diff options
| author | Michael Abbott <michael@araneidae.co.uk> | 2009-09-21 17:04:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 07:17:49 -0700 |
| commit | 905ffdc35e50844ab45bbc59d5302238844f8526 (patch) | |
| tree | 13f5fcb88fe9b8f049181234749ea715b509e34b /drivers | |
| parent | f266889517252bc697e7103bcd6ed46bdf2c1579 (diff) | |
drivers/hwmon/adm1021.c: add low_power support for adm1021 driver
Occasionally it is helpful to be able to turn a temperature sensor off
(for example if it's making unwanted electrical noise). This patch
adds a sysfs node to put any adm1021 compatible device into low power mode.
Signed-off-by: Michael Abbott <michael.abbott@diamond.ac.uk>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/hwmon/adm1021.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/hwmon/adm1021.c b/drivers/hwmon/adm1021.c index de84398775b..afc59431812 100644 --- a/drivers/hwmon/adm1021.c +++ b/drivers/hwmon/adm1021.c @@ -83,6 +83,7 @@ struct adm1021_data { struct mutex update_lock; char valid; /* !=0 if following fields are valid */ + char low_power; /* !=0 if device in low power mode */ unsigned long last_updated; /* In jiffies */ int temp_max[2]; /* Register values */ @@ -213,6 +214,35 @@ static ssize_t set_temp_min(struct device *dev, return count; } +static ssize_t show_low_power(struct device *dev, + struct device_attribute *devattr, char *buf) +{ + struct adm1021_data *data = adm1021_update_device(dev); + return sprintf(buf, "%d\n", data->low_power); +} + +static ssize_t set_low_power(struct device *dev, + struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct adm1021_data *data = i2c_get_clientdata(client); + int low_power = simple_strtol(buf, NULL, 10) != 0; + + mutex_lock(&data->update_lock); + if (low_power != data->low_power) { + int config = i2c_smbus_read_byte_data( + client, ADM1021_REG_CONFIG_R); + data->low_power = low_power; + i2c_smbus_write_byte_data(client, ADM1021_REG_CONFIG_W, + (config & 0xBF) | (low_power << 6)); + } + mutex_unlock(&data->update_lock); + + return count; +} + + static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max, 0); @@ -230,6 +260,7 @@ static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3); static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2); static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); +static DEVICE_ATTR(low_power, S_IWUSR | S_IRUGO, show_low_power, set_low_power); static struct attribute *adm1021_attributes[] = { &sensor_dev_attr_temp1_max.dev_attr.attr, @@ -244,6 +275,7 @@ static struct attribute *adm1021_attributes[] = { &sensor_dev_attr_temp2_min_alarm.dev_attr.attr, &sensor_dev_attr_temp2_fault.dev_attr.attr, &dev_attr_alarms.attr, + &dev_attr_low_power.attr, NULL }; |