hwmon: (max6650) add thermal cooling device capability

This allows max6650 devices to be referenced in dts as a cooling device.

The pwm value seems duplicated in cooling_dev_state but since pwm goes
through rounding logic into data->dac, it is modified and messes with
the thermal zone state algorithms. It's also better to serve a cache
value, thus avoiding periodic actual i2c traffic.

Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 470ba66..1915a18 100644 (file)
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -908,6 +908,7 @@ config SENSORS_MAX6642
 config SENSORS_MAX6650
        tristate "Maxim MAX6650 sensor chip"
        depends on I2C
+       depends on THERMAL || THERMAL=n
        help
          If you say yes here you get support for the MAX6650 / MAX6651
          sensor chips.

diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index 95b2346..e977c2f 100644 (file)
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -40,6 +40,7 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/of_device.h>
+#include <linux/thermal.h>
 
 /*
  * Insmod parameters
@@ -113,6 +114,7 @@ module_param(clock, int, 0444);
 struct max6650_data {
        struct i2c_client *client;
        const struct attribute_group *groups[3];
+       struct thermal_cooling_device *cooling_dev;
        struct mutex update_lock;
        int nr_fans;
        char valid; /* zero until following fields are valid */
@@ -125,6 +127,7 @@ struct max6650_data {
        u8 count;
        u8 dac;
        u8 alarm;
+       unsigned long cooling_dev_state;
 };
 
 static const u8 tach_reg[] = {
@@ -694,6 +697,63 @@ static int max6650_init_client(struct max6650_data *data,
        return 0;
 }
 
+#if IS_ENABLED(CONFIG_THERMAL)
+
+static int max6650_get_max_state(struct thermal_cooling_device *cdev,
+                                unsigned long *state)
+{
+       *state = 255;
+
+       return 0;
+}
+
+static int max6650_get_cur_state(struct thermal_cooling_device *cdev,
+                                unsigned long *state)
+{
+       struct max6650_data *data = cdev->devdata;
+
+       *state = data->cooling_dev_state;
+
+       return 0;
+}
+
+static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
+                                unsigned long state)
+{
+       struct max6650_data *data = cdev->devdata;
+       struct i2c_client *client = data->client;
+       int err;
+
+       state = clamp_val(state, 0, 255);
+
+       mutex_lock(&data->update_lock);
+
+       if (data->config & MAX6650_CFG_V12)
+               data->dac = 180 - (180 * state)/255;
+       else
+               data->dac = 76 - (76 * state)/255;
+
+       err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
+
+       if (!err) {
+               max6650_set_operating_mode(data, state ?
+                                                  MAX6650_CFG_MODE_OPEN_LOOP :
+                                                  MAX6650_CFG_MODE_OFF);
+               data->cooling_dev_state = state;
+       }
+
+       mutex_unlock(&data->update_lock);
+
+       return err < 0 ? err : 0;
+}
+
+static const struct thermal_cooling_device_ops max6650_cooling_ops = {
+       .get_max_state = max6650_get_max_state,
+       .get_cur_state = max6650_get_cur_state,
+       .set_cur_state = max6650_set_cur_state,
+};
+#endif
+
 static int max6650_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
 {
@@ -709,6 +769,7 @@ static int max6650_probe(struct i2c_client *client,
                return -ENOMEM;
 
        data->client = client;
+       i2c_set_clientdata(client, data);
        mutex_init(&data->update_lock);
        data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data;
 
@@ -727,7 +788,33 @@ static int max6650_probe(struct i2c_client *client,
        hwmon_dev = devm_hwmon_device_register_with_groups(dev,
                                                           client->name, data,
                                                           data->groups);
-       return PTR_ERR_OR_ZERO(hwmon_dev);
+       err = PTR_ERR_OR_ZERO(hwmon_dev);
+       if (err)
+               return err;
+
+#if IS_ENABLED(CONFIG_THERMAL)
+       data->cooling_dev =
+               thermal_of_cooling_device_register(client->dev.of_node,
+                                                  client->name, data,
+                                                  &max6650_cooling_ops);
+       if (IS_ERR(data->cooling_dev))
+               dev_warn(&client->dev,
+                        "thermal cooling device register failed: %ld\n",
+                        PTR_ERR(data->cooling_dev));
+       else
+               thermal_cdev_update(data->cooling_dev);
+#endif
+       return 0;
+}
+
+static int max6650_remove(struct i2c_client *client)
+{
+       struct max6650_data *data = i2c_get_clientdata(client);
+
+       if (!IS_ERR(data->cooling_dev))
+               thermal_cooling_device_unregister(data->cooling_dev);
+
+       return 0;
 }
 
 static const struct i2c_device_id max6650_id[] = {
@@ -743,6 +830,7 @@ static struct i2c_driver max6650_driver = {
                .of_match_table = of_match_ptr(max6650_dt_match),
        },
        .probe          = max6650_probe,
+       .remove         = max6650_remove,
        .id_table       = max6650_id,
 };