hwmon: (powr1220) 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/powr1220.c b/drivers/hwmon/powr1220.c
index 5f9ca6543530d9b84f62c712849d187593892a5b..06a2c56016d11776327d5fea147eb287e57932d6 100644 (file)
--- a/drivers/hwmon/powr1220.c
+++ b/drivers/hwmon/powr1220.c
@@ -16,7 +16,6 @@
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
-#include <linux/mutex.h>
 #include <linux/delay.h>
 
 #define ADC_STEP_MV                    2
@@ -75,7 +74,6 @@ enum powr1220_adc_values {
 
 struct powr1220_data {
        struct i2c_client *client;
-       struct mutex update_lock;
        u8 max_channels;
        bool adc_valid[MAX_POWR1220_ADC_VALUES];
         /* the next value is in jiffies */
@@ -111,8 +109,6 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
        int result;
        int adc_range = 0;
 
-       mutex_lock(&data->update_lock);
-
        if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
            !data->adc_valid[ch_num]) {
                /*
@@ -128,8 +124,8 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
                /* set the attenuator and mux */
                result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
                                                   adc_range | ch_num);
-               if (result)
-                       goto exit;
+               if (result < 0)
+                       return result;
 
                /*
                 * wait at least Tconvert time (200 us) for the
@@ -140,14 +136,14 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
                /* get the ADC reading */
                result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
                if (result < 0)
-                       goto exit;
+                       return result;
 
                reading = result >> 4;
 
                /* get the upper half of the reading */
                result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
                if (result < 0)
-                       goto exit;
+                       return result;
 
                reading |= result << 4;
 
@@ -163,10 +159,6 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
        } else {
                result = data->adc_values[ch_num];
        }
-
-exit:
-       mutex_unlock(&data->update_lock);
-
        return result;
 }
 
@@ -302,7 +294,6 @@ static int powr1220_probe(struct i2c_client *client)
                break;
        }
 
-       mutex_init(&data->update_lock);
        data->client = client;
 
        hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,