mfd: max77693: Allow building as a module

The consumer of max77693 regulators on Trats2 board (samsung-usb2-phy
driver) supports deferred probing so the max77693 main MFD driver can be
built now as a module. This gives more flexibility and removes manual
ordering of init calls.
Suggested-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/Kconfig

@@ -543,8 +543,8 @@ config MFD_MAX77686
 	  of the device.
 
 config MFD_MAX77693
-	bool "Maxim Semiconductor MAX77693 PMIC Support"
-	depends on I2C=y
+	tristate "Maxim Semiconductor MAX77693 PMIC Support"
+	depends on I2C
 	select MFD_CORE
 	select REGMAP_I2C
 	select REGMAP_IRQ

drivers/mfd/max77693.c

@@ -368,6 +368,7 @@ static const struct of_device_id max77693_dt_match[] = {
 	{ .compatible = "maxim,max77693" },
 	{},
 };
+MODULE_DEVICE_TABLE(of, max77693_dt_match);
 #endif
 
 static struct i2c_driver max77693_i2c_driver = {
@@ -381,18 +382,7 @@ static struct i2c_driver max77693_i2c_driver = {
 	.id_table = max77693_i2c_id,
 };
 
-static int __init max77693_i2c_init(void)
-{
-	return i2c_add_driver(&max77693_i2c_driver);
-}
-/* init early so consumer devices can complete system boot */
-subsys_initcall(max77693_i2c_init);
-
-static void __exit max77693_i2c_exit(void)
-{
-	i2c_del_driver(&max77693_i2c_driver);
-}
-module_exit(max77693_i2c_exit);
+module_i2c_driver(max77693_i2c_driver);
 
 MODULE_DESCRIPTION("MAXIM 77693 multi-function core driver");
 MODULE_AUTHOR("SangYoung, Son <hello.son@samsung.com>");