hwmon: (lm90) Add power control
The device lm90 can be controlled by the vcc rail.
Adding the regulator support to power on/off the vcc rail.
Enable the "vcc" regulator before accessing the device.
[JD: Rename variables to avoid confusion with registers.]
Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 03735c4..4c4c142 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -95,6 +95,7 @@
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/interrupt.h>
+#include <linux/regulator/consumer.h>
/*
* Addresses to scan
@@ -366,6 +367,7 @@
struct lm90_data {
struct device *hwmon_dev;
struct mutex update_lock;
+ struct regulator *regulator;
char valid; /* zero until following fields are valid */
unsigned long last_updated; /* in jiffies */
int kind;
@@ -1516,8 +1518,20 @@
struct device *dev = &client->dev;
struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
struct lm90_data *data;
+ struct regulator *regulator;
int err;
+ regulator = devm_regulator_get(dev, "vcc");
+ if (IS_ERR(regulator))
+ return PTR_ERR(regulator);
+
+ err = regulator_enable(regulator);
+ if (err < 0) {
+ dev_err(&client->dev,
+ "Failed to enable regulator: %d\n", err);
+ return err;
+ }
+
data = devm_kzalloc(&client->dev, sizeof(struct lm90_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
@@ -1525,6 +1539,8 @@
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
+ data->regulator = regulator;
+
/* Set the device type */
data->kind = id->driver_data;
if (data->kind == adm1032) {
@@ -1604,6 +1620,8 @@
lm90_remove_files(client, data);
exit_restore:
lm90_restore_conf(client, data);
+ regulator_disable(data->regulator);
+
return err;
}
@@ -1614,6 +1632,7 @@
hwmon_device_unregister(data->hwmon_dev);
lm90_remove_files(client, data);
lm90_restore_conf(client, data);
+ regulator_disable(data->regulator);
return 0;
}