[PATCH v2] ARM: dts: Add mask-tpm-reset to the device tree

[PATCH v2] ARM: dts: Add mask-tpm-reset to the device tree

[Vikas Sajjan]

From: Doug Anderson <dianders@chromium.org>

The mask-tpm-reset GPIO is used by the kernel to prevent the TPM from
being reset across sleep/wake.  If we don't set it to anything then
the TPM will be reset.  U-Boot will detect this as invalid
and will reset the system on resume time. This GPIO can always be low
and not hurt anything.  It will get pulled back high again during a
normal warm reset when it will default back to an input.

To properly preserve the TPM state across suspend/resume and to make
the chrome U-Boot happy, properly set the GPIO to mask the
reset to the TPM.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Vikas Sajjan <vikas.sajjan@samsung.com>
---
changes since v1:
	- removed fixed regulator and used hogs instead.

 arch/arm/boot/dts/exynos5420-peach-pit.dts |   12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm/boot/dts/exynos5420-peach-pit.dts b/arch/arm/boot/dts/exynos5420-peach-pit.dts
index 6c7cab0..c036d9e 100644
--- a/arch/arm/boot/dts/exynos5420-peach-pit.dts
+++ b/arch/arm/boot/dts/exynos5420-peach-pit.dts
@@ -211,6 +211,18 @@
 
 
 &pinctrl_0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&mask_tpm_reset>;
+
+	/* We need GPX0_6 to be low at sleep time; just keep it low always */
+	mask_tpm_reset: mask-tpm-reset {
+		samsung,pins = "gpx0-6";
+		samsung,pin-function = <1>;
+		samsung,pin-pud = <0>;
+		samsung,pin-drv = <0>;
+		samsung,pin-val = <0>;
+	};
+
 	max98090_irq: max98090-irq {
 		samsung,pins = "gpx0-2";
 		samsung,pin-function = <0>;
-- 
1.7.9.5

[PATCH v2] ARM: dts: Add mask-tpm-reset to the device tree

[Naveen Krishna Ch]

Hello Vikas,


On 14 July 2014 12:03, Vikas Sajjan <vikas.sajjan@samsung.com> wrote:
> From: Doug Anderson <dianders@chromium.org>
>
> The mask-tpm-reset GPIO is used by the kernel to prevent the TPM from
> being reset across sleep/wake.  If we don't set it to anything then
> the TPM will be reset.  U-Boot will detect this as invalid
> and will reset the system on resume time. This GPIO can always be low
> and not hurt anything.  It will get pulled back high again during a
> normal warm reset when it will default back to an input.
>
> To properly preserve the TPM state across suspend/resume and to make
> the chrome U-Boot happy, properly set the GPIO to mask the
> reset to the TPM.
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> Signed-off-by: Vikas Sajjan <vikas.sajjan@samsung.com>

After merging Linus Walleij's for-next branch of pinctrl git.

S2R on Exynos5420 based Peach PIT works fine.

Tested-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
> ---
> changes since v1:
>         - removed fixed regulator and used hogs instead.
>
>  arch/arm/boot/dts/exynos5420-peach-pit.dts |   12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/arch/arm/boot/dts/exynos5420-peach-pit.dts b/arch/arm/boot/dts/exynos5420-peach-pit.dts
> index 6c7cab0..c036d9e 100644
> --- a/arch/arm/boot/dts/exynos5420-peach-pit.dts
> +++ b/arch/arm/boot/dts/exynos5420-peach-pit.dts
> @@ -211,6 +211,18 @@
>
>
>  &pinctrl_0 {
> +       pinctrl-names = "default";
> +       pinctrl-0 = <&mask_tpm_reset>;
> +
> +       /* We need GPX0_6 to be low at sleep time; just keep it low always */
> +       mask_tpm_reset: mask-tpm-reset {
> +               samsung,pins = "gpx0-6";
> +               samsung,pin-function = <1>;
> +               samsung,pin-pud = <0>;
> +               samsung,pin-drv = <0>;
> +               samsung,pin-val = <0>;
> +       };
> +
>         max98090_irq: max98090-irq {
>                 samsung,pins = "gpx0-2";
>                 samsung,pin-function = <0>;
> --
> 1.7.9.5
>
> --
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-- 
Shine bright,
(: Nav :)

[PATCH v2] ARM: dts: Add mask-tpm-reset to the device tree

[Doug Anderson]

Vikas,

On Sun, Jul 13, 2014 at 11:33 PM, Vikas Sajjan <vikas.sajjan@samsung.com> wrote:
> From: Doug Anderson <dianders@chromium.org>
>
> The mask-tpm-reset GPIO is used by the kernel to prevent the TPM from
> being reset across sleep/wake.  If we don't set it to anything then
> the TPM will be reset.  U-Boot will detect this as invalid
> and will reset the system on resume time. This GPIO can always be low
> and not hurt anything.  It will get pulled back high again during a
> normal warm reset when it will default back to an input.
>
> To properly preserve the TPM state across suspend/resume and to make
> the chrome U-Boot happy, properly set the GPIO to mask the
> reset to the TPM.
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> Signed-off-by: Vikas Sajjan <vikas.sajjan@samsung.com>
> ---
> changes since v1:
>         - removed fixed regulator and used hogs instead.
>
>  arch/arm/boot/dts/exynos5420-peach-pit.dts |   12 ++++++++++++
>  1 file changed, 12 insertions(+)

This looks reasonable to me except for two things:

1. You need to apply this to pit and pi (not just pi)

2. The proper sort ordering for elements within a pin control group is
by pin number, so this pin should be _after_ gpx0-2, not before.

[PATCH v2] ARM: dts: Add mask-tpm-reset to the device tree

[Doug Anderson]

Vikas,

On Mon, Jul 14, 2014 at 10:00 AM, Doug Anderson <dianders@chromium.org> wrote:
> Vikas,
>
> On Sun, Jul 13, 2014 at 11:33 PM, Vikas Sajjan <vikas.sajjan@samsung.com> wrote:
>> From: Doug Anderson <dianders@chromium.org>
>>
>> The mask-tpm-reset GPIO is used by the kernel to prevent the TPM from
>> being reset across sleep/wake.  If we don't set it to anything then
>> the TPM will be reset.  U-Boot will detect this as invalid
>> and will reset the system on resume time. This GPIO can always be low
>> and not hurt anything.  It will get pulled back high again during a
>> normal warm reset when it will default back to an input.
>>
>> To properly preserve the TPM state across suspend/resume and to make
>> the chrome U-Boot happy, properly set the GPIO to mask the
>> reset to the TPM.
>>
>> Signed-off-by: Doug Anderson <dianders@chromium.org>
>> Signed-off-by: Vikas Sajjan <vikas.sajjan@samsung.com>
>> ---
>> changes since v1:
>>         - removed fixed regulator and used hogs instead.
>>
>>  arch/arm/boot/dts/exynos5420-peach-pit.dts |   12 ++++++++++++
>>  1 file changed, 12 insertions(+)
>
> This looks reasonable to me except for two things:
>
> 1. You need to apply this to pit and pi (not just pi)

Sorry, just realized that you had two patches and they weren't just
revisions (I got confused when one was v1 and one was v2).  I would
have just put them in the same patch, but two patches is OK.


> 2. The proper sort ordering for elements within a pin control group is
> by pin number, so this pin should be _after_ gpx0-2, not before.

[PATCH v2] ARM: dts: Add mask-tpm-reset to the device tree

[Vikas Sajjan]

Doug,

On Mon, Jul 14, 2014 at 10:30 PM, Doug Anderson <dianders@chromium.org> wrote:
> Vikas,
>
> On Sun, Jul 13, 2014 at 11:33 PM, Vikas Sajjan <vikas.sajjan@samsung.com> wrote:
>> From: Doug Anderson <dianders@chromium.org>
>>
>> The mask-tpm-reset GPIO is used by the kernel to prevent the TPM from
>> being reset across sleep/wake.  If we don't set it to anything then
>> the TPM will be reset.  U-Boot will detect this as invalid
>> and will reset the system on resume time. This GPIO can always be low
>> and not hurt anything.  It will get pulled back high again during a
>> normal warm reset when it will default back to an input.
>>
>> To properly preserve the TPM state across suspend/resume and to make
>> the chrome U-Boot happy, properly set the GPIO to mask the
>> reset to the TPM.
>>
>> Signed-off-by: Doug Anderson <dianders@chromium.org>
>> Signed-off-by: Vikas Sajjan <vikas.sajjan@samsung.com>
>> ---
>> changes since v1:
>>         - removed fixed regulator and used hogs instead.
>>
>>  arch/arm/boot/dts/exynos5420-peach-pit.dts |   12 ++++++++++++
>>  1 file changed, 12 insertions(+)
>
> This looks reasonable to me except for two things:
>
> 1. You need to apply this to pit and pi (not just pi)
>
> 2. The proper sort ordering for elements within a pin control group is
> by pin number, so this pin should be _after_ gpx0-2, not before.


Sure, will repost both pit and pi by reordering the pin as you suggested.