recipes-kernel/linux/files/0030-Add-PWM-Rate-of-Change-configuration.patch

From 6b627b0ff2a29aa6f9172d906899e691ba99e733 Mon Sep 17 00:00:00 2001
From: Shao-Chieh <jieh.sc.chao@fii-na.corp-partner.google.com>
Date: Mon, 4 Aug 2025 09:42:11 +0800
Subject: [PATCH] Add PWM Rate-of-Change configuration

---
 drivers/hwmon/max31790.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 0cd44c1e9..890d1f614 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -483,7 +483,9 @@ static const struct hwmon_chip_info max31790_chip_info = {
 static int max31790_init_client(struct i2c_client *client,
 				struct max31790_data *data)
 {
-	int i, rv;
+	int i, rv, err;
+	struct device *dev = &client->dev;
+	u32 val;

 	for (i = 0; i < NR_CHANNEL; i++) {
 		rv = i2c_smbus_read_byte_data(client,
@@ -492,6 +494,17 @@ static int max31790_init_client(struct i2c_client *client,
 			return rv;
 		data->fan_config[i] = rv;

+		if (device_property_read_u32(dev, "pwm-rate-of-change", &val) == 0) {
+			rv = i2c_smbus_read_byte_data(client, MAX31790_REG_FAN_DYNAMICS(i));
+			if (rv < 0)
+				return rv;
+			rv &= ~0x1C;
+			rv |= (val & 0x7) << 2;
+			err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_DYNAMICS(i), rv);
+			if (err < 0)
+				return err;
+		}
+
 		rv = i2c_smbus_read_byte_data(client,
 				MAX31790_REG_FAN_DYNAMICS(i));
 		if (rv < 0)
@@ -542,11 +555,18 @@ static const struct i2c_device_id max31790_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, max31790_id);

+static const struct of_device_id max31790_of_match[] = {
+    { .compatible = "maxim,max31790" },
+    { }
+};
+MODULE_DEVICE_TABLE(of, max31790_of_match);
+
 static struct i2c_driver max31790_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.probe		= max31790_probe,
 	.driver = {
 		.name	= "max31790",
+		.of_match_table = max31790_of_match,
 	},
 	.id_table	= max31790_id,
 };
-- 
2.34.1