diff options
Diffstat (limited to 'drivers/hwmon/tmp401.c')
| -rw-r--r-- | drivers/hwmon/tmp401.c | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/drivers/hwmon/tmp401.c b/drivers/hwmon/tmp401.c index 061146288e41..fa6af51b300d 100644 --- a/drivers/hwmon/tmp401.c +++ b/drivers/hwmon/tmp401.c @@ -127,6 +127,8 @@ struct tmp401_data { unsigned long last_updated; /* in jiffies */ enum chips kind; + unsigned int update_interval; /* in milliseconds */ + /* register values */ u8 status; u8 config; @@ -194,10 +196,13 @@ static struct tmp401_data *tmp401_update_device(struct device *dev) struct tmp401_data *data = i2c_get_clientdata(client); struct tmp401_data *ret = data; int val; + unsigned long next_update; mutex_lock(&data->update_lock); - if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { + next_update = data->last_updated + + msecs_to_jiffies(data->update_interval) + 1; + if (time_after(jiffies, next_update) || !data->valid) { val = i2c_smbus_read_byte_data(client, TMP401_STATUS); if (val < 0) { ret = ERR_PTR(val); @@ -372,6 +377,46 @@ static ssize_t reset_temp_history(struct device *dev, return count; } +static ssize_t show_update_interval(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tmp401_data *data = i2c_get_clientdata(client); + + return sprintf(buf, "%u\n", data->update_interval); +} + +static ssize_t set_update_interval(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tmp401_data *data = i2c_get_clientdata(client); + unsigned long val; + int err, rate; + + err = kstrtoul(buf, 10, &val); + if (err) + return err; + + /* + * For valid rates, interval can be calculated as + * interval = (1 << (7 - rate)) * 125; + * Rounded rate is therefore + * rate = 7 - __fls(interval * 4 / (125 * 3)); + * Use clamp_val() to avoid overflows, and to ensure valid input + * for __fls. + */ + val = clamp_val(val, 125, 16000); + rate = 7 - __fls(val * 4 / (125 * 3)); + mutex_lock(&data->update_lock); + i2c_smbus_write_byte_data(client, TMP401_CONVERSION_RATE_WRITE, rate); + data->update_interval = (1 << (7 - rate)) * 125; + mutex_unlock(&data->update_lock); + + return count; +} + static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0); static SENSOR_DEVICE_ATTR_2(temp1_min, S_IWUSR | S_IRUGO, show_temp, store_temp, 1, 0); @@ -405,6 +450,9 @@ static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_status, NULL, static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_status, NULL, TMP401_STATUS_REMOTE_CRIT); +static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval, + set_update_interval); + static struct attribute *tmp401_attributes[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_temp1_min.dev_attr.attr, @@ -425,6 +473,8 @@ static struct attribute *tmp401_attributes[] = { &sensor_dev_attr_temp2_min_alarm.dev_attr.attr, &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr, + &dev_attr_update_interval.attr, + NULL }; @@ -466,9 +516,11 @@ static const struct attribute_group tmp411_group = { static void tmp401_init_client(struct i2c_client *client) { int config, config_orig; + struct tmp401_data *data = i2c_get_clientdata(client); /* Set the conversion rate to 2 Hz */ i2c_smbus_write_byte_data(client, TMP401_CONVERSION_RATE_WRITE, 5); + data->update_interval = 500; /* Start conversions (disable shutdown if necessary) */ config = i2c_smbus_read_byte_data(client, TMP401_CONFIG_READ); |