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authorEduardo Valentin <eduardo.valentin@ti.com>2013-07-16 14:54:55 -0400
committerAlex Shi <alex.shi@linaro.org>2014-03-31 15:47:21 +0800
commit42d63a4b831f8b68c474d72d25dbcf911eabd666 (patch)
tree032072163e90498674bb36fd643e420b522cf911 /drivers/hwmon
parent17dcbf41efd82fd7a1c997d87e23e97f6c993c2e (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> (cherry picked from commit 22e731838b0e337fed5f16c67aa0b954028dfe93) Signed-off-by: Alex Shi <alex.shi@linaro.org>
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 c03b490bba8..1d3600aa4ca 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"
@@ -70,6 +72,7 @@ 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 */
@@ -90,22 +93,36 @@ 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,
@@ -271,6 +288,13 @@ 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);
@@ -285,6 +309,7 @@ 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);