On Tue, Jun 17, 2025 at 04:34:48PM -0300, Hiago De Franco wrote:
> From: Hiago De Franco <[email protected]>
> 
> This helper function returns the current power status of a given generic
> power domain.
> 
> As example, remoteproc/imx_rproc.c can now use this function to check
> the power status of the remote core to properly set "attached" or
> "offline" modes.
> 
> Suggested-by: Ulf Hansson <[email protected]>
> Signed-off-by: Hiago De Franco <[email protected]>

Reviewed-by: Bjorn Andersson <[email protected]>

Regards,
Bjorn

> ---
> v4 -> v5:
> - s/dev_pm_genpd_is_on/dev_pm_genpd_is_on()/ in function description.
> - Updated function description to be explicit the function reflects the
>   current power status and that this might change after the function
>   returns, especially if the genpd is shared.
> 
> v3 -> v4:
> - New patch.
> ---
>  drivers/pmdomain/core.c   | 33 +++++++++++++++++++++++++++++++++
>  include/linux/pm_domain.h |  6 ++++++
>  2 files changed, 39 insertions(+)
> 
> diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
> index ff5c7f2b69ce..2f387e15cb75 100644
> --- a/drivers/pmdomain/core.c
> +++ b/drivers/pmdomain/core.c
> @@ -758,6 +758,39 @@ int dev_pm_genpd_rpm_always_on(struct device *dev, bool 
> on)
>  }
>  EXPORT_SYMBOL_GPL(dev_pm_genpd_rpm_always_on);
>  
> +/**
> + * dev_pm_genpd_is_on() - Get device's current power domain status
> + *
> + * @dev: Device to get the current power status
> + *
> + * This function checks whether the generic power domain associated with the
> + * given device is on or not by verifying if genpd_status_on equals
> + * GENPD_STATE_ON.
> + *
> + * Note: this function returns the power status of the genpd at the time of 
> the
> + * call. The power status may change after due to activity from other devices
> + * sharing the same genpd. Therefore, this information should not be relied 
> for
> + * long-term decisions about the device power state.
> + *
> + * Return: 'true' if the device's power domain is on, 'false' otherwise.
> + */
> +bool dev_pm_genpd_is_on(struct device *dev)
> +{
> +     struct generic_pm_domain *genpd;
> +     bool is_on;
> +
> +     genpd = dev_to_genpd_safe(dev);
> +     if (!genpd)
> +             return false;
> +
> +     genpd_lock(genpd);
> +     is_on = genpd_status_on(genpd);
> +     genpd_unlock(genpd);
> +
> +     return is_on;
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_genpd_is_on);
> +
>  /**
>   * pm_genpd_inc_rejected() - Adjust the rejected/usage counts for an 
> idle-state.
>   *
> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
> index 0b18160901a2..c12580b6579b 100644
> --- a/include/linux/pm_domain.h
> +++ b/include/linux/pm_domain.h
> @@ -301,6 +301,7 @@ void dev_pm_genpd_synced_poweroff(struct device *dev);
>  int dev_pm_genpd_set_hwmode(struct device *dev, bool enable);
>  bool dev_pm_genpd_get_hwmode(struct device *dev);
>  int dev_pm_genpd_rpm_always_on(struct device *dev, bool on);
> +bool dev_pm_genpd_is_on(struct device *dev);
>  
>  extern struct dev_power_governor simple_qos_governor;
>  extern struct dev_power_governor pm_domain_always_on_gov;
> @@ -393,6 +394,11 @@ static inline int dev_pm_genpd_rpm_always_on(struct 
> device *dev, bool on)
>       return -EOPNOTSUPP;
>  }
>  
> +static inline bool dev_pm_genpd_is_on(struct device *dev)
> +{
> +     return false;
> +}
> +
>  #define simple_qos_governor          (*(struct dev_power_governor *)(NULL))
>  #define pm_domain_always_on_gov              (*(struct dev_power_governor 
> *)(NULL))
>  #endif
> -- 
> 2.39.5
> 

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