[PATCH V2] scsi: ufs: core: Let delay value after LPM can be modified by vendor

[PATCH V2] scsi: ufs: core: Let delay value after LPM can be modified by vendor

[Zhe Wang]

From: Zhe Wang <zhe.wang1@unisoc.com>

Some UFS devices require that the VCC should drop below 0.1V after
turning off, otherwise device may not resume successfully. And
because the power-off rate is different on different SOC platforms.
Therefore, we hope that the delay can be modified by vendor to
adjust the most appropriate delay value.

Signed-off-by: Zhe Wang <zhe.wang1@unisoc.com>
---
V1 -> V2
- move turnoff_delay_us to struct ufs_vreg instead
- replace usleep_range with ufshcd_delay_us

 drivers/ufs/core/ufshcd.c | 9 ++++++++-
 include/ufs/ufs.h         | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 7256e6c43ca6..386ff6ed2f20 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -89,6 +89,9 @@
 /* Polling time to wait for fDeviceInit */
 #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
 
+/* Default value of turn off VCC rail: 5000us */
+#define UFS_VCC_TURNOFF_DELAY_US 5000
+
 #define ufshcd_toggle_vreg(_dev, _vreg, _on)				\
 	({                                                              \
 		int _ret;                                               \
@@ -7784,6 +7787,10 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
 
 	ufs_fixup_device_setup(hba);
 
+	if (hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM &&
+	    !hba->vreg_info.vcc->turnoff_delay_us)
+		hba->vreg_info.vcc->turnoff_delay_us = UFS_VCC_TURNOFF_DELAY_US;
+
 	ufshcd_wb_probe(hba, desc_buf);
 
 	ufshcd_temp_notif_probe(hba, desc_buf);
@@ -8918,7 +8925,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba)
 	 */
 	if (vcc_off && hba->vreg_info.vcc &&
 		hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM)
-		usleep_range(5000, 5100);
+		ufshcd_delay_us(hba->vreg_info.vcc->turnoff_delay_us, 100);
 }
 
 #ifdef CONFIG_PM
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index 1bba3fead2ce..792335dfd70b 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -569,6 +569,7 @@ struct ufs_vreg {
 	bool always_on;
 	bool enabled;
 	int max_uA;
+	u32 turnoff_delay_us;
 };
 
 struct ufs_vreg_info {
-- 
2.17.1

RE: [PATCH V2] scsi: ufs: core: Let delay value after LPM can be modified by vendor

[Avri Altman]

> From: Zhe Wang <zhe.wang1@unisoc.com>
> 
> Some UFS devices require that the VCC should drop below 0.1V after
> turning off, otherwise device may not resume successfully. And
> because the power-off rate is different on different SOC platforms.
> Therefore, we hope that the delay can be modified by vendor to
> adjust the most appropriate delay value.
> 
> Signed-off-by: Zhe Wang <zhe.wang1@unisoc.com>
> ---
> V1 -> V2
> - move turnoff_delay_us to struct ufs_vreg instead
> - replace usleep_range with ufshcd_delay_us
> 
>  drivers/ufs/core/ufshcd.c | 9 ++++++++-
>  include/ufs/ufs.h         | 1 +
>  2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 7256e6c43ca6..386ff6ed2f20 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -89,6 +89,9 @@
>  /* Polling time to wait for fDeviceInit */
>  #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
> 
> +/* Default value of turn off VCC rail: 5000us */
> +#define UFS_VCC_TURNOFF_DELAY_US 5000
> +
>  #define ufshcd_toggle_vreg(_dev, _vreg, _on)                           \
>         ({                                                              \
>                 int _ret;                                               \
> @@ -7784,6 +7787,10 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
> 
>         ufs_fixup_device_setup(hba);
> 
> +       if (hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM &&
> +           !hba->vreg_info.vcc->turnoff_delay_us)
> +               hba->vreg_info.vcc->turnoff_delay_us =
> UFS_VCC_TURNOFF_DELAY_US;
> +
You answered my question to your v1 - where otherwise you are setting this value:
"We are still preparing and discussing our own UFS host driver code,
which will be uploaded once we are done."

Well until then - this isn't very useful.

Thanks,
Avri

>         ufshcd_wb_probe(hba, desc_buf);
> 
>         ufshcd_temp_notif_probe(hba, desc_buf);
> @@ -8918,7 +8925,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba)
>          */
>         if (vcc_off && hba->vreg_info.vcc &&
>                 hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM)
> -               usleep_range(5000, 5100);
> +               ufshcd_delay_us(hba->vreg_info.vcc->turnoff_delay_us, 100);
>  }
> 
>  #ifdef CONFIG_PM
> diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
> index 1bba3fead2ce..792335dfd70b 100644
> --- a/include/ufs/ufs.h
> +++ b/include/ufs/ufs.h
> @@ -569,6 +569,7 @@ struct ufs_vreg {
>         bool always_on;
>         bool enabled;
>         int max_uA;
> +       u32 turnoff_delay_us;
>  };
> 
>  struct ufs_vreg_info {
> --
> 2.17.1

Re: [PATCH V2] scsi: ufs: core: Let delay value after LPM can be modified by vendor

[Zhe Wang]

> > From: Zhe Wang <zhe.wang1@unisoc.com>
> >
> > Some UFS devices require that the VCC should drop below 0.1V after
> > turning off, otherwise device may not resume successfully. And
> > because the power-off rate is different on different SOC platforms.
> > Therefore, we hope that the delay can be modified by vendor to
> > adjust the most appropriate delay value.
> >
> > Signed-off-by: Zhe Wang <zhe.wang1@unisoc.com>
> > ---
> > V1 -> V2
> > - move turnoff_delay_us to struct ufs_vreg instead
> > - replace usleep_range with ufshcd_delay_us
> >
> >  drivers/ufs/core/ufshcd.c | 9 ++++++++-
> >  include/ufs/ufs.h         | 1 +
> >  2 files changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> > index 7256e6c43ca6..386ff6ed2f20 100644
> > --- a/drivers/ufs/core/ufshcd.c
> > +++ b/drivers/ufs/core/ufshcd.c
> > @@ -89,6 +89,9 @@
> >  /* Polling time to wait for fDeviceInit */
> >  #define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */
> >
> > +/* Default value of turn off VCC rail: 5000us */
> > +#define UFS_VCC_TURNOFF_DELAY_US 5000
> > +
> >  #define ufshcd_toggle_vreg(_dev, _vreg, _on)                           \
> >         ({                                                              \
> >                 int _ret;                                               \
> > @@ -7784,6 +7787,10 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
> >
> >         ufs_fixup_device_setup(hba);
> >
> > +       if (hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM &&
> > +           !hba->vreg_info.vcc->turnoff_delay_us)
> > +               hba->vreg_info.vcc->turnoff_delay_us =
> > UFS_VCC_TURNOFF_DELAY_US;
> > +
> You answered my question to your v1 - where otherwise you are setting this value:
> "We are still preparing and discussing our own UFS host driver code,
> which will be uploaded once we are done."
>
> Well until then - this isn't very useful.
>
> Thanks,
> Avri
>
> >         ufshcd_wb_probe(hba, desc_buf);
> >
> >         ufshcd_temp_notif_probe(hba, desc_buf);
> > @@ -8918,7 +8925,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba)
> >          */
> >         if (vcc_off && hba->vreg_info.vcc &&
> >                 hba->dev_quirks & UFS_DEVICE_QUIRK_DELAY_AFTER_LPM)
> > -               usleep_range(5000, 5100);
> > +               ufshcd_delay_us(hba->vreg_info.vcc->turnoff_delay_us, 100);
> >  }
> >
> >  #ifdef CONFIG_PM
> > diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
> > index 1bba3fead2ce..792335dfd70b 100644
> > --- a/include/ufs/ufs.h
> > +++ b/include/ufs/ufs.h
> > @@ -569,6 +569,7 @@ struct ufs_vreg {
> >         bool always_on;
> >         bool enabled;
> >         int max_uA;
> > +       u32 turnoff_delay_us;
> >  };
> >
> >  struct ufs_vreg_info {
> > --
> > 2.17.1
>

OK, thanks for your review.

Thanks,
Zhe Wang