[PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Ziqi Chen]

As per specs, e.g, JESD220E chapter 7.2, while powering
off/on the ufs device, RST_N signal and REF_CLK signal
should be between VSS(Ground) and VCCQ/VCCQ2.

To flexibly control device reset line, re-name the function
ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
new parameter "bool down" is used to separate device reset
line pulling down from pulling up.

Cc: Kiwoong Kim <kwmad.kim@samsung.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
---
 drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
 drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
 drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++-----------
 drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
 4 files changed, 56 insertions(+), 46 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 80618af..bff2c42 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,
 	return ret;
 }
 
-static int ufs_mtk_device_reset(struct ufs_hba *hba)
+static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
 	struct arm_smccc_res res;
 
-	ufs_mtk_device_reset_ctrl(0, res);
-
-	/*
-	 * The reset signal is active low. UFS devices shall detect
-	 * more than or equal to 1us of positive or negative RST_n
-	 * pulse width.
-	 *
-	 * To be on safe side, keep the reset low for at least 10us.
-	 */
-	usleep_range(10, 15);
-
-	ufs_mtk_device_reset_ctrl(1, res);
-
-	/* Some devices may need time to respond to rst_n */
-	usleep_range(10000, 15000);
+	if (down) {
+		ufs_mtk_device_reset_ctrl(0, res);
+	} else {
+		ufs_mtk_device_reset_ctrl(1, res);
 
-	dev_info(hba->dev, "device reset done\n");
+		/* Some devices may need time to respond to rst_n */
+		usleep_range(10000, 15000);
+	}
 
 	return 0;
 }
@@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 	.suspend             = ufs_mtk_suspend,
 	.resume              = ufs_mtk_resume,
 	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
-	.device_reset        = ufs_mtk_device_reset,
+	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
 	.event_notify        = ufs_mtk_event_notify,
 };
 
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 2206b1e..c2ccaa5 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
 }
 
 /**
- * ufs_qcom_device_reset() - toggle the (optional) device reset line
+ * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @down: pull down or pull up device reset line
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 
@@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
 	if (!host->device_reset)
 		return -EOPNOTSUPP;
 
-	/*
-	 * The UFS device shall detect reset pulses of 1us, sleep for 10us to
-	 * be on the safe side.
-	 */
-	gpiod_set_value_cansleep(host->device_reset, 1);
-	usleep_range(10, 15);
-
-	gpiod_set_value_cansleep(host->device_reset, 0);
-	usleep_range(10, 15);
+	if (down) {
+		gpiod_set_value_cansleep(host->device_reset, 1);
+	} else {
+		gpiod_set_value_cansleep(host->device_reset, 0);
+		usleep_range(10, 15);
+	}
 
 	return 0;
 }
@@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.suspend		= ufs_qcom_suspend,
 	.resume			= ufs_qcom_resume,
 	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
-	.device_reset		= ufs_qcom_device_reset,
+	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
 	.config_scaling_param = ufs_qcom_config_scaling_param,
 	.program_key		= ufs_qcom_ice_program_key,
 };
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e221add..2ee905f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
 {
 	int err;
 
-	err = ufshcd_vops_device_reset(hba);
+	err = ufshcd_vops_toggle_device_reset(hba, true);
+	if (err) {
+		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);
+		return;
+	}
+
+	/*
+	 * The reset signal is active low. The UFS device
+	 * shall detect reset pulses of 1us, sleep for at
+	 * least 10us to be on the safe side.
+	 */
+	usleep_range(10, 15);
+
+	err = ufshcd_vops_toggle_device_reset(hba, false);
 
 	if (!err) {
 		ufshcd_set_ufs_dev_active(hba);
@@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
 			hba->wb_enabled = false;
 			hba->wb_buf_flush_enabled = false;
 		}
+		dev_info(hba->dev, "device reset done\n");
+	} else {
+		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);
 	}
+
 	if (err != -EOPNOTSUPP)
 		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
 }
@@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (ret)
 		goto set_dev_active;
 
-	ufshcd_vreg_set_lpm(hba);
-
 disable_clks:
 	/*
 	 * Call vendor specific suspend callback. As these callbacks may access
@@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ufshcd_disable_irq(hba);
 
+	if (ufshcd_is_link_off(hba))
+		ufshcd_vops_toggle_device_reset(hba, true);
+
 	ufshcd_setup_clocks(hba, false);
 
 	if (ufshcd_is_clkgating_allowed(hba)) {
@@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 					hba->clk_gating.state);
 	}
 
+	ufshcd_vreg_set_lpm(hba);
+
 	/* Put the host controller in low power mode if possible */
 	ufshcd_hba_vreg_set_lpm(hba);
 	goto out;
@@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	old_link_state = hba->uic_link_state;
 
 	ufshcd_hba_vreg_set_hpm(hba);
+
+	ret = ufshcd_vreg_set_hpm(hba);
+	if (ret)
+		goto out;
+
 	/* Make sure clocks are enabled before accessing controller */
 	ret = ufshcd_setup_clocks(hba, true);
 	if (ret)
-		goto out;
+		goto disable_vreg;
 
 	/* enable the host irq as host controller would be active soon */
 	ufshcd_enable_irq(hba);
 
-	ret = ufshcd_vreg_set_hpm(hba);
-	if (ret)
-		goto disable_irq_and_vops_clks;
-
 	/*
 	 * Call vendor specific resume callback. As these callbacks may access
 	 * vendor specific host controller register space call them when the
@@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ret = ufshcd_vops_resume(hba, pm_op);
 	if (ret)
-		goto disable_vreg;
+		goto disable_irq_and_vops_clks;
 
 	/* For DeepSleep, the only supported option is to have the link off */
 	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
@@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	ufshcd_link_state_transition(hba, old_link_state, 0);
 vendor_suspend:
 	ufshcd_vops_suspend(hba, pm_op);
-disable_vreg:
-	ufshcd_vreg_set_lpm(hba);
 disable_irq_and_vops_clks:
 	ufshcd_disable_irq(hba);
 	if (hba->clk_scaling.is_allowed)
@@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		trace_ufshcd_clk_gating(dev_name(hba->dev),
 					hba->clk_gating.state);
 	}
+disable_vreg:
+	ufshcd_vreg_set_lpm(hba);
 out:
 	hba->pm_op_in_progress = 0;
 	if (ret)
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 9bb5f0e..dccc3eb 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
  * @resume: called during host controller PM callback
  * @dbg_register_dump: used to dump controller debug information
  * @phy_initialization: used to initialize phys
- * @device_reset: called to issue a reset pulse on the UFS device
+ * @toggle_device_reset: called to change logic level of reset gpio on the UFS device
  * @program_key: program or evict an inline encryption key
  * @event_notify: called to notify important events
  */
@@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
 	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
 	void	(*dbg_register_dump)(struct ufs_hba *hba);
 	int	(*phy_initialization)(struct ufs_hba *);
-	int	(*device_reset)(struct ufs_hba *hba);
+	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
 	void	(*config_scaling_param)(struct ufs_hba *hba,
 					struct devfreq_dev_profile *profile,
 					void *data);
@@ -1216,10 +1216,10 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
 		hba->vops->dbg_register_dump(hba);
 }
 
-static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
+static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
-	if (hba->vops && hba->vops->device_reset)
-		return hba->vops->device_reset(hba);
+	if (hba->vops && hba->vops->toggle_device_reset)
+		return hba->vops->toggle_device_reset(hba, down);
 
 	return -EOPNOTSUPP;
 }
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Ziqi Chen]

As per specs, e.g, JESD220E chapter 7.2, while powering
off/on the ufs device, RST_N signal and REF_CLK signal
should be between VSS(Ground) and VCCQ/VCCQ2.

To flexibly control device reset line, re-name the function
ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
new parameter "bool down" is used to separate device reset
line pulling down from pulling up.

Cc: Kiwoong Kim <kwmad.kim@samsung.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
---
 drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
 drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
 drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++-----------
 drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
 4 files changed, 56 insertions(+), 46 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 80618af..bff2c42 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,
 	return ret;
 }
 
-static int ufs_mtk_device_reset(struct ufs_hba *hba)
+static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
 	struct arm_smccc_res res;
 
-	ufs_mtk_device_reset_ctrl(0, res);
-
-	/*
-	 * The reset signal is active low. UFS devices shall detect
-	 * more than or equal to 1us of positive or negative RST_n
-	 * pulse width.
-	 *
-	 * To be on safe side, keep the reset low for at least 10us.
-	 */
-	usleep_range(10, 15);
-
-	ufs_mtk_device_reset_ctrl(1, res);
-
-	/* Some devices may need time to respond to rst_n */
-	usleep_range(10000, 15000);
+	if (down) {
+		ufs_mtk_device_reset_ctrl(0, res);
+	} else {
+		ufs_mtk_device_reset_ctrl(1, res);
 
-	dev_info(hba->dev, "device reset done\n");
+		/* Some devices may need time to respond to rst_n */
+		usleep_range(10000, 15000);
+	}
 
 	return 0;
 }
@@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 	.suspend             = ufs_mtk_suspend,
 	.resume              = ufs_mtk_resume,
 	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
-	.device_reset        = ufs_mtk_device_reset,
+	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
 	.event_notify        = ufs_mtk_event_notify,
 };
 
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 2206b1e..c2ccaa5 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
 }
 
 /**
- * ufs_qcom_device_reset() - toggle the (optional) device reset line
+ * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @down: pull down or pull up device reset line
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 
@@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
 	if (!host->device_reset)
 		return -EOPNOTSUPP;
 
-	/*
-	 * The UFS device shall detect reset pulses of 1us, sleep for 10us to
-	 * be on the safe side.
-	 */
-	gpiod_set_value_cansleep(host->device_reset, 1);
-	usleep_range(10, 15);
-
-	gpiod_set_value_cansleep(host->device_reset, 0);
-	usleep_range(10, 15);
+	if (down) {
+		gpiod_set_value_cansleep(host->device_reset, 1);
+	} else {
+		gpiod_set_value_cansleep(host->device_reset, 0);
+		usleep_range(10, 15);
+	}
 
 	return 0;
 }
@@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.suspend		= ufs_qcom_suspend,
 	.resume			= ufs_qcom_resume,
 	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
-	.device_reset		= ufs_qcom_device_reset,
+	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
 	.config_scaling_param = ufs_qcom_config_scaling_param,
 	.program_key		= ufs_qcom_ice_program_key,
 };
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e221add..2ee905f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
 {
 	int err;
 
-	err = ufshcd_vops_device_reset(hba);
+	err = ufshcd_vops_toggle_device_reset(hba, true);
+	if (err) {
+		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);
+		return;
+	}
+
+	/*
+	 * The reset signal is active low. The UFS device
+	 * shall detect reset pulses of 1us, sleep for at
+	 * least 10us to be on the safe side.
+	 */
+	usleep_range(10, 15);
+
+	err = ufshcd_vops_toggle_device_reset(hba, false);
 
 	if (!err) {
 		ufshcd_set_ufs_dev_active(hba);
@@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
 			hba->wb_enabled = false;
 			hba->wb_buf_flush_enabled = false;
 		}
+		dev_info(hba->dev, "device reset done\n");
+	} else {
+		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);
 	}
+
 	if (err != -EOPNOTSUPP)
 		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
 }
@@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (ret)
 		goto set_dev_active;
 
-	ufshcd_vreg_set_lpm(hba);
-
 disable_clks:
 	/*
 	 * Call vendor specific suspend callback. As these callbacks may access
@@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ufshcd_disable_irq(hba);
 
+	if (ufshcd_is_link_off(hba))
+		ufshcd_vops_toggle_device_reset(hba, true);
+
 	ufshcd_setup_clocks(hba, false);
 
 	if (ufshcd_is_clkgating_allowed(hba)) {
@@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 					hba->clk_gating.state);
 	}
 
+	ufshcd_vreg_set_lpm(hba);
+
 	/* Put the host controller in low power mode if possible */
 	ufshcd_hba_vreg_set_lpm(hba);
 	goto out;
@@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	old_link_state = hba->uic_link_state;
 
 	ufshcd_hba_vreg_set_hpm(hba);
+
+	ret = ufshcd_vreg_set_hpm(hba);
+	if (ret)
+		goto out;
+
 	/* Make sure clocks are enabled before accessing controller */
 	ret = ufshcd_setup_clocks(hba, true);
 	if (ret)
-		goto out;
+		goto disable_vreg;
 
 	/* enable the host irq as host controller would be active soon */
 	ufshcd_enable_irq(hba);
 
-	ret = ufshcd_vreg_set_hpm(hba);
-	if (ret)
-		goto disable_irq_and_vops_clks;
-
 	/*
 	 * Call vendor specific resume callback. As these callbacks may access
 	 * vendor specific host controller register space call them when the
@@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ret = ufshcd_vops_resume(hba, pm_op);
 	if (ret)
-		goto disable_vreg;
+		goto disable_irq_and_vops_clks;
 
 	/* For DeepSleep, the only supported option is to have the link off */
 	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
@@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	ufshcd_link_state_transition(hba, old_link_state, 0);
 vendor_suspend:
 	ufshcd_vops_suspend(hba, pm_op);
-disable_vreg:
-	ufshcd_vreg_set_lpm(hba);
 disable_irq_and_vops_clks:
 	ufshcd_disable_irq(hba);
 	if (hba->clk_scaling.is_allowed)
@@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		trace_ufshcd_clk_gating(dev_name(hba->dev),
 					hba->clk_gating.state);
 	}
+disable_vreg:
+	ufshcd_vreg_set_lpm(hba);
 out:
 	hba->pm_op_in_progress = 0;
 	if (ret)
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 9bb5f0e..dccc3eb 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
  * @resume: called during host controller PM callback
  * @dbg_register_dump: used to dump controller debug information
  * @phy_initialization: used to initialize phys
- * @device_reset: called to issue a reset pulse on the UFS device
+ * @toggle_device_reset: called to change logic level of reset gpio on the UFS device
  * @program_key: program or evict an inline encryption key
  * @event_notify: called to notify important events
  */
@@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
 	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
 	void	(*dbg_register_dump)(struct ufs_hba *hba);
 	int	(*phy_initialization)(struct ufs_hba *);
-	int	(*device_reset)(struct ufs_hba *hba);
+	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
 	void	(*config_scaling_param)(struct ufs_hba *hba,
 					struct devfreq_dev_profile *profile,
 					void *data);
@@ -1216,10 +1216,10 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
 		hba->vops->dbg_register_dump(hba);
 }
 
-static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
+static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
-	if (hba->vops && hba->vops->device_reset)
-		return hba->vops->device_reset(hba);
+	if (hba->vops && hba->vops->toggle_device_reset)
+		return hba->vops->toggle_device_reset(hba, down);
 
 	return -EOPNOTSUPP;
 }
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


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[PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Ziqi Chen]

As per specs, e.g, JESD220E chapter 7.2, while powering
off/on the ufs device, RST_N signal and REF_CLK signal
should be between VSS(Ground) and VCCQ/VCCQ2.

To flexibly control device reset line, re-name the function
ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
new parameter "bool down" is used to separate device reset
line pulling down from pulling up.

Cc: Kiwoong Kim <kwmad.kim@samsung.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
---
 drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
 drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
 drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++-----------
 drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
 4 files changed, 56 insertions(+), 46 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 80618af..bff2c42 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,
 	return ret;
 }
 
-static int ufs_mtk_device_reset(struct ufs_hba *hba)
+static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
 	struct arm_smccc_res res;
 
-	ufs_mtk_device_reset_ctrl(0, res);
-
-	/*
-	 * The reset signal is active low. UFS devices shall detect
-	 * more than or equal to 1us of positive or negative RST_n
-	 * pulse width.
-	 *
-	 * To be on safe side, keep the reset low for at least 10us.
-	 */
-	usleep_range(10, 15);
-
-	ufs_mtk_device_reset_ctrl(1, res);
-
-	/* Some devices may need time to respond to rst_n */
-	usleep_range(10000, 15000);
+	if (down) {
+		ufs_mtk_device_reset_ctrl(0, res);
+	} else {
+		ufs_mtk_device_reset_ctrl(1, res);
 
-	dev_info(hba->dev, "device reset done\n");
+		/* Some devices may need time to respond to rst_n */
+		usleep_range(10000, 15000);
+	}
 
 	return 0;
 }
@@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 	.suspend             = ufs_mtk_suspend,
 	.resume              = ufs_mtk_resume,
 	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
-	.device_reset        = ufs_mtk_device_reset,
+	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
 	.event_notify        = ufs_mtk_event_notify,
 };
 
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 2206b1e..c2ccaa5 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
 }
 
 /**
- * ufs_qcom_device_reset() - toggle the (optional) device reset line
+ * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @down: pull down or pull up device reset line
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 
@@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
 	if (!host->device_reset)
 		return -EOPNOTSUPP;
 
-	/*
-	 * The UFS device shall detect reset pulses of 1us, sleep for 10us to
-	 * be on the safe side.
-	 */
-	gpiod_set_value_cansleep(host->device_reset, 1);
-	usleep_range(10, 15);
-
-	gpiod_set_value_cansleep(host->device_reset, 0);
-	usleep_range(10, 15);
+	if (down) {
+		gpiod_set_value_cansleep(host->device_reset, 1);
+	} else {
+		gpiod_set_value_cansleep(host->device_reset, 0);
+		usleep_range(10, 15);
+	}
 
 	return 0;
 }
@@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.suspend		= ufs_qcom_suspend,
 	.resume			= ufs_qcom_resume,
 	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
-	.device_reset		= ufs_qcom_device_reset,
+	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
 	.config_scaling_param = ufs_qcom_config_scaling_param,
 	.program_key		= ufs_qcom_ice_program_key,
 };
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e221add..2ee905f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
 {
 	int err;
 
-	err = ufshcd_vops_device_reset(hba);
+	err = ufshcd_vops_toggle_device_reset(hba, true);
+	if (err) {
+		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);
+		return;
+	}
+
+	/*
+	 * The reset signal is active low. The UFS device
+	 * shall detect reset pulses of 1us, sleep for at
+	 * least 10us to be on the safe side.
+	 */
+	usleep_range(10, 15);
+
+	err = ufshcd_vops_toggle_device_reset(hba, false);
 
 	if (!err) {
 		ufshcd_set_ufs_dev_active(hba);
@@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
 			hba->wb_enabled = false;
 			hba->wb_buf_flush_enabled = false;
 		}
+		dev_info(hba->dev, "device reset done\n");
+	} else {
+		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);
 	}
+
 	if (err != -EOPNOTSUPP)
 		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
 }
@@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (ret)
 		goto set_dev_active;
 
-	ufshcd_vreg_set_lpm(hba);
-
 disable_clks:
 	/*
 	 * Call vendor specific suspend callback. As these callbacks may access
@@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ufshcd_disable_irq(hba);
 
+	if (ufshcd_is_link_off(hba))
+		ufshcd_vops_toggle_device_reset(hba, true);
+
 	ufshcd_setup_clocks(hba, false);
 
 	if (ufshcd_is_clkgating_allowed(hba)) {
@@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 					hba->clk_gating.state);
 	}
 
+	ufshcd_vreg_set_lpm(hba);
+
 	/* Put the host controller in low power mode if possible */
 	ufshcd_hba_vreg_set_lpm(hba);
 	goto out;
@@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	old_link_state = hba->uic_link_state;
 
 	ufshcd_hba_vreg_set_hpm(hba);
+
+	ret = ufshcd_vreg_set_hpm(hba);
+	if (ret)
+		goto out;
+
 	/* Make sure clocks are enabled before accessing controller */
 	ret = ufshcd_setup_clocks(hba, true);
 	if (ret)
-		goto out;
+		goto disable_vreg;
 
 	/* enable the host irq as host controller would be active soon */
 	ufshcd_enable_irq(hba);
 
-	ret = ufshcd_vreg_set_hpm(hba);
-	if (ret)
-		goto disable_irq_and_vops_clks;
-
 	/*
 	 * Call vendor specific resume callback. As these callbacks may access
 	 * vendor specific host controller register space call them when the
@@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	 */
 	ret = ufshcd_vops_resume(hba, pm_op);
 	if (ret)
-		goto disable_vreg;
+		goto disable_irq_and_vops_clks;
 
 	/* For DeepSleep, the only supported option is to have the link off */
 	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
@@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	ufshcd_link_state_transition(hba, old_link_state, 0);
 vendor_suspend:
 	ufshcd_vops_suspend(hba, pm_op);
-disable_vreg:
-	ufshcd_vreg_set_lpm(hba);
 disable_irq_and_vops_clks:
 	ufshcd_disable_irq(hba);
 	if (hba->clk_scaling.is_allowed)
@@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		trace_ufshcd_clk_gating(dev_name(hba->dev),
 					hba->clk_gating.state);
 	}
+disable_vreg:
+	ufshcd_vreg_set_lpm(hba);
 out:
 	hba->pm_op_in_progress = 0;
 	if (ret)
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 9bb5f0e..dccc3eb 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
  * @resume: called during host controller PM callback
  * @dbg_register_dump: used to dump controller debug information
  * @phy_initialization: used to initialize phys
- * @device_reset: called to issue a reset pulse on the UFS device
+ * @toggle_device_reset: called to change logic level of reset gpio on the UFS device
  * @program_key: program or evict an inline encryption key
  * @event_notify: called to notify important events
  */
@@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
 	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
 	void	(*dbg_register_dump)(struct ufs_hba *hba);
 	int	(*phy_initialization)(struct ufs_hba *);
-	int	(*device_reset)(struct ufs_hba *hba);
+	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
 	void	(*config_scaling_param)(struct ufs_hba *hba,
 					struct devfreq_dev_profile *profile,
 					void *data);
@@ -1216,10 +1216,10 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
 		hba->vops->dbg_register_dump(hba);
 }
 
-static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
+static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba, bool down)
 {
-	if (hba->vops && hba->vops->device_reset)
-		return hba->vops->device_reset(hba);
+	if (hba->vops && hba->vops->toggle_device_reset)
+		return hba->vops->toggle_device_reset(hba, down);
 
 	return -EOPNOTSUPP;
 }
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


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Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Bjorn Andersson]

On Mon 21 Dec 01:51 CST 2020, Ziqi Chen wrote:

> As per specs, e.g, JESD220E chapter 7.2, while powering
> off/on the ufs device, RST_N signal and REF_CLK signal
> should be between VSS(Ground) and VCCQ/VCCQ2.
> 
> To flexibly control device reset line, re-name the function
> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
> new parameter "bool down" is used to separate device reset
> line pulling down from pulling up.
> 
> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>  drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++-----------
>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>  4 files changed, 56 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
> index 80618af..bff2c42 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,
>  	return ret;
>  }
>  
> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct arm_smccc_res res;
>  
> -	ufs_mtk_device_reset_ctrl(0, res);
> -
> -	/*
> -	 * The reset signal is active low. UFS devices shall detect
> -	 * more than or equal to 1us of positive or negative RST_n
> -	 * pulse width.
> -	 *
> -	 * To be on safe side, keep the reset low for at least 10us.
> -	 */
> -	usleep_range(10, 15);
> -
> -	ufs_mtk_device_reset_ctrl(1, res);
> -
> -	/* Some devices may need time to respond to rst_n */
> -	usleep_range(10000, 15000);
> +	if (down) {
> +		ufs_mtk_device_reset_ctrl(0, res);
> +	} else {
> +		ufs_mtk_device_reset_ctrl(1, res);
>  
> -	dev_info(hba->dev, "device reset done\n");
> +		/* Some devices may need time to respond to rst_n */
> +		usleep_range(10000, 15000);
> +	}
>  
>  	return 0;
>  }
> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
>  	.suspend             = ufs_mtk_suspend,
>  	.resume              = ufs_mtk_resume,
>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> -	.device_reset        = ufs_mtk_device_reset,
> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>  	.event_notify        = ufs_mtk_event_notify,
>  };
>  
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2206b1e..c2ccaa5 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
>  }
>  
>  /**
> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset line
>   * @hba: per-adapter instance
> + * @down: pull down or pull up device reset line
>   *
>   * Toggles the (optional) reset line to reset the attached device.
>   */
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>  
> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
>  	if (!host->device_reset)
>  		return -EOPNOTSUPP;
>  
> -	/*
> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us to
> -	 * be on the safe side.
> -	 */
> -	gpiod_set_value_cansleep(host->device_reset, 1);
> -	usleep_range(10, 15);
> -
> -	gpiod_set_value_cansleep(host->device_reset, 0);
> -	usleep_range(10, 15);
> +	if (down) {
> +		gpiod_set_value_cansleep(host->device_reset, 1);
> +	} else {
> +		gpiod_set_value_cansleep(host->device_reset, 0);
> +		usleep_range(10, 15);

The comment above describes that the reset pulse should be 10uS, so the
only reason I can see for the sleep here would be for devices to come
back up after the reset pulse - i.e. what Mediatek believes needs
10-15mS.

As such, I would like you to move this sleep out to the caller and then
turns this snippet into just:

	gpiod_set_value_cansleep(host->device_reset, down);

I don't see a problem using Mediatek's reasoning and sleep values in the
common case.

> +	}
>  
>  	return 0;
>  }
> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
>  	.suspend		= ufs_qcom_suspend,
>  	.resume			= ufs_qcom_resume,
>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> -	.device_reset		= ufs_qcom_device_reset,
> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>  	.program_key		= ufs_qcom_ice_program_key,
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e221add..2ee905f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  {
>  	int err;
>  
> -	err = ufshcd_vops_device_reset(hba);
> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> +	if (err) {
> +		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);

"asserting device reset failed"

> +		return;
> +	}
> +
> +	/*
> +	 * The reset signal is active low. The UFS device
> +	 * shall detect reset pulses of 1us, sleep for at
> +	 * least 10us to be on the safe side.
> +	 */
> +	usleep_range(10, 15);
> +
> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>  
>  	if (!err) {
>  		ufshcd_set_ufs_dev_active(hba);
> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  			hba->wb_enabled = false;
>  			hba->wb_buf_flush_enabled = false;
>  		}
> +		dev_info(hba->dev, "device reset done\n");

Please use dev_dbg(), as this is only interesting to us when we're
actually debugging UFS related issues.

> +	} else {
> +		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);

"deasserting device reset failed"

>  	}
> +
>  	if (err != -EOPNOTSUPP)
>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
>  }
> @@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	if (ret)
>  		goto set_dev_active;
>  
> -	ufshcd_vreg_set_lpm(hba);
> -
>  disable_clks:
>  	/*
>  	 * Call vendor specific suspend callback. As these callbacks may access
> @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	 */
>  	ufshcd_disable_irq(hba);
>  
> +	if (ufshcd_is_link_off(hba))
> +		ufshcd_vops_toggle_device_reset(hba, true);
> +
>  	ufshcd_setup_clocks(hba, false);
>  
>  	if (ufshcd_is_clkgating_allowed(hba)) {
> @@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  					hba->clk_gating.state);
>  	}
>  
> +	ufshcd_vreg_set_lpm(hba);
> +
>  	/* Put the host controller in low power mode if possible */
>  	ufshcd_hba_vreg_set_lpm(hba);
>  	goto out;
> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	old_link_state = hba->uic_link_state;
>  
>  	ufshcd_hba_vreg_set_hpm(hba);
> +
> +	ret = ufshcd_vreg_set_hpm(hba);
> +	if (ret)
> +		goto out;
> +
>  	/* Make sure clocks are enabled before accessing controller */
>  	ret = ufshcd_setup_clocks(hba, true);
>  	if (ret)
> -		goto out;
> +		goto disable_vreg;
>  
>  	/* enable the host irq as host controller would be active soon */
>  	ufshcd_enable_irq(hba);
>  
> -	ret = ufshcd_vreg_set_hpm(hba);
> -	if (ret)
> -		goto disable_irq_and_vops_clks;
> -
>  	/*
>  	 * Call vendor specific resume callback. As these callbacks may access
>  	 * vendor specific host controller register space call them when the
> @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	 */
>  	ret = ufshcd_vops_resume(hba, pm_op);
>  	if (ret)
> -		goto disable_vreg;
> +		goto disable_irq_and_vops_clks;
>  
>  	/* For DeepSleep, the only supported option is to have the link off */
>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
> @@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>  vendor_suspend:
>  	ufshcd_vops_suspend(hba, pm_op);
> -disable_vreg:
> -	ufshcd_vreg_set_lpm(hba);
>  disable_irq_and_vops_clks:
>  	ufshcd_disable_irq(hba);
>  	if (hba->clk_scaling.is_allowed)
> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>  					hba->clk_gating.state);
>  	}
> +disable_vreg:
> +	ufshcd_vreg_set_lpm(hba);
>  out:
>  	hba->pm_op_in_progress = 0;
>  	if (ret)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 9bb5f0e..dccc3eb 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>   * @resume: called during host controller PM callback
>   * @dbg_register_dump: used to dump controller debug information
>   * @phy_initialization: used to initialize phys
> - * @device_reset: called to issue a reset pulse on the UFS device
> + * @toggle_device_reset: called to change logic level of reset gpio on the UFS device
>   * @program_key: program or evict an inline encryption key
>   * @event_notify: called to notify important events
>   */
> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>  	int	(*phy_initialization)(struct ufs_hba *);
> -	int	(*device_reset)(struct ufs_hba *hba);
> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);

I don't think "toggle" adds any value to the understanding of what this
function is expected to do, so I would prefer that you just keep it
"device_reset".

I also would prefer that you replace "down" with "asserted" - as this
avoids questions about active high/low etc from the API.

Thanks,
Bjorn

>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>  					struct devfreq_dev_profile *profile,
>  					void *data);
> @@ -1216,10 +1216,10 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>  		hba->vops->dbg_register_dump(hba);
>  }
>  
> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
> -	if (hba->vops && hba->vops->device_reset)
> -		return hba->vops->device_reset(hba);
> +	if (hba->vops && hba->vops->toggle_device_reset)
> +		return hba->vops->toggle_device_reset(hba, down);
>  
>  	return -EOPNOTSUPP;
>  }
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Bjorn Andersson]

On Mon 21 Dec 01:51 CST 2020, Ziqi Chen wrote:

> As per specs, e.g, JESD220E chapter 7.2, while powering
> off/on the ufs device, RST_N signal and REF_CLK signal
> should be between VSS(Ground) and VCCQ/VCCQ2.
> 
> To flexibly control device reset line, re-name the function
> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
> new parameter "bool down" is used to separate device reset
> line pulling down from pulling up.
> 
> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>  drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++-----------
>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>  4 files changed, 56 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
> index 80618af..bff2c42 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,
>  	return ret;
>  }
>  
> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct arm_smccc_res res;
>  
> -	ufs_mtk_device_reset_ctrl(0, res);
> -
> -	/*
> -	 * The reset signal is active low. UFS devices shall detect
> -	 * more than or equal to 1us of positive or negative RST_n
> -	 * pulse width.
> -	 *
> -	 * To be on safe side, keep the reset low for at least 10us.
> -	 */
> -	usleep_range(10, 15);
> -
> -	ufs_mtk_device_reset_ctrl(1, res);
> -
> -	/* Some devices may need time to respond to rst_n */
> -	usleep_range(10000, 15000);
> +	if (down) {
> +		ufs_mtk_device_reset_ctrl(0, res);
> +	} else {
> +		ufs_mtk_device_reset_ctrl(1, res);
>  
> -	dev_info(hba->dev, "device reset done\n");
> +		/* Some devices may need time to respond to rst_n */
> +		usleep_range(10000, 15000);
> +	}
>  
>  	return 0;
>  }
> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
>  	.suspend             = ufs_mtk_suspend,
>  	.resume              = ufs_mtk_resume,
>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> -	.device_reset        = ufs_mtk_device_reset,
> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>  	.event_notify        = ufs_mtk_event_notify,
>  };
>  
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2206b1e..c2ccaa5 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
>  }
>  
>  /**
> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset line
>   * @hba: per-adapter instance
> + * @down: pull down or pull up device reset line
>   *
>   * Toggles the (optional) reset line to reset the attached device.
>   */
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>  
> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
>  	if (!host->device_reset)
>  		return -EOPNOTSUPP;
>  
> -	/*
> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us to
> -	 * be on the safe side.
> -	 */
> -	gpiod_set_value_cansleep(host->device_reset, 1);
> -	usleep_range(10, 15);
> -
> -	gpiod_set_value_cansleep(host->device_reset, 0);
> -	usleep_range(10, 15);
> +	if (down) {
> +		gpiod_set_value_cansleep(host->device_reset, 1);
> +	} else {
> +		gpiod_set_value_cansleep(host->device_reset, 0);
> +		usleep_range(10, 15);

The comment above describes that the reset pulse should be 10uS, so the
only reason I can see for the sleep here would be for devices to come
back up after the reset pulse - i.e. what Mediatek believes needs
10-15mS.

As such, I would like you to move this sleep out to the caller and then
turns this snippet into just:

	gpiod_set_value_cansleep(host->device_reset, down);

I don't see a problem using Mediatek's reasoning and sleep values in the
common case.

> +	}
>  
>  	return 0;
>  }
> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
>  	.suspend		= ufs_qcom_suspend,
>  	.resume			= ufs_qcom_resume,
>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> -	.device_reset		= ufs_qcom_device_reset,
> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>  	.program_key		= ufs_qcom_ice_program_key,
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e221add..2ee905f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  {
>  	int err;
>  
> -	err = ufshcd_vops_device_reset(hba);
> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> +	if (err) {
> +		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);

"asserting device reset failed"

> +		return;
> +	}
> +
> +	/*
> +	 * The reset signal is active low. The UFS device
> +	 * shall detect reset pulses of 1us, sleep for at
> +	 * least 10us to be on the safe side.
> +	 */
> +	usleep_range(10, 15);
> +
> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>  
>  	if (!err) {
>  		ufshcd_set_ufs_dev_active(hba);
> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  			hba->wb_enabled = false;
>  			hba->wb_buf_flush_enabled = false;
>  		}
> +		dev_info(hba->dev, "device reset done\n");

Please use dev_dbg(), as this is only interesting to us when we're
actually debugging UFS related issues.

> +	} else {
> +		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);

"deasserting device reset failed"

>  	}
> +
>  	if (err != -EOPNOTSUPP)
>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
>  }
> @@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	if (ret)
>  		goto set_dev_active;
>  
> -	ufshcd_vreg_set_lpm(hba);
> -
>  disable_clks:
>  	/*
>  	 * Call vendor specific suspend callback. As these callbacks may access
> @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	 */
>  	ufshcd_disable_irq(hba);
>  
> +	if (ufshcd_is_link_off(hba))
> +		ufshcd_vops_toggle_device_reset(hba, true);
> +
>  	ufshcd_setup_clocks(hba, false);
>  
>  	if (ufshcd_is_clkgating_allowed(hba)) {
> @@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  					hba->clk_gating.state);
>  	}
>  
> +	ufshcd_vreg_set_lpm(hba);
> +
>  	/* Put the host controller in low power mode if possible */
>  	ufshcd_hba_vreg_set_lpm(hba);
>  	goto out;
> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	old_link_state = hba->uic_link_state;
>  
>  	ufshcd_hba_vreg_set_hpm(hba);
> +
> +	ret = ufshcd_vreg_set_hpm(hba);
> +	if (ret)
> +		goto out;
> +
>  	/* Make sure clocks are enabled before accessing controller */
>  	ret = ufshcd_setup_clocks(hba, true);
>  	if (ret)
> -		goto out;
> +		goto disable_vreg;
>  
>  	/* enable the host irq as host controller would be active soon */
>  	ufshcd_enable_irq(hba);
>  
> -	ret = ufshcd_vreg_set_hpm(hba);
> -	if (ret)
> -		goto disable_irq_and_vops_clks;
> -
>  	/*
>  	 * Call vendor specific resume callback. As these callbacks may access
>  	 * vendor specific host controller register space call them when the
> @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	 */
>  	ret = ufshcd_vops_resume(hba, pm_op);
>  	if (ret)
> -		goto disable_vreg;
> +		goto disable_irq_and_vops_clks;
>  
>  	/* For DeepSleep, the only supported option is to have the link off */
>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
> @@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>  vendor_suspend:
>  	ufshcd_vops_suspend(hba, pm_op);
> -disable_vreg:
> -	ufshcd_vreg_set_lpm(hba);
>  disable_irq_and_vops_clks:
>  	ufshcd_disable_irq(hba);
>  	if (hba->clk_scaling.is_allowed)
> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>  					hba->clk_gating.state);
>  	}
> +disable_vreg:
> +	ufshcd_vreg_set_lpm(hba);
>  out:
>  	hba->pm_op_in_progress = 0;
>  	if (ret)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 9bb5f0e..dccc3eb 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>   * @resume: called during host controller PM callback
>   * @dbg_register_dump: used to dump controller debug information
>   * @phy_initialization: used to initialize phys
> - * @device_reset: called to issue a reset pulse on the UFS device
> + * @toggle_device_reset: called to change logic level of reset gpio on the UFS device
>   * @program_key: program or evict an inline encryption key
>   * @event_notify: called to notify important events
>   */
> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>  	int	(*phy_initialization)(struct ufs_hba *);
> -	int	(*device_reset)(struct ufs_hba *hba);
> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);

I don't think "toggle" adds any value to the understanding of what this
function is expected to do, so I would prefer that you just keep it
"device_reset".

I also would prefer that you replace "down" with "asserted" - as this
avoids questions about active high/low etc from the API.

Thanks,
Bjorn

>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>  					struct devfreq_dev_profile *profile,
>  					void *data);
> @@ -1216,10 +1216,10 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>  		hba->vops->dbg_register_dump(hba);
>  }
>  
> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
> -	if (hba->vops && hba->vops->device_reset)
> -		return hba->vops->device_reset(hba);
> +	if (hba->vops && hba->vops->toggle_device_reset)
> +		return hba->vops->toggle_device_reset(hba, down);
>  
>  	return -EOPNOTSUPP;
>  }
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Bjorn Andersson]

On Mon 21 Dec 01:51 CST 2020, Ziqi Chen wrote:

> As per specs, e.g, JESD220E chapter 7.2, while powering
> off/on the ufs device, RST_N signal and REF_CLK signal
> should be between VSS(Ground) and VCCQ/VCCQ2.
> 
> To flexibly control device reset line, re-name the function
> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
> new parameter "bool down" is used to separate device reset
> line pulling down from pulling up.
> 
> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>  drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++-----------
>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>  4 files changed, 56 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
> index 80618af..bff2c42 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct ufs_hba *hba,
>  	return ret;
>  }
>  
> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct arm_smccc_res res;
>  
> -	ufs_mtk_device_reset_ctrl(0, res);
> -
> -	/*
> -	 * The reset signal is active low. UFS devices shall detect
> -	 * more than or equal to 1us of positive or negative RST_n
> -	 * pulse width.
> -	 *
> -	 * To be on safe side, keep the reset low for at least 10us.
> -	 */
> -	usleep_range(10, 15);
> -
> -	ufs_mtk_device_reset_ctrl(1, res);
> -
> -	/* Some devices may need time to respond to rst_n */
> -	usleep_range(10000, 15000);
> +	if (down) {
> +		ufs_mtk_device_reset_ctrl(0, res);
> +	} else {
> +		ufs_mtk_device_reset_ctrl(1, res);
>  
> -	dev_info(hba->dev, "device reset done\n");
> +		/* Some devices may need time to respond to rst_n */
> +		usleep_range(10000, 15000);
> +	}
>  
>  	return 0;
>  }
> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
>  	.suspend             = ufs_mtk_suspend,
>  	.resume              = ufs_mtk_resume,
>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> -	.device_reset        = ufs_mtk_device_reset,
> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>  	.event_notify        = ufs_mtk_event_notify,
>  };
>  
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2206b1e..c2ccaa5 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
>  }
>  
>  /**
> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset line
>   * @hba: per-adapter instance
> + * @down: pull down or pull up device reset line
>   *
>   * Toggles the (optional) reset line to reset the attached device.
>   */
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>  
> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
>  	if (!host->device_reset)
>  		return -EOPNOTSUPP;
>  
> -	/*
> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us to
> -	 * be on the safe side.
> -	 */
> -	gpiod_set_value_cansleep(host->device_reset, 1);
> -	usleep_range(10, 15);
> -
> -	gpiod_set_value_cansleep(host->device_reset, 0);
> -	usleep_range(10, 15);
> +	if (down) {
> +		gpiod_set_value_cansleep(host->device_reset, 1);
> +	} else {
> +		gpiod_set_value_cansleep(host->device_reset, 0);
> +		usleep_range(10, 15);

The comment above describes that the reset pulse should be 10uS, so the
only reason I can see for the sleep here would be for devices to come
back up after the reset pulse - i.e. what Mediatek believes needs
10-15mS.

As such, I would like you to move this sleep out to the caller and then
turns this snippet into just:

	gpiod_set_value_cansleep(host->device_reset, down);

I don't see a problem using Mediatek's reasoning and sleep values in the
common case.

> +	}
>  
>  	return 0;
>  }
> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
>  	.suspend		= ufs_qcom_suspend,
>  	.resume			= ufs_qcom_resume,
>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> -	.device_reset		= ufs_qcom_device_reset,
> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>  	.program_key		= ufs_qcom_ice_program_key,
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e221add..2ee905f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  {
>  	int err;
>  
> -	err = ufshcd_vops_device_reset(hba);
> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> +	if (err) {
> +		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);

"asserting device reset failed"

> +		return;
> +	}
> +
> +	/*
> +	 * The reset signal is active low. The UFS device
> +	 * shall detect reset pulses of 1us, sleep for at
> +	 * least 10us to be on the safe side.
> +	 */
> +	usleep_range(10, 15);
> +
> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>  
>  	if (!err) {
>  		ufshcd_set_ufs_dev_active(hba);
> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  			hba->wb_enabled = false;
>  			hba->wb_buf_flush_enabled = false;
>  		}
> +		dev_info(hba->dev, "device reset done\n");

Please use dev_dbg(), as this is only interesting to us when we're
actually debugging UFS related issues.

> +	} else {
> +		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);

"deasserting device reset failed"

>  	}
> +
>  	if (err != -EOPNOTSUPP)
>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
>  }
> @@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	if (ret)
>  		goto set_dev_active;
>  
> -	ufshcd_vreg_set_lpm(hba);
> -
>  disable_clks:
>  	/*
>  	 * Call vendor specific suspend callback. As these callbacks may access
> @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	 */
>  	ufshcd_disable_irq(hba);
>  
> +	if (ufshcd_is_link_off(hba))
> +		ufshcd_vops_toggle_device_reset(hba, true);
> +
>  	ufshcd_setup_clocks(hba, false);
>  
>  	if (ufshcd_is_clkgating_allowed(hba)) {
> @@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  					hba->clk_gating.state);
>  	}
>  
> +	ufshcd_vreg_set_lpm(hba);
> +
>  	/* Put the host controller in low power mode if possible */
>  	ufshcd_hba_vreg_set_lpm(hba);
>  	goto out;
> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	old_link_state = hba->uic_link_state;
>  
>  	ufshcd_hba_vreg_set_hpm(hba);
> +
> +	ret = ufshcd_vreg_set_hpm(hba);
> +	if (ret)
> +		goto out;
> +
>  	/* Make sure clocks are enabled before accessing controller */
>  	ret = ufshcd_setup_clocks(hba, true);
>  	if (ret)
> -		goto out;
> +		goto disable_vreg;
>  
>  	/* enable the host irq as host controller would be active soon */
>  	ufshcd_enable_irq(hba);
>  
> -	ret = ufshcd_vreg_set_hpm(hba);
> -	if (ret)
> -		goto disable_irq_and_vops_clks;
> -
>  	/*
>  	 * Call vendor specific resume callback. As these callbacks may access
>  	 * vendor specific host controller register space call them when the
> @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	 */
>  	ret = ufshcd_vops_resume(hba, pm_op);
>  	if (ret)
> -		goto disable_vreg;
> +		goto disable_irq_and_vops_clks;
>  
>  	/* For DeepSleep, the only supported option is to have the link off */
>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && !ufshcd_is_link_off(hba));
> @@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>  vendor_suspend:
>  	ufshcd_vops_suspend(hba, pm_op);
> -disable_vreg:
> -	ufshcd_vreg_set_lpm(hba);
>  disable_irq_and_vops_clks:
>  	ufshcd_disable_irq(hba);
>  	if (hba->clk_scaling.is_allowed)
> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>  					hba->clk_gating.state);
>  	}
> +disable_vreg:
> +	ufshcd_vreg_set_lpm(hba);
>  out:
>  	hba->pm_op_in_progress = 0;
>  	if (ret)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 9bb5f0e..dccc3eb 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>   * @resume: called during host controller PM callback
>   * @dbg_register_dump: used to dump controller debug information
>   * @phy_initialization: used to initialize phys
> - * @device_reset: called to issue a reset pulse on the UFS device
> + * @toggle_device_reset: called to change logic level of reset gpio on the UFS device
>   * @program_key: program or evict an inline encryption key
>   * @event_notify: called to notify important events
>   */
> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>  	int	(*phy_initialization)(struct ufs_hba *);
> -	int	(*device_reset)(struct ufs_hba *hba);
> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);

I don't think "toggle" adds any value to the understanding of what this
function is expected to do, so I would prefer that you just keep it
"device_reset".

I also would prefer that you replace "down" with "asserted" - as this
avoids questions about active high/low etc from the API.

Thanks,
Bjorn

>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>  					struct devfreq_dev_profile *profile,
>  					void *data);
> @@ -1216,10 +1216,10 @@ static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>  		hba->vops->dbg_register_dump(hba);
>  }
>  
> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
> -	if (hba->vops && hba->vops->device_reset)
> -		return hba->vops->device_reset(hba);
> +	if (hba->vops && hba->vops->toggle_device_reset)
> +		return hba->vops->toggle_device_reset(hba, down);
>  
>  	return -EOPNOTSUPP;
>  }
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

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Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[ziqichen]

On 2020-12-22 02:41, Bjorn Andersson wrote:
> On Mon 21 Dec 01:51 CST 2020, Ziqi Chen wrote:
> 
>> As per specs, e.g, JESD220E chapter 7.2, while powering
>> off/on the ufs device, RST_N signal and REF_CLK signal
>> should be between VSS(Ground) and VCCQ/VCCQ2.
>> 
>> To flexibly control device reset line, re-name the function
>> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
>> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
>> new parameter "bool down" is used to separate device reset
>> line pulling down from pulling up.
>> 
>> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
>> Cc: Stanley Chu <stanley.chu@mediatek.com>
>> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
>> ---
>>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>>  drivers/scsi/ufs/ufshcd.c       | 43 
>> ++++++++++++++++++++++++++++++-----------
>>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>>  4 files changed, 56 insertions(+), 46 deletions(-)
>> 
>> diff --git a/drivers/scsi/ufs/ufs-mediatek.c 
>> b/drivers/scsi/ufs/ufs-mediatek.c
>> index 80618af..bff2c42 100644
>> --- a/drivers/scsi/ufs/ufs-mediatek.c
>> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct 
>> ufs_hba *hba,
>>  	return ret;
>>  }
>> 
>> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
>> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct arm_smccc_res res;
>> 
>> -	ufs_mtk_device_reset_ctrl(0, res);
>> -
>> -	/*
>> -	 * The reset signal is active low. UFS devices shall detect
>> -	 * more than or equal to 1us of positive or negative RST_n
>> -	 * pulse width.
>> -	 *
>> -	 * To be on safe side, keep the reset low for at least 10us.
>> -	 */
>> -	usleep_range(10, 15);
>> -
>> -	ufs_mtk_device_reset_ctrl(1, res);
>> -
>> -	/* Some devices may need time to respond to rst_n */
>> -	usleep_range(10000, 15000);
>> +	if (down) {
>> +		ufs_mtk_device_reset_ctrl(0, res);
>> +	} else {
>> +		ufs_mtk_device_reset_ctrl(1, res);
>> 
>> -	dev_info(hba->dev, "device reset done\n");
>> +		/* Some devices may need time to respond to rst_n */
>> +		usleep_range(10000, 15000);
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops 
>> ufs_hba_mtk_vops = {
>>  	.suspend             = ufs_mtk_suspend,
>>  	.resume              = ufs_mtk_resume,
>>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
>> -	.device_reset        = ufs_mtk_device_reset,
>> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>>  	.event_notify        = ufs_mtk_event_notify,
>>  };
>> 
>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>> index 2206b1e..c2ccaa5 100644
>> --- a/drivers/scsi/ufs/ufs-qcom.c
>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct 
>> ufs_hba *hba)
>>  }
>> 
>>  /**
>> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
>> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device 
>> reset line
>>   * @hba: per-adapter instance
>> + * @down: pull down or pull up device reset line
>>   *
>>   * Toggles the (optional) reset line to reset the attached device.
>>   */
>> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
>> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> 
>> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct 
>> ufs_hba *hba)
>>  	if (!host->device_reset)
>>  		return -EOPNOTSUPP;
>> 
>> -	/*
>> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us 
>> to
>> -	 * be on the safe side.
>> -	 */
>> -	gpiod_set_value_cansleep(host->device_reset, 1);
>> -	usleep_range(10, 15);
>> -
>> -	gpiod_set_value_cansleep(host->device_reset, 0);
>> -	usleep_range(10, 15);
>> +	if (down) {
>> +		gpiod_set_value_cansleep(host->device_reset, 1);
>> +	} else {
>> +		gpiod_set_value_cansleep(host->device_reset, 0);
>> +		usleep_range(10, 15);
> 
> The comment above describes that the reset pulse should be 10uS, so the
> only reason I can see for the sleep here would be for devices to come
> back up after the reset pulse - i.e. what Mediatek believes needs
> 10-15mS.
> 
> As such, I would like you to move this sleep out to the caller and then
> turns this snippet into just:
> 
> 	gpiod_set_value_cansleep(host->device_reset, down);
> 
> I don't see a problem using Mediatek's reasoning and sleep values in 
> the
> common case.

Understood. It would better to move this sleep (10-15ms)out to the 
caller and
simplify this function.

> 
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops 
>> ufs_hba_qcom_vops = {
>>  	.suspend		= ufs_qcom_suspend,
>>  	.resume			= ufs_qcom_resume,
>>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
>> -	.device_reset		= ufs_qcom_device_reset,
>> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>>  	.program_key		= ufs_qcom_ice_program_key,
>>  };
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index e221add..2ee905f 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>>  {
>>  	int err;
>> 
>> -	err = ufshcd_vops_device_reset(hba);
>> +	err = ufshcd_vops_toggle_device_reset(hba, true);
>> +	if (err) {
>> +		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);
> 
> "asserting device reset failed"

Agree, thanks.

> 
>> +		return;
>> +	}
>> +
>> +	/*
>> +	 * The reset signal is active low. The UFS device
>> +	 * shall detect reset pulses of 1us, sleep for at
>> +	 * least 10us to be on the safe side.
>> +	 */
>> +	usleep_range(10, 15);
>> +
>> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>> 
>>  	if (!err) {
>>  		ufshcd_set_ufs_dev_active(hba);
>> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>>  			hba->wb_enabled = false;
>>  			hba->wb_buf_flush_enabled = false;
>>  		}
>> +		dev_info(hba->dev, "device reset done\n");
> 
> Please use dev_dbg(), as this is only interesting to us when we're
> actually debugging UFS related issues.

Agree, thanks.

> 
>> +	} else {
>> +		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);
> 
> "deasserting device reset failed"

Agree, thanks.

> 
>>  	}
>> +
>>  	if (err != -EOPNOTSUPP)
>>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
>>  }
>> @@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	if (ret)
>>  		goto set_dev_active;
>> 
>> -	ufshcd_vreg_set_lpm(hba);
>> -
>>  disable_clks:
>>  	/*
>>  	 * Call vendor specific suspend callback. As these callbacks may 
>> access
>> @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ufshcd_disable_irq(hba);
>> 
>> +	if (ufshcd_is_link_off(hba))
>> +		ufshcd_vops_toggle_device_reset(hba, true);
>> +
>>  	ufshcd_setup_clocks(hba, false);
>> 
>>  	if (ufshcd_is_clkgating_allowed(hba)) {
>> @@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  					hba->clk_gating.state);
>>  	}
>> 
>> +	ufshcd_vreg_set_lpm(hba);
>> +
>>  	/* Put the host controller in low power mode if possible */
>>  	ufshcd_hba_vreg_set_lpm(hba);
>>  	goto out;
>> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	old_link_state = hba->uic_link_state;
>> 
>>  	ufshcd_hba_vreg_set_hpm(hba);
>> +
>> +	ret = ufshcd_vreg_set_hpm(hba);
>> +	if (ret)
>> +		goto out;
>> +
>>  	/* Make sure clocks are enabled before accessing controller */
>>  	ret = ufshcd_setup_clocks(hba, true);
>>  	if (ret)
>> -		goto out;
>> +		goto disable_vreg;
>> 
>>  	/* enable the host irq as host controller would be active soon */
>>  	ufshcd_enable_irq(hba);
>> 
>> -	ret = ufshcd_vreg_set_hpm(hba);
>> -	if (ret)
>> -		goto disable_irq_and_vops_clks;
>> -
>>  	/*
>>  	 * Call vendor specific resume callback. As these callbacks may 
>> access
>>  	 * vendor specific host controller register space call them when the
>> @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ret = ufshcd_vops_resume(hba, pm_op);
>>  	if (ret)
>> -		goto disable_vreg;
>> +		goto disable_irq_and_vops_clks;
>> 
>>  	/* For DeepSleep, the only supported option is to have the link off 
>> */
>>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && 
>> !ufshcd_is_link_off(hba));
>> @@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>>  vendor_suspend:
>>  	ufshcd_vops_suspend(hba, pm_op);
>> -disable_vreg:
>> -	ufshcd_vreg_set_lpm(hba);
>>  disable_irq_and_vops_clks:
>>  	ufshcd_disable_irq(hba);
>>  	if (hba->clk_scaling.is_allowed)
>> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>>  					hba->clk_gating.state);
>>  	}
>> +disable_vreg:
>> +	ufshcd_vreg_set_lpm(hba);
>>  out:
>>  	hba->pm_op_in_progress = 0;
>>  	if (ret)
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index 9bb5f0e..dccc3eb 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>>   * @resume: called during host controller PM callback
>>   * @dbg_register_dump: used to dump controller debug information
>>   * @phy_initialization: used to initialize phys
>> - * @device_reset: called to issue a reset pulse on the UFS device
>> + * @toggle_device_reset: called to change logic level of reset gpio 
>> on the UFS device
>>   * @program_key: program or evict an inline encryption key
>>   * @event_notify: called to notify important events
>>   */
>> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>>  	int	(*phy_initialization)(struct ufs_hba *);
>> -	int	(*device_reset)(struct ufs_hba *hba);
>> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
> 
> I don't think "toggle" adds any value to the understanding of what this
> function is expected to do, so I would prefer that you just keep it
> "device_reset".
> 
> I also would prefer that you replace "down" with "asserted" - as this
> avoids questions about active high/low etc from the API.
> 
> Thanks,
> Bjorn

Agree, thanks.

Best Regards,
Ziqi


> 
>>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>>  					struct devfreq_dev_profile *profile,
>>  					void *data);
>> @@ -1216,10 +1216,10 @@ static inline void 
>> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>>  		hba->vops->dbg_register_dump(hba);
>>  }
>> 
>> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
>> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba 
>> *hba, bool down)
>>  {
>> -	if (hba->vops && hba->vops->device_reset)
>> -		return hba->vops->device_reset(hba);
>> +	if (hba->vops && hba->vops->toggle_device_reset)
>> +		return hba->vops->toggle_device_reset(hba, down);
>> 
>>  	return -EOPNOTSUPP;
>>  }
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project
>> 

Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[ziqichen]

On 2020-12-22 02:41, Bjorn Andersson wrote:
> On Mon 21 Dec 01:51 CST 2020, Ziqi Chen wrote:
> 
>> As per specs, e.g, JESD220E chapter 7.2, while powering
>> off/on the ufs device, RST_N signal and REF_CLK signal
>> should be between VSS(Ground) and VCCQ/VCCQ2.
>> 
>> To flexibly control device reset line, re-name the function
>> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
>> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The
>> new parameter "bool down" is used to separate device reset
>> line pulling down from pulling up.
>> 
>> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
>> Cc: Stanley Chu <stanley.chu@mediatek.com>
>> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
>> ---
>>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>>  drivers/scsi/ufs/ufshcd.c       | 43 
>> ++++++++++++++++++++++++++++++-----------
>>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>>  4 files changed, 56 insertions(+), 46 deletions(-)
>> 
>> diff --git a/drivers/scsi/ufs/ufs-mediatek.c 
>> b/drivers/scsi/ufs/ufs-mediatek.c
>> index 80618af..bff2c42 100644
>> --- a/drivers/scsi/ufs/ufs-mediatek.c
>> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct 
>> ufs_hba *hba,
>>  	return ret;
>>  }
>> 
>> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
>> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct arm_smccc_res res;
>> 
>> -	ufs_mtk_device_reset_ctrl(0, res);
>> -
>> -	/*
>> -	 * The reset signal is active low. UFS devices shall detect
>> -	 * more than or equal to 1us of positive or negative RST_n
>> -	 * pulse width.
>> -	 *
>> -	 * To be on safe side, keep the reset low for at least 10us.
>> -	 */
>> -	usleep_range(10, 15);
>> -
>> -	ufs_mtk_device_reset_ctrl(1, res);
>> -
>> -	/* Some devices may need time to respond to rst_n */
>> -	usleep_range(10000, 15000);
>> +	if (down) {
>> +		ufs_mtk_device_reset_ctrl(0, res);
>> +	} else {
>> +		ufs_mtk_device_reset_ctrl(1, res);
>> 
>> -	dev_info(hba->dev, "device reset done\n");
>> +		/* Some devices may need time to respond to rst_n */
>> +		usleep_range(10000, 15000);
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops 
>> ufs_hba_mtk_vops = {
>>  	.suspend             = ufs_mtk_suspend,
>>  	.resume              = ufs_mtk_resume,
>>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
>> -	.device_reset        = ufs_mtk_device_reset,
>> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>>  	.event_notify        = ufs_mtk_event_notify,
>>  };
>> 
>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>> index 2206b1e..c2ccaa5 100644
>> --- a/drivers/scsi/ufs/ufs-qcom.c
>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct 
>> ufs_hba *hba)
>>  }
>> 
>>  /**
>> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
>> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device 
>> reset line
>>   * @hba: per-adapter instance
>> + * @down: pull down or pull up device reset line
>>   *
>>   * Toggles the (optional) reset line to reset the attached device.
>>   */
>> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
>> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> 
>> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct 
>> ufs_hba *hba)
>>  	if (!host->device_reset)
>>  		return -EOPNOTSUPP;
>> 
>> -	/*
>> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us 
>> to
>> -	 * be on the safe side.
>> -	 */
>> -	gpiod_set_value_cansleep(host->device_reset, 1);
>> -	usleep_range(10, 15);
>> -
>> -	gpiod_set_value_cansleep(host->device_reset, 0);
>> -	usleep_range(10, 15);
>> +	if (down) {
>> +		gpiod_set_value_cansleep(host->device_reset, 1);
>> +	} else {
>> +		gpiod_set_value_cansleep(host->device_reset, 0);
>> +		usleep_range(10, 15);
> 
> The comment above describes that the reset pulse should be 10uS, so the
> only reason I can see for the sleep here would be for devices to come
> back up after the reset pulse - i.e. what Mediatek believes needs
> 10-15mS.
> 
> As such, I would like you to move this sleep out to the caller and then
> turns this snippet into just:
> 
> 	gpiod_set_value_cansleep(host->device_reset, down);
> 
> I don't see a problem using Mediatek's reasoning and sleep values in 
> the
> common case.

Understood. It would better to move this sleep (10-15ms)out to the 
caller and
simplify this function.

> 
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops 
>> ufs_hba_qcom_vops = {
>>  	.suspend		= ufs_qcom_suspend,
>>  	.resume			= ufs_qcom_resume,
>>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
>> -	.device_reset		= ufs_qcom_device_reset,
>> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>>  	.program_key		= ufs_qcom_ice_program_key,
>>  };
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index e221add..2ee905f 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>>  {
>>  	int err;
>> 
>> -	err = ufshcd_vops_device_reset(hba);
>> +	err = ufshcd_vops_toggle_device_reset(hba, true);
>> +	if (err) {
>> +		dev_err(hba->dev, "device reset pulling down failure: %d\n", err);
> 
> "asserting device reset failed"

Agree, thanks.

> 
>> +		return;
>> +	}
>> +
>> +	/*
>> +	 * The reset signal is active low. The UFS device
>> +	 * shall detect reset pulses of 1us, sleep for at
>> +	 * least 10us to be on the safe side.
>> +	 */
>> +	usleep_range(10, 15);
>> +
>> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>> 
>>  	if (!err) {
>>  		ufshcd_set_ufs_dev_active(hba);
>> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>>  			hba->wb_enabled = false;
>>  			hba->wb_buf_flush_enabled = false;
>>  		}
>> +		dev_info(hba->dev, "device reset done\n");
> 
> Please use dev_dbg(), as this is only interesting to us when we're
> actually debugging UFS related issues.

Agree, thanks.

> 
>> +	} else {
>> +		dev_err(hba->dev, "device reset pulling up failure: %d\n", err);
> 
> "deasserting device reset failed"

Agree, thanks.

> 
>>  	}
>> +
>>  	if (err != -EOPNOTSUPP)
>>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);
>>  }
>> @@ -8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	if (ret)
>>  		goto set_dev_active;
>> 
>> -	ufshcd_vreg_set_lpm(hba);
>> -
>>  disable_clks:
>>  	/*
>>  	 * Call vendor specific suspend callback. As these callbacks may 
>> access
>> @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ufshcd_disable_irq(hba);
>> 
>> +	if (ufshcd_is_link_off(hba))
>> +		ufshcd_vops_toggle_device_reset(hba, true);
>> +
>>  	ufshcd_setup_clocks(hba, false);
>> 
>>  	if (ufshcd_is_clkgating_allowed(hba)) {
>> @@ -8711,6 +8729,8 @@ static int ufshcd_suspend(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  					hba->clk_gating.state);
>>  	}
>> 
>> +	ufshcd_vreg_set_lpm(hba);
>> +
>>  	/* Put the host controller in low power mode if possible */
>>  	ufshcd_hba_vreg_set_lpm(hba);
>>  	goto out;
>> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	old_link_state = hba->uic_link_state;
>> 
>>  	ufshcd_hba_vreg_set_hpm(hba);
>> +
>> +	ret = ufshcd_vreg_set_hpm(hba);
>> +	if (ret)
>> +		goto out;
>> +
>>  	/* Make sure clocks are enabled before accessing controller */
>>  	ret = ufshcd_setup_clocks(hba, true);
>>  	if (ret)
>> -		goto out;
>> +		goto disable_vreg;
>> 
>>  	/* enable the host irq as host controller would be active soon */
>>  	ufshcd_enable_irq(hba);
>> 
>> -	ret = ufshcd_vreg_set_hpm(hba);
>> -	if (ret)
>> -		goto disable_irq_and_vops_clks;
>> -
>>  	/*
>>  	 * Call vendor specific resume callback. As these callbacks may 
>> access
>>  	 * vendor specific host controller register space call them when the
>> @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ret = ufshcd_vops_resume(hba, pm_op);
>>  	if (ret)
>> -		goto disable_vreg;
>> +		goto disable_irq_and_vops_clks;
>> 
>>  	/* For DeepSleep, the only supported option is to have the link off 
>> */
>>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) && 
>> !ufshcd_is_link_off(hba));
>> @@ -8864,8 +8885,6 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>>  vendor_suspend:
>>  	ufshcd_vops_suspend(hba, pm_op);
>> -disable_vreg:
>> -	ufshcd_vreg_set_lpm(hba);
>>  disable_irq_and_vops_clks:
>>  	ufshcd_disable_irq(hba);
>>  	if (hba->clk_scaling.is_allowed)
>> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum ufs_pm_op pm_op)
>>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>>  					hba->clk_gating.state);
>>  	}
>> +disable_vreg:
>> +	ufshcd_vreg_set_lpm(hba);
>>  out:
>>  	hba->pm_op_in_progress = 0;
>>  	if (ret)
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> index 9bb5f0e..dccc3eb 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>>   * @resume: called during host controller PM callback
>>   * @dbg_register_dump: used to dump controller debug information
>>   * @phy_initialization: used to initialize phys
>> - * @device_reset: called to issue a reset pulse on the UFS device
>> + * @toggle_device_reset: called to change logic level of reset gpio 
>> on the UFS device
>>   * @program_key: program or evict an inline encryption key
>>   * @event_notify: called to notify important events
>>   */
>> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>>  	int	(*phy_initialization)(struct ufs_hba *);
>> -	int	(*device_reset)(struct ufs_hba *hba);
>> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
> 
> I don't think "toggle" adds any value to the understanding of what this
> function is expected to do, so I would prefer that you just keep it
> "device_reset".
> 
> I also would prefer that you replace "down" with "asserted" - as this
> avoids questions about active high/low etc from the API.
> 
> Thanks,
> Bjorn

Agree, thanks.

Best Regards,
Ziqi


> 
>>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>>  					struct devfreq_dev_profile *profile,
>>  					void *data);
>> @@ -1216,10 +1216,10 @@ static inline void 
>> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>>  		hba->vops->dbg_register_dump(hba);
>>  }
>> 
>> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
>> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba 
>> *hba, bool down)
>>  {
>> -	if (hba->vops && hba->vops->device_reset)
>> -		return hba->vops->device_reset(hba);
>> +	if (hba->vops && hba->vops->toggle_device_reset)
>> +		return hba->vops->toggle_device_reset(hba, down);
>> 
>>  	return -EOPNOTSUPP;
>>  }
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project
>> 

_______________________________________________
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Linux-mediatek@lists.infradead.org
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RE: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Kiwoong Kim]

> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the ufs
> device, RST_N signal and REF_CLK signal should be between VSS(Ground) and
> VCCQ/VCCQ2.
> 
> To flexibly control device reset line, re-name the function
> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
> parameter "bool down" is used to separate device reset line pulling down
> from pulling up.
> 
> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>  drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++------
--
> ---
>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>  4 files changed, 56 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
> mediatek.c index 80618af..bff2c42 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
> ufs_hba *hba,
>  	return ret;
>  }
> 
> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct arm_smccc_res res;
> 
> -	ufs_mtk_device_reset_ctrl(0, res);
> -
> -	/*
> -	 * The reset signal is active low. UFS devices shall detect
> -	 * more than or equal to 1us of positive or negative RST_n
> -	 * pulse width.
> -	 *
> -	 * To be on safe side, keep the reset low for at least 10us.
> -	 */
> -	usleep_range(10, 15);
> -
> -	ufs_mtk_device_reset_ctrl(1, res);
> -
> -	/* Some devices may need time to respond to rst_n */
> -	usleep_range(10000, 15000);
> +	if (down) {
> +		ufs_mtk_device_reset_ctrl(0, res);
> +	} else {
> +		ufs_mtk_device_reset_ctrl(1, res);
> 
> -	dev_info(hba->dev, "device reset done\n");
> +		/* Some devices may need time to respond to rst_n */
> +		usleep_range(10000, 15000);
> +	}
> 
>  	return 0;
>  }
> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
> ufs_hba_mtk_vops = {
>  	.suspend             = ufs_mtk_suspend,
>  	.resume              = ufs_mtk_resume,
>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> -	.device_reset        = ufs_mtk_device_reset,
> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>  	.event_notify        = ufs_mtk_event_notify,
>  };
> 
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2206b1e..c2ccaa5 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba
> *hba)  }
> 
>  /**
> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset
> + line
>   * @hba: per-adapter instance
> + * @down: pull down or pull up device reset line
>   *
>   * Toggles the (optional) reset line to reset the attached device.
>   */
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> 
> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba
> *hba)
>  	if (!host->device_reset)
>  		return -EOPNOTSUPP;
> 
> -	/*
> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
> to
> -	 * be on the safe side.
> -	 */
> -	gpiod_set_value_cansleep(host->device_reset, 1);
> -	usleep_range(10, 15);
> -
> -	gpiod_set_value_cansleep(host->device_reset, 0);
> -	usleep_range(10, 15);
> +	if (down) {
> +		gpiod_set_value_cansleep(host->device_reset, 1);
> +	} else {
> +		gpiod_set_value_cansleep(host->device_reset, 0);
> +		usleep_range(10, 15);
> +	}
> 
>  	return 0;
>  }
> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
> ufs_hba_qcom_vops = {
>  	.suspend		= ufs_qcom_suspend,
>  	.resume			= ufs_qcom_resume,
>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> -	.device_reset		= ufs_qcom_device_reset,
> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>  	.program_key		= ufs_qcom_ice_program_key,
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index
> e221add..2ee905f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
> {
>  	int err;
> 
> -	err = ufshcd_vops_device_reset(hba);
> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> +	if (err) {
> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
> err);
> +		return;
> +	}
> +
> +	/*
> +	 * The reset signal is active low. The UFS device
> +	 * shall detect reset pulses of 1us, sleep for at
> +	 * least 10us to be on the safe side.
> +	 */
> +	usleep_range(10, 15);

Is there any point where UFS specification tells this explicitly?
I think this should be moved only if the number, i.e. 10 and 15  just
relies on hardware conditions.


Thanks.
Kiwoong Kim

> +	err = ufshcd_vops_toggle_device_reset(hba, false);
> 
>  	if (!err) {
>  		ufshcd_set_ufs_dev_active(hba);
> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  			hba->wb_enabled = false;
>  			hba->wb_buf_flush_enabled = false;
>  		}
> +		dev_info(hba->dev, "device reset done\n");
> +	} else {
> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
> err);
>  	}
> +
>  	if (err != -EOPNOTSUPP)
>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  	if (ret)
>  		goto set_dev_active;
> 
> -	ufshcd_vreg_set_lpm(hba);
> -
>  disable_clks:
>  	/*
>  	 * Call vendor specific suspend callback. As these callbacks may
> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
*hba,
> enum ufs_pm_op pm_op)
>  	 */
>  	ufshcd_disable_irq(hba);
> 
> +	if (ufshcd_is_link_off(hba))
> +		ufshcd_vops_toggle_device_reset(hba, true);
> +
>  	ufshcd_setup_clocks(hba, false);
> 
>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  					hba->clk_gating.state);
>  	}
> 
> +	ufshcd_vreg_set_lpm(hba);
> +
>  	/* Put the host controller in low power mode if possible */
>  	ufshcd_hba_vreg_set_lpm(hba);
>  	goto out;
> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  	old_link_state = hba->uic_link_state;
> 
>  	ufshcd_hba_vreg_set_hpm(hba);
> +
> +	ret = ufshcd_vreg_set_hpm(hba);
> +	if (ret)
> +		goto out;
> +
>  	/* Make sure clocks are enabled before accessing controller */
>  	ret = ufshcd_setup_clocks(hba, true);
>  	if (ret)
> -		goto out;
> +		goto disable_vreg;
> 
>  	/* enable the host irq as host controller would be active soon */
>  	ufshcd_enable_irq(hba);
> 
> -	ret = ufshcd_vreg_set_hpm(hba);
> -	if (ret)
> -		goto disable_irq_and_vops_clks;
> -
>  	/*
>  	 * Call vendor specific resume callback. As these callbacks may
> access
>  	 * vendor specific host controller register space call them when
> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
>  	 */
>  	ret = ufshcd_vops_resume(hba, pm_op);
>  	if (ret)
> -		goto disable_vreg;
> +		goto disable_irq_and_vops_clks;
> 
>  	/* For DeepSleep, the only supported option is to have the link off
> */
>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>  vendor_suspend:
>  	ufshcd_vops_suspend(hba, pm_op);
> -disable_vreg:
> -	ufshcd_vreg_set_lpm(hba);
>  disable_irq_and_vops_clks:
>  	ufshcd_disable_irq(hba);
>  	if (hba->clk_scaling.is_allowed)
> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>  					hba->clk_gating.state);
>  	}
> +disable_vreg:
> +	ufshcd_vreg_set_lpm(hba);
>  out:
>  	hba->pm_op_in_progress = 0;
>  	if (ret)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index
> 9bb5f0e..dccc3eb 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>   * @resume: called during host controller PM callback
>   * @dbg_register_dump: used to dump controller debug information
>   * @phy_initialization: used to initialize phys
> - * @device_reset: called to issue a reset pulse on the UFS device
> + * @toggle_device_reset: called to change logic level of reset gpio on
> + the UFS device
>   * @program_key: program or evict an inline encryption key
>   * @event_notify: called to notify important events
>   */
> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>  	int	(*phy_initialization)(struct ufs_hba *);
> -	int	(*device_reset)(struct ufs_hba *hba);
> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>  					struct devfreq_dev_profile *profile,
>  					void *data);
> @@ -1216,10 +1216,10 @@ static inline void
> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>  		hba->vops->dbg_register_dump(hba);
>  }
> 
> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba,
> +bool down)
>  {
> -	if (hba->vops && hba->vops->device_reset)
> -		return hba->vops->device_reset(hba);
> +	if (hba->vops && hba->vops->toggle_device_reset)
> +		return hba->vops->toggle_device_reset(hba, down);
> 
>  	return -EOPNOTSUPP;
>  }
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project

RE: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Kiwoong Kim]

> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the ufs
> device, RST_N signal and REF_CLK signal should be between VSS(Ground) and
> VCCQ/VCCQ2.
> 
> To flexibly control device reset line, re-name the function
> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
> parameter "bool down" is used to separate device reset line pulling down
> from pulling up.
> 
> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>  drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++------
--
> ---
>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>  4 files changed, 56 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
> mediatek.c index 80618af..bff2c42 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
> ufs_hba *hba,
>  	return ret;
>  }
> 
> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct arm_smccc_res res;
> 
> -	ufs_mtk_device_reset_ctrl(0, res);
> -
> -	/*
> -	 * The reset signal is active low. UFS devices shall detect
> -	 * more than or equal to 1us of positive or negative RST_n
> -	 * pulse width.
> -	 *
> -	 * To be on safe side, keep the reset low for at least 10us.
> -	 */
> -	usleep_range(10, 15);
> -
> -	ufs_mtk_device_reset_ctrl(1, res);
> -
> -	/* Some devices may need time to respond to rst_n */
> -	usleep_range(10000, 15000);
> +	if (down) {
> +		ufs_mtk_device_reset_ctrl(0, res);
> +	} else {
> +		ufs_mtk_device_reset_ctrl(1, res);
> 
> -	dev_info(hba->dev, "device reset done\n");
> +		/* Some devices may need time to respond to rst_n */
> +		usleep_range(10000, 15000);
> +	}
> 
>  	return 0;
>  }
> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
> ufs_hba_mtk_vops = {
>  	.suspend             = ufs_mtk_suspend,
>  	.resume              = ufs_mtk_resume,
>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> -	.device_reset        = ufs_mtk_device_reset,
> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>  	.event_notify        = ufs_mtk_event_notify,
>  };
> 
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2206b1e..c2ccaa5 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba
> *hba)  }
> 
>  /**
> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset
> + line
>   * @hba: per-adapter instance
> + * @down: pull down or pull up device reset line
>   *
>   * Toggles the (optional) reset line to reset the attached device.
>   */
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> 
> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba
> *hba)
>  	if (!host->device_reset)
>  		return -EOPNOTSUPP;
> 
> -	/*
> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
> to
> -	 * be on the safe side.
> -	 */
> -	gpiod_set_value_cansleep(host->device_reset, 1);
> -	usleep_range(10, 15);
> -
> -	gpiod_set_value_cansleep(host->device_reset, 0);
> -	usleep_range(10, 15);
> +	if (down) {
> +		gpiod_set_value_cansleep(host->device_reset, 1);
> +	} else {
> +		gpiod_set_value_cansleep(host->device_reset, 0);
> +		usleep_range(10, 15);
> +	}
> 
>  	return 0;
>  }
> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
> ufs_hba_qcom_vops = {
>  	.suspend		= ufs_qcom_suspend,
>  	.resume			= ufs_qcom_resume,
>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> -	.device_reset		= ufs_qcom_device_reset,
> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>  	.program_key		= ufs_qcom_ice_program_key,
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index
> e221add..2ee905f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
> {
>  	int err;
> 
> -	err = ufshcd_vops_device_reset(hba);
> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> +	if (err) {
> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
> err);
> +		return;
> +	}
> +
> +	/*
> +	 * The reset signal is active low. The UFS device
> +	 * shall detect reset pulses of 1us, sleep for at
> +	 * least 10us to be on the safe side.
> +	 */
> +	usleep_range(10, 15);

Is there any point where UFS specification tells this explicitly?
I think this should be moved only if the number, i.e. 10 and 15  just
relies on hardware conditions.


Thanks.
Kiwoong Kim

> +	err = ufshcd_vops_toggle_device_reset(hba, false);
> 
>  	if (!err) {
>  		ufshcd_set_ufs_dev_active(hba);
> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  			hba->wb_enabled = false;
>  			hba->wb_buf_flush_enabled = false;
>  		}
> +		dev_info(hba->dev, "device reset done\n");
> +	} else {
> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
> err);
>  	}
> +
>  	if (err != -EOPNOTSUPP)
>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  	if (ret)
>  		goto set_dev_active;
> 
> -	ufshcd_vreg_set_lpm(hba);
> -
>  disable_clks:
>  	/*
>  	 * Call vendor specific suspend callback. As these callbacks may
> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
*hba,
> enum ufs_pm_op pm_op)
>  	 */
>  	ufshcd_disable_irq(hba);
> 
> +	if (ufshcd_is_link_off(hba))
> +		ufshcd_vops_toggle_device_reset(hba, true);
> +
>  	ufshcd_setup_clocks(hba, false);
> 
>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  					hba->clk_gating.state);
>  	}
> 
> +	ufshcd_vreg_set_lpm(hba);
> +
>  	/* Put the host controller in low power mode if possible */
>  	ufshcd_hba_vreg_set_lpm(hba);
>  	goto out;
> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  	old_link_state = hba->uic_link_state;
> 
>  	ufshcd_hba_vreg_set_hpm(hba);
> +
> +	ret = ufshcd_vreg_set_hpm(hba);
> +	if (ret)
> +		goto out;
> +
>  	/* Make sure clocks are enabled before accessing controller */
>  	ret = ufshcd_setup_clocks(hba, true);
>  	if (ret)
> -		goto out;
> +		goto disable_vreg;
> 
>  	/* enable the host irq as host controller would be active soon */
>  	ufshcd_enable_irq(hba);
> 
> -	ret = ufshcd_vreg_set_hpm(hba);
> -	if (ret)
> -		goto disable_irq_and_vops_clks;
> -
>  	/*
>  	 * Call vendor specific resume callback. As these callbacks may
> access
>  	 * vendor specific host controller register space call them when
> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
>  	 */
>  	ret = ufshcd_vops_resume(hba, pm_op);
>  	if (ret)
> -		goto disable_vreg;
> +		goto disable_irq_and_vops_clks;
> 
>  	/* For DeepSleep, the only supported option is to have the link off
> */
>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>  vendor_suspend:
>  	ufshcd_vops_suspend(hba, pm_op);
> -disable_vreg:
> -	ufshcd_vreg_set_lpm(hba);
>  disable_irq_and_vops_clks:
>  	ufshcd_disable_irq(hba);
>  	if (hba->clk_scaling.is_allowed)
> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>  					hba->clk_gating.state);
>  	}
> +disable_vreg:
> +	ufshcd_vreg_set_lpm(hba);
>  out:
>  	hba->pm_op_in_progress = 0;
>  	if (ret)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index
> 9bb5f0e..dccc3eb 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>   * @resume: called during host controller PM callback
>   * @dbg_register_dump: used to dump controller debug information
>   * @phy_initialization: used to initialize phys
> - * @device_reset: called to issue a reset pulse on the UFS device
> + * @toggle_device_reset: called to change logic level of reset gpio on
> + the UFS device
>   * @program_key: program or evict an inline encryption key
>   * @event_notify: called to notify important events
>   */
> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>  	int	(*phy_initialization)(struct ufs_hba *);
> -	int	(*device_reset)(struct ufs_hba *hba);
> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>  					struct devfreq_dev_profile *profile,
>  					void *data);
> @@ -1216,10 +1216,10 @@ static inline void
> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>  		hba->vops->dbg_register_dump(hba);
>  }
> 
> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba,
> +bool down)
>  {
> -	if (hba->vops && hba->vops->device_reset)
> -		return hba->vops->device_reset(hba);
> +	if (hba->vops && hba->vops->toggle_device_reset)
> +		return hba->vops->toggle_device_reset(hba, down);
> 
>  	return -EOPNOTSUPP;
>  }
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project



_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

RE: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Kiwoong Kim]

> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the ufs
> device, RST_N signal and REF_CLK signal should be between VSS(Ground) and
> VCCQ/VCCQ2.
> 
> To flexibly control device reset line, re-name the function
> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
> parameter "bool down" is used to separate device reset line pulling down
> from pulling up.
> 
> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> Cc: Stanley Chu <stanley.chu@mediatek.com>
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>  drivers/scsi/ufs/ufshcd.c       | 43 ++++++++++++++++++++++++++++++------
--
> ---
>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>  4 files changed, 56 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
> mediatek.c index 80618af..bff2c42 100644
> --- a/drivers/scsi/ufs/ufs-mediatek.c
> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
> ufs_hba *hba,
>  	return ret;
>  }
> 
> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct arm_smccc_res res;
> 
> -	ufs_mtk_device_reset_ctrl(0, res);
> -
> -	/*
> -	 * The reset signal is active low. UFS devices shall detect
> -	 * more than or equal to 1us of positive or negative RST_n
> -	 * pulse width.
> -	 *
> -	 * To be on safe side, keep the reset low for at least 10us.
> -	 */
> -	usleep_range(10, 15);
> -
> -	ufs_mtk_device_reset_ctrl(1, res);
> -
> -	/* Some devices may need time to respond to rst_n */
> -	usleep_range(10000, 15000);
> +	if (down) {
> +		ufs_mtk_device_reset_ctrl(0, res);
> +	} else {
> +		ufs_mtk_device_reset_ctrl(1, res);
> 
> -	dev_info(hba->dev, "device reset done\n");
> +		/* Some devices may need time to respond to rst_n */
> +		usleep_range(10000, 15000);
> +	}
> 
>  	return 0;
>  }
> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
> ufs_hba_mtk_vops = {
>  	.suspend             = ufs_mtk_suspend,
>  	.resume              = ufs_mtk_resume,
>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> -	.device_reset        = ufs_mtk_device_reset,
> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>  	.event_notify        = ufs_mtk_event_notify,
>  };
> 
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2206b1e..c2ccaa5 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba
> *hba)  }
> 
>  /**
> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device reset
> + line
>   * @hba: per-adapter instance
> + * @down: pull down or pull up device reset line
>   *
>   * Toggles the (optional) reset line to reset the attached device.
>   */
> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool down)
>  {
>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> 
> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct ufs_hba
> *hba)
>  	if (!host->device_reset)
>  		return -EOPNOTSUPP;
> 
> -	/*
> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
> to
> -	 * be on the safe side.
> -	 */
> -	gpiod_set_value_cansleep(host->device_reset, 1);
> -	usleep_range(10, 15);
> -
> -	gpiod_set_value_cansleep(host->device_reset, 0);
> -	usleep_range(10, 15);
> +	if (down) {
> +		gpiod_set_value_cansleep(host->device_reset, 1);
> +	} else {
> +		gpiod_set_value_cansleep(host->device_reset, 0);
> +		usleep_range(10, 15);
> +	}
> 
>  	return 0;
>  }
> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
> ufs_hba_qcom_vops = {
>  	.suspend		= ufs_qcom_suspend,
>  	.resume			= ufs_qcom_resume,
>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> -	.device_reset		= ufs_qcom_device_reset,
> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>  	.program_key		= ufs_qcom_ice_program_key,
>  };
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index
> e221add..2ee905f 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
> {
>  	int err;
> 
> -	err = ufshcd_vops_device_reset(hba);
> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> +	if (err) {
> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
> err);
> +		return;
> +	}
> +
> +	/*
> +	 * The reset signal is active low. The UFS device
> +	 * shall detect reset pulses of 1us, sleep for at
> +	 * least 10us to be on the safe side.
> +	 */
> +	usleep_range(10, 15);

Is there any point where UFS specification tells this explicitly?
I think this should be moved only if the number, i.e. 10 and 15  just
relies on hardware conditions.


Thanks.
Kiwoong Kim

> +	err = ufshcd_vops_toggle_device_reset(hba, false);
> 
>  	if (!err) {
>  		ufshcd_set_ufs_dev_active(hba);
> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba *hba)
>  			hba->wb_enabled = false;
>  			hba->wb_buf_flush_enabled = false;
>  		}
> +		dev_info(hba->dev, "device reset done\n");
> +	} else {
> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
> err);
>  	}
> +
>  	if (err != -EOPNOTSUPP)
>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  	if (ret)
>  		goto set_dev_active;
> 
> -	ufshcd_vreg_set_lpm(hba);
> -
>  disable_clks:
>  	/*
>  	 * Call vendor specific suspend callback. As these callbacks may
> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
*hba,
> enum ufs_pm_op pm_op)
>  	 */
>  	ufshcd_disable_irq(hba);
> 
> +	if (ufshcd_is_link_off(hba))
> +		ufshcd_vops_toggle_device_reset(hba, true);
> +
>  	ufshcd_setup_clocks(hba, false);
> 
>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  					hba->clk_gating.state);
>  	}
> 
> +	ufshcd_vreg_set_lpm(hba);
> +
>  	/* Put the host controller in low power mode if possible */
>  	ufshcd_hba_vreg_set_lpm(hba);
>  	goto out;
> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  	old_link_state = hba->uic_link_state;
> 
>  	ufshcd_hba_vreg_set_hpm(hba);
> +
> +	ret = ufshcd_vreg_set_hpm(hba);
> +	if (ret)
> +		goto out;
> +
>  	/* Make sure clocks are enabled before accessing controller */
>  	ret = ufshcd_setup_clocks(hba, true);
>  	if (ret)
> -		goto out;
> +		goto disable_vreg;
> 
>  	/* enable the host irq as host controller would be active soon */
>  	ufshcd_enable_irq(hba);
> 
> -	ret = ufshcd_vreg_set_hpm(hba);
> -	if (ret)
> -		goto disable_irq_and_vops_clks;
> -
>  	/*
>  	 * Call vendor specific resume callback. As these callbacks may
> access
>  	 * vendor specific host controller register space call them when
> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba *hba,
> enum ufs_pm_op pm_op)
>  	 */
>  	ret = ufshcd_vops_resume(hba, pm_op);
>  	if (ret)
> -		goto disable_vreg;
> +		goto disable_irq_and_vops_clks;
> 
>  	/* For DeepSleep, the only supported option is to have the link off
> */
>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>  vendor_suspend:
>  	ufshcd_vops_suspend(hba, pm_op);
> -disable_vreg:
> -	ufshcd_vreg_set_lpm(hba);
>  disable_irq_and_vops_clks:
>  	ufshcd_disable_irq(hba);
>  	if (hba->clk_scaling.is_allowed)
> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum
> ufs_pm_op pm_op)
>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>  					hba->clk_gating.state);
>  	}
> +disable_vreg:
> +	ufshcd_vreg_set_lpm(hba);
>  out:
>  	hba->pm_op_in_progress = 0;
>  	if (ret)
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index
> 9bb5f0e..dccc3eb 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>   * @resume: called during host controller PM callback
>   * @dbg_register_dump: used to dump controller debug information
>   * @phy_initialization: used to initialize phys
> - * @device_reset: called to issue a reset pulse on the UFS device
> + * @toggle_device_reset: called to change logic level of reset gpio on
> + the UFS device
>   * @program_key: program or evict an inline encryption key
>   * @event_notify: called to notify important events
>   */
> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>  	int	(*phy_initialization)(struct ufs_hba *);
> -	int	(*device_reset)(struct ufs_hba *hba);
> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>  					struct devfreq_dev_profile *profile,
>  					void *data);
> @@ -1216,10 +1216,10 @@ static inline void
> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>  		hba->vops->dbg_register_dump(hba);
>  }
> 
> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba *hba,
> +bool down)
>  {
> -	if (hba->vops && hba->vops->device_reset)
> -		return hba->vops->device_reset(hba);
> +	if (hba->vops && hba->vops->toggle_device_reset)
> +		return hba->vops->toggle_device_reset(hba, down);
> 
>  	return -EOPNOTSUPP;
>  }
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project



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Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[ziqichen]

On 2020-12-22 10:04, Kiwoong Kim wrote:
>> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the ufs
>> device, RST_N signal and REF_CLK signal should be between VSS(Ground) 
>> and
>> VCCQ/VCCQ2.
>> 
>> To flexibly control device reset line, re-name the function
>> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
>> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
>> parameter "bool down" is used to separate device reset line pulling 
>> down
>> from pulling up.
>> 
>> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
>> Cc: Stanley Chu <stanley.chu@mediatek.com>
>> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
>> ---
>>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>>  drivers/scsi/ufs/ufshcd.c       | 43 
>> ++++++++++++++++++++++++++++++------
> --
>> ---
>>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>>  4 files changed, 56 insertions(+), 46 deletions(-)
>> 
>> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
>> mediatek.c index 80618af..bff2c42 100644
>> --- a/drivers/scsi/ufs/ufs-mediatek.c
>> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
>> ufs_hba *hba,
>>  	return ret;
>>  }
>> 
>> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
>> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct arm_smccc_res res;
>> 
>> -	ufs_mtk_device_reset_ctrl(0, res);
>> -
>> -	/*
>> -	 * The reset signal is active low. UFS devices shall detect
>> -	 * more than or equal to 1us of positive or negative RST_n
>> -	 * pulse width.
>> -	 *
>> -	 * To be on safe side, keep the reset low for at least 10us.
>> -	 */
>> -	usleep_range(10, 15);
>> -
>> -	ufs_mtk_device_reset_ctrl(1, res);
>> -
>> -	/* Some devices may need time to respond to rst_n */
>> -	usleep_range(10000, 15000);
>> +	if (down) {
>> +		ufs_mtk_device_reset_ctrl(0, res);
>> +	} else {
>> +		ufs_mtk_device_reset_ctrl(1, res);
>> 
>> -	dev_info(hba->dev, "device reset done\n");
>> +		/* Some devices may need time to respond to rst_n */
>> +		usleep_range(10000, 15000);
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
>> ufs_hba_mtk_vops = {
>>  	.suspend             = ufs_mtk_suspend,
>>  	.resume              = ufs_mtk_resume,
>>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
>> -	.device_reset        = ufs_mtk_device_reset,
>> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>>  	.event_notify        = ufs_mtk_event_notify,
>>  };
>> 
>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>> index 2206b1e..c2ccaa5 100644
>> --- a/drivers/scsi/ufs/ufs-qcom.c
>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct 
>> ufs_hba
>> *hba)  }
>> 
>>  /**
>> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
>> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device 
>> reset
>> + line
>>   * @hba: per-adapter instance
>> + * @down: pull down or pull up device reset line
>>   *
>>   * Toggles the (optional) reset line to reset the attached device.
>>   */
>> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
>> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> 
>> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct 
>> ufs_hba
>> *hba)
>>  	if (!host->device_reset)
>>  		return -EOPNOTSUPP;
>> 
>> -	/*
>> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
>> to
>> -	 * be on the safe side.
>> -	 */
>> -	gpiod_set_value_cansleep(host->device_reset, 1);
>> -	usleep_range(10, 15);
>> -
>> -	gpiod_set_value_cansleep(host->device_reset, 0);
>> -	usleep_range(10, 15);
>> +	if (down) {
>> +		gpiod_set_value_cansleep(host->device_reset, 1);
>> +	} else {
>> +		gpiod_set_value_cansleep(host->device_reset, 0);
>> +		usleep_range(10, 15);
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
>> ufs_hba_qcom_vops = {
>>  	.suspend		= ufs_qcom_suspend,
>>  	.resume			= ufs_qcom_resume,
>>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
>> -	.device_reset		= ufs_qcom_device_reset,
>> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>>  	.program_key		= ufs_qcom_ice_program_key,
>>  };
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c 
>> index
>> e221add..2ee905f 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>> {
>>  	int err;
>> 
>> -	err = ufshcd_vops_device_reset(hba);
>> +	err = ufshcd_vops_toggle_device_reset(hba, true);
>> +	if (err) {
>> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
>> err);
>> +		return;
>> +	}
>> +
>> +	/*
>> +	 * The reset signal is active low. The UFS device
>> +	 * shall detect reset pulses of 1us, sleep for at
>> +	 * least 10us to be on the safe side.
>> +	 */
>> +	usleep_range(10, 15);
> 
> Is there any point where UFS specification tells this explicitly?
> I think this should be moved only if the number, i.e. 10 and 15  just
> relies on hardware conditions.
> 
> 
> Thanks.
> Kiwoong Kim

Hi Kiwoong,

Thanks for your comment. JESD220E Line 610~611 "The UFS device shall 
detect more than or equal to 1us
of positive or negative RST_n pulse". Both QCOM and Mediatek use 
10~15us. What
number do you think more appropriate?

Best Regards,
Ziqi

> 
>> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>> 
>>  	if (!err) {
>>  		ufshcd_set_ufs_dev_active(hba);
>> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>>  			hba->wb_enabled = false;
>>  			hba->wb_buf_flush_enabled = false;
>>  		}
>> +		dev_info(hba->dev, "device reset done\n");
>> +	} else {
>> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
>> err);
>>  	}
>> +
>>  	if (err != -EOPNOTSUPP)
>>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
>> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
>> ufs_pm_op pm_op)
>>  	if (ret)
>>  		goto set_dev_active;
>> 
>> -	ufshcd_vreg_set_lpm(hba);
>> -
>>  disable_clks:
>>  	/*
>>  	 * Call vendor specific suspend callback. As these callbacks may
>> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
>> *hba,
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ufshcd_disable_irq(hba);
>> 
>> +	if (ufshcd_is_link_off(hba))
>> +		ufshcd_vops_toggle_device_reset(hba, true);
>> +
>>  	ufshcd_setup_clocks(hba, false);
>> 
>>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
>> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>  					hba->clk_gating.state);
>>  	}
>> 
>> +	ufshcd_vreg_set_lpm(hba);
>> +
>>  	/* Put the host controller in low power mode if possible */
>>  	ufshcd_hba_vreg_set_lpm(hba);
>>  	goto out;
>> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum
>> ufs_pm_op pm_op)
>>  	old_link_state = hba->uic_link_state;
>> 
>>  	ufshcd_hba_vreg_set_hpm(hba);
>> +
>> +	ret = ufshcd_vreg_set_hpm(hba);
>> +	if (ret)
>> +		goto out;
>> +
>>  	/* Make sure clocks are enabled before accessing controller */
>>  	ret = ufshcd_setup_clocks(hba, true);
>>  	if (ret)
>> -		goto out;
>> +		goto disable_vreg;
>> 
>>  	/* enable the host irq as host controller would be active soon */
>>  	ufshcd_enable_irq(hba);
>> 
>> -	ret = ufshcd_vreg_set_hpm(hba);
>> -	if (ret)
>> -		goto disable_irq_and_vops_clks;
>> -
>>  	/*
>>  	 * Call vendor specific resume callback. As these callbacks may
>> access
>>  	 * vendor specific host controller register space call them when
>> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba 
>> *hba,
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ret = ufshcd_vops_resume(hba, pm_op);
>>  	if (ret)
>> -		goto disable_vreg;
>> +		goto disable_irq_and_vops_clks;
>> 
>>  	/* For DeepSleep, the only supported option is to have the link off
>> */
>>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
>> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
>> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>>  vendor_suspend:
>>  	ufshcd_vops_suspend(hba, pm_op);
>> -disable_vreg:
>> -	ufshcd_vreg_set_lpm(hba);
>>  disable_irq_and_vops_clks:
>>  	ufshcd_disable_irq(hba);
>>  	if (hba->clk_scaling.is_allowed)
>> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum
>> ufs_pm_op pm_op)
>>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>>  					hba->clk_gating.state);
>>  	}
>> +disable_vreg:
>> +	ufshcd_vreg_set_lpm(hba);
>>  out:
>>  	hba->pm_op_in_progress = 0;
>>  	if (ret)
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h 
>> index
>> 9bb5f0e..dccc3eb 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>>   * @resume: called during host controller PM callback
>>   * @dbg_register_dump: used to dump controller debug information
>>   * @phy_initialization: used to initialize phys
>> - * @device_reset: called to issue a reset pulse on the UFS device
>> + * @toggle_device_reset: called to change logic level of reset gpio 
>> on
>> + the UFS device
>>   * @program_key: program or evict an inline encryption key
>>   * @event_notify: called to notify important events
>>   */
>> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>>  	int	(*phy_initialization)(struct ufs_hba *);
>> -	int	(*device_reset)(struct ufs_hba *hba);
>> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
>>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>>  					struct devfreq_dev_profile *profile,
>>  					void *data);
>> @@ -1216,10 +1216,10 @@ static inline void
>> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>>  		hba->vops->dbg_register_dump(hba);
>>  }
>> 
>> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
>> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba 
>> *hba,
>> +bool down)
>>  {
>> -	if (hba->vops && hba->vops->device_reset)
>> -		return hba->vops->device_reset(hba);
>> +	if (hba->vops && hba->vops->toggle_device_reset)
>> +		return hba->vops->toggle_device_reset(hba, down);
>> 
>>  	return -EOPNOTSUPP;
>>  }
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project

Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[ziqichen]

On 2020-12-22 10:04, Kiwoong Kim wrote:
>> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the ufs
>> device, RST_N signal and REF_CLK signal should be between VSS(Ground) 
>> and
>> VCCQ/VCCQ2.
>> 
>> To flexibly control device reset line, re-name the function
>> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
>> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
>> parameter "bool down" is used to separate device reset line pulling 
>> down
>> from pulling up.
>> 
>> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
>> Cc: Stanley Chu <stanley.chu@mediatek.com>
>> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
>> ---
>>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>>  drivers/scsi/ufs/ufshcd.c       | 43 
>> ++++++++++++++++++++++++++++++------
> --
>> ---
>>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>>  4 files changed, 56 insertions(+), 46 deletions(-)
>> 
>> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
>> mediatek.c index 80618af..bff2c42 100644
>> --- a/drivers/scsi/ufs/ufs-mediatek.c
>> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
>> ufs_hba *hba,
>>  	return ret;
>>  }
>> 
>> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
>> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct arm_smccc_res res;
>> 
>> -	ufs_mtk_device_reset_ctrl(0, res);
>> -
>> -	/*
>> -	 * The reset signal is active low. UFS devices shall detect
>> -	 * more than or equal to 1us of positive or negative RST_n
>> -	 * pulse width.
>> -	 *
>> -	 * To be on safe side, keep the reset low for at least 10us.
>> -	 */
>> -	usleep_range(10, 15);
>> -
>> -	ufs_mtk_device_reset_ctrl(1, res);
>> -
>> -	/* Some devices may need time to respond to rst_n */
>> -	usleep_range(10000, 15000);
>> +	if (down) {
>> +		ufs_mtk_device_reset_ctrl(0, res);
>> +	} else {
>> +		ufs_mtk_device_reset_ctrl(1, res);
>> 
>> -	dev_info(hba->dev, "device reset done\n");
>> +		/* Some devices may need time to respond to rst_n */
>> +		usleep_range(10000, 15000);
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
>> ufs_hba_mtk_vops = {
>>  	.suspend             = ufs_mtk_suspend,
>>  	.resume              = ufs_mtk_resume,
>>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
>> -	.device_reset        = ufs_mtk_device_reset,
>> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>>  	.event_notify        = ufs_mtk_event_notify,
>>  };
>> 
>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>> index 2206b1e..c2ccaa5 100644
>> --- a/drivers/scsi/ufs/ufs-qcom.c
>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct 
>> ufs_hba
>> *hba)  }
>> 
>>  /**
>> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
>> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device 
>> reset
>> + line
>>   * @hba: per-adapter instance
>> + * @down: pull down or pull up device reset line
>>   *
>>   * Toggles the (optional) reset line to reset the attached device.
>>   */
>> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
>> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool 
>> down)
>>  {
>>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> 
>> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct 
>> ufs_hba
>> *hba)
>>  	if (!host->device_reset)
>>  		return -EOPNOTSUPP;
>> 
>> -	/*
>> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
>> to
>> -	 * be on the safe side.
>> -	 */
>> -	gpiod_set_value_cansleep(host->device_reset, 1);
>> -	usleep_range(10, 15);
>> -
>> -	gpiod_set_value_cansleep(host->device_reset, 0);
>> -	usleep_range(10, 15);
>> +	if (down) {
>> +		gpiod_set_value_cansleep(host->device_reset, 1);
>> +	} else {
>> +		gpiod_set_value_cansleep(host->device_reset, 0);
>> +		usleep_range(10, 15);
>> +	}
>> 
>>  	return 0;
>>  }
>> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
>> ufs_hba_qcom_vops = {
>>  	.suspend		= ufs_qcom_suspend,
>>  	.resume			= ufs_qcom_resume,
>>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
>> -	.device_reset		= ufs_qcom_device_reset,
>> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>>  	.program_key		= ufs_qcom_ice_program_key,
>>  };
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c 
>> index
>> e221add..2ee905f 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>> {
>>  	int err;
>> 
>> -	err = ufshcd_vops_device_reset(hba);
>> +	err = ufshcd_vops_toggle_device_reset(hba, true);
>> +	if (err) {
>> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
>> err);
>> +		return;
>> +	}
>> +
>> +	/*
>> +	 * The reset signal is active low. The UFS device
>> +	 * shall detect reset pulses of 1us, sleep for at
>> +	 * least 10us to be on the safe side.
>> +	 */
>> +	usleep_range(10, 15);
> 
> Is there any point where UFS specification tells this explicitly?
> I think this should be moved only if the number, i.e. 10 and 15  just
> relies on hardware conditions.
> 
> 
> Thanks.
> Kiwoong Kim

Hi Kiwoong,

Thanks for your comment. JESD220E Line 610~611 "The UFS device shall 
detect more than or equal to 1us
of positive or negative RST_n pulse". Both QCOM and Mediatek use 
10~15us. What
number do you think more appropriate?

Best Regards,
Ziqi

> 
>> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>> 
>>  	if (!err) {
>>  		ufshcd_set_ufs_dev_active(hba);
>> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba 
>> *hba)
>>  			hba->wb_enabled = false;
>>  			hba->wb_buf_flush_enabled = false;
>>  		}
>> +		dev_info(hba->dev, "device reset done\n");
>> +	} else {
>> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
>> err);
>>  	}
>> +
>>  	if (err != -EOPNOTSUPP)
>>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
>> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
>> ufs_pm_op pm_op)
>>  	if (ret)
>>  		goto set_dev_active;
>> 
>> -	ufshcd_vreg_set_lpm(hba);
>> -
>>  disable_clks:
>>  	/*
>>  	 * Call vendor specific suspend callback. As these callbacks may
>> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
>> *hba,
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ufshcd_disable_irq(hba);
>> 
>> +	if (ufshcd_is_link_off(hba))
>> +		ufshcd_vops_toggle_device_reset(hba, true);
>> +
>>  	ufshcd_setup_clocks(hba, false);
>> 
>>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
>> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>  					hba->clk_gating.state);
>>  	}
>> 
>> +	ufshcd_vreg_set_lpm(hba);
>> +
>>  	/* Put the host controller in low power mode if possible */
>>  	ufshcd_hba_vreg_set_lpm(hba);
>>  	goto out;
>> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum
>> ufs_pm_op pm_op)
>>  	old_link_state = hba->uic_link_state;
>> 
>>  	ufshcd_hba_vreg_set_hpm(hba);
>> +
>> +	ret = ufshcd_vreg_set_hpm(hba);
>> +	if (ret)
>> +		goto out;
>> +
>>  	/* Make sure clocks are enabled before accessing controller */
>>  	ret = ufshcd_setup_clocks(hba, true);
>>  	if (ret)
>> -		goto out;
>> +		goto disable_vreg;
>> 
>>  	/* enable the host irq as host controller would be active soon */
>>  	ufshcd_enable_irq(hba);
>> 
>> -	ret = ufshcd_vreg_set_hpm(hba);
>> -	if (ret)
>> -		goto disable_irq_and_vops_clks;
>> -
>>  	/*
>>  	 * Call vendor specific resume callback. As these callbacks may
>> access
>>  	 * vendor specific host controller register space call them when
>> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba 
>> *hba,
>> enum ufs_pm_op pm_op)
>>  	 */
>>  	ret = ufshcd_vops_resume(hba, pm_op);
>>  	if (ret)
>> -		goto disable_vreg;
>> +		goto disable_irq_and_vops_clks;
>> 
>>  	/* For DeepSleep, the only supported option is to have the link off
>> */
>>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
>> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
>> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>>  vendor_suspend:
>>  	ufshcd_vops_suspend(hba, pm_op);
>> -disable_vreg:
>> -	ufshcd_vreg_set_lpm(hba);
>>  disable_irq_and_vops_clks:
>>  	ufshcd_disable_irq(hba);
>>  	if (hba->clk_scaling.is_allowed)
>> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba, 
>> enum
>> ufs_pm_op pm_op)
>>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>>  					hba->clk_gating.state);
>>  	}
>> +disable_vreg:
>> +	ufshcd_vreg_set_lpm(hba);
>>  out:
>>  	hba->pm_op_in_progress = 0;
>>  	if (ret)
>> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h 
>> index
>> 9bb5f0e..dccc3eb 100644
>> --- a/drivers/scsi/ufs/ufshcd.h
>> +++ b/drivers/scsi/ufs/ufshcd.h
>> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>>   * @resume: called during host controller PM callback
>>   * @dbg_register_dump: used to dump controller debug information
>>   * @phy_initialization: used to initialize phys
>> - * @device_reset: called to issue a reset pulse on the UFS device
>> + * @toggle_device_reset: called to change logic level of reset gpio 
>> on
>> + the UFS device
>>   * @program_key: program or evict an inline encryption key
>>   * @event_notify: called to notify important events
>>   */
>> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>>  	int	(*phy_initialization)(struct ufs_hba *);
>> -	int	(*device_reset)(struct ufs_hba *hba);
>> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
>>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>>  					struct devfreq_dev_profile *profile,
>>  					void *data);
>> @@ -1216,10 +1216,10 @@ static inline void
>> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>>  		hba->vops->dbg_register_dump(hba);
>>  }
>> 
>> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
>> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba 
>> *hba,
>> +bool down)
>>  {
>> -	if (hba->vops && hba->vops->device_reset)
>> -		return hba->vops->device_reset(hba);
>> +	if (hba->vops && hba->vops->toggle_device_reset)
>> +		return hba->vops->toggle_device_reset(hba, down);
>> 
>>  	return -EOPNOTSUPP;
>>  }
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
>> Forum,
>> a Linux Foundation Collaborative Project

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RE: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Kiwoong Kim]

> On 2020-12-22 10:04, Kiwoong Kim wrote:
> >> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the
> >> ufs device, RST_N signal and REF_CLK signal should be between
> >> VSS(Ground) and VCCQ/VCCQ2.
> >>
> >> To flexibly control device reset line, re-name the function
> >> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> >> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
> >> parameter "bool down" is used to separate device reset line pulling
> >> down from pulling up.
> >>
> >> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> >> Cc: Stanley Chu <stanley.chu@mediatek.com>
> >> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> >> ---
> >>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
> >>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
> >>  drivers/scsi/ufs/ufshcd.c       | 43
> >> ++++++++++++++++++++++++++++++------
> > --
> >> ---
> >>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
> >>  4 files changed, 56 insertions(+), 46 deletions(-)
> >>
> >> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
> >> mediatek.c index 80618af..bff2c42 100644
> >> --- a/drivers/scsi/ufs/ufs-mediatek.c
> >> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> >> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
> >> ufs_hba *hba,
> >>  	return ret;
> >>  }
> >>
> >> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> >> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool
> >> down)
> >>  {
> >>  	struct arm_smccc_res res;
> >>
> >> -	ufs_mtk_device_reset_ctrl(0, res);
> >> -
> >> -	/*
> >> -	 * The reset signal is active low. UFS devices shall detect
> >> -	 * more than or equal to 1us of positive or negative RST_n
> >> -	 * pulse width.
> >> -	 *
> >> -	 * To be on safe side, keep the reset low for at least 10us.
> >> -	 */
> >> -	usleep_range(10, 15);
> >> -
> >> -	ufs_mtk_device_reset_ctrl(1, res);
> >> -
> >> -	/* Some devices may need time to respond to rst_n */
> >> -	usleep_range(10000, 15000);
> >> +	if (down) {
> >> +		ufs_mtk_device_reset_ctrl(0, res);
> >> +	} else {
> >> +		ufs_mtk_device_reset_ctrl(1, res);
> >>
> >> -	dev_info(hba->dev, "device reset done\n");
> >> +		/* Some devices may need time to respond to rst_n */
> >> +		usleep_range(10000, 15000);
> >> +	}
> >>
> >>  	return 0;
> >>  }
> >> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
> >> ufs_hba_mtk_vops = {
> >>  	.suspend             = ufs_mtk_suspend,
> >>  	.resume              = ufs_mtk_resume,
> >>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> >> -	.device_reset        = ufs_mtk_device_reset,
> >> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
> >>  	.event_notify        = ufs_mtk_event_notify,
> >>  };
> >>
> >> diff --git a/drivers/scsi/ufs/ufs-qcom.c
> >> b/drivers/scsi/ufs/ufs-qcom.c index 2206b1e..c2ccaa5 100644
> >> --- a/drivers/scsi/ufs/ufs-qcom.c
> >> +++ b/drivers/scsi/ufs/ufs-qcom.c
> >> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct
> >> ufs_hba
> >> *hba)  }
> >>
> >>  /**
> >> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> >> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device
> >> reset
> >> + line
> >>   * @hba: per-adapter instance
> >> + * @down: pull down or pull up device reset line
> >>   *
> >>   * Toggles the (optional) reset line to reset the attached device.
> >>   */
> >> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> >> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool
> >> down)
> >>  {
> >>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> >>
> >> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct
> >> ufs_hba
> >> *hba)
> >>  	if (!host->device_reset)
> >>  		return -EOPNOTSUPP;
> >>
> >> -	/*
> >> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
> >> to
> >> -	 * be on the safe side.
> >> -	 */
> >> -	gpiod_set_value_cansleep(host->device_reset, 1);
> >> -	usleep_range(10, 15);
> >> -
> >> -	gpiod_set_value_cansleep(host->device_reset, 0);
> >> -	usleep_range(10, 15);
> >> +	if (down) {
> >> +		gpiod_set_value_cansleep(host->device_reset, 1);
> >> +	} else {
> >> +		gpiod_set_value_cansleep(host->device_reset, 0);
> >> +		usleep_range(10, 15);
> >> +	}
> >>
> >>  	return 0;
> >>  }
> >> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
> >> ufs_hba_qcom_vops = {
> >>  	.suspend		= ufs_qcom_suspend,
> >>  	.resume			= ufs_qcom_resume,
> >>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> >> -	.device_reset		= ufs_qcom_device_reset,
> >> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
> >>  	.config_scaling_param = ufs_qcom_config_scaling_param,
> >>  	.program_key		= ufs_qcom_ice_program_key,
> >>  };
> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> >> index e221add..2ee905f 100644
> >> --- a/drivers/scsi/ufs/ufshcd.c
> >> +++ b/drivers/scsi/ufs/ufshcd.c
> >> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba
> >> *hba)
> >> {
> >>  	int err;
> >>
> >> -	err = ufshcd_vops_device_reset(hba);
> >> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> >> +	if (err) {
> >> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
> >> err);
> >> +		return;
> >> +	}
> >> +
> >> +	/*
> >> +	 * The reset signal is active low. The UFS device
> >> +	 * shall detect reset pulses of 1us, sleep for at
> >> +	 * least 10us to be on the safe side.
> >> +	 */
> >> +	usleep_range(10, 15);
> >
> > Is there any point where UFS specification tells this explicitly?
> > I think this should be moved only if the number, i.e. 10 and 15  just
> > relies on hardware conditions.
> >
> >
> > Thanks.
> > Kiwoong Kim
> 
> Hi Kiwoong,
> 
> Thanks for your comment. JESD220E Line 610~611 "The UFS device shall
> detect more than or equal to 1us of positive or negative RST_n pulse".
> Both QCOM and Mediatek use 10~15us. What number do you think more
> appropriate?
> 
> Best Regards,
> Ziqi

With yours, all the SoC vendors should wait for around 10us unconditionally
even if there will be a possibility that some can use shorter period.
I see this as a sort of optimization point.


Thanks.
Kiwoong Kim
> 
> >
> >> +	err = ufshcd_vops_toggle_device_reset(hba, false);
> >>
> >>  	if (!err) {
> >>  		ufshcd_set_ufs_dev_active(hba);
> >> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba
> >> *hba)
> >>  			hba->wb_enabled = false;
> >>  			hba->wb_buf_flush_enabled = false;
> >>  		}
> >> +		dev_info(hba->dev, "device reset done\n");
> >> +	} else {
> >> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
> >> err);
> >>  	}
> >> +
> >>  	if (err != -EOPNOTSUPP)
> >>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
> >> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
> >> ufs_pm_op pm_op)
> >>  	if (ret)
> >>  		goto set_dev_active;
> >>
> >> -	ufshcd_vreg_set_lpm(hba);
> >> -
> >>  disable_clks:
> >>  	/*
> >>  	 * Call vendor specific suspend callback. As these callbacks may
> >> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
> >> *hba, enum ufs_pm_op pm_op)
> >>  	 */
> >>  	ufshcd_disable_irq(hba);
> >>
> >> +	if (ufshcd_is_link_off(hba))
> >> +		ufshcd_vops_toggle_device_reset(hba, true);
> >> +
> >>  	ufshcd_setup_clocks(hba, false);
> >>
> >>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
> >> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> >>  					hba->clk_gating.state);
> >>  	}
> >>
> >> +	ufshcd_vreg_set_lpm(hba);
> >> +
> >>  	/* Put the host controller in low power mode if possible */
> >>  	ufshcd_hba_vreg_set_lpm(hba);
> >>  	goto out;
> >> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba,
> >> enum ufs_pm_op pm_op)
> >>  	old_link_state = hba->uic_link_state;
> >>
> >>  	ufshcd_hba_vreg_set_hpm(hba);
> >> +
> >> +	ret = ufshcd_vreg_set_hpm(hba);
> >> +	if (ret)
> >> +		goto out;
> >> +
> >>  	/* Make sure clocks are enabled before accessing controller */
> >>  	ret = ufshcd_setup_clocks(hba, true);
> >>  	if (ret)
> >> -		goto out;
> >> +		goto disable_vreg;
> >>
> >>  	/* enable the host irq as host controller would be active soon */
> >>  	ufshcd_enable_irq(hba);
> >>
> >> -	ret = ufshcd_vreg_set_hpm(hba);
> >> -	if (ret)
> >> -		goto disable_irq_and_vops_clks;
> >> -
> >>  	/*
> >>  	 * Call vendor specific resume callback. As these callbacks may
> >> access
> >>  	 * vendor specific host controller register space call them when
> >> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba
> >> *hba, enum ufs_pm_op pm_op)
> >>  	 */
> >>  	ret = ufshcd_vops_resume(hba, pm_op);
> >>  	if (ret)
> >> -		goto disable_vreg;
> >> +		goto disable_irq_and_vops_clks;
> >>
> >>  	/* For DeepSleep, the only supported option is to have the link off
> >> */
> >>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
> >> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
> >> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> >>  	ufshcd_link_state_transition(hba, old_link_state, 0);
> >>  vendor_suspend:
> >>  	ufshcd_vops_suspend(hba, pm_op);
> >> -disable_vreg:
> >> -	ufshcd_vreg_set_lpm(hba);
> >>  disable_irq_and_vops_clks:
> >>  	ufshcd_disable_irq(hba);
> >>  	if (hba->clk_scaling.is_allowed)
> >> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
> >> enum ufs_pm_op pm_op)
> >>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
> >>  					hba->clk_gating.state);
> >>  	}
> >> +disable_vreg:
> >> +	ufshcd_vreg_set_lpm(hba);
> >>  out:
> >>  	hba->pm_op_in_progress = 0;
> >>  	if (ret)
> >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> >> index 9bb5f0e..dccc3eb 100644
> >> --- a/drivers/scsi/ufs/ufshcd.h
> >> +++ b/drivers/scsi/ufs/ufshcd.h
> >> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
> >>   * @resume: called during host controller PM callback
> >>   * @dbg_register_dump: used to dump controller debug information
> >>   * @phy_initialization: used to initialize phys
> >> - * @device_reset: called to issue a reset pulse on the UFS device
> >> + * @toggle_device_reset: called to change logic level of reset gpio
> >> on
> >> + the UFS device
> >>   * @program_key: program or evict an inline encryption key
> >>   * @event_notify: called to notify important events
> >>   */
> >> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
> >>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
> >>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
> >>  	int	(*phy_initialization)(struct ufs_hba *);
> >> -	int	(*device_reset)(struct ufs_hba *hba);
> >> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
> >>  	void	(*config_scaling_param)(struct ufs_hba *hba,
> >>  					struct devfreq_dev_profile *profile,
> >>  					void *data);
> >> @@ -1216,10 +1216,10 @@ static inline void
> >> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
> >>  		hba->vops->dbg_register_dump(hba);
> >>  }
> >>
> >> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> >> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba
> >> *hba,
> >> +bool down)
> >>  {
> >> -	if (hba->vops && hba->vops->device_reset)
> >> -		return hba->vops->device_reset(hba);
> >> +	if (hba->vops && hba->vops->toggle_device_reset)
> >> +		return hba->vops->toggle_device_reset(hba, down);
> >>
> >>  	return -EOPNOTSUPP;
> >>  }
> >> --
> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> >> Forum, a Linux Foundation Collaborative Project

RE: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Kiwoong Kim]

> On 2020-12-22 10:04, Kiwoong Kim wrote:
> >> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the
> >> ufs device, RST_N signal and REF_CLK signal should be between
> >> VSS(Ground) and VCCQ/VCCQ2.
> >>
> >> To flexibly control device reset line, re-name the function
> >> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> >> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
> >> parameter "bool down" is used to separate device reset line pulling
> >> down from pulling up.
> >>
> >> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> >> Cc: Stanley Chu <stanley.chu@mediatek.com>
> >> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> >> ---
> >>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
> >>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
> >>  drivers/scsi/ufs/ufshcd.c       | 43
> >> ++++++++++++++++++++++++++++++------
> > --
> >> ---
> >>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
> >>  4 files changed, 56 insertions(+), 46 deletions(-)
> >>
> >> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
> >> mediatek.c index 80618af..bff2c42 100644
> >> --- a/drivers/scsi/ufs/ufs-mediatek.c
> >> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> >> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
> >> ufs_hba *hba,
> >>  	return ret;
> >>  }
> >>
> >> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> >> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool
> >> down)
> >>  {
> >>  	struct arm_smccc_res res;
> >>
> >> -	ufs_mtk_device_reset_ctrl(0, res);
> >> -
> >> -	/*
> >> -	 * The reset signal is active low. UFS devices shall detect
> >> -	 * more than or equal to 1us of positive or negative RST_n
> >> -	 * pulse width.
> >> -	 *
> >> -	 * To be on safe side, keep the reset low for at least 10us.
> >> -	 */
> >> -	usleep_range(10, 15);
> >> -
> >> -	ufs_mtk_device_reset_ctrl(1, res);
> >> -
> >> -	/* Some devices may need time to respond to rst_n */
> >> -	usleep_range(10000, 15000);
> >> +	if (down) {
> >> +		ufs_mtk_device_reset_ctrl(0, res);
> >> +	} else {
> >> +		ufs_mtk_device_reset_ctrl(1, res);
> >>
> >> -	dev_info(hba->dev, "device reset done\n");
> >> +		/* Some devices may need time to respond to rst_n */
> >> +		usleep_range(10000, 15000);
> >> +	}
> >>
> >>  	return 0;
> >>  }
> >> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
> >> ufs_hba_mtk_vops = {
> >>  	.suspend             = ufs_mtk_suspend,
> >>  	.resume              = ufs_mtk_resume,
> >>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> >> -	.device_reset        = ufs_mtk_device_reset,
> >> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
> >>  	.event_notify        = ufs_mtk_event_notify,
> >>  };
> >>
> >> diff --git a/drivers/scsi/ufs/ufs-qcom.c
> >> b/drivers/scsi/ufs/ufs-qcom.c index 2206b1e..c2ccaa5 100644
> >> --- a/drivers/scsi/ufs/ufs-qcom.c
> >> +++ b/drivers/scsi/ufs/ufs-qcom.c
> >> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct
> >> ufs_hba
> >> *hba)  }
> >>
> >>  /**
> >> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> >> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device
> >> reset
> >> + line
> >>   * @hba: per-adapter instance
> >> + * @down: pull down or pull up device reset line
> >>   *
> >>   * Toggles the (optional) reset line to reset the attached device.
> >>   */
> >> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> >> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool
> >> down)
> >>  {
> >>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> >>
> >> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct
> >> ufs_hba
> >> *hba)
> >>  	if (!host->device_reset)
> >>  		return -EOPNOTSUPP;
> >>
> >> -	/*
> >> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
> >> to
> >> -	 * be on the safe side.
> >> -	 */
> >> -	gpiod_set_value_cansleep(host->device_reset, 1);
> >> -	usleep_range(10, 15);
> >> -
> >> -	gpiod_set_value_cansleep(host->device_reset, 0);
> >> -	usleep_range(10, 15);
> >> +	if (down) {
> >> +		gpiod_set_value_cansleep(host->device_reset, 1);
> >> +	} else {
> >> +		gpiod_set_value_cansleep(host->device_reset, 0);
> >> +		usleep_range(10, 15);
> >> +	}
> >>
> >>  	return 0;
> >>  }
> >> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
> >> ufs_hba_qcom_vops = {
> >>  	.suspend		= ufs_qcom_suspend,
> >>  	.resume			= ufs_qcom_resume,
> >>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> >> -	.device_reset		= ufs_qcom_device_reset,
> >> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
> >>  	.config_scaling_param = ufs_qcom_config_scaling_param,
> >>  	.program_key		= ufs_qcom_ice_program_key,
> >>  };
> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> >> index e221add..2ee905f 100644
> >> --- a/drivers/scsi/ufs/ufshcd.c
> >> +++ b/drivers/scsi/ufs/ufshcd.c
> >> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba
> >> *hba)
> >> {
> >>  	int err;
> >>
> >> -	err = ufshcd_vops_device_reset(hba);
> >> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> >> +	if (err) {
> >> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
> >> err);
> >> +		return;
> >> +	}
> >> +
> >> +	/*
> >> +	 * The reset signal is active low. The UFS device
> >> +	 * shall detect reset pulses of 1us, sleep for at
> >> +	 * least 10us to be on the safe side.
> >> +	 */
> >> +	usleep_range(10, 15);
> >
> > Is there any point where UFS specification tells this explicitly?
> > I think this should be moved only if the number, i.e. 10 and 15  just
> > relies on hardware conditions.
> >
> >
> > Thanks.
> > Kiwoong Kim
> 
> Hi Kiwoong,
> 
> Thanks for your comment. JESD220E Line 610~611 "The UFS device shall
> detect more than or equal to 1us of positive or negative RST_n pulse".
> Both QCOM and Mediatek use 10~15us. What number do you think more
> appropriate?
> 
> Best Regards,
> Ziqi

With yours, all the SoC vendors should wait for around 10us unconditionally
even if there will be a possibility that some can use shorter period.
I see this as a sort of optimization point.


Thanks.
Kiwoong Kim
> 
> >
> >> +	err = ufshcd_vops_toggle_device_reset(hba, false);
> >>
> >>  	if (!err) {
> >>  		ufshcd_set_ufs_dev_active(hba);
> >> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba
> >> *hba)
> >>  			hba->wb_enabled = false;
> >>  			hba->wb_buf_flush_enabled = false;
> >>  		}
> >> +		dev_info(hba->dev, "device reset done\n");
> >> +	} else {
> >> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
> >> err);
> >>  	}
> >> +
> >>  	if (err != -EOPNOTSUPP)
> >>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
> >> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
> >> ufs_pm_op pm_op)
> >>  	if (ret)
> >>  		goto set_dev_active;
> >>
> >> -	ufshcd_vreg_set_lpm(hba);
> >> -
> >>  disable_clks:
> >>  	/*
> >>  	 * Call vendor specific suspend callback. As these callbacks may
> >> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
> >> *hba, enum ufs_pm_op pm_op)
> >>  	 */
> >>  	ufshcd_disable_irq(hba);
> >>
> >> +	if (ufshcd_is_link_off(hba))
> >> +		ufshcd_vops_toggle_device_reset(hba, true);
> >> +
> >>  	ufshcd_setup_clocks(hba, false);
> >>
> >>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
> >> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> >>  					hba->clk_gating.state);
> >>  	}
> >>
> >> +	ufshcd_vreg_set_lpm(hba);
> >> +
> >>  	/* Put the host controller in low power mode if possible */
> >>  	ufshcd_hba_vreg_set_lpm(hba);
> >>  	goto out;
> >> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba,
> >> enum ufs_pm_op pm_op)
> >>  	old_link_state = hba->uic_link_state;
> >>
> >>  	ufshcd_hba_vreg_set_hpm(hba);
> >> +
> >> +	ret = ufshcd_vreg_set_hpm(hba);
> >> +	if (ret)
> >> +		goto out;
> >> +
> >>  	/* Make sure clocks are enabled before accessing controller */
> >>  	ret = ufshcd_setup_clocks(hba, true);
> >>  	if (ret)
> >> -		goto out;
> >> +		goto disable_vreg;
> >>
> >>  	/* enable the host irq as host controller would be active soon */
> >>  	ufshcd_enable_irq(hba);
> >>
> >> -	ret = ufshcd_vreg_set_hpm(hba);
> >> -	if (ret)
> >> -		goto disable_irq_and_vops_clks;
> >> -
> >>  	/*
> >>  	 * Call vendor specific resume callback. As these callbacks may
> >> access
> >>  	 * vendor specific host controller register space call them when
> >> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba
> >> *hba, enum ufs_pm_op pm_op)
> >>  	 */
> >>  	ret = ufshcd_vops_resume(hba, pm_op);
> >>  	if (ret)
> >> -		goto disable_vreg;
> >> +		goto disable_irq_and_vops_clks;
> >>
> >>  	/* For DeepSleep, the only supported option is to have the link off
> >> */
> >>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
> >> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
> >> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> >>  	ufshcd_link_state_transition(hba, old_link_state, 0);
> >>  vendor_suspend:
> >>  	ufshcd_vops_suspend(hba, pm_op);
> >> -disable_vreg:
> >> -	ufshcd_vreg_set_lpm(hba);
> >>  disable_irq_and_vops_clks:
> >>  	ufshcd_disable_irq(hba);
> >>  	if (hba->clk_scaling.is_allowed)
> >> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
> >> enum ufs_pm_op pm_op)
> >>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
> >>  					hba->clk_gating.state);
> >>  	}
> >> +disable_vreg:
> >> +	ufshcd_vreg_set_lpm(hba);
> >>  out:
> >>  	hba->pm_op_in_progress = 0;
> >>  	if (ret)
> >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> >> index 9bb5f0e..dccc3eb 100644
> >> --- a/drivers/scsi/ufs/ufshcd.h
> >> +++ b/drivers/scsi/ufs/ufshcd.h
> >> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
> >>   * @resume: called during host controller PM callback
> >>   * @dbg_register_dump: used to dump controller debug information
> >>   * @phy_initialization: used to initialize phys
> >> - * @device_reset: called to issue a reset pulse on the UFS device
> >> + * @toggle_device_reset: called to change logic level of reset gpio
> >> on
> >> + the UFS device
> >>   * @program_key: program or evict an inline encryption key
> >>   * @event_notify: called to notify important events
> >>   */
> >> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
> >>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
> >>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
> >>  	int	(*phy_initialization)(struct ufs_hba *);
> >> -	int	(*device_reset)(struct ufs_hba *hba);
> >> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
> >>  	void	(*config_scaling_param)(struct ufs_hba *hba,
> >>  					struct devfreq_dev_profile *profile,
> >>  					void *data);
> >> @@ -1216,10 +1216,10 @@ static inline void
> >> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
> >>  		hba->vops->dbg_register_dump(hba);
> >>  }
> >>
> >> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> >> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba
> >> *hba,
> >> +bool down)
> >>  {
> >> -	if (hba->vops && hba->vops->device_reset)
> >> -		return hba->vops->device_reset(hba);
> >> +	if (hba->vops && hba->vops->toggle_device_reset)
> >> +		return hba->vops->toggle_device_reset(hba, down);
> >>
> >>  	return -EOPNOTSUPP;
> >>  }
> >> --
> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> >> Forum, a Linux Foundation Collaborative Project


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RE: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[Kiwoong Kim]

> On 2020-12-22 10:04, Kiwoong Kim wrote:
> >> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the
> >> ufs device, RST_N signal and REF_CLK signal should be between
> >> VSS(Ground) and VCCQ/VCCQ2.
> >>
> >> To flexibly control device reset line, re-name the function
> >> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
> >> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
> >> parameter "bool down" is used to separate device reset line pulling
> >> down from pulling up.
> >>
> >> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> >> Cc: Stanley Chu <stanley.chu@mediatek.com>
> >> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> >> ---
> >>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
> >>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
> >>  drivers/scsi/ufs/ufshcd.c       | 43
> >> ++++++++++++++++++++++++++++++------
> > --
> >> ---
> >>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
> >>  4 files changed, 56 insertions(+), 46 deletions(-)
> >>
> >> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
> >> mediatek.c index 80618af..bff2c42 100644
> >> --- a/drivers/scsi/ufs/ufs-mediatek.c
> >> +++ b/drivers/scsi/ufs/ufs-mediatek.c
> >> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
> >> ufs_hba *hba,
> >>  	return ret;
> >>  }
> >>
> >> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
> >> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool
> >> down)
> >>  {
> >>  	struct arm_smccc_res res;
> >>
> >> -	ufs_mtk_device_reset_ctrl(0, res);
> >> -
> >> -	/*
> >> -	 * The reset signal is active low. UFS devices shall detect
> >> -	 * more than or equal to 1us of positive or negative RST_n
> >> -	 * pulse width.
> >> -	 *
> >> -	 * To be on safe side, keep the reset low for at least 10us.
> >> -	 */
> >> -	usleep_range(10, 15);
> >> -
> >> -	ufs_mtk_device_reset_ctrl(1, res);
> >> -
> >> -	/* Some devices may need time to respond to rst_n */
> >> -	usleep_range(10000, 15000);
> >> +	if (down) {
> >> +		ufs_mtk_device_reset_ctrl(0, res);
> >> +	} else {
> >> +		ufs_mtk_device_reset_ctrl(1, res);
> >>
> >> -	dev_info(hba->dev, "device reset done\n");
> >> +		/* Some devices may need time to respond to rst_n */
> >> +		usleep_range(10000, 15000);
> >> +	}
> >>
> >>  	return 0;
> >>  }
> >> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
> >> ufs_hba_mtk_vops = {
> >>  	.suspend             = ufs_mtk_suspend,
> >>  	.resume              = ufs_mtk_resume,
> >>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
> >> -	.device_reset        = ufs_mtk_device_reset,
> >> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
> >>  	.event_notify        = ufs_mtk_event_notify,
> >>  };
> >>
> >> diff --git a/drivers/scsi/ufs/ufs-qcom.c
> >> b/drivers/scsi/ufs/ufs-qcom.c index 2206b1e..c2ccaa5 100644
> >> --- a/drivers/scsi/ufs/ufs-qcom.c
> >> +++ b/drivers/scsi/ufs/ufs-qcom.c
> >> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct
> >> ufs_hba
> >> *hba)  }
> >>
> >>  /**
> >> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
> >> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device
> >> reset
> >> + line
> >>   * @hba: per-adapter instance
> >> + * @down: pull down or pull up device reset line
> >>   *
> >>   * Toggles the (optional) reset line to reset the attached device.
> >>   */
> >> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
> >> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool
> >> down)
> >>  {
> >>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> >>
> >> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct
> >> ufs_hba
> >> *hba)
> >>  	if (!host->device_reset)
> >>  		return -EOPNOTSUPP;
> >>
> >> -	/*
> >> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
> >> to
> >> -	 * be on the safe side.
> >> -	 */
> >> -	gpiod_set_value_cansleep(host->device_reset, 1);
> >> -	usleep_range(10, 15);
> >> -
> >> -	gpiod_set_value_cansleep(host->device_reset, 0);
> >> -	usleep_range(10, 15);
> >> +	if (down) {
> >> +		gpiod_set_value_cansleep(host->device_reset, 1);
> >> +	} else {
> >> +		gpiod_set_value_cansleep(host->device_reset, 0);
> >> +		usleep_range(10, 15);
> >> +	}
> >>
> >>  	return 0;
> >>  }
> >> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
> >> ufs_hba_qcom_vops = {
> >>  	.suspend		= ufs_qcom_suspend,
> >>  	.resume			= ufs_qcom_resume,
> >>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
> >> -	.device_reset		= ufs_qcom_device_reset,
> >> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
> >>  	.config_scaling_param = ufs_qcom_config_scaling_param,
> >>  	.program_key		= ufs_qcom_ice_program_key,
> >>  };
> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> >> index e221add..2ee905f 100644
> >> --- a/drivers/scsi/ufs/ufshcd.c
> >> +++ b/drivers/scsi/ufs/ufshcd.c
> >> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba
> >> *hba)
> >> {
> >>  	int err;
> >>
> >> -	err = ufshcd_vops_device_reset(hba);
> >> +	err = ufshcd_vops_toggle_device_reset(hba, true);
> >> +	if (err) {
> >> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
> >> err);
> >> +		return;
> >> +	}
> >> +
> >> +	/*
> >> +	 * The reset signal is active low. The UFS device
> >> +	 * shall detect reset pulses of 1us, sleep for at
> >> +	 * least 10us to be on the safe side.
> >> +	 */
> >> +	usleep_range(10, 15);
> >
> > Is there any point where UFS specification tells this explicitly?
> > I think this should be moved only if the number, i.e. 10 and 15  just
> > relies on hardware conditions.
> >
> >
> > Thanks.
> > Kiwoong Kim
> 
> Hi Kiwoong,
> 
> Thanks for your comment. JESD220E Line 610~611 "The UFS device shall
> detect more than or equal to 1us of positive or negative RST_n pulse".
> Both QCOM and Mediatek use 10~15us. What number do you think more
> appropriate?
> 
> Best Regards,
> Ziqi

With yours, all the SoC vendors should wait for around 10us unconditionally
even if there will be a possibility that some can use shorter period.
I see this as a sort of optimization point.


Thanks.
Kiwoong Kim
> 
> >
> >> +	err = ufshcd_vops_toggle_device_reset(hba, false);
> >>
> >>  	if (!err) {
> >>  		ufshcd_set_ufs_dev_active(hba);
> >> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba
> >> *hba)
> >>  			hba->wb_enabled = false;
> >>  			hba->wb_buf_flush_enabled = false;
> >>  		}
> >> +		dev_info(hba->dev, "device reset done\n");
> >> +	} else {
> >> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
> >> err);
> >>  	}
> >> +
> >>  	if (err != -EOPNOTSUPP)
> >>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
> >> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
> >> ufs_pm_op pm_op)
> >>  	if (ret)
> >>  		goto set_dev_active;
> >>
> >> -	ufshcd_vreg_set_lpm(hba);
> >> -
> >>  disable_clks:
> >>  	/*
> >>  	 * Call vendor specific suspend callback. As these callbacks may
> >> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
> >> *hba, enum ufs_pm_op pm_op)
> >>  	 */
> >>  	ufshcd_disable_irq(hba);
> >>
> >> +	if (ufshcd_is_link_off(hba))
> >> +		ufshcd_vops_toggle_device_reset(hba, true);
> >> +
> >>  	ufshcd_setup_clocks(hba, false);
> >>
> >>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
> >> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> >>  					hba->clk_gating.state);
> >>  	}
> >>
> >> +	ufshcd_vreg_set_lpm(hba);
> >> +
> >>  	/* Put the host controller in low power mode if possible */
> >>  	ufshcd_hba_vreg_set_lpm(hba);
> >>  	goto out;
> >> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba,
> >> enum ufs_pm_op pm_op)
> >>  	old_link_state = hba->uic_link_state;
> >>
> >>  	ufshcd_hba_vreg_set_hpm(hba);
> >> +
> >> +	ret = ufshcd_vreg_set_hpm(hba);
> >> +	if (ret)
> >> +		goto out;
> >> +
> >>  	/* Make sure clocks are enabled before accessing controller */
> >>  	ret = ufshcd_setup_clocks(hba, true);
> >>  	if (ret)
> >> -		goto out;
> >> +		goto disable_vreg;
> >>
> >>  	/* enable the host irq as host controller would be active soon */
> >>  	ufshcd_enable_irq(hba);
> >>
> >> -	ret = ufshcd_vreg_set_hpm(hba);
> >> -	if (ret)
> >> -		goto disable_irq_and_vops_clks;
> >> -
> >>  	/*
> >>  	 * Call vendor specific resume callback. As these callbacks may
> >> access
> >>  	 * vendor specific host controller register space call them when
> >> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba
> >> *hba, enum ufs_pm_op pm_op)
> >>  	 */
> >>  	ret = ufshcd_vops_resume(hba, pm_op);
> >>  	if (ret)
> >> -		goto disable_vreg;
> >> +		goto disable_irq_and_vops_clks;
> >>
> >>  	/* For DeepSleep, the only supported option is to have the link off
> >> */
> >>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
> >> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
> >> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> >>  	ufshcd_link_state_transition(hba, old_link_state, 0);
> >>  vendor_suspend:
> >>  	ufshcd_vops_suspend(hba, pm_op);
> >> -disable_vreg:
> >> -	ufshcd_vreg_set_lpm(hba);
> >>  disable_irq_and_vops_clks:
> >>  	ufshcd_disable_irq(hba);
> >>  	if (hba->clk_scaling.is_allowed)
> >> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
> >> enum ufs_pm_op pm_op)
> >>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
> >>  					hba->clk_gating.state);
> >>  	}
> >> +disable_vreg:
> >> +	ufshcd_vreg_set_lpm(hba);
> >>  out:
> >>  	hba->pm_op_in_progress = 0;
> >>  	if (ret)
> >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> >> index 9bb5f0e..dccc3eb 100644
> >> --- a/drivers/scsi/ufs/ufshcd.h
> >> +++ b/drivers/scsi/ufs/ufshcd.h
> >> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
> >>   * @resume: called during host controller PM callback
> >>   * @dbg_register_dump: used to dump controller debug information
> >>   * @phy_initialization: used to initialize phys
> >> - * @device_reset: called to issue a reset pulse on the UFS device
> >> + * @toggle_device_reset: called to change logic level of reset gpio
> >> on
> >> + the UFS device
> >>   * @program_key: program or evict an inline encryption key
> >>   * @event_notify: called to notify important events
> >>   */
> >> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
> >>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
> >>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
> >>  	int	(*phy_initialization)(struct ufs_hba *);
> >> -	int	(*device_reset)(struct ufs_hba *hba);
> >> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
> >>  	void	(*config_scaling_param)(struct ufs_hba *hba,
> >>  					struct devfreq_dev_profile *profile,
> >>  					void *data);
> >> @@ -1216,10 +1216,10 @@ static inline void
> >> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
> >>  		hba->vops->dbg_register_dump(hba);
> >>  }
> >>
> >> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
> >> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba
> >> *hba,
> >> +bool down)
> >>  {
> >> -	if (hba->vops && hba->vops->device_reset)
> >> -		return hba->vops->device_reset(hba);
> >> +	if (hba->vops && hba->vops->toggle_device_reset)
> >> +		return hba->vops->toggle_device_reset(hba, down);
> >>
> >>  	return -EOPNOTSUPP;
> >>  }
> >> --
> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> >> Forum, a Linux Foundation Collaborative Project


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Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[ziqichen]

On 2020-12-22 14:00, Kiwoong Kim wrote:
>> On 2020-12-22 10:04, Kiwoong Kim wrote:
>> >> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the
>> >> ufs device, RST_N signal and REF_CLK signal should be between
>> >> VSS(Ground) and VCCQ/VCCQ2.
>> >>
>> >> To flexibly control device reset line, re-name the function
>> >> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
>> >> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
>> >> parameter "bool down" is used to separate device reset line pulling
>> >> down from pulling up.
>> >>
>> >> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
>> >> Cc: Stanley Chu <stanley.chu@mediatek.com>
>> >> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
>> >> ---
>> >>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>> >>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>> >>  drivers/scsi/ufs/ufshcd.c       | 43
>> >> ++++++++++++++++++++++++++++++------
>> > --
>> >> ---
>> >>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>> >>  4 files changed, 56 insertions(+), 46 deletions(-)
>> >>
>> >> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
>> >> mediatek.c index 80618af..bff2c42 100644
>> >> --- a/drivers/scsi/ufs/ufs-mediatek.c
>> >> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>> >> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
>> >> ufs_hba *hba,
>> >>  	return ret;
>> >>  }
>> >>
>> >> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
>> >> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool
>> >> down)
>> >>  {
>> >>  	struct arm_smccc_res res;
>> >>
>> >> -	ufs_mtk_device_reset_ctrl(0, res);
>> >> -
>> >> -	/*
>> >> -	 * The reset signal is active low. UFS devices shall detect
>> >> -	 * more than or equal to 1us of positive or negative RST_n
>> >> -	 * pulse width.
>> >> -	 *
>> >> -	 * To be on safe side, keep the reset low for at least 10us.
>> >> -	 */
>> >> -	usleep_range(10, 15);
>> >> -
>> >> -	ufs_mtk_device_reset_ctrl(1, res);
>> >> -
>> >> -	/* Some devices may need time to respond to rst_n */
>> >> -	usleep_range(10000, 15000);
>> >> +	if (down) {
>> >> +		ufs_mtk_device_reset_ctrl(0, res);
>> >> +	} else {
>> >> +		ufs_mtk_device_reset_ctrl(1, res);
>> >>
>> >> -	dev_info(hba->dev, "device reset done\n");
>> >> +		/* Some devices may need time to respond to rst_n */
>> >> +		usleep_range(10000, 15000);
>> >> +	}
>> >>
>> >>  	return 0;
>> >>  }
>> >> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
>> >> ufs_hba_mtk_vops = {
>> >>  	.suspend             = ufs_mtk_suspend,
>> >>  	.resume              = ufs_mtk_resume,
>> >>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
>> >> -	.device_reset        = ufs_mtk_device_reset,
>> >> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>> >>  	.event_notify        = ufs_mtk_event_notify,
>> >>  };
>> >>
>> >> diff --git a/drivers/scsi/ufs/ufs-qcom.c
>> >> b/drivers/scsi/ufs/ufs-qcom.c index 2206b1e..c2ccaa5 100644
>> >> --- a/drivers/scsi/ufs/ufs-qcom.c
>> >> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> >> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct
>> >> ufs_hba
>> >> *hba)  }
>> >>
>> >>  /**
>> >> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
>> >> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device
>> >> reset
>> >> + line
>> >>   * @hba: per-adapter instance
>> >> + * @down: pull down or pull up device reset line
>> >>   *
>> >>   * Toggles the (optional) reset line to reset the attached device.
>> >>   */
>> >> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
>> >> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool
>> >> down)
>> >>  {
>> >>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> >>
>> >> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct
>> >> ufs_hba
>> >> *hba)
>> >>  	if (!host->device_reset)
>> >>  		return -EOPNOTSUPP;
>> >>
>> >> -	/*
>> >> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
>> >> to
>> >> -	 * be on the safe side.
>> >> -	 */
>> >> -	gpiod_set_value_cansleep(host->device_reset, 1);
>> >> -	usleep_range(10, 15);
>> >> -
>> >> -	gpiod_set_value_cansleep(host->device_reset, 0);
>> >> -	usleep_range(10, 15);
>> >> +	if (down) {
>> >> +		gpiod_set_value_cansleep(host->device_reset, 1);
>> >> +	} else {
>> >> +		gpiod_set_value_cansleep(host->device_reset, 0);
>> >> +		usleep_range(10, 15);
>> >> +	}
>> >>
>> >>  	return 0;
>> >>  }
>> >> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
>> >> ufs_hba_qcom_vops = {
>> >>  	.suspend		= ufs_qcom_suspend,
>> >>  	.resume			= ufs_qcom_resume,
>> >>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
>> >> -	.device_reset		= ufs_qcom_device_reset,
>> >> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>> >>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>> >>  	.program_key		= ufs_qcom_ice_program_key,
>> >>  };
>> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> >> index e221add..2ee905f 100644
>> >> --- a/drivers/scsi/ufs/ufshcd.c
>> >> +++ b/drivers/scsi/ufs/ufshcd.c
>> >> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba
>> >> *hba)
>> >> {
>> >>  	int err;
>> >>
>> >> -	err = ufshcd_vops_device_reset(hba);
>> >> +	err = ufshcd_vops_toggle_device_reset(hba, true);
>> >> +	if (err) {
>> >> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
>> >> err);
>> >> +		return;
>> >> +	}
>> >> +
>> >> +	/*
>> >> +	 * The reset signal is active low. The UFS device
>> >> +	 * shall detect reset pulses of 1us, sleep for at
>> >> +	 * least 10us to be on the safe side.
>> >> +	 */
>> >> +	usleep_range(10, 15);
>> >
>> > Is there any point where UFS specification tells this explicitly?
>> > I think this should be moved only if the number, i.e. 10 and 15  just
>> > relies on hardware conditions.
>> >
>> >
>> > Thanks.
>> > Kiwoong Kim
>> 
>> Hi Kiwoong,
>> 
>> Thanks for your comment. JESD220E Line 610~611 "The UFS device shall
>> detect more than or equal to 1us of positive or negative RST_n pulse".
>> Both QCOM and Mediatek use 10~15us. What number do you think more
>> appropriate?
>> 
>> Best Regards,
>> Ziqi
> 
> With yours, all the SoC vendors should wait for around 10us 
> unconditionally
> even if there will be a possibility that some can use shorter period.
> I see this as a sort of optimization point.
> 
> 
> Thanks.
> Kiwoong Kim

Got your point. As it is a controversial delay among different SoC 
vendor, I'll
move it back to vops and handle it by vendor's driver.

Best Regards,
Ziqi
>> 
>> >
>> >> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>> >>
>> >>  	if (!err) {
>> >>  		ufshcd_set_ufs_dev_active(hba);
>> >> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba
>> >> *hba)
>> >>  			hba->wb_enabled = false;
>> >>  			hba->wb_buf_flush_enabled = false;
>> >>  		}
>> >> +		dev_info(hba->dev, "device reset done\n");
>> >> +	} else {
>> >> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
>> >> err);
>> >>  	}
>> >> +
>> >>  	if (err != -EOPNOTSUPP)
>> >>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
>> >> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
>> >> ufs_pm_op pm_op)
>> >>  	if (ret)
>> >>  		goto set_dev_active;
>> >>
>> >> -	ufshcd_vreg_set_lpm(hba);
>> >> -
>> >>  disable_clks:
>> >>  	/*
>> >>  	 * Call vendor specific suspend callback. As these callbacks may
>> >> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
>> >> *hba, enum ufs_pm_op pm_op)
>> >>  	 */
>> >>  	ufshcd_disable_irq(hba);
>> >>
>> >> +	if (ufshcd_is_link_off(hba))
>> >> +		ufshcd_vops_toggle_device_reset(hba, true);
>> >> +
>> >>  	ufshcd_setup_clocks(hba, false);
>> >>
>> >>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
>> >> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>> >>  					hba->clk_gating.state);
>> >>  	}
>> >>
>> >> +	ufshcd_vreg_set_lpm(hba);
>> >> +
>> >>  	/* Put the host controller in low power mode if possible */
>> >>  	ufshcd_hba_vreg_set_lpm(hba);
>> >>  	goto out;
>> >> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba,
>> >> enum ufs_pm_op pm_op)
>> >>  	old_link_state = hba->uic_link_state;
>> >>
>> >>  	ufshcd_hba_vreg_set_hpm(hba);
>> >> +
>> >> +	ret = ufshcd_vreg_set_hpm(hba);
>> >> +	if (ret)
>> >> +		goto out;
>> >> +
>> >>  	/* Make sure clocks are enabled before accessing controller */
>> >>  	ret = ufshcd_setup_clocks(hba, true);
>> >>  	if (ret)
>> >> -		goto out;
>> >> +		goto disable_vreg;
>> >>
>> >>  	/* enable the host irq as host controller would be active soon */
>> >>  	ufshcd_enable_irq(hba);
>> >>
>> >> -	ret = ufshcd_vreg_set_hpm(hba);
>> >> -	if (ret)
>> >> -		goto disable_irq_and_vops_clks;
>> >> -
>> >>  	/*
>> >>  	 * Call vendor specific resume callback. As these callbacks may
>> >> access
>> >>  	 * vendor specific host controller register space call them when
>> >> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba
>> >> *hba, enum ufs_pm_op pm_op)
>> >>  	 */
>> >>  	ret = ufshcd_vops_resume(hba, pm_op);
>> >>  	if (ret)
>> >> -		goto disable_vreg;
>> >> +		goto disable_irq_and_vops_clks;
>> >>
>> >>  	/* For DeepSleep, the only supported option is to have the link off
>> >> */
>> >>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
>> >> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
>> >> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>> >>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>> >>  vendor_suspend:
>> >>  	ufshcd_vops_suspend(hba, pm_op);
>> >> -disable_vreg:
>> >> -	ufshcd_vreg_set_lpm(hba);
>> >>  disable_irq_and_vops_clks:
>> >>  	ufshcd_disable_irq(hba);
>> >>  	if (hba->clk_scaling.is_allowed)
>> >> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
>> >> enum ufs_pm_op pm_op)
>> >>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>> >>  					hba->clk_gating.state);
>> >>  	}
>> >> +disable_vreg:
>> >> +	ufshcd_vreg_set_lpm(hba);
>> >>  out:
>> >>  	hba->pm_op_in_progress = 0;
>> >>  	if (ret)
>> >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> >> index 9bb5f0e..dccc3eb 100644
>> >> --- a/drivers/scsi/ufs/ufshcd.h
>> >> +++ b/drivers/scsi/ufs/ufshcd.h
>> >> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>> >>   * @resume: called during host controller PM callback
>> >>   * @dbg_register_dump: used to dump controller debug information
>> >>   * @phy_initialization: used to initialize phys
>> >> - * @device_reset: called to issue a reset pulse on the UFS device
>> >> + * @toggle_device_reset: called to change logic level of reset gpio
>> >> on
>> >> + the UFS device
>> >>   * @program_key: program or evict an inline encryption key
>> >>   * @event_notify: called to notify important events
>> >>   */
>> >> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>> >>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>> >>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>> >>  	int	(*phy_initialization)(struct ufs_hba *);
>> >> -	int	(*device_reset)(struct ufs_hba *hba);
>> >> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
>> >>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>> >>  					struct devfreq_dev_profile *profile,
>> >>  					void *data);
>> >> @@ -1216,10 +1216,10 @@ static inline void
>> >> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>> >>  		hba->vops->dbg_register_dump(hba);
>> >>  }
>> >>
>> >> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
>> >> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba
>> >> *hba,
>> >> +bool down)
>> >>  {
>> >> -	if (hba->vops && hba->vops->device_reset)
>> >> -		return hba->vops->device_reset(hba);
>> >> +	if (hba->vops && hba->vops->toggle_device_reset)
>> >> +		return hba->vops->toggle_device_reset(hba, down);
>> >>
>> >>  	return -EOPNOTSUPP;
>> >>  }
>> >> --
>> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> >> Forum, a Linux Foundation Collaborative Project

Re: [PATCH RFC v3 1/1] scsi: ufs: Fix ufs power down/on specs violation

[ziqichen]

On 2020-12-22 14:00, Kiwoong Kim wrote:
>> On 2020-12-22 10:04, Kiwoong Kim wrote:
>> >> As per specs, e.g, JESD220E chapter 7.2, while powering off/on the
>> >> ufs device, RST_N signal and REF_CLK signal should be between
>> >> VSS(Ground) and VCCQ/VCCQ2.
>> >>
>> >> To flexibly control device reset line, re-name the function
>> >> ufschd_vops_device_reset(sturct ufs_hba *hba) to ufshcd_
>> >> vops_toggle_device_reset(sturct ufs_hba *hba, bool down). The new
>> >> parameter "bool down" is used to separate device reset line pulling
>> >> down from pulling up.
>> >>
>> >> Cc: Kiwoong Kim <kwmad.kim@samsung.com>
>> >> Cc: Stanley Chu <stanley.chu@mediatek.com>
>> >> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
>> >> ---
>> >>  drivers/scsi/ufs/ufs-mediatek.c | 27 +++++++++-----------------
>> >>  drivers/scsi/ufs/ufs-qcom.c     | 22 ++++++++++-----------
>> >>  drivers/scsi/ufs/ufshcd.c       | 43
>> >> ++++++++++++++++++++++++++++++------
>> > --
>> >> ---
>> >>  drivers/scsi/ufs/ufshcd.h       | 10 +++++-----
>> >>  4 files changed, 56 insertions(+), 46 deletions(-)
>> >>
>> >> diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-
>> >> mediatek.c index 80618af..bff2c42 100644
>> >> --- a/drivers/scsi/ufs/ufs-mediatek.c
>> >> +++ b/drivers/scsi/ufs/ufs-mediatek.c
>> >> @@ -841,27 +841,18 @@ static int ufs_mtk_link_startup_notify(struct
>> >> ufs_hba *hba,
>> >>  	return ret;
>> >>  }
>> >>
>> >> -static int ufs_mtk_device_reset(struct ufs_hba *hba)
>> >> +static int ufs_mtk_toggle_device_reset(struct ufs_hba *hba, bool
>> >> down)
>> >>  {
>> >>  	struct arm_smccc_res res;
>> >>
>> >> -	ufs_mtk_device_reset_ctrl(0, res);
>> >> -
>> >> -	/*
>> >> -	 * The reset signal is active low. UFS devices shall detect
>> >> -	 * more than or equal to 1us of positive or negative RST_n
>> >> -	 * pulse width.
>> >> -	 *
>> >> -	 * To be on safe side, keep the reset low for at least 10us.
>> >> -	 */
>> >> -	usleep_range(10, 15);
>> >> -
>> >> -	ufs_mtk_device_reset_ctrl(1, res);
>> >> -
>> >> -	/* Some devices may need time to respond to rst_n */
>> >> -	usleep_range(10000, 15000);
>> >> +	if (down) {
>> >> +		ufs_mtk_device_reset_ctrl(0, res);
>> >> +	} else {
>> >> +		ufs_mtk_device_reset_ctrl(1, res);
>> >>
>> >> -	dev_info(hba->dev, "device reset done\n");
>> >> +		/* Some devices may need time to respond to rst_n */
>> >> +		usleep_range(10000, 15000);
>> >> +	}
>> >>
>> >>  	return 0;
>> >>  }
>> >> @@ -1052,7 +1043,7 @@ static const struct ufs_hba_variant_ops
>> >> ufs_hba_mtk_vops = {
>> >>  	.suspend             = ufs_mtk_suspend,
>> >>  	.resume              = ufs_mtk_resume,
>> >>  	.dbg_register_dump   = ufs_mtk_dbg_register_dump,
>> >> -	.device_reset        = ufs_mtk_device_reset,
>> >> +	.toggle_device_reset        = ufs_mtk_toggle_device_reset,
>> >>  	.event_notify        = ufs_mtk_event_notify,
>> >>  };
>> >>
>> >> diff --git a/drivers/scsi/ufs/ufs-qcom.c
>> >> b/drivers/scsi/ufs/ufs-qcom.c index 2206b1e..c2ccaa5 100644
>> >> --- a/drivers/scsi/ufs/ufs-qcom.c
>> >> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> >> @@ -1404,12 +1404,13 @@ static void ufs_qcom_dump_dbg_regs(struct
>> >> ufs_hba
>> >> *hba)  }
>> >>
>> >>  /**
>> >> - * ufs_qcom_device_reset() - toggle the (optional) device reset line
>> >> + * ufs_qcom_toggle_device_reset() - toggle the (optional) device
>> >> reset
>> >> + line
>> >>   * @hba: per-adapter instance
>> >> + * @down: pull down or pull up device reset line
>> >>   *
>> >>   * Toggles the (optional) reset line to reset the attached device.
>> >>   */
>> >> -static int ufs_qcom_device_reset(struct ufs_hba *hba)
>> >> +static int ufs_qcom_toggle_device_reset(struct ufs_hba *hba, bool
>> >> down)
>> >>  {
>> >>  	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> >>
>> >> @@ -1417,15 +1418,12 @@ static int ufs_qcom_device_reset(struct
>> >> ufs_hba
>> >> *hba)
>> >>  	if (!host->device_reset)
>> >>  		return -EOPNOTSUPP;
>> >>
>> >> -	/*
>> >> -	 * The UFS device shall detect reset pulses of 1us, sleep for 10us
>> >> to
>> >> -	 * be on the safe side.
>> >> -	 */
>> >> -	gpiod_set_value_cansleep(host->device_reset, 1);
>> >> -	usleep_range(10, 15);
>> >> -
>> >> -	gpiod_set_value_cansleep(host->device_reset, 0);
>> >> -	usleep_range(10, 15);
>> >> +	if (down) {
>> >> +		gpiod_set_value_cansleep(host->device_reset, 1);
>> >> +	} else {
>> >> +		gpiod_set_value_cansleep(host->device_reset, 0);
>> >> +		usleep_range(10, 15);
>> >> +	}
>> >>
>> >>  	return 0;
>> >>  }
>> >> @@ -1473,7 +1471,7 @@ static const struct ufs_hba_variant_ops
>> >> ufs_hba_qcom_vops = {
>> >>  	.suspend		= ufs_qcom_suspend,
>> >>  	.resume			= ufs_qcom_resume,
>> >>  	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
>> >> -	.device_reset		= ufs_qcom_device_reset,
>> >> +	.toggle_device_reset		= ufs_qcom_toggle_device_reset,
>> >>  	.config_scaling_param = ufs_qcom_config_scaling_param,
>> >>  	.program_key		= ufs_qcom_ice_program_key,
>> >>  };
>> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> >> index e221add..2ee905f 100644
>> >> --- a/drivers/scsi/ufs/ufshcd.c
>> >> +++ b/drivers/scsi/ufs/ufshcd.c
>> >> @@ -585,7 +585,20 @@ static void ufshcd_device_reset(struct ufs_hba
>> >> *hba)
>> >> {
>> >>  	int err;
>> >>
>> >> -	err = ufshcd_vops_device_reset(hba);
>> >> +	err = ufshcd_vops_toggle_device_reset(hba, true);
>> >> +	if (err) {
>> >> +		dev_err(hba->dev, "device reset pulling down failure: %d\n",
>> >> err);
>> >> +		return;
>> >> +	}
>> >> +
>> >> +	/*
>> >> +	 * The reset signal is active low. The UFS device
>> >> +	 * shall detect reset pulses of 1us, sleep for at
>> >> +	 * least 10us to be on the safe side.
>> >> +	 */
>> >> +	usleep_range(10, 15);
>> >
>> > Is there any point where UFS specification tells this explicitly?
>> > I think this should be moved only if the number, i.e. 10 and 15  just
>> > relies on hardware conditions.
>> >
>> >
>> > Thanks.
>> > Kiwoong Kim
>> 
>> Hi Kiwoong,
>> 
>> Thanks for your comment. JESD220E Line 610~611 "The UFS device shall
>> detect more than or equal to 1us of positive or negative RST_n pulse".
>> Both QCOM and Mediatek use 10~15us. What number do you think more
>> appropriate?
>> 
>> Best Regards,
>> Ziqi
> 
> With yours, all the SoC vendors should wait for around 10us 
> unconditionally
> even if there will be a possibility that some can use shorter period.
> I see this as a sort of optimization point.
> 
> 
> Thanks.
> Kiwoong Kim

Got your point. As it is a controversial delay among different SoC 
vendor, I'll
move it back to vops and handle it by vendor's driver.

Best Regards,
Ziqi
>> 
>> >
>> >> +	err = ufshcd_vops_toggle_device_reset(hba, false);
>> >>
>> >>  	if (!err) {
>> >>  		ufshcd_set_ufs_dev_active(hba);
>> >> @@ -593,7 +606,11 @@ static void ufshcd_device_reset(struct ufs_hba
>> >> *hba)
>> >>  			hba->wb_enabled = false;
>> >>  			hba->wb_buf_flush_enabled = false;
>> >>  		}
>> >> +		dev_info(hba->dev, "device reset done\n");
>> >> +	} else {
>> >> +		dev_err(hba->dev, "device reset pulling up failure: %d\n",
>> >> err);
>> >>  	}
>> >> +
>> >>  	if (err != -EOPNOTSUPP)
>> >>  		ufshcd_update_evt_hist(hba, UFS_EVT_DEV_RESET, err);  } @@ -
>> >> 8686,8 +8703,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum
>> >> ufs_pm_op pm_op)
>> >>  	if (ret)
>> >>  		goto set_dev_active;
>> >>
>> >> -	ufshcd_vreg_set_lpm(hba);
>> >> -
>> >>  disable_clks:
>> >>  	/*
>> >>  	 * Call vendor specific suspend callback. As these callbacks may
>> >> access @@ -8703,6 +8718,9 @@ static int ufshcd_suspend(struct ufs_hba
>> >> *hba, enum ufs_pm_op pm_op)
>> >>  	 */
>> >>  	ufshcd_disable_irq(hba);
>> >>
>> >> +	if (ufshcd_is_link_off(hba))
>> >> +		ufshcd_vops_toggle_device_reset(hba, true);
>> >> +
>> >>  	ufshcd_setup_clocks(hba, false);
>> >>
>> >>  	if (ufshcd_is_clkgating_allowed(hba)) { @@ -8711,6 +8729,8 @@
>> >> static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>> >>  					hba->clk_gating.state);
>> >>  	}
>> >>
>> >> +	ufshcd_vreg_set_lpm(hba);
>> >> +
>> >>  	/* Put the host controller in low power mode if possible */
>> >>  	ufshcd_hba_vreg_set_lpm(hba);
>> >>  	goto out;
>> >> @@ -8778,18 +8798,19 @@ static int ufshcd_resume(struct ufs_hba *hba,
>> >> enum ufs_pm_op pm_op)
>> >>  	old_link_state = hba->uic_link_state;
>> >>
>> >>  	ufshcd_hba_vreg_set_hpm(hba);
>> >> +
>> >> +	ret = ufshcd_vreg_set_hpm(hba);
>> >> +	if (ret)
>> >> +		goto out;
>> >> +
>> >>  	/* Make sure clocks are enabled before accessing controller */
>> >>  	ret = ufshcd_setup_clocks(hba, true);
>> >>  	if (ret)
>> >> -		goto out;
>> >> +		goto disable_vreg;
>> >>
>> >>  	/* enable the host irq as host controller would be active soon */
>> >>  	ufshcd_enable_irq(hba);
>> >>
>> >> -	ret = ufshcd_vreg_set_hpm(hba);
>> >> -	if (ret)
>> >> -		goto disable_irq_and_vops_clks;
>> >> -
>> >>  	/*
>> >>  	 * Call vendor specific resume callback. As these callbacks may
>> >> access
>> >>  	 * vendor specific host controller register space call them when
>> >> the @@ -8797,7 +8818,7 @@ static int ufshcd_resume(struct ufs_hba
>> >> *hba, enum ufs_pm_op pm_op)
>> >>  	 */
>> >>  	ret = ufshcd_vops_resume(hba, pm_op);
>> >>  	if (ret)
>> >> -		goto disable_vreg;
>> >> +		goto disable_irq_and_vops_clks;
>> >>
>> >>  	/* For DeepSleep, the only supported option is to have the link off
>> >> */
>> >>  	WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba)
>> >> && !ufshcd_is_link_off(hba)); @@ -8864,8 +8885,6 @@ static int
>> >> ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
>> >>  	ufshcd_link_state_transition(hba, old_link_state, 0);
>> >>  vendor_suspend:
>> >>  	ufshcd_vops_suspend(hba, pm_op);
>> >> -disable_vreg:
>> >> -	ufshcd_vreg_set_lpm(hba);
>> >>  disable_irq_and_vops_clks:
>> >>  	ufshcd_disable_irq(hba);
>> >>  	if (hba->clk_scaling.is_allowed)
>> >> @@ -8876,6 +8895,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
>> >> enum ufs_pm_op pm_op)
>> >>  		trace_ufshcd_clk_gating(dev_name(hba->dev),
>> >>  					hba->clk_gating.state);
>> >>  	}
>> >> +disable_vreg:
>> >> +	ufshcd_vreg_set_lpm(hba);
>> >>  out:
>> >>  	hba->pm_op_in_progress = 0;
>> >>  	if (ret)
>> >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
>> >> index 9bb5f0e..dccc3eb 100644
>> >> --- a/drivers/scsi/ufs/ufshcd.h
>> >> +++ b/drivers/scsi/ufs/ufshcd.h
>> >> @@ -319,7 +319,7 @@ struct ufs_pwr_mode_info {
>> >>   * @resume: called during host controller PM callback
>> >>   * @dbg_register_dump: used to dump controller debug information
>> >>   * @phy_initialization: used to initialize phys
>> >> - * @device_reset: called to issue a reset pulse on the UFS device
>> >> + * @toggle_device_reset: called to change logic level of reset gpio
>> >> on
>> >> + the UFS device
>> >>   * @program_key: program or evict an inline encryption key
>> >>   * @event_notify: called to notify important events
>> >>   */
>> >> @@ -350,7 +350,7 @@ struct ufs_hba_variant_ops {
>> >>  	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
>> >>  	void	(*dbg_register_dump)(struct ufs_hba *hba);
>> >>  	int	(*phy_initialization)(struct ufs_hba *);
>> >> -	int	(*device_reset)(struct ufs_hba *hba);
>> >> +	int	(*toggle_device_reset)(struct ufs_hba *hba, bool down);
>> >>  	void	(*config_scaling_param)(struct ufs_hba *hba,
>> >>  					struct devfreq_dev_profile *profile,
>> >>  					void *data);
>> >> @@ -1216,10 +1216,10 @@ static inline void
>> >> ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
>> >>  		hba->vops->dbg_register_dump(hba);
>> >>  }
>> >>
>> >> -static inline int ufshcd_vops_device_reset(struct ufs_hba *hba)
>> >> +static inline int ufshcd_vops_toggle_device_reset(struct ufs_hba
>> >> *hba,
>> >> +bool down)
>> >>  {
>> >> -	if (hba->vops && hba->vops->device_reset)
>> >> -		return hba->vops->device_reset(hba);
>> >> +	if (hba->vops && hba->vops->toggle_device_reset)
>> >> +		return hba->vops->toggle_device_reset(hba, down);
>> >>
>> >>  	return -EOPNOTSUPP;
>> >>  }
>> >> --
>> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> >> Forum, a Linux Foundation Collaborative Project

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