[PATCH v9 2/4] pm: add to_power_supply macro to the API

[Ognjen Galic <smclt30p@gmail.com>]

This patch adds the to_power_supply macro to upcast
a device to a power_supply struct.

This is needed because the same piece of code using
container_of is used in various other places, so we
abstract away such low-level operations via a macro.
---

v9:
* Split the pm changes from the thinkpad_acpi patch
into its own patch

Signed-off-by: Ognjen Galic <smclt30p@gmail.com>
---
 drivers/power/supply/power_supply_core.c | 2 +-
 include/linux/power_supply.h             | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 82f998a..feac7b0 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -668,7 +668,7 @@ EXPORT_SYMBOL_GPL(power_supply_powers);
 
 static void power_supply_dev_release(struct device *dev)
 {
-	struct power_supply *psy = container_of(dev, struct power_supply, dev);
+	struct power_supply *psy = to_power_supply(dev);
 	dev_dbg(dev, "%s\n", __func__);
 	kfree(psy);
 }
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 79e90b3..f0139b4 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -371,6 +371,8 @@ devm_power_supply_register_no_ws(struct device *parent,
 extern void power_supply_unregister(struct power_supply *psy);
 extern int power_supply_powers(struct power_supply *psy, struct device *dev);
 
+#define to_power_supply(device) container_of(device, struct power_supply, dev)
+
 extern void *power_supply_get_drvdata(struct power_supply *psy);
 /* For APM emulation, think legacy userspace. */
 extern struct class *power_supply_class;
-- 
2.7.4