally
-      made available from TI-SCI controller.
-    const: debug_messages
+    items:
+      - const: debug_messages
+      - const: lpm
+    minItems: 1
 
   reg:
+    items:
+      - description: |
+          Specifies the debug messages memory mapped region that is optionally
+          made available from TI-SCI controller.
+      - description: |
+          Specifies the lpm memory mapped region where the FS Stub low power
+          firmware is to be loaded.
     minItems: 1
 
   mbox-names:
@@ -83,6 +90,12 @@ properties:
     type: object
     $ref: /schemas/reset/ti,sci-reset.yaml#
 
+  firmware-name:
+    description: |
+      Name of binary of FS Stub low power firmware located on the
+      firmware search path.
+    $ref: /schemas/types.yaml#/definitions/string
+
 required:
   - compatible
   - mbox-names
-- 
2.30.2

[PATCH v3 2/5] firmware: ti_sci: Introduce Power Management Ops

[Georgi Vlaev]

From: Dave Gerlach <d-gerlach@ti.com>

Introduce power management ops supported by the TISCI
Low Power Mode API [0]. These messages are currently
supported only on AM62x platforms.

1) TISCI_MSG_PREPARE_SLEEP [1]:
Prepare the SOC for entering into a low power mode and
provide details to firmware about the state being entered.

2) TISCI_MSG_LPM_WAKE_REASON [2]:
Get which wake up source woke the SoC from Low Power Mode.
The wake up source IDs will be common for all K3 platforms.

3) TISCI_MSG_SET_IO_ISOLATION [3]:
Control the IO isolation for Low Power Mode.

[0] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html
[1] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#pm-lpm-msg-prepare-sleep
[2] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#pm-lpm-msg-wake-reason
[3] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#pm-lpm-msg-set-io-isolation

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Vibhore Vardhan <vibhore@ti.com>
[g-vlaev@ti.com: LPM_WAKE_REASON and IO_ISOLATION support]
Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
Tested-by: Roger Quadros <rogerq@kernel.org>
---
 drivers/firmware/ti_sci.c              | 174 +++++++++++++++++++++++++
 drivers/firmware/ti_sci.h              |  64 ++++++++-
 include/linux/soc/ti/ti_sci_protocol.h |  44 +++++++
 3 files changed, 281 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index ebc32bbd9b83..f13cf19587e3 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -1667,6 +1667,175 @@ static int ti_sci_cmd_clk_get_freq(const struct ti_sci_handle *handle,
 	return ret;
 }
 
+/**
+ * ti_sci_cmd_prepare_sleep() - Prepare system for system suspend
+ * @handle:		pointer to TI SCI handle
+ * @mode:		Device identifier
+ * @ctx_lo:		Low part of address for context save
+ * @ctx_hi:		High part of address for context save
+ * @debug_flags:	Debug flags to pass to firmware
+ *
+ * Return: 0 if all went well, else returns appropriate error value.
+ */
+static int ti_sci_cmd_prepare_sleep(const struct ti_sci_handle *handle, u8 mode,
+				    u32 ctx_lo, u32 ctx_hi, u32 debug_flags)
+{
+	struct ti_sci_info *info;
+	struct ti_sci_msg_req_prepare_sleep *req;
+	struct ti_sci_msg_hdr *resp;
+	struct ti_sci_xfer *xfer;
+	struct device *dev;
+	int ret = 0;
+
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	if (!handle)
+		return -EINVAL;
+
+	info = handle_to_ti_sci_info(handle);
+	dev = info->dev;
+
+	xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_PREPARE_SLEEP,
+				   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
+				   sizeof(*req), sizeof(*resp));
+	if (IS_ERR(xfer)) {
+		ret = PTR_ERR(xfer);
+		dev_err(dev, "Message alloc failed(%d)\n", ret);
+		return ret;
+	}
+
+	req = (struct ti_sci_msg_req_prepare_sleep *)xfer->xfer_buf;
+	req->mode = mode;
+	req->ctx_lo = ctx_lo;
+	req->ctx_hi = ctx_hi;
+	req->debug_flags = debug_flags;
+
+	ret = ti_sci_do_xfer(info, xfer);
+	if (ret) {
+		dev_err(dev, "Mbox send fail %d\n", ret);
+		goto fail;
+	}
+
+	resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;
+
+	ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;
+
+fail:
+	ti_sci_put_one_xfer(&info->minfo, xfer);
+
+	return ret;
+}
+
+/**
+ * ti_sci_msg_cmd_lpm_wake_reason() - Get the wakeup source from LPM
+ * @handle:		Pointer to TI SCI handle
+ * @source:		The wakeup source that woke the SoC from LPM
+ * @timestamp:		Timestamp of the wakeup event
+ *
+ * Return: 0 if all went well, else returns appropriate error value.
+ */
+static int ti_sci_msg_cmd_lpm_wake_reason(const struct ti_sci_handle *handle,
+					  u32 *source, u64 *timestamp)
+{
+	struct ti_sci_info *info;
+	struct ti_sci_xfer *xfer;
+	struct ti_sci_msg_resp_lpm_wake_reason *resp;
+	struct device *dev;
+	int ret = 0;
+
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	if (!handle)
+		return -EINVAL;
+
+	info = handle_to_ti_sci_info(handle);
+	dev = info->dev;
+
+	xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_LPM_WAKE_REASON,
+				   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
+				   sizeof(struct ti_sci_msg_hdr),
+				   sizeof(*resp));
+	if (IS_ERR(xfer)) {
+		ret = PTR_ERR(xfer);
+		dev_err(dev, "Message alloc failed(%d)\n", ret);
+		return ret;
+	}
+
+	ret = ti_sci_do_xfer(info, xfer);
+	if (ret) {
+		dev_err(dev, "Mbox send fail %d\n", ret);
+		goto fail;
+	}
+
+	resp = (struct ti_sci_msg_resp_lpm_wake_reason *)xfer->xfer_buf;
+
+	if (!ti_sci_is_response_ack(resp)) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	if (source)
+		*source = resp->wake_source;
+	if (timestamp)
+		*timestamp = resp->wake_timestamp;
+
+fail:
+	ti_sci_put_one_xfer(&info->minfo, xfer);
+
+	return ret;
+}
+/**
+ * ti_sci_cmd_set_io_isolation() - Enable IO isolation in LPM
+ * @handle:		Pointer to TI SCI handle
+ * @state:		The desired state of the IO isolation
+ *
+ * Return: 0 if all went well, else returns appropriate error value.
+ */
+static int ti_sci_cmd_set_io_isolation(const struct ti_sci_handle *handle,
+				       u8 state)
+{
+	struct ti_sci_info *info;
+	struct ti_sci_msg_req_set_io_isolation *req;
+	struct ti_sci_msg_hdr *resp;
+	struct ti_sci_xfer *xfer;
+	struct device *dev;
+	int ret = 0;
+
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	if (!handle)
+		return -EINVAL;
+
+	info = handle_to_ti_sci_info(handle);
+	dev = info->dev;
+
+	xfer = ti_sci_get_one_xfer(info, TI_SCI_MSG_SET_IO_ISOLATION,
+				   TI_SCI_FLAG_REQ_ACK_ON_PROCESSED,
+				   sizeof(*req), sizeof(*resp));
+	if (IS_ERR(xfer)) {
+		ret = PTR_ERR(xfer);
+		dev_err(dev, "Message alloc failed(%d)\n", ret);
+		return ret;
+	}
+	req = (struct ti_sci_msg_req_set_io_isolation *)xfer->xfer_buf;
+	req->state = state;
+
+	ret = ti_sci_do_xfer(info, xfer);
+	if (ret) {
+		dev_err(dev, "Mbox send fail %d\n", ret);
+		goto fail;
+	}
+
+	resp = (struct ti_sci_msg_hdr *)xfer->xfer_buf;
+
+	ret = ti_sci_is_response_ack(resp) ? 0 : -ENODEV;
+
+fail:
+	ti_sci_put_one_xfer(&info->minfo, xfer);
+
+	return ret;
+}
+
 static int ti_sci_cmd_core_reboot(const struct ti_sci_handle *handle)
 {
 	struct ti_sci_info *info;
@@ -2808,6 +2977,7 @@ static void ti_sci_setup_ops(struct ti_sci_info *info)
 	struct ti_sci_core_ops *core_ops = &ops->core_ops;
 	struct ti_sci_dev_ops *dops = &ops->dev_ops;
 	struct ti_sci_clk_ops *cops = &ops->clk_ops;
+	struct ti_sci_pm_ops *pmops = &ops->pm_ops;
 	struct ti_sci_rm_core_ops *rm_core_ops = &ops->rm_core_ops;
 	struct ti_sci_rm_irq_ops *iops = &ops->rm_irq_ops;
 	struct ti_sci_rm_ringacc_ops *rops = &ops->rm_ring_ops;
@@ -2847,6 +3017,10 @@ static void ti_sci_setup_ops(struct ti_sci_info *info)
 	cops->set_freq = ti_sci_cmd_clk_set_freq;
 	cops->get_freq = ti_sci_cmd_clk_get_freq;
 
+	pmops->prepare_sleep = ti_sci_cmd_prepare_sleep;
+	pmops->lpm_wake_reason = ti_sci_msg_cmd_lpm_wake_reason;
+	pmops->set_io_isolation = ti_sci_cmd_set_io_isolation;
+
 	rm_core_ops->get_range = ti_sci_cmd_get_resource_range;
 	rm_core_ops->get_range_from_shost =
 				ti_sci_cmd_get_resource_range_from_shost;
diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h
index ef3a8214d002..e4bfe146c43d 100644
--- a/drivers/firmware/ti_sci.h
+++ b/drivers/firmware/ti_sci.h
@@ -6,7 +6,7 @@
  * The system works in a message response protocol
  * See: http://processors.wiki.ti.com/index.php/TISCI for details
  *
- * Copyright (C)  2015-2016 Texas Instruments Incorporated - https://www.ti.com/
+ * Copyright (C)  2015-2022 Texas Instruments Incorporated - https://www.ti.com/
  */
 
 #ifndef __TI_SCI_H
@@ -35,6 +35,11 @@
 #define TI_SCI_MSG_QUERY_CLOCK_FREQ	0x010d
 #define TI_SCI_MSG_GET_CLOCK_FREQ	0x010e
 
+/* Low Power Mode Requests */
+#define TI_SCI_MSG_PREPARE_SLEEP       0x0300
+#define TI_SCI_MSG_LPM_WAKE_REASON	0x0306
+#define TI_SCI_MSG_SET_IO_ISOLATION	0x0307
+
 /* Resource Management Requests */
 #define TI_SCI_MSG_GET_RESOURCE_RANGE	0x1500
 
@@ -545,6 +550,63 @@ struct ti_sci_msg_resp_get_clock_freq {
 	u64 freq_hz;
 } __packed;
 
+#define TISCI_MSG_VALUE_SLEEP_MODE_DEEP_SLEEP				0x0
+#define TISCI_MSG_VALUE_SLEEP_MODE_MCU_ONLY				0x1
+#define TISCI_MSG_VALUE_SLEEP_MODE_STANDBY				0x2
+
+/**
+ * struct tisci_msg_prepare_sleep_req - Request for TISCI_MSG_PREPARE_SLEEP.
+ *
+ * @hdr				TISCI header to provide ACK/NAK flags to the host.
+ * @mode			Low power mode to enter.
+ * @ctx_lo			Low 32-bits of physical pointer to address to use for context save.
+ * @ctx_hi			High 32-bits of physical pointer to address to use for context save.
+ * @debug_flags			Flags that can be set to halt the sequence during suspend or
+ *				resume to allow JTAG connection and debug.
+ *
+ * This message is used as the first step of entering a low power mode. It
+ * allows configurable information, including which state to enter to be
+ * easily shared from the application, as this is a non-secure message and
+ * therefore can be sent by anyone.
+ */
+struct ti_sci_msg_req_prepare_sleep {
+	struct ti_sci_msg_hdr	hdr;
+	u8			mode;
+	u32			ctx_lo;
+	u32			ctx_hi;
+	u32			debug_flags;
+} __packed;
+
+/**
+ * struct ti_sci_msg_resp_lpm_wake_reason - Response for TI_SCI_MSG_LPM_WAKE_REASON.
+ *
+ * @hdr:		Generic header.
+ * @wake_source:	The wake up source that woke soc from LPM.
+ * @wake_timestamp:	Timestamp at which soc woke.
+ *
+ * Response to a generic message with message type TI_SCI_MSG_LPM_WAKE_REASON,
+ * used to query the wake up source from low power mode.
+ */
+struct ti_sci_msg_resp_lpm_wake_reason {
+	struct ti_sci_msg_hdr hdr;
+	u32 wake_source;
+	u64 wake_timestamp;
+} __packed;
+
+/**
+ * struct tisci_msg_set_io_isolation_req - Request for TI_SCI_MSG_SET_IO_ISOLATION.
+ *
+ * @hdr:	Generic header
+ * @state:	The deseared state of the IO isolation.
+ *
+ * This message is used to enable/disable IO isolation for low power modes.
+ * Response is generic ACK / NACK message.
+ */
+struct ti_sci_msg_req_set_io_isolation {
+	struct ti_sci_msg_hdr hdr;
+	u8 state;
+} __packed;
+
 #define TI_SCI_IRQ_SECONDARY_HOST_INVALID	0xff
 
 /**
diff --git a/include/linux/soc/ti/ti_sci_protocol.h b/include/linux/soc/ti/ti_sci_protocol.h
index bd0d11af76c5..f2d1d74ab8fc 100644
--- a/include/linux/soc/ti/ti_sci_protocol.h
+++ b/include/linux/soc/ti/ti_sci_protocol.h
@@ -195,6 +195,49 @@ struct ti_sci_clk_ops {
 			u64 *current_freq);
 };
 
+/* TISCI LPM wake up sources */
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_I2C0	0x00
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_UART0	0x10
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_MCU_GPIO0	0x20
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_ICEMELTER0	0x30
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_TIMER0	0x40
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_TIMER1	0x41
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_WKUP_RTC0	0x50
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_RESET		0x60
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_USB0		0x70
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_USB1		0x71
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_MAIN_IO		0x80
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_MCU_IO		0x81
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_CAN_IO		0x82
+#define TISCI_MSG_VALUE_LPM_WAKE_SOURCE_INVALID		0xFF
+
+/* TISCI LPM IO isolation control values */
+#define TISCI_MSG_VALUE_IO_ENABLE			1
+#define TISCI_MSG_VALUE_IO_DISABLE			0
+
+/**
+ * struct ti_sci_pm_ops - Low Power Mode (LPM) control operations
+ * @prepare_sleep: Prepare to enter low power mode
+ *		- mode: Low power mode to enter.
+ *		- ctx_lo: Low 32-bits of physical address for context save.
+ *		- ctx_hi: High 32-bits of physical address for context save.
+ *		- ctx_lo: 'true' if frequency change is desired.
+ *		- debug_flags: JTAG control flags for debug.
+ * @lpm_wake_reason: Get the wake up source that woke the SoC from LPM
+ *		- source: The wake up source that woke soc from LPM.
+ *		- timestamp: Timestamp at which soc woke.
+ * @set_io_isolation: Enable or disable IO isolation
+ *		- state: The desired state of the IO isolation.
+ */
+struct ti_sci_pm_ops {
+	int (*prepare_sleep)(const struct ti_sci_handle *handle, u8 mode,
+			     u32 ctx_lo, u32 ctx_hi, u32 flags);
+	int (*lpm_wake_reason)(const struct ti_sci_handle *handle,
+			       u32 *source, u64 *timestamp);
+	int (*set_io_isolation)(const struct ti_sci_handle *handle,
+				u8 state);
+};
+
 /**
  * struct ti_sci_resource_desc - Description of TI SCI resource instance range.
  * @start:	Start index of the first resource range.
@@ -539,6 +582,7 @@ struct ti_sci_ops {
 	struct ti_sci_core_ops core_ops;
 	struct ti_sci_dev_ops dev_ops;
 	struct ti_sci_clk_ops clk_ops;
+	struct ti_sci_pm_ops pm_ops;
 	struct ti_sci_rm_core_ops rm_core_ops;
 	struct ti_sci_rm_irq_ops rm_irq_ops;
 	struct ti_sci_rm_ringacc_ops rm_ring_ops;
-- 
2.30.2

[PATCH v3 3/5] firmware: ti_sci: Allocate memory for the LPM modes

[Georgi Vlaev]

From: Dave Gerlach <d-gerlach@ti.com>

A region of memory in DDR must be used during Deep Sleep for saving
of some system context when using the ti_sci firmware. From DM's point
of view, this can be any contiguous region in the DDR, so can allocate
512KB of DMA reserved memory in probe(), instead of another carveout.

Also send a TISCI_MSG_PREPARE_SUSPEND message to the firmware during
probe to determine if system suspend is supported and if
ti_sci_init_suspend should be called based on the response received.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Vibhore Vardhan <vibhore@ti.com>
Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
Tested-by: Roger Quadros <rogerq@kernel.org>
---
 drivers/firmware/ti_sci.c | 55 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index f13cf19587e3..2434cf1ec5e6 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -10,6 +10,7 @@
 
 #include <linux/bitmap.h>
 #include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -25,6 +26,9 @@
 
 #include "ti_sci.h"
 
+/* Low power mode memory context size */
+#define LPM_CTX_MEM_SIZE 0x80000
+
 /* List of all TI SCI devices active in system */
 static LIST_HEAD(ti_sci_list);
 /* Protection for the entire list */
@@ -96,6 +100,8 @@ struct ti_sci_desc {
  * @minfo:	Message info
  * @node:	list head
  * @host_id:	Host ID
+ * @ctx_mem_addr: Low power context memory phys address
+ * @ctx_mem_buf: Low power context memory buffer
  * @users:	Number of users of this instance
  * @is_suspending: Flag set to indicate in suspend path.
  */
@@ -114,6 +120,8 @@ struct ti_sci_info {
 	struct ti_sci_xfers_info minfo;
 	struct list_head node;
 	u8 host_id;
+	dma_addr_t ctx_mem_addr;
+	void* ctx_mem_buf;
 	/* protected by ti_sci_list_mutex */
 	int users;
 	bool is_suspending;
@@ -3486,6 +3494,41 @@ static int ti_sci_resume(struct device *dev)
 
 static DEFINE_SIMPLE_DEV_PM_OPS(ti_sci_pm_ops, ti_sci_suspend, ti_sci_resume);
 
+static int ti_sci_init_suspend(struct platform_device *pdev,
+			       struct ti_sci_info *info)
+{
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	info->ctx_mem_buf = dma_alloc_coherent(info->dev, LPM_CTX_MEM_SIZE,
+					       &info->ctx_mem_addr,
+					       GFP_KERNEL);
+	if (!info->ctx_mem_buf) {
+		dev_err(info->dev, "Failed to allocate LPM context memory\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * Attempt to call prepare_sleep, this will be NAK'd if suspend is not
+	 * supported by firmware in use, in which case we will not attempt to
+	 * init suspend.
+	 */
+	ret = ti_sci_cmd_prepare_sleep(&info->handle, 0,
+				       (u32)(info->ctx_mem_addr & 0xffffffff) ,
+				       (u32)((u64)info->ctx_mem_addr >> 32), 0);
+
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	dma_free_coherent(info->dev, LPM_CTX_MEM_SIZE,
+			  info->ctx_mem_buf,
+			  info->ctx_mem_addr);
+	return ret;
+}
+
 /* Description for K2G */
 static const struct ti_sci_desc ti_sci_pmmc_k2g_desc = {
 	.default_host_id = 2,
@@ -3638,6 +3681,14 @@ static int ti_sci_probe(struct platform_device *pdev)
 		}
 	}
 
+	ret = ti_sci_init_suspend(pdev, info);
+	if (ret)
+		dev_warn(dev,
+			 "ti_sci_init_suspend failed, mem suspend will be non-functional.\n");
+
+	/* Suspend is an optional feature, reset return value and continue. */
+	ret = 0;
+
 	dev_info(dev, "ABI: %d.%d (firmware rev 0x%04x '%s')\n",
 		 info->handle.version.abi_major, info->handle.version.abi_minor,
 		 info->handle.version.firmware_revision,
@@ -3685,6 +3736,10 @@ static int ti_sci_remove(struct platform_device *pdev)
 		mbox_free_channel(info->chan_rx);
 	}
 
+	if (info->ctx_mem_buf)
+		dma_free_coherent(info->dev, LPM_CTX_MEM_SIZE,
+				  info->ctx_mem_buf,
+				  info->ctx_mem_addr);
 	return ret;
 }
 
-- 
2.30.2

[PATCH v3 4/5] firmware: ti_sci: Use dt provided fw name and address to load at suspend time

[Georgi Vlaev]

From: Dave Gerlach <d-gerlach@ti.com>

Use request_firmware_direct to load the fs stub LPM firmware to a
provided memory region. The filename for the firmware is provided
in the device tree as "firmware-name".

Use a pm_notifier for loading of the low power firmware during
PM_SUSPEND_PREPARE phase so that it can be loaded from the rootfs
before it is suspended. It is possible in the future for this
firmware to require reload, so add a check to indicate that the
firmware is currently loaded so it is only loaded once.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Vibhore Vardhan <vibhore@ti.com>
Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
Tested-by: Roger Quadros <rogerq@kernel.org>
---
 drivers/firmware/ti_sci.c | 97 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 2434cf1ec5e6..a961506dbbc4 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -12,6 +12,7 @@
 #include <linux/debugfs.h>
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
+#include <linux/firmware.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
@@ -22,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/soc/ti/ti-msgmgr.h>
 #include <linux/soc/ti/ti_sci_protocol.h>
+#include <linux/suspend.h>
 #include <linux/reboot.h>
 
 #include "ti_sci.h"
@@ -89,10 +91,13 @@ struct ti_sci_desc {
  * @dev:	Device pointer
  * @desc:	SoC description for this instance
  * @nb:	Reboot Notifier block
+ * @pm_nb:	PM notifier block
  * @d:		Debugfs file entry
  * @debug_region: Memory region where the debug message are available
  * @debug_region_size: Debug region size
  * @debug_buffer: Buffer allocated to copy debug messages.
+ * @lpm_region: Memory region where the FS Stub LPM Firmware will be stored
+ * @lpm_region_size: LPM region size
  * @handle:	Instance of TI SCI handle to send to clients.
  * @cl:		Mailbox Client
  * @chan_tx:	Transmit mailbox channel
@@ -104,15 +109,20 @@ struct ti_sci_desc {
  * @ctx_mem_buf: Low power context memory buffer
  * @users:	Number of users of this instance
  * @is_suspending: Flag set to indicate in suspend path.
+ * @lpm_firmware_loaded: Flag to indicate if LPM firmware has been loaded
+ * @lpm_firmware_name: Name of firmware binary to load from fw search path
  */
 struct ti_sci_info {
 	struct device *dev;
 	struct notifier_block nb;
+	struct notifier_block pm_nb;
 	const struct ti_sci_desc *desc;
 	struct dentry *d;
 	void __iomem *debug_region;
 	char *debug_buffer;
 	size_t debug_region_size;
+	void __iomem *lpm_region;
+	size_t lpm_region_size;
 	struct ti_sci_handle handle;
 	struct mbox_client cl;
 	struct mbox_chan *chan_tx;
@@ -125,11 +135,14 @@ struct ti_sci_info {
 	/* protected by ti_sci_list_mutex */
 	int users;
 	bool is_suspending;
+	bool lpm_firmware_loaded;
+	const char *lpm_firmware_name;
 };
 
 #define cl_to_ti_sci_info(c)	container_of(c, struct ti_sci_info, cl)
 #define handle_to_ti_sci_info(h) container_of(h, struct ti_sci_info, handle)
 #define reboot_to_ti_sci_info(n) container_of(n, struct ti_sci_info, nb)
+#define pm_nb_to_ti_sci_info(n) container_of(n, struct ti_sci_info, pm_nb)
 
 #ifdef CONFIG_DEBUG_FS
 
@@ -3465,6 +3478,32 @@ static int tisci_reboot_handler(struct notifier_block *nb, unsigned long mode,
 	return NOTIFY_BAD;
 }
 
+static int ti_sci_load_lpm_firmware(struct device *dev, struct ti_sci_info *info)
+{
+	const struct firmware *firmware;
+	int ret = 0;
+
+	/* If no firmware name is set, do not attempt to load. */
+	if (!info->lpm_firmware_name)
+		return -EINVAL;
+
+	ret = request_firmware_direct(&firmware, info->lpm_firmware_name, dev);
+	if (ret) {
+		dev_warn(dev, "Cannot load %s\n", info->lpm_firmware_name);
+		return ret;
+	}
+
+	if (firmware->size > info->lpm_region_size) {
+		release_firmware(firmware);
+		return -ENOMEM;
+	}
+
+	memcpy_toio(info->lpm_region, firmware->data, firmware->size);
+
+	release_firmware(firmware);
+
+	return ret;
+}
 static void ti_sci_set_is_suspending(struct ti_sci_info *info, bool is_suspending)
 {
 	info->is_suspending = is_suspending;
@@ -3494,10 +3533,33 @@ static int ti_sci_resume(struct device *dev)
 
 static DEFINE_SIMPLE_DEV_PM_OPS(ti_sci_pm_ops, ti_sci_suspend, ti_sci_resume);
 
+static int tisci_pm_handler(struct notifier_block *nb, unsigned long pm_event,
+			    void *unused)
+{
+	struct ti_sci_info *info = pm_nb_to_ti_sci_info(nb);
+	int ret;
+
+	/* Load the LPM firmware on PM_SUSPEND_PREPARE if not loaded yet */
+	if (pm_event != PM_SUSPEND_PREPARE || info->lpm_firmware_loaded)
+		return NOTIFY_DONE;
+
+	ret = ti_sci_load_lpm_firmware(info->dev, info);
+	if (ret) {
+		dev_err(info->dev, "Failed to LPM firmware, suspend is disabled (%d)\n",
+			ret);
+		return NOTIFY_BAD;
+	}
+
+	info->lpm_firmware_loaded = true;
+
+	return NOTIFY_OK;
+}
+
 static int ti_sci_init_suspend(struct platform_device *pdev,
 			       struct ti_sci_info *info)
 {
 	struct device *dev = &pdev->dev;
+	struct resource *res;
 	int ret;
 
 	dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
@@ -3521,6 +3583,38 @@ static int ti_sci_init_suspend(struct platform_device *pdev,
 	if (ret)
 		goto err;
 
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "lpm");
+	if (!res) {
+		dev_warn(dev,
+			 "lpm region is required for suspend but not provided.\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	info->lpm_region = devm_ioremap_resource(dev, res);
+	if (IS_ERR(info->lpm_region)) {
+		ret = PTR_ERR(info->lpm_region);
+		goto err;
+	}
+	info->lpm_region_size = resource_size(res);
+
+	if (of_property_read_string(dev->of_node, "firmware-name",
+				    &info->lpm_firmware_name)) {
+		dev_warn(dev,
+			 "firmware-name is required for suspend but not provided.\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	info->pm_nb.notifier_call = tisci_pm_handler;
+	info->pm_nb.priority = 128;
+
+	ret = register_pm_notifier(&info->pm_nb);
+	if (ret) {
+		dev_err(dev, "pm_notifier registration fail(%d)\n", ret);
+		goto err;
+	}
+
 	return 0;
 err:
 	dma_free_coherent(info->dev, LPM_CTX_MEM_SIZE,
@@ -3718,6 +3812,9 @@ static int ti_sci_remove(struct platform_device *pdev)
 
 	info = platform_get_drvdata(pdev);
 
+	if (info->pm_nb.notifier_call)
+		unregister_pm_notifier(&info->pm_nb);
+
 	if (info->nb.notifier_call)
 		unregister_restart_handler(&info->nb);
 
-- 
2.30.2

[PATCH v3 5/5] firmware: ti_sci: Introduce prepare system suspend call

[Georgi Vlaev]

From: Dave Gerlach <d-gerlach@ti.com>

Introduce a ti_sci_prepare_system_suspend call to be used in the driver
suspend handler to allow the system to identify the low power mode being
entered and if necessary, send TI_SCI_MSG_BEGIN_SLEEP with information
about the mode is being entered and the address for allocated memory for
storing the context during Deep Sleep.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Vibhore Vardhan <vibhore@ti.com>
Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
Tested-by: Roger Quadros <rogerq@kernel.org>
---
 drivers/firmware/ti_sci.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index a961506dbbc4..18734b506e72 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -3509,9 +3509,39 @@ static void ti_sci_set_is_suspending(struct ti_sci_info *info, bool is_suspendin
 	info->is_suspending = is_suspending;
 }
 
+static int ti_sci_prepare_system_suspend(struct ti_sci_info *info)
+{
+	int ret = 0;
+	int mode;
+
+	switch (pm_suspend_target_state) {
+	case PM_SUSPEND_MEM:
+		mode = TISCI_MSG_VALUE_SLEEP_MODE_DEEP_SLEEP;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	/*
+	 * Do not fail if we don't have action to take for a
+	 * specific suspend mode.
+	 */
+	if (ret)
+		return 0;
+
+	return ti_sci_cmd_prepare_sleep(&info->handle, mode,
+					(u32)(info->ctx_mem_addr & 0xffffffff),
+					(u32)((u64)info->ctx_mem_addr >> 32), 0);
+}
+
 static int ti_sci_suspend(struct device *dev)
 {
 	struct ti_sci_info *info = dev_get_drvdata(dev);
+	int ret;
+
+	ret = ti_sci_prepare_system_suspend(info);
+	if (ret)
+		return ret;
 	/*
 	 * We must switch operation to polled mode now as drivers and the genpd
 	 * layer may make late TI SCI calls to change clock and device states
-- 
2.30.2

Re: [PATCH v3 1/5] dt-bindings: ti, sci: Add lpm region and firmware-name

[Rob Herring]

On Fri, 11 Nov 2022 19:17:35 +0200, Georgi Vlaev wrote:
> From: Dave Gerlach <d-gerlach@ti.com>
> 
> Add documentation for the lpm region which tells the ti-sci driver where
> to load the FS Stub low power mode firmware and also the firmware-name
> which tells the driver which binary to load. Both of these are optional
> for normal system operation but required to enabled suspend-to-mem usage
> of Deep Sleep state.
> 
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
> Signed-off-by: Vibhore Vardhan <vibhore@ti.com>
> Signed-off-by: Georgi Vlaev <g-vlaev@ti.com>
> ---
>  .../bindings/arm/keystone/ti,sci.yaml         | 21 +++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>