From: Eduardo Valentin eduardo.valentin@ti.com
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 --- drivers/hwmon/lm75.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index c03b490..1d3600a 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);