hwmon: (amc6821) Move reading fan data from OF to a function

Move fan property reading from OF to a separate function. This keeps OF
data handling separate from the code logic and makes it easier to add
features like cooling device support that use the same fan node.

Signed-off-by: João Paulo Gonçalves <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/amc6821.c

···
 struct amc6821_data {
 	struct regmap *regmap;
 	struct mutex update_lock;
+	enum pwm_polarity pwm_polarity;
 };
 
 /*
···
 	return 0;
 }
 
-static enum pwm_polarity amc6821_pwm_polarity(struct i2c_client *client)
+static enum pwm_polarity amc6821_pwm_polarity(struct i2c_client *client,
+					      struct device_node *fan_np)
 {
 	enum pwm_polarity polarity = PWM_POLARITY_NORMAL;
 	struct of_phandle_args args;
-	struct device_node *fan_np;
 
 	/*
 	 * For backward compatibility, the pwminv module parameter takes
···
 		return PWM_POLARITY_NORMAL;
 	if (pwminv > 0)
 		return PWM_POLARITY_INVERSED;
-
-	fan_np = of_get_child_by_name(client->dev.of_node, "fan");
-	if (!fan_np)
-		return PWM_POLARITY_NORMAL;
 
 	if (of_parse_phandle_with_args(fan_np, "pwms", "#pwm-cells", 0, &args))
 		goto out;
···
 	if (args.args[1] & PWM_POLARITY_INVERTED)
 		polarity = PWM_POLARITY_INVERSED;
 out:
-	of_node_put(fan_np);
 	return polarity;
+}
+
+static void amc6821_of_fan_read_data(struct i2c_client *client,
+				     struct amc6821_data *data,
+				     struct device_node *fan_np)
+{
+	data->pwm_polarity = amc6821_pwm_polarity(client, fan_np);
 }
 
 static int amc6821_init_client(struct i2c_client *client, struct amc6821_data *data)
···
 			return err;
 
 		regval = AMC6821_CONF1_START;
-		if (amc6821_pwm_polarity(client) == PWM_POLARITY_INVERSED)
+		if (data->pwm_polarity == PWM_POLARITY_INVERSED)
 			regval |= AMC6821_CONF1_PWMINV;
 
 		err = regmap_update_bits(regmap, AMC6821_REG_CONF1,
···
 	struct amc6821_data *data;
 	struct device *hwmon_dev;
 	struct regmap *regmap;
+	struct device_node *fan_np __free(device_node) = NULL;
 	int err;
 
 	data = devm_kzalloc(dev, sizeof(struct amc6821_data), GFP_KERNEL);
···
 		return dev_err_probe(dev, PTR_ERR(regmap),
 				     "Failed to initialize regmap\n");
 	data->regmap = regmap;
+
+	fan_np = of_get_child_by_name(dev->of_node, "fan");
+	if (fan_np)
+		amc6821_of_fan_read_data(client, data, fan_np);
 
 	err = amc6821_init_client(client, data);
 	if (err)