Re: [PATCH v6 1/2] clocksource: acpi_pm: Add external callback for suspend/resume

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 8/12/24 8:41 PM, Marek Maslanka wrote:
> Provides the capability to register an external callback for the ACPI PM
> timer, which is called during the suspend and resume processes.
> 
> Signed-off-by: Marek Maslanka <mmaslanka@google.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans



> 
> ---
> Changes in v6:
> - Add the acpi_pmtmr_unregister_suspend_resume_callback function to remove callback
> - Add EXPORT_SYMBOL_GPL to the added functions
> - Link to v5: https://lore.kernel.org/lkml/20240812043741.3434744-1-mmaslanka@google.com/
> ---
> ---
>  drivers/clocksource/acpi_pm.c | 32 ++++++++++++++++++++++++++++++++
>  include/linux/acpi_pmtmr.h    | 13 +++++++++++++
>  2 files changed, 45 insertions(+)
> 
> diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
> index 82338773602ca..b4330a01a566b 100644
> --- a/drivers/clocksource/acpi_pm.c
> +++ b/drivers/clocksource/acpi_pm.c
> @@ -25,6 +25,10 @@
>  #include <asm/io.h>
>  #include <asm/time.h>
>  
> +static void *suspend_resume_cb_data;
> +
> +static void (*suspend_resume_callback)(void *data, bool suspend);
> +
>  /*
>   * The I/O port the PMTMR resides at.
>   * The location is detected during setup_arch(),
> @@ -58,6 +62,32 @@ u32 acpi_pm_read_verified(void)
>  	return v2;
>  }
>  
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
> +{
> +	suspend_resume_callback = cb;
> +	suspend_resume_cb_data = data;
> +}
> +EXPORT_SYMBOL_GPL(acpi_pmtmr_register_suspend_resume_callback);
> +
> +void acpi_pmtmr_unregister_suspend_resume_callback(void)
> +{
> +	suspend_resume_callback = NULL;
> +	suspend_resume_cb_data = NULL;
> +}
> +EXPORT_SYMBOL_GPL(acpi_pmtmr_unregister_suspend_resume_callback);
> +
> +static void acpi_pm_suspend(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, true);
> +}
> +
> +static void acpi_pm_resume(struct clocksource *cs)
> +{
> +	if (suspend_resume_callback)
> +		suspend_resume_callback(suspend_resume_cb_data, false);
> +}
> +
>  static u64 acpi_pm_read(struct clocksource *cs)
>  {
>  	return (u64)read_pmtmr();
> @@ -69,6 +99,8 @@ static struct clocksource clocksource_acpi_pm = {
>  	.read		= acpi_pm_read,
>  	.mask		= (u64)ACPI_PM_MASK,
>  	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
> +	.suspend	= acpi_pm_suspend,
> +	.resume		= acpi_pm_resume,
>  };
>  
>  
> diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
> index 50d88bf1498d7..0ded9220d379c 100644
> --- a/include/linux/acpi_pmtmr.h
> +++ b/include/linux/acpi_pmtmr.h
> @@ -26,6 +26,19 @@ static inline u32 acpi_pm_read_early(void)
>  	return acpi_pm_read_verified() & ACPI_PM_MASK;
>  }
>  
> +/**
> + * Register callback for suspend and resume event
> + *
> + * @cb Callback triggered on suspend and resume
> + * @data Data passed with the callback
> + */
> +void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data);
> +
> +/**
> + * Remove registered callback for suspend and resume event
> + */
> +void acpi_pmtmr_unregister_suspend_resume_callback(void);
> +
>  #else
>  
>  static inline u32 acpi_pm_read_early(void)