[PATCH 2/7] i3c: master: Allow controller drivers to select runtime PM device

[Adrian Hunter <adrian.hunter@intel.com>]

Some I3C controller drivers need runtime PM to operate on a device other
than the parent device.  To support that, add an rpm_dev pointer to
struct i3c_master_controller so drivers can specify which device should
be used for runtime power management.

If a driver does not set rpm_dev explicitly, default to using the parent
device to maintain existing behaviour.

Update the runtime PM helpers to use rpm_dev instead of dev.parent.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/i3c/master.c       | 9 ++++++---
 include/linux/i3c/master.h | 2 ++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 49fb6e30a68e..bcc493dc9d04 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -108,10 +108,10 @@ static struct i3c_master_controller *dev_to_i3cmaster(struct device *dev)
 
 static int __must_check i3c_master_rpm_get(struct i3c_master_controller *master)
 {
-	int ret = master->rpm_allowed ? pm_runtime_resume_and_get(master->dev.parent) : 0;
+	int ret = master->rpm_allowed ? pm_runtime_resume_and_get(master->rpm_dev) : 0;
 
 	if (ret < 0) {
-		dev_err(master->dev.parent, "runtime resume failed, error %d\n", ret);
+		dev_err(master->rpm_dev, "runtime resume failed, error %d\n", ret);
 		return ret;
 	}
 	return 0;
@@ -120,7 +120,7 @@ static int __must_check i3c_master_rpm_get(struct i3c_master_controller *master)
 static void i3c_master_rpm_put(struct i3c_master_controller *master)
 {
 	if (master->rpm_allowed)
-		pm_runtime_put_autosuspend(master->dev.parent);
+		pm_runtime_put_autosuspend(master->rpm_dev);
 }
 
 int i3c_bus_rpm_get(struct i3c_bus *bus)
@@ -2975,6 +2975,9 @@ int i3c_master_register(struct i3c_master_controller *master,
 	INIT_LIST_HEAD(&master->boardinfo.i2c);
 	INIT_LIST_HEAD(&master->boardinfo.i3c);
 
+	if (!master->rpm_dev)
+		master->rpm_dev = parent;
+
 	ret = i3c_master_rpm_get(master);
 	if (ret)
 		return ret;
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index af2bb48363ba..4be67a902dd8 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -501,6 +501,7 @@ struct i3c_master_controller_ops {
  *	 registered to the I2C subsystem to be as transparent as possible to
  *	 existing I2C drivers
  * @ops: master operations. See &struct i3c_master_controller_ops
+ * @rpm_dev: Runtime PM device
  * @secondary: true if the master is a secondary master
  * @init_done: true when the bus initialization is done
  * @hotjoin: true if the master support hotjoin
@@ -526,6 +527,7 @@ struct i3c_master_controller {
 	struct i3c_dev_desc *this;
 	struct i2c_adapter i2c;
 	const struct i3c_master_controller_ops *ops;
+	struct device *rpm_dev;
 	unsigned int secondary : 1;
 	unsigned int init_done : 1;
 	unsigned int hotjoin: 1;
-- 
2.51.0