Re: [PATCH 18/19] ARM: at91: suspend both memory controllers on at91sam9263

From: Nicolas Ferre
Date: Thu Apr 18 2013 - 09:45:43 EST


I come back to this for AT91


On 01/25/2013 11:44 PM, Arnd Bergmann :
> For the past three years, we have had a #warning in
> mach-at91 about the sdram_selfrefresh_enable or
> at91sam9_standby functions possibly not working on
> at91sam9263. In the meantime a function was added
> to do the right thing on at91sam9g45, which looks like
> it should also work on '9263.
>
> This patch blindly removes the warning and changes the
> at91sam9263 to use the same code at at91sam9g45, which
> may or may not be the right solution. If it is not,
> maybe someone could provide a better fix.

Maybe you can remove this paragraph: now you are using the proper fix
with proper RAM type.

> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

What is the future of this patch series: do you want us to take this
patch separately or to you want to apply the whole series on the arm-soc
tree?


> Cc: Jean-Christophe Plagniol-Villard <plagnioj@xxxxxxxxxxxx>
> Cc: Andrew Victor <linux@xxxxxxxxxxxx>
> Cc: Albin Tonnerre <albin.tonnerre@xxxxxxxxxxxxxxxxxx>
> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>

Moreover, this patch my conflict with Daniel's current initiative to
move cpuidle driver to its own directory: how do we coordinate with each
other?

Arnd,
Thanks a lot for having taking care of this old warning...


Best regards,

> ---
> arch/arm/mach-at91/cpuidle.c | 2 ++
> arch/arm/mach-at91/pm.c | 2 ++
> arch/arm/mach-at91/pm.h | 30 ++++++++++++++++++++++++------
> 3 files changed, 28 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/mach-at91/cpuidle.c b/arch/arm/mach-at91/cpuidle.c
> index 0c63815..4c67946 100644
> --- a/arch/arm/mach-at91/cpuidle.c
> +++ b/arch/arm/mach-at91/cpuidle.c
> @@ -38,6 +38,8 @@ static int at91_enter_idle(struct cpuidle_device *dev,
> at91rm9200_standby();
> else if (cpu_is_at91sam9g45())
> at91sam9g45_standby();
> + else if (cpu_is_at91sam9263())
> + at91sam9263_standby();
> else
> at91sam9_standby();
>
> diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
> index adb6db8..b8017c1 100644
> --- a/arch/arm/mach-at91/pm.c
> +++ b/arch/arm/mach-at91/pm.c
> @@ -267,6 +267,8 @@ static int at91_pm_enter(suspend_state_t state)
> at91rm9200_standby();
> else if (cpu_is_at91sam9g45())
> at91sam9g45_standby();
> + else if (cpu_is_at91sam9263())
> + at91sam9263_standby();
> else
> at91sam9_standby();
> break;
> diff --git a/arch/arm/mach-at91/pm.h b/arch/arm/mach-at91/pm.h
> index 38f467c..2f5908f 100644
> --- a/arch/arm/mach-at91/pm.h
> +++ b/arch/arm/mach-at91/pm.h
> @@ -70,13 +70,31 @@ static inline void at91sam9g45_standby(void)
> at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1);
> }
>
> -#ifdef CONFIG_SOC_AT91SAM9263
> -/*
> - * FIXME either or both the SDRAM controllers (EB0, EB1) might be in use;
> - * handle those cases both here and in the Suspend-To-RAM support.
> +/* We manage both DDRAM/SDRAM controllers, we need more than one value to
> + * remember.
> */
> -#warning Assuming EB1 SDRAM controller is *NOT* used
> -#endif
> +static inline void at91sam9263_standby(void)
> +{
> + u32 lpr0, lpr1;
> + u32 saved_lpr0, saved_lpr1;
> +
> + saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR);
> + lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB;
> + lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
> +
> + saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR);
> + lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB;
> + lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH;
> +
> + /* self-refresh mode now */
> + at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0);
> + at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1);
> +
> + cpu_do_idle();
> +
> + at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0);
> + at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1);
> +}
>
> static inline void at91sam9_standby(void)
> {
>


--
Nicolas Ferre
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