hwmon: (lm73) Add support for max/min alarms
Add support for temp1_min_alarm and temp1_max_alarm
Signed-off-by: Chris Verges <kg4ysn@gmail.com>
[linux@roeck-us.net: cleanup; dropped platform data and interrupt support]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/Documentation/hwmon/lm73 b/Documentation/hwmon/lm73
index 782b3e1..8af059d 100644
--- a/Documentation/hwmon/lm73
+++ b/Documentation/hwmon/lm73
@@ -77,3 +77,14 @@
where 'x' is the output from 'update_interval' and 'g(x)' is the
resolution in degrees C per LSB.
+
+Alarm Support
+-------------
+
+The LM73 features a simple over-temperature alarm mechanism. This
+feature is exposed via the sysfs attributes.
+
+The attributes 'temp1_max_alarm' and 'temp1_min_alarm' are flags
+provided by the LM73 that indicate whether the measured temperature has
+passed the 'temp1_max' and 'temp1_min' thresholds, respectively. These
+values _must_ be read to clear the registers on the LM73.
diff --git a/drivers/hwmon/lm73.c b/drivers/hwmon/lm73.c
index 0b19f03..9bde964 100644
--- a/drivers/hwmon/lm73.c
+++ b/drivers/hwmon/lm73.c
@@ -8,6 +8,7 @@
* Guillaume Ligneul <guillaume.ligneul@gmail.com>
* Adrien Demarez <adrien.demarez@bolloretelecom.eu>
* Jeremy Laine <jeremy.laine@bolloretelecom.eu>
+ * Chris Verges <kg4ysn@gmail.com>
*
* This software program is licensed subject to the GNU General Public License
* (GPL).Version 2,June 1991, available at
@@ -43,6 +44,9 @@
#define LM73_CTRL_RES_MASK (BIT(5) | BIT(6))
#define LM73_CTRL_TO_MASK BIT(7)
+#define LM73_CTRL_HI_SHIFT 2
+#define LM73_CTRL_LO_SHIFT 1
+
static const unsigned short lm73_convrates[] = {
14, /* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */
28, /* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */
@@ -140,6 +144,28 @@
return scnprintf(buf, PAGE_SIZE, "%hu\n", lm73_convrates[res]);
}
+static ssize_t show_maxmin_alarm(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct lm73_data *data = i2c_get_clientdata(client);
+ s32 ctrl;
+
+ mutex_lock(&data->lock);
+ ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL);
+ if (ctrl < 0)
+ goto abort;
+ data->ctrl = ctrl;
+ mutex_unlock(&data->lock);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", (ctrl >> attr->index) & 1);
+
+abort:
+ mutex_unlock(&data->lock);
+ return ctrl;
+}
+
/*-----------------------------------------------------------------------*/
/* sysfs attributes for hwmon */
@@ -152,12 +178,18 @@
show_temp, NULL, LM73_REG_INPUT);
static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
show_convrate, set_convrate, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO,
+ show_maxmin_alarm, NULL, LM73_CTRL_HI_SHIFT);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO,
+ show_maxmin_alarm, NULL, LM73_CTRL_LO_SHIFT);
static struct attribute *lm73_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_update_interval.dev_attr.attr,
+ &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+ &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
NULL
};