Adds an MFD driver for SMpro found on the Mt.Jade hardware reference
platform with Ampere's Altra processor family.

Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
---
 drivers/mfd/Kconfig          | 10 ++++++++++
 drivers/mfd/simple-mfd-i2c.c | 15 +++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b74efa469e90..5414371bdea1 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig

@@ -77,6 +77,16 @@ config MFD_AS3711
 	help
 	  Support for the AS3711 PMIC from AMS
 
+config MFD_SMPRO
+	tristate "Ampere Computing MFD SMpro core driver"
+	select MFD_SIMPLE_MFD_I2C

+	help
+	  Say yes here to enable SMpro driver support for Ampere's Altra
+	  processor family.
+
+	  Ampere's Altra SMpro exposes an I2C regmap interface that can
+	  be accessed by child devices.
+
 config MFD_AS3722
 	tristate "ams AS3722 Power Management IC"
 	select MFD_CORE

diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
index 87f684cff9a1..0459a9fbd3f5 100644
--- a/drivers/mfd/simple-mfd-i2c.c
+++ b/drivers/mfd/simple-mfd-i2c.c

@@ -21,14 +21,24 @@ static const struct regmap_config simple_regmap_config = {
 	.val_bits = 8,
 };
 
+static const struct regmap_config simple_word_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+};
+
 static int simple_mfd_i2c_probe(struct i2c_client *i2c)
 {
 	const struct regmap_config *config;
 	struct regmap *regmap;
 
 	config = device_get_match_data(&i2c->dev);
-	if (!config)
-		config = &simple_regmap_config;
+	if (!config) {
+		if (of_device_is_compatible(i2c->dev.of_node,
+						"ampere,ac01-smpro"))

+			config = &simple_word_regmap_config;
+		else
+			config = &simple_regmap_config;
+	}
 
 	regmap = devm_regmap_init_i2c(i2c, config);
 	if (IS_ERR(regmap))

@@ -39,6 +49,7 @@ static int simple_mfd_i2c_probe(struct i2c_client *i2c)
 
 static const struct of_device_id simple_mfd_i2c_of_match[] = {
 	{ .compatible = "kontron,sl28cpld" },
+	{ .compatible = "ampere,ac01-smpro" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);