From: Peng Fan <peng.fan@nxp.com>

Take platform_pm_ops as reference. Add pm ops for scmi_bus_type,
then the scmi devices under scmi bus could have their own hooks for
suspend, resume function.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/firmware/arm_scmi/bus.c | 45 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 1adef03894751dae9bb752b8c7f86e5d01c5d4fd..2d1ef73cb6d39ac611afa5d0008c46515e297b93 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -323,6 +323,50 @@ static struct attribute *scmi_device_attributes_attrs[] = {
 };
 ATTRIBUTE_GROUPS(scmi_device_attributes);
 
+#ifdef CONFIG_SUSPEND
+static int scmi_pm_suspend(struct device *dev)
+{
+	const struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->suspend)
+			ret = drv->pm->suspend(dev);
+	}
+
+	return ret;
+}
+
+static int scmi_pm_resume(struct device *dev)
+{
+	const struct device_driver *drv = dev->driver;
+	int ret = 0;
+
+	if (!drv)
+		return 0;
+
+	if (drv->pm) {
+		if (drv->pm->resume)
+			ret = drv->pm->resume(dev);
+	}
+
+	return ret;
+}
+
+static const struct dev_pm_ops scmi_dev_pm_ops = {
+	.suspend = scmi_pm_suspend,
+	.resume = scmi_pm_resume,
+};
+#else
+static const struct dev_pm_ops scmi_dev_pm_ops = {
+	.suspend = NULL,
+	.resume = NULL,
+};
+#endif
+
 const struct bus_type scmi_bus_type = {
 	.name =	"scmi_protocol",
 	.match = scmi_dev_match,
@@ -330,6 +374,7 @@ const struct bus_type scmi_bus_type = {
 	.remove = scmi_dev_remove,
 	.uevent	= scmi_device_uevent,
 	.dev_groups = scmi_device_attributes_groups,
+	.pm = &scmi_dev_pm_ops,
 };
 EXPORT_SYMBOL_GPL(scmi_bus_type);
 

-- 
2.37.1

On Fri, Jun 20, 2025 at 11:37:13AM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> Take platform_pm_ops as reference. Add pm ops for scmi_bus_type,
> then the scmi devices under scmi bus could have their own hooks for
> suspend, resume function.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/firmware/arm_scmi/bus.c | 45 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
> index 1adef03894751dae9bb752b8c7f86e5d01c5d4fd..2d1ef73cb6d39ac611afa5d0008c46515e297b93 100644
> --- a/drivers/firmware/arm_scmi/bus.c
> +++ b/drivers/firmware/arm_scmi/bus.c
> @@ -323,6 +323,50 @@ static struct attribute *scmi_device_attributes_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(scmi_device_attributes);
>  
> +#ifdef CONFIG_SUSPEND
> +static int scmi_pm_suspend(struct device *dev)
> +{
> +	const struct device_driver *drv = dev->driver;
> +	int ret = 0;
> +
> +	if (!drv)
> +		return 0;
> +
> +	if (drv->pm) {
> +		if (drv->pm->suspend)
> +			ret = drv->pm->suspend(dev);
> +	}
> +
> +	return ret;
> +}

These could be done on one line:

static int scmi_pm_suspend(struct device *dev)
{
	const struct device_driver *drv = dev->driver;

	if (drv && drv->pm && drv->pm->suspend)
		return drv->pm->suspend(dev);

	return 0;
}

regards,
dan carpenter