[PATCH v8 4/8] hwmon: (amc6821) add support for tsd,mule

[Farouk Bouabid <farouk.bouabid@cherry.de>]

Theobroma Systems Mule is an MCU that emulates a set of I2C devices,
among which is an amc6821 and other devices that are reachable through
an I2C-mux.

The devices on the mux can be selected by writing the appropriate device
number to an I2C config register (amc6821: reg 0xff)

Implement "tsd,mule" compatible to instantiate the I2C-mux platform device
when probing the amc6821.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Farouk Bouabid <farouk.bouabid@cherry.de>
---
 drivers/hwmon/amc6821.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c
index ec94392fcb65..a3fdbcf01ecd 100644
--- a/drivers/hwmon/amc6821.c
+++ b/drivers/hwmon/amc6821.c
@@ -22,6 +22,7 @@
 #include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/of_platform.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
@@ -897,7 +898,6 @@ static bool amc6821_volatile_reg(struct device *dev, unsigned int reg)
 static const struct regmap_config amc6821_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
-	.max_register = AMC6821_REG_CONF3,
 	.volatile_reg = amc6821_volatile_reg,
 	.cache_type = REGCACHE_MAPLE,
 };
@@ -924,6 +924,13 @@ static int amc6821_probe(struct i2c_client *client)
 	if (err)
 		return err;
 
+	if (of_device_is_compatible(dev->of_node, "tsd,mule")) {
+		err = devm_of_platform_populate(dev);
+		if (err)
+			return dev_err_probe(dev, err,
+				     "Failed to create sub-devices\n");
+	}
+
 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							 data, &amc6821_chip_info,
 							 amc6821_groups);
@@ -941,6 +948,9 @@ static const struct of_device_id __maybe_unused amc6821_of_match[] = {
 	{
 		.compatible = "ti,amc6821",
 	},
+	{
+		.compatible = "tsd,mule",
+	},
 	{ }
 };
 

-- 
2.34.1