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authorKrzysztof Kozlowski <k.kozlowski@samsung.com>2015-03-12 08:44:13 +0100
committerSebastian Reichel <sre@kernel.org>2015-03-13 23:15:52 +0100
commit03e81acce5568c7105dc5bef6984c8b0edfe8d45 (patch)
tree5a23f5c2245e9d4f170e644e2050638c225b51a1 /drivers/power
parent1a352462b5377ac68f5955d674b3460c7bac52a3 (diff)
power_supply: Increment power supply use counter when obtaining references
Increment the power_supply.use_cnt usage counter on: - power_supply_get_by_phandle() - power_supply_get_by_name() and decrement it on power_supply_put() call. This helps tracking of valid usage of power supply instance by consumers. The usage counter itself also allows safe calling of power_supply_get_property-like functions even when driver unregisters this power supply. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Sebastian Reichel <sre@kernel.org>
Diffstat (limited to 'drivers/power')
-rw-r--r--drivers/power/power_supply_core.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index b4ec14683b7f..2ed4a4a6b3c5 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -349,10 +349,16 @@ static int power_supply_match_device_by_name(struct device *dev, const void *dat
*/
struct power_supply *power_supply_get_by_name(const char *name)
{
+ struct power_supply *psy = NULL;
struct device *dev = class_find_device(power_supply_class, NULL, name,
power_supply_match_device_by_name);
- return dev ? dev_get_drvdata(dev) : NULL;
+ if (dev) {
+ psy = dev_get_drvdata(dev);
+ atomic_inc(&psy->use_cnt);
+ }
+
+ return psy;
}
EXPORT_SYMBOL_GPL(power_supply_get_by_name);
@@ -367,6 +373,7 @@ void power_supply_put(struct power_supply *psy)
{
might_sleep();
+ atomic_dec(&psy->use_cnt);
put_device(&psy->dev);
}
EXPORT_SYMBOL_GPL(power_supply_put);
@@ -393,6 +400,7 @@ struct power_supply *power_supply_get_by_phandle(struct device_node *np,
const char *property)
{
struct device_node *power_supply_np;
+ struct power_supply *psy = NULL;
struct device *dev;
power_supply_np = of_parse_phandle(np, property, 0);
@@ -404,7 +412,12 @@ struct power_supply *power_supply_get_by_phandle(struct device_node *np,
of_node_put(power_supply_np);
- return dev ? dev_get_drvdata(dev) : NULL;
+ if (dev) {
+ psy = dev_get_drvdata(dev);
+ atomic_inc(&psy->use_cnt);
+ }
+
+ return psy;
}
EXPORT_SYMBOL_GPL(power_supply_get_by_phandle);
#endif /* CONFIG_OF */