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authorEduardo Valentin <eduardo.valentin@ti.com>2013-07-16 14:54:55 -0400
committerEduardo Valentin <eduardo.valentin@ti.com>2013-12-04 09:34:24 -0400
commit22e731838b0e337fed5f16c67aa0b954028dfe93 (patch)
tree1078bfdd1249fd0f5c3c7c49238ff749626fd8fa /drivers/hwmon
parent77cff5926a14e80d4545be5841d5938b87b654a4 (diff)
hwmon: lm75: expose to thermal fw via DT nodes
This patch adds to lm75 temperature sensor the possibility to expose itself as thermal zone device, registered on the thermal framework. The thermal zone is built only if a device tree node describing a thermal zone for this sensor is present inside the lm75 DT node. Otherwise, the driver behavior will be the same. Note: This patch has also been reviewed by Jean D. He has requested to perform a wider inspection of possible users of thermal and hwmon interaction API. On the other hand, the change on this patch is acceptable on first step of overall code change. Cc: Jean Delvare <khali@linux-fr.org> Cc: lm-sensors@lm-sensors.org Cc: linux-kernel@vger.kernel.org Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/lm75.c35
1 files changed, 30 insertions, 5 deletions
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 7e3ef134f1d2..84a55eacd903 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -27,6 +27,8 @@
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/thermal.h>
#include "lm75.h"
@@ -71,6 +73,7 @@ static const u8 LM75_REG_TEMP[3] = {
/* Each client has this additional data */
struct lm75_data {
struct device *hwmon_dev;
+ struct thermal_zone_device *tz;
struct mutex update_lock;
u8 orig_conf;
u8 resolution; /* In bits, between 9 and 12 */
@@ -91,22 +94,36 @@ static struct lm75_data *lm75_update_device(struct device *dev);
/*-----------------------------------------------------------------------*/
+static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
+{
+ return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
+}
+
/* sysfs attributes for hwmon */
+static int lm75_read_temp(void *dev, long *temp)
+{
+ struct lm75_data *data = lm75_update_device(dev);
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ *temp = lm75_reg_to_mc(data->temp[0], data->resolution);
+
+ return 0;
+}
+
static ssize_t show_temp(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct lm75_data *data = lm75_update_device(dev);
- long temp;
if (IS_ERR(data))
return PTR_ERR(data);
- temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000)
- >> (data->resolution - 8);
-
- return sprintf(buf, "%ld\n", temp);
+ return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index],
+ data->resolution));
}
static ssize_t set_temp(struct device *dev, struct device_attribute *da,
@@ -273,6 +290,13 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
goto exit_remove;
}
+ data->tz = thermal_zone_of_sensor_register(&client->dev,
+ 0,
+ &client->dev,
+ lm75_read_temp, NULL);
+ if (IS_ERR(data->tz))
+ data->tz = NULL;
+
dev_info(&client->dev, "%s: sensor '%s'\n",
dev_name(data->hwmon_dev), client->name);
@@ -287,6 +311,7 @@ static int lm75_remove(struct i2c_client *client)
{
struct lm75_data *data = i2c_get_clientdata(client);
+ thermal_zone_of_sensor_unregister(&client->dev, data->tz);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &lm75_group);
lm75_write_value(client, LM75_REG_CONF, data->orig_conf);