hwmon: (adt7470) Create functions for updating readings and limits

Split the body of adt7470_update_device() into two helper functions
adt7470_update_sensors() and adt7470_update_limits(). Although neither
of the new helpers returns an error yet lay the groundwork for
propagating failures through to the sysfs readers.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20201019223423.31488-2-chris.packham@alliedtelesis.co.nz
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
index 740f39a..2e8feac 100644 (file)
--- a/drivers/hwmon/adt7470.c
+++ b/drivers/hwmon/adt7470.c
@@ -270,37 +270,11 @@ static int adt7470_update_thread(void *p)
        return 0;
 }
 
-static struct adt7470_data *adt7470_update_device(struct device *dev)
+static int adt7470_update_sensors(struct adt7470_data *data)
 {
-       struct adt7470_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
-       unsigned long local_jiffies = jiffies;
        u8 cfg;
        int i;
-       int need_sensors = 1;
-       int need_limits = 1;
-
-       /*
-        * Figure out if we need to update the shadow registers.
-        * Lockless means that we may occasionally report out of
-        * date data.
-        */
-       if (time_before(local_jiffies, data->sensors_last_updated +
-                       SENSOR_REFRESH_INTERVAL) &&
-           data->sensors_valid)
-               need_sensors = 0;
-
-       if (time_before(local_jiffies, data->limits_last_updated +
-                       LIMIT_REFRESH_INTERVAL) &&
-           data->limits_valid)
-               need_limits = 0;
-
-       if (!need_sensors && !need_limits)
-               return data;
-
-       mutex_lock(&data->lock);
-       if (!need_sensors)
-               goto no_sensor_update;
 
        if (!data->temperatures_probed)
                adt7470_read_temperatures(client, data);
@@ -352,12 +326,13 @@ static struct adt7470_data *adt7470_update_device(struct device *dev)
        data->alarms_mask = adt7470_read_word_data(client,
                                                   ADT7470_REG_ALARM1_MASK);
 
-       data->sensors_last_updated = local_jiffies;
-       data->sensors_valid = 1;
+       return 0;
+}
 
-no_sensor_update:
-       if (!need_limits)
-               goto out;
+static int adt7470_update_limits(struct adt7470_data *data)
+{
+       struct i2c_client *client = data->client;
+       int i;
 
        for (i = 0; i < ADT7470_TEMP_COUNT; i++) {
                data->temp_min[i] = i2c_smbus_read_byte_data(client,
@@ -382,12 +357,55 @@ no_sensor_update:
                                                ADT7470_REG_PWM_TMIN(i));
        }
 
-       data->limits_last_updated = local_jiffies;
-       data->limits_valid = 1;
+       return 0;
+}
 
+static struct adt7470_data *adt7470_update_device(struct device *dev)
+{
+       struct adt7470_data *data = dev_get_drvdata(dev);
+       unsigned long local_jiffies = jiffies;
+       int need_sensors = 1;
+       int need_limits = 1;
+       int err;
+
+       /*
+        * Figure out if we need to update the shadow registers.
+        * Lockless means that we may occasionally report out of
+        * date data.
+        */
+       if (time_before(local_jiffies, data->sensors_last_updated +
+                       SENSOR_REFRESH_INTERVAL) &&
+           data->sensors_valid)
+               need_sensors = 0;
+
+       if (time_before(local_jiffies, data->limits_last_updated +
+                       LIMIT_REFRESH_INTERVAL) &&
+           data->limits_valid)
+               need_limits = 0;
+
+       if (!need_sensors && !need_limits)
+               return data;
+
+       mutex_lock(&data->lock);
+       if (need_sensors) {
+               err = adt7470_update_sensors(data);
+               if (err < 0)
+                       goto out;
+               data->sensors_last_updated = local_jiffies;
+               data->sensors_valid = 1;
+       }
+
+       if (need_limits) {
+               err = adt7470_update_limits(data);
+               if (err < 0)
+                       goto out;
+               data->limits_last_updated = local_jiffies;
+               data->limits_valid = 1;
+       }
 out:
        mutex_unlock(&data->lock);
-       return data;
+
+       return err < 0 ? ERR_PTR(err) : data;
 }
 
 static ssize_t auto_update_interval_show(struct device *dev,
@@ -395,6 +413,10 @@ static ssize_t auto_update_interval_show(struct device *dev,
                                         char *buf)
 {
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->auto_update_interval);
 }
 
@@ -422,6 +444,10 @@ static ssize_t num_temp_sensors_show(struct device *dev,
                                     char *buf)
 {
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->num_temp_sensors);
 }
 
@@ -451,6 +477,10 @@ static ssize_t temp_min_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", 1000 * data->temp_min[attr->index]);
 }
 
@@ -483,6 +513,10 @@ static ssize_t temp_max_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", 1000 * data->temp_max[attr->index]);
 }
 
@@ -515,6 +549,10 @@ static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", 1000 * data->temp[attr->index]);
 }
 
@@ -524,6 +562,9 @@ static ssize_t alarm_mask_show(struct device *dev,
 {
        struct adt7470_data *data = adt7470_update_device(dev);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%x\n", data->alarms_mask);
 }
 
@@ -554,6 +595,9 @@ static ssize_t fan_max_show(struct device *dev,
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        if (FAN_DATA_VALID(data->fan_max[attr->index]))
                return sprintf(buf, "%d\n",
                               FAN_PERIOD_TO_RPM(data->fan_max[attr->index]));
@@ -590,6 +634,9 @@ static ssize_t fan_min_show(struct device *dev,
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        if (FAN_DATA_VALID(data->fan_min[attr->index]))
                return sprintf(buf, "%d\n",
                               FAN_PERIOD_TO_RPM(data->fan_min[attr->index]));
@@ -626,6 +673,9 @@ static ssize_t fan_show(struct device *dev, struct device_attribute *devattr,
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
 
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        if (FAN_DATA_VALID(data->fan[attr->index]))
                return sprintf(buf, "%d\n",
                               FAN_PERIOD_TO_RPM(data->fan[attr->index]));
@@ -637,6 +687,10 @@ static ssize_t force_pwm_max_show(struct device *dev,
                                  struct device_attribute *devattr, char *buf)
 {
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->force_pwm_max);
 }
 
@@ -670,6 +724,10 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *devattr,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->pwm[attr->index]);
 }
 
@@ -763,6 +821,10 @@ static ssize_t pwm_max_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->pwm_max[attr->index]);
 }
 
@@ -794,6 +856,10 @@ static ssize_t pwm_min_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", data->pwm_min[attr->index]);
 }
 
@@ -825,6 +891,10 @@ static ssize_t pwm_tmax_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        /* the datasheet says that tmax = tmin + 20C */
        return sprintf(buf, "%d\n", 1000 * (20 + data->pwm_tmin[attr->index]));
 }
@@ -834,6 +904,10 @@ static ssize_t pwm_tmin_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", 1000 * data->pwm_tmin[attr->index]);
 }
 
@@ -866,6 +940,10 @@ static ssize_t pwm_auto_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
        return sprintf(buf, "%d\n", 1 + data->pwm_automatic[attr->index]);
 }
 
@@ -911,8 +989,12 @@ static ssize_t pwm_auto_temp_show(struct device *dev,
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct adt7470_data *data = adt7470_update_device(dev);
-       u8 ctrl = data->pwm_auto_temp[attr->index];
+       u8 ctrl;
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
 
+       ctrl = data->pwm_auto_temp[attr->index];
        if (ctrl)
                return sprintf(buf, "%d\n", 1 << (ctrl - 1));
        else