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From:   Qiang Yu <quic_qianyu@quicinc.com>
To:     mani@kernel.org, quic_jhugo@quicinc.com
Cc:     mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, quic_cang@quicinc.com,
        quic_mrana@quicinc.com, Qiang Yu <quic_qianyu@quicinc.com>
Subject: [PATCH v3 1/2] bus: mhi: host: Add a separate timeout parameter for waiting ready
Date:   Tue,  7 Nov 2023 16:14:49 +0800
Message-Id: <1699344890-87076-2-git-send-email-quic_qianyu@quicinc.com>
In-Reply-To: <1699344890-87076-1-git-send-email-quic_qianyu@quicinc.com>
References: <1699344890-87076-1-git-send-email-quic_qianyu@quicinc.com>
Precedence: bulk

Some devices(eg. SDX75) take longer than expected (default, 8 seconds) to
set ready after reboot. Hence add optional ready timeout parameter and pass
the appropriate timeout value to mhi_poll_reg_field() to wait enough for
device ready as part of power up sequence.

Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/host/init.c     |  1 +
 drivers/bus/mhi/host/internal.h |  2 +-
 drivers/bus/mhi/host/main.c     |  5 +++--
 drivers/bus/mhi/host/pm.c       | 24 +++++++++++++++++-------
 include/linux/mhi.h             |  4 ++++
 5 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index f78aefd..65ceac1 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -881,6 +881,7 @@ static int parse_config(struct mhi_controller *mhi_cntrl,
 	if (!mhi_cntrl->timeout_ms)
 		mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;
 
+	mhi_cntrl->ready_timeout_ms = config->ready_timeout_ms;
 	mhi_cntrl->bounce_buf = config->use_bounce_buf;
 	mhi_cntrl->buffer_len = config->buf_len;
 	if (!mhi_cntrl->buffer_len)
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 2e139e7..30ac415 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -321,7 +321,7 @@ int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
 				    u32 *out);
 int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl,
 				    void __iomem *base, u32 offset, u32 mask,
-				    u32 val, u32 delayus);
+				    u32 val, u32 delayus, u32 timeout_ms);
 void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
 		   u32 offset, u32 val);
 int __must_check mhi_write_reg_field(struct mhi_controller *mhi_cntrl,
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index dcf627b..6cf1145 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -40,10 +40,11 @@ int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
 
 int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl,
 				    void __iomem *base, u32 offset,
-				    u32 mask, u32 val, u32 delayus)
+				    u32 mask, u32 val, u32 delayus,
+				    u32 timeout_ms)
 {
 	int ret;
-	u32 out, retry = (mhi_cntrl->timeout_ms * 1000) / delayus;
+	u32 out, retry = (timeout_ms * 1000) / delayus;
 
 	while (retry--) {
 		ret = mhi_read_reg_field(mhi_cntrl, base, offset, mask, &out);
diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
index 8a4362d..a2f2fee 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -163,6 +163,7 @@ int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
 	enum mhi_pm_state cur_state;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	u32 interval_us = 25000; /* poll register field every 25 milliseconds */
+	u32 timeout_ms;
 	int ret, i;
 
 	/* Check if device entered error state */
@@ -173,14 +174,18 @@ int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl)
 
 	/* Wait for RESET to be cleared and READY bit to be set by the device */
 	ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
-				 MHICTRL_RESET_MASK, 0, interval_us);
+				 MHICTRL_RESET_MASK, 0, interval_us,
+				 mhi_cntrl->timeout_ms);
 	if (ret) {
 		dev_err(dev, "Device failed to clear MHI Reset\n");
 		return ret;
 	}
 
+	timeout_ms = mhi_cntrl->ready_timeout_ms ?
+		mhi_cntrl->ready_timeout_ms : mhi_cntrl->timeout_ms;
 	ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHISTATUS,
-				 MHISTATUS_READY_MASK, 1, interval_us);
+				 MHISTATUS_READY_MASK, 1, interval_us,
+				 timeout_ms);
 	if (ret) {
 		dev_err(dev, "Device failed to enter MHI Ready\n");
 		return ret;
@@ -479,7 +484,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
 
 		/* Wait for the reset bit to be cleared by the device */
 		ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
-				 MHICTRL_RESET_MASK, 0, 25000);
+				 MHICTRL_RESET_MASK, 0, 25000, mhi_cntrl->timeout_ms);
 		if (ret)
 			dev_err(dev, "Device failed to clear MHI Reset\n");
 
@@ -492,8 +497,8 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
 		if (!MHI_IN_PBL(mhi_get_exec_env(mhi_cntrl))) {
 			/* wait for ready to be set */
 			ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs,
-						 MHISTATUS,
-						 MHISTATUS_READY_MASK, 1, 25000);
+						 MHISTATUS, MHISTATUS_READY_MASK,
+						 1, 25000, mhi_cntrl->timeout_ms);
 			if (ret)
 				dev_err(dev, "Device failed to enter READY state\n");
 		}
@@ -1111,7 +1116,8 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 	if (state == MHI_STATE_SYS_ERR) {
 		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
 		ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL,
-				 MHICTRL_RESET_MASK, 0, interval_us);
+				 MHICTRL_RESET_MASK, 0, interval_us,
+				 mhi_cntrl->timeout_ms);
 		if (ret) {
 			dev_info(dev, "Failed to reset MHI due to syserr state\n");
 			goto error_exit;
@@ -1202,14 +1208,18 @@ EXPORT_SYMBOL_GPL(mhi_power_down);
 int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
 {
 	int ret = mhi_async_power_up(mhi_cntrl);
+	u32 timeout_ms;
 
 	if (ret)
 		return ret;
 
+	/* Some devices need more time to set ready during power up */
+	timeout_ms = mhi_cntrl->ready_timeout_ms ?
+		mhi_cntrl->ready_timeout_ms : mhi_cntrl->timeout_ms;
 	wait_event_timeout(mhi_cntrl->state_event,
 			   MHI_IN_MISSION_MODE(mhi_cntrl->ee) ||
 			   MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
-			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
+			   msecs_to_jiffies(timeout_ms));
 
 	ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;
 	if (ret)
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 039943e..d0f9b522 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -266,6 +266,7 @@ struct mhi_event_config {
  * struct mhi_controller_config - Root MHI controller configuration
  * @max_channels: Maximum number of channels supported
  * @timeout_ms: Timeout value for operations. 0 means use default
+ * @ready_timeout_ms: Timeout value for waiting device to be ready (optional)
  * @buf_len: Size of automatically allocated buffers. 0 means use default
  * @num_channels: Number of channels defined in @ch_cfg
  * @ch_cfg: Array of defined channels
@@ -277,6 +278,7 @@ struct mhi_event_config {
 struct mhi_controller_config {
 	u32 max_channels;
 	u32 timeout_ms;
+	u32 ready_timeout_ms;
 	u32 buf_len;
 	u32 num_channels;
 	const struct mhi_channel_config *ch_cfg;
@@ -330,6 +332,7 @@ struct mhi_controller_config {
  * @pm_mutex: Mutex for suspend/resume operation
  * @pm_lock: Lock for protecting MHI power management state
  * @timeout_ms: Timeout in ms for state transitions
+ * @ready_timeout_ms: Timeout in ms for waiting device to be ready (optional)
  * @pm_state: MHI power management state
  * @db_access: DB access states
  * @ee: MHI device execution environment
@@ -419,6 +422,7 @@ struct mhi_controller {
 	struct mutex pm_mutex;
 	rwlock_t pm_lock;
 	u32 timeout_ms;
+	u32 ready_timeout_ms;
 	u32 pm_state;
 	u32 db_access;
 	enum mhi_ee_type ee;
-- 
2.7.4