Re: [PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation

2020-12-09 Thread Can Guo

On 2020-12-09 15:09, 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.

Power down:
1. Assert RST_N low
2. Turn-off REF_CLK
3. Turn-off VCC
4. Turn-off VCCQ/VCCQ2.
power on:
1. Turn-on VCC
2. Turn-on VCCQ/VCCQ2
3. Turn-On REF_CLK
4. Deassert RST_N high.

Signed-off-by: Ziqi Chen 
---
 drivers/scsi/ufs/ufs-qcom.c | 14 ++
 drivers/scsi/ufs/ufshcd.c   | 19 +--
 drivers/scsi/ufs/ufshcd.h   |  4 ++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 1e434cc..5ed3a63d 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -582,6 +582,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
ufs_qcom_disable_lane_clks(host);
phy_power_off(phy);

+   if (hba->vops && hba->vops->device_reset)
+   hba->vops->device_reset(hba, false);
+
} else if (!ufs_qcom_is_link_active(hba)) {
ufs_qcom_disable_lane_clks(host);
}
@@ -1400,10 +1403,11 @@ static void ufs_qcom_dump_dbg_regs(struct 
ufs_hba *hba)

 /**
  * ufs_qcom_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @toggle: need pulling up or not
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_device_reset(struct ufs_hba *hba, bool toggle)
 {
struct ufs_qcom_host *host = ufshcd_get_variant(hba);

@@ -1416,10 +1420,12 @@ static int ufs_qcom_device_reset(struct ufs_hba 
*hba)

 * 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 (toggle) {
+   usleep_range(10, 15);
+   gpiod_set_value_cansleep(host->device_reset, 0);
+   usleep_range(10, 15);
+   }

return 0;
 }
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 92d433d..5ab1c02 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8633,8 +8633,6 @@ 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

@@ -8664,6 +8662,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)

/* Put the host controller in low power mode if possible */
ufshcd_hba_vreg_set_lpm(hba);
+   ufshcd_vreg_set_lpm(hba);
goto out;

 set_link_active:
@@ -8729,18 +8728,18 @@ 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
@@ -8748,7 +8747,7 @@ 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));

@@ -8815,8 +8814,6 @@ 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)
@@ -8827,6 +8824,8 @@ 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 61344c4..47c7dab6 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -323,7 +323,7 @@ 

Re: [PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation

2020-12-08 Thread ziqichen



Hi Can,

On 2020-12-09 15:27, Can Guo wrote:

On 2020-12-09 15:09, 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.

Power down:
1. Assert RST_N low
2. Turn-off REF_CLK
3. Turn-off VCC
4. Turn-off VCCQ/VCCQ2.
power on:
1. Turn-on VCC
2. Turn-on VCCQ/VCCQ2
3. Turn-On REF_CLK
4. Deassert RST_N high.

Signed-off-by: Ziqi Chen 
---
 drivers/scsi/ufs/ufs-qcom.c | 14 ++
 drivers/scsi/ufs/ufshcd.c   | 19 +--
 drivers/scsi/ufs/ufshcd.h   |  4 ++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 1e434cc..5ed3a63d 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -582,6 +582,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
ufs_qcom_disable_lane_clks(host);
phy_power_off(phy);

+   if (hba->vops && hba->vops->device_reset)
+   hba->vops->device_reset(hba, false);
+


Instead of doing the pull-down in ufshcd_vops_suspend(), can we do
it in ufshcd_suspend()? Since it is a common problem for all soc
vendors.


Sure, agree, Thanks.




} else if (!ufs_qcom_is_link_active(hba)) {
ufs_qcom_disable_lane_clks(host);
}
@@ -1400,10 +1403,11 @@ static void ufs_qcom_dump_dbg_regs(struct 
ufs_hba *hba)

 /**
  * ufs_qcom_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @toggle: need pulling up or not
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_device_reset(struct ufs_hba *hba, bool toggle)
 {
struct ufs_qcom_host *host = ufshcd_get_variant(hba);

@@ -1416,10 +1420,12 @@ static int ufs_qcom_device_reset(struct 
ufs_hba *hba)

 * 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 (toggle) {
+   usleep_range(10, 15);
+   gpiod_set_value_cansleep(host->device_reset, 0);
+   usleep_range(10, 15);
+   }

return 0;
 }
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 92d433d..5ab1c02 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8633,8 +8633,6 @@ 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

@@ -8664,6 +8662,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)

/* Put the host controller in low power mode if possible */
ufshcd_hba_vreg_set_lpm(hba);
+   ufshcd_vreg_set_lpm(hba);


Can you put ufshcd_vreg_set_lpm() before ufshcd_hba_vreg_set_lpm()?


Sure, thanks.




goto out;

 set_link_active:
@@ -8729,18 +8728,18 @@ 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
@@ -8748,7 +8747,7 @@ 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));

@@ -8815,8 +8814,6 @@ 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)
@@ -8827,6 +8824,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
trace_ufshcd_clk_gating(dev_name(hba->dev),

Re: [PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation

2020-12-08 Thread Can Guo

On 2020-12-09 15:09, 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.

Power down:
1. Assert RST_N low
2. Turn-off REF_CLK
3. Turn-off VCC
4. Turn-off VCCQ/VCCQ2.
power on:
1. Turn-on VCC
2. Turn-on VCCQ/VCCQ2
3. Turn-On REF_CLK
4. Deassert RST_N high.

Signed-off-by: Ziqi Chen 
---
 drivers/scsi/ufs/ufs-qcom.c | 14 ++
 drivers/scsi/ufs/ufshcd.c   | 19 +--
 drivers/scsi/ufs/ufshcd.h   |  4 ++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 1e434cc..5ed3a63d 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -582,6 +582,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
ufs_qcom_disable_lane_clks(host);
phy_power_off(phy);

+   if (hba->vops && hba->vops->device_reset)
+   hba->vops->device_reset(hba, false);
+


Instead of doing the pull-down in ufshcd_vops_suspend(), can we do
it in ufshcd_suspend()? Since it is a common problem for all soc
vendors.


} else if (!ufs_qcom_is_link_active(hba)) {
ufs_qcom_disable_lane_clks(host);
}
@@ -1400,10 +1403,11 @@ static void ufs_qcom_dump_dbg_regs(struct 
ufs_hba *hba)

 /**
  * ufs_qcom_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @toggle: need pulling up or not
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_device_reset(struct ufs_hba *hba, bool toggle)
 {
struct ufs_qcom_host *host = ufshcd_get_variant(hba);

@@ -1416,10 +1420,12 @@ static int ufs_qcom_device_reset(struct ufs_hba 
*hba)

 * 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 (toggle) {
+   usleep_range(10, 15);
+   gpiod_set_value_cansleep(host->device_reset, 0);
+   usleep_range(10, 15);
+   }

return 0;
 }
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 92d433d..5ab1c02 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8633,8 +8633,6 @@ 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

@@ -8664,6 +8662,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)

/* Put the host controller in low power mode if possible */
ufshcd_hba_vreg_set_lpm(hba);
+   ufshcd_vreg_set_lpm(hba);


Can you put ufshcd_vreg_set_lpm() before ufshcd_hba_vreg_set_lpm()?


goto out;

 set_link_active:
@@ -8729,18 +8728,18 @@ 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
@@ -8748,7 +8747,7 @@ 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));

@@ -8815,8 +8814,6 @@ 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)
@@ -8827,6 +8824,8 @@ 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:

Re: [PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation

2020-12-08 Thread Can Guo

On 2020-12-09 15:09, 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.

Power down:
1. Assert RST_N low
2. Turn-off REF_CLK
3. Turn-off VCC
4. Turn-off VCCQ/VCCQ2.
power on:
1. Turn-on VCC
2. Turn-on VCCQ/VCCQ2
3. Turn-On REF_CLK
4. Deassert RST_N high.

Signed-off-by: Ziqi Chen 
---
 drivers/scsi/ufs/ufs-qcom.c | 14 ++
 drivers/scsi/ufs/ufshcd.c   | 19 +--
 drivers/scsi/ufs/ufshcd.h   |  4 ++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 1e434cc..5ed3a63d 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -582,6 +582,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
ufs_qcom_disable_lane_clks(host);
phy_power_off(phy);

+   if (hba->vops && hba->vops->device_reset)
+   hba->vops->device_reset(hba, false);
+


Can you make a new wrapper func to do this? ufs-qcom.c is the vendor
driver, why call hba->vops->func() in vendor driver?


} else if (!ufs_qcom_is_link_active(hba)) {
ufs_qcom_disable_lane_clks(host);
}
@@ -1400,10 +1403,11 @@ static void ufs_qcom_dump_dbg_regs(struct 
ufs_hba *hba)

 /**
  * ufs_qcom_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @toggle: need pulling up or not
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_device_reset(struct ufs_hba *hba, bool toggle)
 {
struct ufs_qcom_host *host = ufshcd_get_variant(hba);

@@ -1416,10 +1420,12 @@ static int ufs_qcom_device_reset(struct ufs_hba 
*hba)

 * 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 (toggle) {
+   usleep_range(10, 15);
+   gpiod_set_value_cansleep(host->device_reset, 0);
+   usleep_range(10, 15);
+   }

return 0;
 }
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 92d433d..5ab1c02 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8633,8 +8633,6 @@ 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

@@ -8664,6 +8662,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)

/* Put the host controller in low power mode if possible */
ufshcd_hba_vreg_set_lpm(hba);
+   ufshcd_vreg_set_lpm(hba);
goto out;

 set_link_active:
@@ -8729,18 +8728,18 @@ 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
@@ -8748,7 +8747,7 @@ 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));

@@ -8815,8 +8814,6 @@ 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)
@@ -8827,6 +8824,8 @@ 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 

[PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation

2020-12-08 Thread 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.

Power down:
1. Assert RST_N low
2. Turn-off REF_CLK
3. Turn-off VCC
4. Turn-off VCCQ/VCCQ2.
power on:
1. Turn-on VCC
2. Turn-on VCCQ/VCCQ2
3. Turn-On REF_CLK
4. Deassert RST_N high.

Signed-off-by: Ziqi Chen 
---
 drivers/scsi/ufs/ufs-qcom.c | 14 ++
 drivers/scsi/ufs/ufshcd.c   | 19 +--
 drivers/scsi/ufs/ufshcd.h   |  4 ++--
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 1e434cc..5ed3a63d 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -582,6 +582,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba, enum 
ufs_pm_op pm_op)
ufs_qcom_disable_lane_clks(host);
phy_power_off(phy);
 
+   if (hba->vops && hba->vops->device_reset)
+   hba->vops->device_reset(hba, false);
+
} else if (!ufs_qcom_is_link_active(hba)) {
ufs_qcom_disable_lane_clks(host);
}
@@ -1400,10 +1403,11 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
 /**
  * ufs_qcom_device_reset() - toggle the (optional) device reset line
  * @hba: per-adapter instance
+ * @toggle: need pulling up or not
  *
  * Toggles the (optional) reset line to reset the attached device.
  */
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_device_reset(struct ufs_hba *hba, bool toggle)
 {
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 
@@ -1416,10 +1420,12 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
 * 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 (toggle) {
+   usleep_range(10, 15);
+   gpiod_set_value_cansleep(host->device_reset, 0);
+   usleep_range(10, 15);
+   }
 
return 0;
 }
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 92d433d..5ab1c02 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8633,8 +8633,6 @@ 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
@@ -8664,6 +8662,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum 
ufs_pm_op pm_op)
 
/* Put the host controller in low power mode if possible */
ufshcd_hba_vreg_set_lpm(hba);
+   ufshcd_vreg_set_lpm(hba);
goto out;
 
 set_link_active:
@@ -8729,18 +8728,18 @@ 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
@@ -8748,7 +8747,7 @@ 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));
@@ -8815,8 +8814,6 @@ 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)
@@ -8827,6 +8824,8 @@ 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 61344c4..47c7dab6 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -323,7 +323,7 @@ struct