diff mbox

ARM: dts: Add mask-tpm-reset DT node to the exynos5800-peach-pi

Message ID 1405339577-7878-1-git-send-email-vikas.sajjan@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Vikas Sajjan July 14, 2014, 12:06 p.m. UTC
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: Vikas Sajjan <vikas.sajjan@samsung.com>
---
 arch/arm/boot/dts/exynos5800-peach-pi.dts |   12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Naveen Krishna Ch July 14, 2014, 12:41 p.m. UTC | #1
Hello Vikas,

On 14 July 2014 17:36, Vikas Sajjan <vikas.sajjan@samsung.com> wrote:
> 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: Vikas Sajjan <vikas.sajjan@samsung.com>

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

S2R on Exynos5800 based Peach PI works fine.

Tested-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>

> ---
>  arch/arm/boot/dts/exynos5800-peach-pi.dts |   12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/arch/arm/boot/dts/exynos5800-peach-pi.dts b/arch/arm/boot/dts/exynos5800-peach-pi.dts
> index 28f2a25..caa8952 100644
> --- a/arch/arm/boot/dts/exynos5800-peach-pi.dts
> +++ b/arch/arm/boot/dts/exynos5800-peach-pi.dts
> @@ -209,6 +209,18 @@
>
>
>  &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>;
> +       };
> +
>         max98091_irq: max98091-irq {
>                 samsung,pins = "gpx0-2";
>                 samsung,pin-function = <0>;
> --
> 1.7.9.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/arm/boot/dts/exynos5800-peach-pi.dts b/arch/arm/boot/dts/exynos5800-peach-pi.dts
index 28f2a25..caa8952 100644
--- a/arch/arm/boot/dts/exynos5800-peach-pi.dts
+++ b/arch/arm/boot/dts/exynos5800-peach-pi.dts
@@ -209,6 +209,18 @@ 
 
 
 &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>;
+	};
+
 	max98091_irq: max98091-irq {
 		samsung,pins = "gpx0-2";
 		samsung,pin-function = <0>;