From: t.figa@samsung•com (Tomasz Figa)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: dts: Add mask-tpm-reset to the device tree
Date: Thu, 26 Jun 2014 11:52:27 +0200 [thread overview]
Message-ID: <53ABED5B.8010506@samsung.com> (raw)
In-Reply-To: <1403774127-21892-1-git-send-email-vikas.sajjan@samsung.com>
Hi Vikas, Doug,
On 26.06.2014 11:15, Vikas Sajjan 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>
> ---
> arch/arm/boot/dts/exynos5420-peach-pit.dts | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/arch/arm/boot/dts/exynos5420-peach-pit.dts b/arch/arm/boot/dts/exynos5420-peach-pit.dts
> index 7649982..8fd990a 100644
> --- a/arch/arm/boot/dts/exynos5420-peach-pit.dts
> +++ b/arch/arm/boot/dts/exynos5420-peach-pit.dts
> @@ -87,6 +87,18 @@
> pinctrl-0 = <&usb301_vbus_en>;
> enable-active-high;
> };
> +
> + /* We need GPX0_6 to be low at sleep time; just keep it low always */
> + mask_tpm_reset_regulator: mask-tpm-reset-regulator {
> + compatible = "regulator-fixed";
> + regulator-name = "mask-tpm-reset ";
> + gpio = <&gpx0 6 0>;
> + enable-active-low;
> + regulator-boot-on;
> + regulator-always-on;
> + pinctrl-names = "default";
> + pinctrl-0 = <&mask_tpm_reset>;
> + };
I don't think this pin is supposed to be a real regulator. If I'm right,
you should just add a hog for it, if you don't have a proper driver to
handle it.
> };
>
> &dp {
> @@ -210,6 +222,14 @@
>
>
> &pinctrl_0 {
> +
nit: No need for this blank line.
Best regards,
Tomasz
next prev parent reply other threads:[~2014-06-26 9:52 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-26 9:15 [PATCH] ARM: dts: Add mask-tpm-reset to the device tree Vikas Sajjan
2014-06-26 9:52 ` Tomasz Figa [this message]
2014-06-26 15:25 ` Doug Anderson
2014-06-27 12:17 ` Tomasz Figa
2014-06-27 15:10 ` Doug Anderson
2014-06-27 15:14 ` Tomasz Figa
2014-06-27 15:22 ` Doug Anderson
2014-06-27 15:49 ` Vikas Sajjan
2014-06-27 16:10 ` Stephen Warren
2014-06-27 16:45 ` Doug Anderson
2014-06-27 18:20 ` Stephen Warren
2014-06-27 18:30 ` Doug Anderson
2014-06-27 19:56 ` Stephen Warren
2014-06-27 19:58 ` Doug Anderson
2014-07-08 7:46 ` Linus Walleij
2014-07-08 15:27 ` Doug Anderson
2014-07-08 16:20 ` Tomasz Figa
2014-07-09 15:22 ` Doug Anderson
2014-07-10 4:35 ` Vikas Sajjan
2014-07-10 15:25 ` Doug Anderson
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