Re: [PATCH v6 2/6] ARM: imx6: register pm_power_off handler if "fsl,pmic-stby-poweroff" is set

From: Russell King - ARM Linux
Date: Tue May 08 2018 - 08:41:03 EST


On Mon, Mar 05, 2018 at 11:25:19AM +0100, Oleksij Rempel wrote:
> One of the Freescale recommended sequences for power off with external
> PMIC is the following:
> ...
> 3. SoC is programming PMIC for power off when standby is asserted.
> 4. In CCM STOP mode, Standby is asserted, PMIC gates SoC supplies.
>
> See:
> http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6DQRM.pdf
> page 5083
>
> This patch implements step 4. of this sequence.
>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
> ---
> arch/arm/mach-imx/pm-imx6.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
> index ecdf071653d4..24689260a2a5 100644
> --- a/arch/arm/mach-imx/pm-imx6.c
> +++ b/arch/arm/mach-imx/pm-imx6.c
> @@ -604,6 +604,28 @@ static void __init imx6_pm_common_init(const struct imx6_pm_socdata
> IMX6Q_GPR1_GINT);
> }
>
> +static void imx6_pm_stby_poweroff(void)
> +{
> + imx6_set_lpm(STOP_POWER_OFF);
> + cpu_suspend(0, imx6q_suspend_finish);

Do you actually need to save the processor state etc here - the request
is after all to power down the system and not to suspend. Would calling
imx6q_suspend_finish() directly work (and hence simplify the code) ?

--
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