hwmon: (adt7475) Change show functions to return error data correctly

Change update device function to return an error pointer if needed,
and report the error to user space.

Signed-off-by: Tokunori Ikegami <ikegami@allied-telesis.co.jp>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
[groeck: Clarified/updated description]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 9f7e1a5..90837f7 100644 (file)
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -325,6 +325,9 @@ static ssize_t show_voltage(struct device *dev, struct device_attribute *attr,
        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
        unsigned short val;
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        switch (sattr->nr) {
        case ALARM:
                return sprintf(buf, "%d\n",
@@ -380,6 +383,9 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *attr,
        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
        int out;
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        switch (sattr->nr) {
        case HYSTERSIS:
                mutex_lock(&data->lock);
@@ -624,6 +630,9 @@ static ssize_t show_point2(struct device *dev, struct device_attribute *attr,
        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
        int out, val;
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        mutex_lock(&data->lock);
        out = (data->range[sattr->index] >> 4) & 0x0F;
        val = reg2temp(data, data->temp[AUTOMIN][sattr->index]);
@@ -682,6 +691,9 @@ static ssize_t show_tach(struct device *dev, struct device_attribute *attr,
        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
        int out;
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        if (sattr->nr == ALARM)
                out = (data->alarms >> (sattr->index + 10)) & 1;
        else
@@ -719,6 +731,9 @@ static ssize_t show_pwm(struct device *dev, struct device_attribute *attr,
        struct adt7475_data *data = adt7475_update_device(dev);
        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->pwm[sattr->nr][sattr->index]);
 }
 
@@ -728,6 +743,9 @@ static ssize_t show_pwmchan(struct device *dev, struct device_attribute *attr,
        struct adt7475_data *data = adt7475_update_device(dev);
        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->pwmchan[sattr->index]);
 }
 
@@ -737,6 +755,9 @@ static ssize_t show_pwmctrl(struct device *dev, struct device_attribute *attr,
        struct adt7475_data *data = adt7475_update_device(dev);
        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->pwmctl[sattr->index]);
 }
 
@@ -944,6 +965,9 @@ static ssize_t show_pwmfreq(struct device *dev, struct device_attribute *attr,
        int i = clamp_val(data->range[sattr->index] & 0xf, 0,
                          ARRAY_SIZE(pwmfreq_table) - 1);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", pwmfreq_table[i]);
 }
 
@@ -1034,6 +1058,10 @@ static ssize_t cpu0_vid_show(struct device *dev,
                             struct device_attribute *devattr, char *buf)
 {
        struct adt7475_data *data = adt7475_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", vid_from_reg(data->vid, data->vrm));
 }
 
@@ -1677,7 +1705,9 @@ static int adt7475_probe(struct i2c_client *client,
                         (data->bypass_attn & (1 << 4)) ? " in4" : "");
 
        /* Limits and settings, should never change update more than once */
-       adt7475_update_limits(client);
+       ret = adt7475_update_limits(client);
+       if (ret)
+               goto eremove;
 
        return 0;
 
@@ -1876,13 +1906,19 @@ static struct adt7475_data *adt7475_update_device(struct device *dev)
 {
        struct i2c_client *client = to_i2c_client(dev);
        struct adt7475_data *data = i2c_get_clientdata(client);
+       int ret;
 
        mutex_lock(&data->lock);
 
        /* Measurement values update every 2 seconds */
        if (time_after(jiffies, data->measure_updated + HZ * 2) ||
            !data->valid) {
-               adt7475_update_measure(dev);
+               ret = adt7475_update_measure(dev);
+               if (ret) {
+                       data->valid = false;
+                       mutex_unlock(&data->lock);
+                       return ERR_PTR(ret);
+               }
                data->measure_updated = jiffies;
                data->valid = true;
        }