2019-06-04 07:22:36

by Bjorn Andersson

[permalink] [raw]
Subject: [PATCH 0/3] (Qualcomm) UFS device reset support

This series exposes the ufs_reset line as a gpio, adds support for ufshcd to
acquire and toggle this and then adds this to SDM845 MTP.

Bjorn Andersson (3):
pinctrl: qcom: sdm845: Expose ufs_reset as gpio
scsi: ufs: Allow resetting the UFS device
arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO

.../bindings/pinctrl/qcom,sdm845-pinctrl.txt | 2 +-
arch/arm64/boot/dts/qcom/sdm845-mtp.dts | 2 +
drivers/pinctrl/qcom/pinctrl-sdm845.c | 12 ++---
drivers/scsi/ufs/ufshcd.c | 44 +++++++++++++++++++
drivers/scsi/ufs/ufshcd.h | 4 ++
5 files changed, 57 insertions(+), 7 deletions(-)

--
2.18.0


2019-06-04 22:02:10

by John Stultz

[permalink] [raw]
Subject: Re: [PATCH 0/3] (Qualcomm) UFS device reset support

On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
<[email protected]> wrote:
>
> This series exposes the ufs_reset line as a gpio, adds support for ufshcd to
> acquire and toggle this and then adds this to SDM845 MTP.
>
> Bjorn Andersson (3):
> pinctrl: qcom: sdm845: Expose ufs_reset as gpio
> scsi: ufs: Allow resetting the UFS device
> arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO

Adding similar change as in sdm845-mtp to the not yet upstream
blueline dts, I validated this allows my micron UFS pixel3 to boot.

Tested-by: John Stultz <[email protected]>

thanks
-john

2019-06-05 05:52:08

by Avri Altman

[permalink] [raw]
Subject: RE: [PATCH 0/3] (Qualcomm) UFS device reset support

Hi,

>
> On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
> <[email protected]> wrote:
> >
> > This series exposes the ufs_reset line as a gpio, adds support for ufshcd to
> > acquire and toggle this and then adds this to SDM845 MTP.
> >
> > Bjorn Andersson (3):
> > pinctrl: qcom: sdm845: Expose ufs_reset as gpio
> > scsi: ufs: Allow resetting the UFS device
> > arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO
>
> Adding similar change as in sdm845-mtp to the not yet upstream
> blueline dts, I validated this allows my micron UFS pixel3 to boot.
>
> Tested-by: John Stultz <[email protected]>
Maybe ufs_hba_variant_ops would be the proper place to add this?

Thanks,
Avri



>
> thanks
> -john

2019-06-05 06:03:00

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH 0/3] (Qualcomm) UFS device reset support

On Tue 04 Jun 22:50 PDT 2019, Avri Altman wrote:

> Hi,
>
> >
> > On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
> > <[email protected]> wrote:
> > >
> > > This series exposes the ufs_reset line as a gpio, adds support for ufshcd to
> > > acquire and toggle this and then adds this to SDM845 MTP.
> > >
> > > Bjorn Andersson (3):
> > > pinctrl: qcom: sdm845: Expose ufs_reset as gpio
> > > scsi: ufs: Allow resetting the UFS device
> > > arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO
> >
> > Adding similar change as in sdm845-mtp to the not yet upstream
> > blueline dts, I validated this allows my micron UFS pixel3 to boot.
> >
> > Tested-by: John Stultz <[email protected]>
> Maybe ufs_hba_variant_ops would be the proper place to add this?
>

Are you saying that these memories only need a reset when they are
paired with the Qualcomm host controller?

The way it's implemented it here is that the device-reset GPIO is
optional and only if you specify it we'll toggle the reset. So if your
board design has a UFS memory that requires a reset pulse during
initialization you specify this, regardless of which vendor your SoC
comes from.

Regards,
Bjorn

2019-06-05 09:34:12

by Avri Altman

[permalink] [raw]
Subject: RE: [PATCH 0/3] (Qualcomm) UFS device reset support

>
> On Tue 04 Jun 22:50 PDT 2019, Avri Altman wrote:
>
> > Hi,
> >
> > >
> > > On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
> > > <[email protected]> wrote:
> > > >
> > > > This series exposes the ufs_reset line as a gpio, adds support for ufshcd to
> > > > acquire and toggle this and then adds this to SDM845 MTP.
> > > >
> > > > Bjorn Andersson (3):
> > > > pinctrl: qcom: sdm845: Expose ufs_reset as gpio
> > > > scsi: ufs: Allow resetting the UFS device
> > > > arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO
> > >
> > > Adding similar change as in sdm845-mtp to the not yet upstream
> > > blueline dts, I validated this allows my micron UFS pixel3 to boot.
> > >
> > > Tested-by: John Stultz <[email protected]>
> > Maybe ufs_hba_variant_ops would be the proper place to add this?
> >
>
> Are you saying that these memories only need a reset when they are
> paired with the Qualcomm host controller?
ufs_hba_variant_ops is for vendors to implement their own vops,
and as you can see, many of them do.
Adding hw_reset to that template seems like the proper way
to do what you are doing.

Thanks,
Avri
>
> The way it's implemented it here is that the device-reset GPIO is
> optional and only if you specify it we'll toggle the reset. So if your
> board design has a UFS memory that requires a reset pulse during
> initialization you specify this, regardless of which vendor your SoC
> comes from.
>
> Regards,
> Bjorn

2019-06-06 00:41:25

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH 0/3] (Qualcomm) UFS device reset support

On Wed 05 Jun 02:32 PDT 2019, Avri Altman wrote:

> >
> > On Tue 04 Jun 22:50 PDT 2019, Avri Altman wrote:
> >
> > > Hi,
> > >
> > > >
> > > > On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
> > > > <[email protected]> wrote:
> > > > >
> > > > > This series exposes the ufs_reset line as a gpio, adds support for ufshcd to
> > > > > acquire and toggle this and then adds this to SDM845 MTP.
> > > > >
> > > > > Bjorn Andersson (3):
> > > > > pinctrl: qcom: sdm845: Expose ufs_reset as gpio
> > > > > scsi: ufs: Allow resetting the UFS device
> > > > > arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO
> > > >
> > > > Adding similar change as in sdm845-mtp to the not yet upstream
> > > > blueline dts, I validated this allows my micron UFS pixel3 to boot.
> > > >
> > > > Tested-by: John Stultz <[email protected]>
> > > Maybe ufs_hba_variant_ops would be the proper place to add this?
> > >
> >
> > Are you saying that these memories only need a reset when they are
> > paired with the Qualcomm host controller?
> ufs_hba_variant_ops is for vendors to implement their own vops,
> and as you can see, many of them do.
> Adding hw_reset to that template seems like the proper way
> to do what you are doing.
>

Right, but the vops is operations related to the UFS controller, this
property relates to the memory connected.

E.g I have a Hynix memory and John have a Micron memory that needs this
reset and my assumption is that these memories will need their RESET pin
toggled regardless of which controller they are connected to.

Regards,
Bjorn

2019-06-06 06:34:07

by Avri Altman

[permalink] [raw]
Subject: RE: [PATCH 0/3] (Qualcomm) UFS device reset support

>
> On Wed 05 Jun 02:32 PDT 2019, Avri Altman wrote:
>
> > >
> > > On Tue 04 Jun 22:50 PDT 2019, Avri Altman wrote:
> > >
> > > > Hi,
> > > >
> > > > >
> > > > > On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
> > > > > <[email protected]> wrote:
> > > > > >
> > > > > > This series exposes the ufs_reset line as a gpio, adds support for ufshcd
> to
> > > > > > acquire and toggle this and then adds this to SDM845 MTP.
> > > > > >
> > > > > > Bjorn Andersson (3):
> > > > > > pinctrl: qcom: sdm845: Expose ufs_reset as gpio
> > > > > > scsi: ufs: Allow resetting the UFS device
> > > > > > arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO
> > > > >
> > > > > Adding similar change as in sdm845-mtp to the not yet upstream
> > > > > blueline dts, I validated this allows my micron UFS pixel3 to boot.
> > > > >
> > > > > Tested-by: John Stultz <[email protected]>
> > > > Maybe ufs_hba_variant_ops would be the proper place to add this?
> > > >
> > >
> > > Are you saying that these memories only need a reset when they are
> > > paired with the Qualcomm host controller?
> > ufs_hba_variant_ops is for vendors to implement their own vops,
> > and as you can see, many of them do.
> > Adding hw_reset to that template seems like the proper way
> > to do what you are doing.
> >
>
> Right, but the vops is operations related to the UFS controller, this
> property relates to the memory connected.
This is not entirely accurate. Those are vendor/board specific,
As the original commit log indicates:
" vendor/board specific and hence determined with
the help of compatible property in device tree."

I would rather have this new vop:
void (*device_reset)(struct ufs_hba *), Or whatever,
actively set in ufs_hba_variant_ops, rather than ufshcd_init_device_reset
failing as part of the default init flow.

Thanks,
Avri

>
> E.g I have a Hynix memory and John have a Micron memory that needs this
> reset and my assumption is that these memories will need their RESET pin
> toggled regardless of which controller they are connected to.
>
> Regards,
> Bjorn

2019-06-06 07:11:49

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH 0/3] (Qualcomm) UFS device reset support

On Wed 05 Jun 23:32 PDT 2019, Avri Altman wrote:

> >
> > On Wed 05 Jun 02:32 PDT 2019, Avri Altman wrote:
> >
> > > >
> > > > On Tue 04 Jun 22:50 PDT 2019, Avri Altman wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > >
> > > > > > On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
> > > > > > <[email protected]> wrote:
> > > > > > >
> > > > > > > This series exposes the ufs_reset line as a gpio, adds support for ufshcd
> > to
> > > > > > > acquire and toggle this and then adds this to SDM845 MTP.
> > > > > > >
> > > > > > > Bjorn Andersson (3):
> > > > > > > pinctrl: qcom: sdm845: Expose ufs_reset as gpio
> > > > > > > scsi: ufs: Allow resetting the UFS device
> > > > > > > arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO
> > > > > >
> > > > > > Adding similar change as in sdm845-mtp to the not yet upstream
> > > > > > blueline dts, I validated this allows my micron UFS pixel3 to boot.
> > > > > >
> > > > > > Tested-by: John Stultz <[email protected]>
> > > > > Maybe ufs_hba_variant_ops would be the proper place to add this?
> > > > >
> > > >
> > > > Are you saying that these memories only need a reset when they are
> > > > paired with the Qualcomm host controller?
> > > ufs_hba_variant_ops is for vendors to implement their own vops,
> > > and as you can see, many of them do.
> > > Adding hw_reset to that template seems like the proper way
> > > to do what you are doing.
> > >
> >
> > Right, but the vops is operations related to the UFS controller, this
> > property relates to the memory connected.
> This is not entirely accurate. Those are vendor/board specific,
> As the original commit log indicates:
> " vendor/board specific and hence determined with
> the help of compatible property in device tree."
>
> I would rather have this new vop:
> void (*device_reset)(struct ufs_hba *), Or whatever,
> actively set in ufs_hba_variant_ops, rather than ufshcd_init_device_reset
> failing as part of the default init flow.
>

But such an vops would allow me to provide a Qualcomm-specific way of
toggling the GPIO that is connected to the UFS_RESET pin on the
Hynix/Micron memory.

But acquiring and toggling GPIOs is not a Qualcomm thing, it's a
completely generic thing, and as it's not a chip-internal line it is a
GPIO and not a reset - regardless of SoC vendor.
Further more, it's optional so boards that does not have this pin
connected will just omit the property in their hardware description
(DeviceTree).


So I think the halting part here is that we don't have a representation
of the memory device's resources, because this is really a matter of
toggling the reset pin on the memory device.

Regards,
Bjorn