[PATCH v5 0/2] Two changes to fix ufs power down/on specs violation

[PATCH v5 0/2] Two changes to fix ufs power down/on specs violation

[Ziqi Chen]

This series is made based on 5.11-scsi-staging branch.

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. The sequence after fixing as below:

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.

The 1st change let ref-clk to be disabled before VCC & VCCQ turning off while to be enabled after VCC & VCCQ turning on.
The 2nd change is used to pull down RST_n during UFS power off.

Change since v4:
- Split the original change "scsi: ufs: Fix ufs power down/on specs violation" into two changes, one fixs clk specs violation and the other one fixs RST_n specs violation.
- The 2nd change is just only for QCOM platform.

Change since v3:
- Rename vops callback func toggle_device_reset(sturct ufs_hba *hba, bool down) to device_reset(sturct ufs_hba *hba, bool assert).
- Move the dealy after pulling donw RST_n back into vops. 

Change since v2:
- Correct commit message.

Change since v1:
- Rename vops callback func device_reset(sturct ufs_hba *hba) to toggle_device_reset(sturct ufs_hba *hba, bool down) to fix this specs violation for all SoC vendors platform. 

Ziqi Chen (2):
  scsi: ufs: Fix ufs clk specs violation
  scsi: ufs-qcom: Fix ufs RST_n specs violation

 drivers/scsi/ufs/ufs-qcom.c |  4 ++++
 drivers/scsi/ufs/ufshcd.c   | 20 ++++++++++----------
 2 files changed, 14 insertions(+), 10 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v5 1/2] scsi: ufs: Fix ufs clk specs violation

[Ziqi Chen]

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

Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e221add..3f807f7 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8686,8 +8686,6 @@ 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
@@ -8711,6 +8709,8 @@ 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 +8778,18 @@ 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
@@ -8797,7 +8797,7 @@ 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 +8864,6 @@ 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 +8874,8 @@ 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)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v5 1/2] scsi: ufs: Fix ufs clk specs violation

[Can Guo]

On 2021-01-08 15:28, Ziqi Chen wrote:
> As per specs, e.g, JESD220E chapter 7.2, while powering
> off/on the ufs device, REF_CLK signal should be between
> VSS(Ground) and VCCQ/VCCQ2.
> 
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>

Reviewed-by: Can Guo <cang@codeaurora.org>

> ---
>  drivers/scsi/ufs/ufshcd.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index e221add..3f807f7 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -8686,8 +8686,6 @@ 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
> @@ -8711,6 +8709,8 @@ 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 +8778,18 @@ 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
> @@ -8797,7 +8797,7 @@ 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 +8864,6 @@ 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 +8874,8 @@ 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)

[PATCH v5 2/2] scsi: ufs-qcom: Fix ufs RST_n specs violation

[Ziqi Chen]

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

Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
---
 drivers/scsi/ufs/ufs-qcom.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 2206b1e..d8b896c 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -582,6 +582,10 @@ 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);
 
+		/* reset the connected UFS device during power down */
+		if (host->device_reset)
+			gpiod_set_value_cansleep(host->device_reset, 1);
+
 	} else if (!ufs_qcom_is_link_active(hba)) {
 		ufs_qcom_disable_lane_clks(host);
 	}
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v5 2/2] scsi: ufs-qcom: Fix ufs RST_n specs violation

[Can Guo]

On 2021-01-08 15:28, Ziqi Chen wrote:
> As per specs, e.g, JESD220E chapter 7.2, while powering
> off/on the ufs device, RST_n signal should be between
> VSS(Ground) and VCCQ/VCCQ2.
> 
> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-qcom.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2206b1e..d8b896c 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -582,6 +582,10 @@ 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);
> 
> +		/* reset the connected UFS device during power down */
> +		if (host->device_reset)
> +			gpiod_set_value_cansleep(host->device_reset, 1);
> +

Instead of calling gpiod_set_value(1/0) directly,
can we have a wrapper func for it?

Thanks,
Can Guo.

>  	} else if (!ufs_qcom_is_link_active(hba)) {
>  		ufs_qcom_disable_lane_clks(host);
>  	}

Re: [PATCH v5 2/2] scsi: ufs-qcom: Fix ufs RST_n specs violation

[ziqichen]

On 2021-01-08 16:05, Can Guo wrote:
> On 2021-01-08 15:28, Ziqi Chen wrote:
>> As per specs, e.g, JESD220E chapter 7.2, while powering
>> off/on the ufs device, RST_n signal should be between
>> VSS(Ground) and VCCQ/VCCQ2.
>> 
>> Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>
>> ---
>>  drivers/scsi/ufs/ufs-qcom.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>> 
>> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
>> index 2206b1e..d8b896c 100644
>> --- a/drivers/scsi/ufs/ufs-qcom.c
>> +++ b/drivers/scsi/ufs/ufs-qcom.c
>> @@ -582,6 +582,10 @@ 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);
>> 
>> +		/* reset the connected UFS device during power down */
>> +		if (host->device_reset)
>> +			gpiod_set_value_cansleep(host->device_reset, 1);
>> +
> 
> Instead of calling gpiod_set_value(1/0) directly,
> can we have a wrapper func for it?
> 
> Thanks,
> Can Guo.

Sure, it'll be better that way.

Best Regards,
Ziqi

> 
>>  	} else if (!ufs_qcom_is_link_active(hba)) {
>>  		ufs_qcom_disable_lane_clks(host);
>>  	}