From: marc_gonzalez@sigmadesigns•com (Marc Gonzalez)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC PATCH v2] ARM: tango: add Suspend-to-RAM support
Date: Mon, 4 Jul 2016 11:01:44 +0200 [thread overview]
Message-ID: <577A25F8.80702@sigmadesigns.com> (raw)
In-Reply-To: <5774DBDE.1070605@sigmadesigns.com>
On 30/06/2016 10:44, Marc Gonzalez wrote:
> Ask firmware to put RAM in self-refresh mode and power system down.
>
> echo mem > /sys/power/state
>
> See Documentation/power/states.txt
>
> Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns•com>
> ---
>
> This is a RFC because I have a few doubts:
>
> 1) return value when tango_suspend() fails and unexpectedly returns (I used -EIO)
> Is there a better error to return?
>
> 2) conditionally building pm.c (using CONFIG_SUSPEND? CONFIG_PM_SLEEP? other?)
> Is there a better config knob to use?
>
> 3) .valid is required, right?
> AFAICS, the answer is "yes", .valid is indeed required:
> ("no valid callback implies that none are valid")
>
> static bool valid_state(suspend_state_t state)
> {
> /*
> * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
> * support and need to be valid to the low level
> * implementation, no valid callback implies that none are valid.
> */
> return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
> }
>
> ---
> arch/arm/mach-tango/Makefile | 1 +
> arch/arm/mach-tango/pm.c | 32 ++++++++++++++++++++++++++++++++
> arch/arm/mach-tango/smc.h | 1 +
> 3 files changed, 34 insertions(+)
> create mode 100644 arch/arm/mach-tango/pm.c
>
> diff --git a/arch/arm/mach-tango/Makefile b/arch/arm/mach-tango/Makefile
> index 7ca753aa9fb6..822b7ca803c6 100644
> --- a/arch/arm/mach-tango/Makefile
> +++ b/arch/arm/mach-tango/Makefile
> @@ -3,3 +3,4 @@ AFLAGS_smc.o := -Wa,-march=armv7-a$(plus_sec)
>
> obj-y += setup.o smc.o xenv.o
> obj-$(CONFIG_SMP) += platsmp.o
> +obj-$(CONFIG_SUSPEND) += pm.o
> diff --git a/arch/arm/mach-tango/pm.c b/arch/arm/mach-tango/pm.c
> new file mode 100644
> index 000000000000..b05c6d6f99d0
> --- /dev/null
> +++ b/arch/arm/mach-tango/pm.c
> @@ -0,0 +1,32 @@
> +#include <linux/init.h>
> +#include <linux/suspend.h>
> +#include <asm/suspend.h>
> +#include "smc.h"
> +
> +static int tango_pm_powerdown(unsigned long arg)
> +{
> + tango_suspend(virt_to_phys(cpu_resume));
> +
> + return -EIO; /* tango_suspend has failed */
> +}
> +
> +static int tango_pm_enter(suspend_state_t state)
> +{
> + if (state == PM_SUSPEND_MEM)
> + return cpu_suspend(0, tango_pm_powerdown);
> +
> + return -EINVAL;
> +}
> +
> +static const struct platform_suspend_ops tango_pm_ops = {
> + .enter = tango_pm_enter,
> + .valid = suspend_valid_only_mem,
> +};
> +
> +static int __init tango_pm_init(void)
> +{
> + suspend_set_ops(&tango_pm_ops);
> + return 0;
> +}
> +
> +late_initcall(tango_pm_init);
> diff --git a/arch/arm/mach-tango/smc.h b/arch/arm/mach-tango/smc.h
> index 3d31f984f44c..57919539da1b 100644
> --- a/arch/arm/mach-tango/smc.h
> +++ b/arch/arm/mach-tango/smc.h
> @@ -3,5 +3,6 @@ extern int tango_smc(unsigned int val, unsigned int service);
> #define tango_set_l2_control(val) tango_smc(val, 0x102)
> #define tango_start_aux_core(val) tango_smc(val, 0x104)
> #define tango_set_aux_boot_addr(val) tango_smc(val, 0x105)
> +#define tango_suspend(val) tango_smc(val, 0x120)
> #define tango_aux_core_die(val) tango_smc(val, 0x121)
> #define tango_aux_core_kill(val) tango_smc(val, 0x122)
>
Hello everyone,
I'll wait a few more days for comments, then I'll submit the patch
to arm-soc for inclusion in v4.8 (if no issues are raised).
(I suppose the return value for tango_pm_powerdown() is not that
big a deal.)
Regards.
next prev parent reply other threads:[~2016-07-04 9:01 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-29 13:58 [RFC PATCH v1] ARM: tango: add Suspend-to-RAM support Marc Gonzalez
2016-06-29 17:48 ` Sudeep Holla
2016-06-30 8:44 ` [RFC PATCH v2] " Marc Gonzalez
2016-07-04 9:01 ` Marc Gonzalez [this message]
2016-07-07 13:08 ` [PATCH v3] " Marc Gonzalez
2016-07-07 14:01 ` Arnd Bergmann
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