Re: [PATCH V6 1/4] firmware: ti_sci: Introduce Power Management Ops

From: Andrew Davis
Date: Thu Aug 03 2023 - 11:15:01 EST


On 8/3/23 1:42 AM, Dhruva Gole wrote:
From: Dave Gerlach <d-gerlach@xxxxxx>

Introduce power management ops supported by the TISCI
Low Power Mode API [1]. These messages are currently
supported only on AM62x platforms.

1) TISCI_MSG_PREPARE_SLEEP
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
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
Control the IO isolation for Low Power Mode.

[1] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html

Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx>
Signed-off-by: Vibhore Vardhan <vibhore@xxxxxx>
[g-vlaev@xxxxxx: LPM_WAKE_REASON and IO_ISOLATION support]
Signed-off-by: Georgi Vlaev <g-vlaev@xxxxxx>
Tested-by: Roger Quadros <rogerq@xxxxxxxxxx>
---
drivers/firmware/ti_sci.c | 175 +++++++++++++++++++++++++
drivers/firmware/ti_sci.h | 64 ++++++++-
include/linux/soc/ti/ti_sci_protocol.h | 44 +++++++
3 files changed, 282 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 26a37f47f4ca..31a71613ca54 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -1664,6 +1664,176 @@ 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;
@@ -2806,6 +2976,7 @@ 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;
@@ -2845,6 +3016,10 @@ 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

Feels like excessive alignment tabs..

+
+/**
+ * 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

I don't see these used in this series, do you need them? lpm_wake_reason()
doesn't seem used either and I'm not sure how you plan to use it, could
you detail that?

Andrew

+
+/* 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;