hwmon: (max6639) Add regulator support

Add regulator support for boards where the fan-supply have to be
powered up before it can be used.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Link: https://lore.kernel.org/r/2cb9ed600fb43cdc604799746fbde2e2942cdca6.1643299570.git.sylv@sylv.io
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
index ccc0f047bd446ee5fc70c61125c05e9cdcc2396e..14bb7726f8d7e18582e4404323851bc43a498a0a 100644 (file)
--- a/drivers/hwmon/max6639.c
+++ b/drivers/hwmon/max6639.c
@@ -87,6 +87,9 @@ struct max6639_data {
        /* Register values initialized only once */
        u8 ppr;                 /* Pulses per rotation 0..3 for 1..4 ppr */
        u8 rpm_range;           /* Index in above rpm_ranges table */
+
+       /* Optional regulator for FAN supply */
+       struct regulator *reg;
 };
 
 static struct max6639_data *max6639_update_device(struct device *dev)
@@ -516,6 +519,11 @@ static int max6639_detect(struct i2c_client *client,
        return 0;
 }
 
+static void max6639_regulator_disable(void *data)
+{
+       regulator_disable(data);
+}
+
 static int max6639_probe(struct i2c_client *client)
 {
        struct device *dev = &client->dev;
@@ -528,6 +536,28 @@ static int max6639_probe(struct i2c_client *client)
                return -ENOMEM;
 
        data->client = client;
+
+       data->reg = devm_regulator_get_optional(dev, "fan");
+       if (IS_ERR(data->reg)) {
+               if (PTR_ERR(data->reg) != -ENODEV)
+                       return PTR_ERR(data->reg);
+
+               data->reg = NULL;
+       } else {
+               /* Spin up fans */
+               err = regulator_enable(data->reg);
+               if (err) {
+                       dev_err(dev, "Failed to enable fan supply: %d\n", err);
+                       return err;
+               }
+               err = devm_add_action_or_reset(dev, max6639_regulator_disable,
+                                              data->reg);
+               if (err) {
+                       dev_err(dev, "Failed to register action: %d\n", err);
+                       return err;
+               }
+       }
+
        mutex_init(&data->update_lock);
 
        /* Initialize the max6639 chip */
@@ -545,23 +575,39 @@ static int max6639_probe(struct i2c_client *client)
 static int max6639_suspend(struct device *dev)
 {
        struct i2c_client *client = to_i2c_client(dev);
-       int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
-       if (data < 0)
-               return data;
+       struct max6639_data *data = dev_get_drvdata(dev);
+       int ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+
+       if (ret < 0)
+               return ret;
+
+       if (data->reg)
+               regulator_disable(data->reg);
 
        return i2c_smbus_write_byte_data(client,
-                       MAX6639_REG_GCONFIG, data | MAX6639_GCONFIG_STANDBY);
+                       MAX6639_REG_GCONFIG, ret | MAX6639_GCONFIG_STANDBY);
 }
 
 static int max6639_resume(struct device *dev)
 {
        struct i2c_client *client = to_i2c_client(dev);
-       int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
-       if (data < 0)
-               return data;
+       struct max6639_data *data = dev_get_drvdata(dev);
+       int ret;
+
+       if (data->reg) {
+               ret = regulator_enable(data->reg);
+               if (ret) {
+                       dev_err(dev, "Failed to enable fan supply: %d\n", ret);
+                       return ret;
+               }
+       }
+
+       ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+       if (ret < 0)
+               return ret;
 
        return i2c_smbus_write_byte_data(client,
-                       MAX6639_REG_GCONFIG, data & ~MAX6639_GCONFIG_STANDBY);
+                       MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
 }
 #endif /* CONFIG_PM_SLEEP */