hwmon: pmbus: mpq8785: Prepare driver for multiple device support

Refactor the driver to support multiple Monolithic Power Systems devices.
Introduce chip ID handling based on device tree matching.

No functional changes intended.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Link: https://lore.kernel.org/r/20250511035701.2607947-3-paweldembicki@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Author: CHKDSK88

drivers/hwmon/pmbus/mpq8785.c

@@ -8,6 +8,8 @@
 #include <linux/of_device.h>
 #include "pmbus.h"
 
+enum chips { mpq8785 };
+
 static int mpq8785_identify(struct i2c_client *client,
 			    struct pmbus_driver_info *info)
 {
@@ -53,26 +55,46 @@ static struct pmbus_driver_info mpq8785_info = {
 		PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
 		PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
 		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
-	.identify = mpq8785_identify,
-};
-
-static int mpq8785_probe(struct i2c_client *client)
-{
-	return pmbus_do_probe(client, &mpq8785_info);
 };
 
 static const struct i2c_device_id mpq8785_id[] = {
-	{ "mpq8785" },
+	{ "mpq8785", mpq8785 },
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, mpq8785_id);
 
 static const struct of_device_id __maybe_unused mpq8785_of_match[] = {
-	{ .compatible = "mps,mpq8785" },
+	{ .compatible = "mps,mpq8785", .data = (void *)mpq8785 },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mpq8785_of_match);
 
+static int mpq8785_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct pmbus_driver_info *info;
+	enum chips chip_id;
+
+	info = devm_kmemdup(dev, &mpq8785_info, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	if (dev->of_node)
+		chip_id = (kernel_ulong_t)of_device_get_match_data(dev);
+	else
+		chip_id = (kernel_ulong_t)i2c_get_match_data(client);
+
+	switch (chip_id) {
+	case mpq8785:
+		info->identify = mpq8785_identify;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	return pmbus_do_probe(client, info);
+};
+
 static struct i2c_driver mpq8785_driver = {
 	.driver = {
 		   .name = "mpq8785",