[PATCH 2/3] hwmon: (nct6775) Use custom scale for ASUS motherboards.

[Denis Pauk <pauk.denis@gmail.com>]

Use custom scaling factor for:
* TUF GAMING Z490-PLUS
* TUF GAMING Z490-PLUS (WI-FI)

Voltage scaling factors are based on Asus software on Windows.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204807
Signed-off-by: Denis Pauk <pauk.denis@gmail.com>
Tested-by: Kamil Pietrzak <kpietrzak@disroot.org>
Cc: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/nct6775.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
index 8eaf86ea2433..ba18c1cbf572 100644
--- a/drivers/hwmon/nct6775.c
+++ b/drivers/hwmon/nct6775.c
@@ -140,6 +140,7 @@ struct nct6775_sio_data {
 	int ld;
 	enum kinds kind;
 	enum sensor_access access;
+	bool custom_scale;
 
 	/* superio_() callbacks  */
 	void (*sio_outb)(struct nct6775_sio_data *sio_data, int reg, int val);
@@ -1159,14 +1160,19 @@ static const u16 scale_in[15] = {
 	800, 800
 };
 
-static inline long in_from_reg(u8 reg, u8 nr)
+static const u16 scale_in_z490[15] = {
+	888, 4000, 1600, 1600, 9600, 800, 800, 1600, 1600, 1600, 1600, 1600, 800,
+	800, 800
+};
+
+static inline long in_from_reg(u8 reg, u8 nr, const u16 *scale)
 {
-	return DIV_ROUND_CLOSEST(reg * scale_in[nr], 100);
+	return DIV_ROUND_CLOSEST(reg * scale[nr], 100);
 }
 
-static inline u8 in_to_reg(u32 val, u8 nr)
+static inline u8 in_to_reg(u32 val, u8 nr, const u16 *scale)
 {
-	return clamp_val(DIV_ROUND_CLOSEST(val * 100, scale_in[nr]), 0, 255);
+	return clamp_val(DIV_ROUND_CLOSEST(val * 100, scale[nr]), 0, 255);
 }
 
 /*
@@ -1323,6 +1329,9 @@ struct nct6775_data {
 	u8 fandiv2;
 	u8 sio_reg_enable;
 
+	/* voltage scaling factors */
+	const u16 *scale;
+
 	/* nct6775_*() callbacks  */
 	u16 (*read_value)(struct nct6775_data *data, u16 reg);
 	int (*write_value)(struct nct6775_data *data, u16 reg, u16 value);
@@ -2026,7 +2035,7 @@ show_in_reg(struct device *dev, struct device_attribute *attr, char *buf)
 	int index = sattr->index;
 	int nr = sattr->nr;
 
-	return sprintf(buf, "%ld\n", in_from_reg(data->in[nr][index], nr));
+	return sprintf(buf, "%ld\n", in_from_reg(data->in[nr][index], nr, data->scale));
 }
 
 static ssize_t
@@ -2044,7 +2053,7 @@ store_in_reg(struct device *dev, struct device_attribute *attr, const char *buf,
 	if (err < 0)
 		return err;
 	mutex_lock(&data->update_lock);
-	data->in[nr][index] = in_to_reg(val, nr);
+	data->in[nr][index] = in_to_reg(val, nr, data->scale);
 	data->write_value(data, data->REG_IN_MINMAX[index - 1][nr],
 			  data->in[nr][index]);
 	mutex_unlock(&data->update_lock);
@@ -3980,6 +3989,11 @@ static int nct6775_probe(struct platform_device *pdev)
 		data->write_value = nct6775_wmi_write_value;
 	}
 
+	if (sio_data->custom_scale)
+		data->scale = scale_in_z490;
+	else
+		data->scale = scale_in;
+
 	mutex_init(&data->update_lock);
 	data->name = nct6775_device_names[data->kind];
 	data->bank = 0xff;		/* Force initial bank selection */
@@ -5020,6 +5034,7 @@ static int __init sensors_nct6775_init(void)
 	struct nct6775_sio_data sio_data;
 	int sioaddr[2] = { 0x2e, 0x4e };
 	enum sensor_access access = access_direct;
+	bool custom_scale = false;
 	const char *board_vendor, *board_name;
 	u8 tmp;
 
@@ -5043,6 +5058,10 @@ static int __init sensors_nct6775_init(void)
 				pr_err("Can't read ChipID by Asus WMI.\n");
 			}
 		}
+
+		if (strcmp(board_name, "TUF GAMING Z490-PLUS") == 0 ||
+		    strcmp(board_name, "TUF GAMING Z490-PLUS (WI-FI)") == 0)
+			custom_scale = true;
 	}
 
 	/*
@@ -5066,6 +5085,7 @@ static int __init sensors_nct6775_init(void)
 		found = true;
 
 		sio_data.access = access;
+		sio_data.custom_scale = custom_scale;
 
 		if (access == access_asuswmi) {
 			sio_data.sio_outb = superio_wmi_outb;
-- 
2.33.0