2019-11-18 03:58:35

by Can Guo

[permalink] [raw]
Subject: [PATCH v2 2/4] scsi: ufs: Update VCCQ2 and VCCQ min/max voltage hard codes

Per UFS 3.0 JEDEC standard, the VCCQ2 min voltage is 1.7v and the VCCQ
voltage range is 1.14v ~ 1.26v. Update their hard codes accordingly to
make sure they work in a safe range compliant for ver 1.0/2.0/2.1/3.0
UFS devices.

Signed-off-by: Can Guo <[email protected]>
---
drivers/scsi/ufs/ufs.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 385bac8..9df4f4d 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -500,9 +500,9 @@ struct ufs_query_res {
#define UFS_VREG_VCC_MAX_UV 3600000 /* uV */
#define UFS_VREG_VCC_1P8_MIN_UV 1700000 /* uV */
#define UFS_VREG_VCC_1P8_MAX_UV 1950000 /* uV */
-#define UFS_VREG_VCCQ_MIN_UV 1100000 /* uV */
+#define UFS_VREG_VCCQ_MIN_UV 1140000 /* uV */
#define UFS_VREG_VCCQ_MAX_UV 1300000 /* uV */
-#define UFS_VREG_VCCQ2_MIN_UV 1650000 /* uV */
+#define UFS_VREG_VCCQ2_MIN_UV 1700000 /* uV */
#define UFS_VREG_VCCQ2_MAX_UV 1950000 /* uV */

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


2019-11-18 13:21:56

by Alim Akhtar

[permalink] [raw]
Subject: Re: [PATCH v2 2/4] scsi: ufs: Update VCCQ2 and VCCQ min/max voltage hard codes

I agree with Avri, you can just drop this patch, unless you see
anything affected because of not setting VDDQ/VDDQ2 as per spec.
or alternatively you can have different marco of each spec and handle
the same in the code as per ufs specification version.

On Mon, Nov 18, 2019 at 9:25 AM Can Guo <[email protected]> wrote:
>
> Per UFS 3.0 JEDEC standard, the VCCQ2 min voltage is 1.7v and the VCCQ
> voltage range is 1.14v ~ 1.26v. Update their hard codes accordingly to
> make sure they work in a safe range compliant for ver 1.0/2.0/2.1/3.0
> UFS devices.
>
> Signed-off-by: Can Guo <[email protected]>
> ---
> drivers/scsi/ufs/ufs.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 385bac8..9df4f4d 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -500,9 +500,9 @@ struct ufs_query_res {
> #define UFS_VREG_VCC_MAX_UV 3600000 /* uV */
> #define UFS_VREG_VCC_1P8_MIN_UV 1700000 /* uV */
> #define UFS_VREG_VCC_1P8_MAX_UV 1950000 /* uV */
> -#define UFS_VREG_VCCQ_MIN_UV 1100000 /* uV */
> +#define UFS_VREG_VCCQ_MIN_UV 1140000 /* uV */
> #define UFS_VREG_VCCQ_MAX_UV 1300000 /* uV */
> -#define UFS_VREG_VCCQ2_MIN_UV 1650000 /* uV */
> +#define UFS_VREG_VCCQ2_MIN_UV 1700000 /* uV */
> #define UFS_VREG_VCCQ2_MAX_UV 1950000 /* uV */
>
> /*
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>


--
Regards,
Alim

2019-11-19 12:45:03

by Avri Altman

[permalink] [raw]
Subject: RE: [PATCH v2 2/4] scsi: ufs: Update VCCQ2 and VCCQ min/max voltage hard codes

>
> On 2019-11-18 15:15, Avri Altman wrote:
> >>
> >> From: Can Guo <[email protected]>
> >>
> >> Per UFS 3.0 JEDEC standard, the VCCQ2 min voltage is 1.7v and the
> >> VCCQ voltage range is 1.14v ~ 1.26v. Update their hard codes
> >> accordingly to make sure they work in a safe range compliant for ver
> >> 1.0/2.0/2.1/3.0 UFS devices.
> > So to keep it safe, we need to use largest range:
> > min_uV = min over all spec ranges, and max_uV = max over all spec
> > ranges.
> > Meaning leave it as it is if we want to be backward compatible with
> > UFS1.0.
> >
> > Thanks,
> > Avri
> >
>
> Hi Avri,
>
> Sorry I don't quite follow you here.
> Leaving it as it is means for UFS2.1 devices, when boot up, if we call
> regulator_set_voltage(1.65, 1.95) to setup its VCCQ2,
> regulator_set_voltage() will
> give you 1.65v on VCCQ2 if the voltage level of this regulator is wider, say (1.60,
> 1.95).
> Meaning you will finally set 1.65v to VCCQ2. But 1.65v is out of spec for UFS
> v2.1 as it requires min voltage to be 1.7v on VCCQ2. So, the smallest range is
> safe.
> Of course, in real board design, the regulator's voltage level is limited/designed
> by power team to be in a safe range, say (1.8, 1.92), so that calling
> regulator_set_voltage(1.65, 1.95) still gives you 1.8v. But it does not mean the
> current hard codes are compliant for all UFS devices.
You are correct - the narrowest the range the better - as long as you don't cross the limits of previous spec.
So changing 1.1 -> 1.14 and 1.65 -> 1.7 is fine.
While at it, Vccq max in UFS3.0 is 1.26, why not change 1.3 -> 1.26, like you indicated in your commit log?

Thanks,
Avri

>
> Best Regards,
> Can Guo.
>
> >>
> >> Signed-off-by: Can Guo <[email protected]>
> >> ---
> >> drivers/scsi/ufs/ufs.h | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h index
> >> 385bac8..9df4f4d
> >> 100644
> >> --- a/drivers/scsi/ufs/ufs.h
> >> +++ b/drivers/scsi/ufs/ufs.h
> >> @@ -500,9 +500,9 @@ struct ufs_query_res {
> >> #define UFS_VREG_VCC_MAX_UV 3600000 /* uV */
> >> #define UFS_VREG_VCC_1P8_MIN_UV 1700000 /* uV */
> >> #define UFS_VREG_VCC_1P8_MAX_UV 1950000 /* uV */
> >> -#define UFS_VREG_VCCQ_MIN_UV 1100000 /* uV */
> >> +#define UFS_VREG_VCCQ_MIN_UV 1140000 /* uV */
> >> #define UFS_VREG_VCCQ_MAX_UV 1300000 /* uV */
> >> -#define UFS_VREG_VCCQ2_MIN_UV 1650000 /* uV */
> >> +#define UFS_VREG_VCCQ2_MIN_UV 1700000 /* uV */
> >> #define UFS_VREG_VCCQ2_MAX_UV 1950000 /* uV */
> >>
> >> /*
> >> --
> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> >> Forum, a Linux Foundation Collaborative Project

2019-11-20 04:18:26

by Can Guo

[permalink] [raw]
Subject: Re: [PATCH v2 2/4] scsi: ufs: Update VCCQ2 and VCCQ min/max voltage hard codes

On 2019-11-19 20:41, Avri Altman wrote:
>>
>> On 2019-11-18 15:15, Avri Altman wrote:
>> >>
>> >> From: Can Guo <[email protected]>
>> >>
>> >> Per UFS 3.0 JEDEC standard, the VCCQ2 min voltage is 1.7v and the
>> >> VCCQ voltage range is 1.14v ~ 1.26v. Update their hard codes
>> >> accordingly to make sure they work in a safe range compliant for ver
>> >> 1.0/2.0/2.1/3.0 UFS devices.
>> > So to keep it safe, we need to use largest range:
>> > min_uV = min over all spec ranges, and max_uV = max over all spec
>> > ranges.
>> > Meaning leave it as it is if we want to be backward compatible with
>> > UFS1.0.
>> >
>> > Thanks,
>> > Avri
>> >
>>
>> Hi Avri,
>>
>> Sorry I don't quite follow you here.
>> Leaving it as it is means for UFS2.1 devices, when boot up, if we call
>> regulator_set_voltage(1.65, 1.95) to setup its VCCQ2,
>> regulator_set_voltage() will
>> give you 1.65v on VCCQ2 if the voltage level of this regulator is
>> wider, say (1.60,
>> 1.95).
>> Meaning you will finally set 1.65v to VCCQ2. But 1.65v is out of spec
>> for UFS
>> v2.1 as it requires min voltage to be 1.7v on VCCQ2. So, the smallest
>> range is
>> safe.
>> Of course, in real board design, the regulator's voltage level is
>> limited/designed
>> by power team to be in a safe range, say (1.8, 1.92), so that calling
>> regulator_set_voltage(1.65, 1.95) still gives you 1.8v. But it does
>> not mean the
>> current hard codes are compliant for all UFS devices.
> You are correct - the narrowest the range the better - as long as you
> don't cross the limits of previous spec.
> So changing 1.1 -> 1.14 and 1.65 -> 1.7 is fine.
> While at it, Vccq max in UFS3.0 is 1.26, why not change 1.3 -> 1.26,
> like you indicated in your commit log?
>
> Thanks,
> Avri
>

Thank you Avri, sorry I missed the change to max voltage of VCCQ, I
will update it in the next version.

Best Regards,
Can Guo.

>>
>> Best Regards,
>> Can Guo.
>>
>> >>
>> >> Signed-off-by: Can Guo <[email protected]>
>> >> ---
>> >> drivers/scsi/ufs/ufs.h | 4 ++--
>> >> 1 file changed, 2 insertions(+), 2 deletions(-)
>> >>
>> >> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h index
>> >> 385bac8..9df4f4d
>> >> 100644
>> >> --- a/drivers/scsi/ufs/ufs.h
>> >> +++ b/drivers/scsi/ufs/ufs.h
>> >> @@ -500,9 +500,9 @@ struct ufs_query_res {
>> >> #define UFS_VREG_VCC_MAX_UV 3600000 /* uV */
>> >> #define UFS_VREG_VCC_1P8_MIN_UV 1700000 /* uV */
>> >> #define UFS_VREG_VCC_1P8_MAX_UV 1950000 /* uV */
>> >> -#define UFS_VREG_VCCQ_MIN_UV 1100000 /* uV */
>> >> +#define UFS_VREG_VCCQ_MIN_UV 1140000 /* uV */
>> >> #define UFS_VREG_VCCQ_MAX_UV 1300000 /* uV */
>> >> -#define UFS_VREG_VCCQ2_MIN_UV 1650000 /* uV */
>> >> +#define UFS_VREG_VCCQ2_MIN_UV 1700000 /* uV */
>> >> #define UFS_VREG_VCCQ2_MAX_UV 1950000 /* uV */
>> >>
>> >> /*
>> >> --
>> >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> >> Forum, a Linux Foundation Collaborative Project