hwmon: (lochnagar-hwmon) Rely on subsystem locking

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/lochnagar-hwmon.c b/drivers/hwmon/lochnagar-hwmon.c
index 5202dddfd61efc3521b83c840575994e261f4fd2..c1ba72f6132ef0882092621ae334ef483c238916 100644 (file)
--- a/drivers/hwmon/lochnagar-hwmon.c
+++ b/drivers/hwmon/lochnagar-hwmon.c
@@ -10,7 +10,6 @@
 
 #include <linux/delay.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/math64.h>
 #include <linux/mfd/lochnagar.h>
 #include <linux/mfd/lochnagar2_regs.h>
@@ -42,9 +41,6 @@ struct lochnagar_hwmon {
        struct regmap *regmap;
 
        long power_nsamples[ARRAY_SIZE(lochnagar_chan_names)];
-
-       /* Lock to ensure only a single sensor is read at a time */
-       struct mutex sensor_lock;
 };
 
 enum lochnagar_measure_mode {
@@ -178,26 +174,20 @@ static int read_sensor(struct device *dev, int chan,
        u32 data;
        int ret;
 
-       mutex_lock(&priv->sensor_lock);
-
        ret = do_measurement(regmap, chan, mode, nsamples);
        if (ret < 0) {
                dev_err(dev, "Failed to perform measurement: %d\n", ret);
-               goto error;
+               return ret;
        }
 
        ret = request_data(regmap, chan, &data);
        if (ret < 0) {
                dev_err(dev, "Failed to read measurement: %d\n", ret);
-               goto error;
+               return ret;
        }
 
        *val = float_to_long(data, precision);
-
-error:
-       mutex_unlock(&priv->sensor_lock);
-
-       return ret;
+       return 0;
 }
 
 static int read_power(struct device *dev, int chan, long *val)
@@ -378,8 +368,6 @@ static int lochnagar_hwmon_probe(struct platform_device *pdev)
        if (!priv)
                return -ENOMEM;
 
-       mutex_init(&priv->sensor_lock);
-
        priv->regmap = dev_get_regmap(dev->parent, NULL);
        if (!priv->regmap) {
                dev_err(dev, "No register map found\n");