hwmon: (max6650) Introduce pwm_to_dac and dac_to_pwm

[linux-2.6-block.git] / drivers / hwmon / max6650.c

diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index 6b9056f9483f552e62d8f226fd7fc31e8811fa63..461484e7828a219fb66cfc17b7211330a80be8dd 100644 (file)
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -92,7 +92,8 @@ module_param(clock, int, 0444);
 #define FAN_RPM_MIN 240
 #define FAN_RPM_MAX 30000
 
-#define DIV_FROM_REG(reg) (1 << (reg & 7))
+#define DIV_FROM_REG(reg)      (1 << ((reg) & 7))
+#define DAC_LIMIT(v12)         ((v12) ? 180 : 76)
 
 /*
  * Client data (each client gets its own)
@@ -101,7 +102,6 @@ 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 */
@@ -137,6 +137,22 @@ static const struct of_device_id __maybe_unused max6650_dt_match[] = {
 };
 MODULE_DEVICE_TABLE(of, max6650_dt_match);
 
+static int dac_to_pwm(int dac, bool v12)
+{
+       /*
+        * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
+        * Lower DAC values mean higher speeds.
+        */
+       return clamp_val(255 - (255 * dac) / DAC_LIMIT(v12), 0, 255);
+}
+
+static u8 pwm_to_dac(unsigned int pwm, bool v12)
+{
+       int limit = DAC_LIMIT(v12);
+
+       return limit - (limit * pwm) / 255;
+}
+
 static struct max6650_data *max6650_update_device(struct device *dev)
 {
        struct max6650_data *data = dev_get_drvdata(dev);
@@ -344,22 +360,10 @@ static ssize_t fan1_target_store(struct device *dev,
 static ssize_t pwm1_show(struct device *dev, struct device_attribute *devattr,
                         char *buf)
 {
-       int pwm;
        struct max6650_data *data = max6650_update_device(dev);
 
-       /*
-        * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
-        * Lower DAC values mean higher speeds.
-        */
-       if (data->config & MAX6650_CFG_V12)
-               pwm = 255 - (255 * (int)data->dac)/180;
-       else
-               pwm = 255 - (255 * (int)data->dac)/76;
-
-       if (pwm < 0)
-               pwm = 0;
-
-       return sprintf(buf, "%d\n", pwm);
+       return sprintf(buf, "%d\n", dac_to_pwm(data->dac,
+                                              data->config & MAX6650_CFG_V12));
 }
 
 static ssize_t pwm1_store(struct device *dev,
@@ -370,6 +374,7 @@ static ssize_t pwm1_store(struct device *dev,
        struct i2c_client *client = data->client;
        unsigned long pwm;
        int err;
+       u8 dac;
 
        err = kstrtoul(buf, 10, &pwm);
        if (err)
@@ -378,13 +383,10 @@ static ssize_t pwm1_store(struct device *dev,
        pwm = clamp_val(pwm, 0, 255);
 
        mutex_lock(&data->update_lock);
-
-       if (data->config & MAX6650_CFG_V12)
-               data->dac = 180 - (180 * pwm)/255;
-       else
-               data->dac = 76 - (76 * pwm)/255;
-       err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
-
+       dac = pwm_to_dac(pwm, data->config & MAX6650_CFG_V12);
+       err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, dac);
+       if (!err)
+               data->dac = dac;
        mutex_unlock(&data->update_lock);
 
        return err < 0 ? err : count;
@@ -715,11 +717,7 @@ static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
 
        mutex_lock(&data->update_lock);
 
-       if (data->config & MAX6650_CFG_V12)
-               data->dac = 180 - (180 * state)/255;
-       else
-               data->dac = 76 - (76 * state)/255;
-
+       data->dac = pwm_to_dac(state, data->config & MAX6650_CFG_V12);
        err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
 
        if (!err) {
@@ -731,7 +729,7 @@ static int max6650_set_cur_state(struct thermal_cooling_device *cdev,
 
        mutex_unlock(&data->update_lock);
 
-       return err < 0 ? err : 0;
+       return err;
 }
 
 static const struct thermal_cooling_device_ops max6650_cooling_ops = {
@@ -744,6 +742,7 @@ static const struct thermal_cooling_device_ops max6650_cooling_ops = {
 static int max6650_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
 {
+       struct thermal_cooling_device *cooling_dev;
        struct device *dev = &client->dev;
        const struct of_device_id *of_id =
                of_match_device(of_match_ptr(max6650_dt_match), dev);
@@ -780,28 +779,16 @@ static int max6650_probe(struct i2c_client *client,
                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));
+       cooling_dev = devm_thermal_of_cooling_device_register(dev, dev->of_node,
+                               client->name, data, &max6650_cooling_ops);
+       if (IS_ERR(cooling_dev)) {
+               dev_warn(dev, "thermal cooling device register failed: %ld\n",
+                        PTR_ERR(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[] = {
        { "max6650", 1 },
        { "max6651", 4 },
@@ -815,7 +802,6 @@ 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,
 };