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

Adrian Hunter
2026-01-29T18:19:03Z

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