[PATCH v2 3/3] drivers: firmware: psci: add system suspend support

[Lorenzo Pieralisi]

On Thu, Jun 18, 2015 at 03:41:34PM +0100, Sudeep Holla wrote:
> PSCI v1.0 introduces a new API called PSCI_SYSTEM_SUSPEND. This API
> provides the mechanism by which the calling OS can request entry into
> the deepest possible system sleep state.
> 
> It meets all the necessary preconditions for entering suspend to RAM
> state in Linux. This patch adds support for PSCI_SYSTEM_SUSPEND in psci
> firmware and registers a psci system suspend operation to implement the
> suspend-to-RAM(s2r) in a generic way on all the platforms implementing
> PSCI.
> 
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> ---
>  drivers/firmware/psci.c   | 31 +++++++++++++++++++++++++++++++
>  include/uapi/linux/psci.h |  3 +++
>  2 files changed, 34 insertions(+)
> 
> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 752ca7c9eb97..f2b2b3e1c6e4 100644
> --- a/drivers/firmware/psci.c
> +++ b/drivers/firmware/psci.c
> @@ -20,11 +20,13 @@
>  #include <linux/printk.h>
>  #include <linux/psci.h>
>  #include <linux/reboot.h>
> +#include <linux/suspend.h>
>  
>  #include <uapi/linux/psci.h>
>  
>  #include <asm/system_misc.h>
>  #include <asm/smp_plat.h>
> +#include <asm/suspend.h>
>  
>  /*
>   * While a 64-bit OS can make calls with SMC32 calling conventions, for some
> @@ -222,6 +224,33 @@ static int __init psci_features(u32 psci_func_id)
>  			      psci_func_id, 0, 0);
>  }
>  
> +static int psci_system_suspend(unsigned long unused)
> +{
> +	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
> +			      virt_to_phys(cpu_resume), 0, 0);
> +}
> +
> +static int psci_system_suspend_enter(suspend_state_t state)
> +{
> +	return cpu_suspend(0, psci_system_suspend);
> +}
> +
> +static const struct platform_suspend_ops psci_suspend_ops = {
> +	.valid          = suspend_valid_only_mem,
> +	.enter          = psci_system_suspend_enter,
> +};
> +
> +static void __init psci_init_system_suspend(void)
> +{
> +	if (!IS_ENABLED(CONFIG_SUSPEND))
> +		return;
> +
> +	if (psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND)))
> +		return;
> +
> +	suspend_set_ops(&psci_suspend_ops);

For consistency with psci_init_cpu_suspend I rewrote it like this:

static void __init psci_init_system_suspend(void)
{
	int ret;

	if (!IS_ENABLED(CONFIG_SUSPEND))
		return;

	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));

	if (ret != PSCI_RET_NOT_SUPPORTED)
		suspend_set_ops(&psci_suspend_ops);
}

Let me know if it is ok with you. Other than that:

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>