[PATCH V2] firmware: arm_scmi: power_control: support suspend command

[Peng Fan]

Hi Sudeep,

> Subject: [PATCH V2] firmware: arm_scmi: power_control: support suspend
> command

Is this patch good for you to pick up?

Thanks,
Peng.

> 
> From: Peng Fan <peng.fan at nxp.com>
> 
> Support System suspend notification. Using a work struct to call pm_suspend.
> There is no way to pass suspend level to pm_suspend, so use MEM as of now.
> 
> - The choice of S2R(MEM) by default. The userspace can configure whatever
>   default behaviour expected as S2R, if issuing suspend from userspace.
> 
> - The userspace needs to keep the wakeup source enabled, otherwise the
>   system may never resume back.
> 
> Signed-off-by: Peng Fan <peng.fan at nxp.com>
> ---
> 
> V2:
>  Update commit log
>  Add comment for suspend_work
> 
>  .../firmware/arm_scmi/scmi_power_control.c    | 21 ++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/arm_scmi/scmi_power_control.c
> b/drivers/firmware/arm_scmi/scmi_power_control.c
> index 6eb7d2a4b6b1..21f467a92942 100644
> --- a/drivers/firmware/arm_scmi/scmi_power_control.c
> +++ b/drivers/firmware/arm_scmi/scmi_power_control.c
> @@ -50,6 +50,7 @@
>  #include <linux/reboot.h>
>  #include <linux/scmi_protocol.h>
>  #include <linux/slab.h>
> +#include <linux/suspend.h>
>  #include <linux/time64.h>
>  #include <linux/timer.h>
>  #include <linux/types.h>
> @@ -78,6 +79,7 @@ enum scmi_syspower_state {
>   * @reboot_nb: A notifier_block optionally used to track reboot progress
>   * @forceful_work: A worker used to trigger a forceful transition once a
>   *		   graceful has timed out.
> + * @suspend_work: A worker used to trigger system suspend
>   */
>  struct scmi_syspower_conf {
>  	struct device *dev;
> @@ -90,6 +92,7 @@ struct scmi_syspower_conf {
>  	struct notifier_block reboot_nb;
> 
>  	struct delayed_work forceful_work;
> +	struct work_struct suspend_work;
>  };
> 
>  #define userspace_nb_to_sconf(x)	\
> @@ -249,6 +252,9 @@ static void scmi_request_graceful_transition(struct
> scmi_syspower_conf *sc,
>  	case SCMI_SYSTEM_WARMRESET:
>  		orderly_reboot();
>  		break;
> +	case SCMI_SYSTEM_SUSPEND:
> +		schedule_work(&sc->suspend_work);
> +		break;
>  	default:
>  		break;
>  	}
> @@ -277,7 +283,8 @@ static int scmi_userspace_notifier(struct
> notifier_block *nb,
>  	struct scmi_system_power_state_notifier_report *er = data;
>  	struct scmi_syspower_conf *sc = userspace_nb_to_sconf(nb);
> 
> -	if (er->system_state >= SCMI_SYSTEM_POWERUP) {
> +	if (er->system_state >= SCMI_SYSTEM_MAX ||
> +	    er->system_state == SCMI_SYSTEM_POWERUP) {
>  		dev_err(sc->dev, "Ignoring unsupported system_state:
> 0x%X\n",
>  			er->system_state);
>  		return NOTIFY_DONE;
> @@ -315,6 +322,16 @@ static int scmi_userspace_notifier(struct
> notifier_block *nb,
>  	return NOTIFY_OK;
>  }
> 
> +static void scmi_suspend_work_func(struct work_struct *work) {
> +	struct scmi_syspower_conf *sc =
> +		container_of(work, struct scmi_syspower_conf,
> suspend_work);
> +
> +	pm_suspend(PM_SUSPEND_MEM);
> +
> +	sc->state = SCMI_SYSPOWER_IDLE;
> +}
> +
>  static int scmi_syspower_probe(struct scmi_device *sdev)  {
>  	int ret;
> @@ -338,6 +355,8 @@ static int scmi_syspower_probe(struct scmi_device
> *sdev)
>  	sc->userspace_nb.notifier_call = &scmi_userspace_notifier;
>  	sc->dev = &sdev->dev;
> 
> +	INIT_WORK(&sc->suspend_work, scmi_suspend_work_func);
> +
>  	return handle->notify_ops->devm_event_notifier_register(sdev,
> 
> SCMI_PROTOCOL_SYSTEM,
> 
> SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER,
> --
> 2.37.1