hwmon: (emc1403) Add support for EMC1428 and EMC1438.

EMC1428 and EMC1438 are similar to EMC14xx, but have eight temperature
channels, as well as signed data and limit registers. Chips currently
supported by this driver have unsigned registers only.

Signed-off-by: Lars Petter Mostad <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

Documentation/hwmon/emc1403.rst

···
 
 	- https://ww1.microchip.com/downloads/en/DeviceDoc/1423_1424.pdf
 
+  * SMSC / Microchip EMC1428, EMC1438
+
+    Addresses scanned: I2C 0x18, 0x4c, 0x4d
+
+    Prefix: 'emc1428', 'emc1438'
+
+    Datasheets:
+
+	- https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/20005275A.pdf
+	- https://ww1.microchip.com/downloads/en/DeviceDoc/EMC1438%20DS%20Rev.%201.0%20(04-29-10).pdf
+
 Author:
     Kalhan Trisal <[e-mail]
 
···
 -----------
 
 The Standard Microsystems Corporation (SMSC) / Microchip EMC14xx chips
-contain up to four temperature sensors. EMC14x2 support two sensors
+contain up to eight temperature sensors. EMC14x2 support two sensors
 (one internal, one external). EMC14x3 support three sensors (one internal,
-two external), and EMC14x4 support four sensors (one internal, three
-external).
+two external), EMC14x4 support four sensors (one internal, three external),
+and EMC14x8 support eight sensors (one internal, seven external).
 
 The chips implement three limits for each sensor: low (tempX_min), high
 (tempX_max) and critical (tempX_crit.) The chips also implement an

drivers/hwmon/emc1403.c

···
 #define THERMAL_SMSC_ID_REG	0xfe
 #define THERMAL_REVISION_REG	0xff
 
-enum emc1403_chip { emc1402, emc1403, emc1404 };
+enum emc1403_chip { emc1402, emc1403, emc1404, emc1428 };
 
 struct thermal_data {
 	enum emc1403_chip chip;
···
 	case 0x27:
 		strscpy(info->type, "emc1424", I2C_NAME_SIZE);
 		break;
+	case 0x29:
+		strscpy(info->type, "emc1428", I2C_NAME_SIZE);
+		break;
+	case 0x59:
+		strscpy(info->type, "emc1438", I2C_NAME_SIZE);
+		break;
 	case 0x60:
 		strscpy(info->type, "emc1442", I2C_NAME_SIZE);
 		break;
···
 	case 0x35:	/* high limit status */
 	case 0x36:	/* low limit status */
 	case 0x37:	/* therm limit status */
+	case 0x41:	/* external diode 4 high byte */
+	case 0x42:	/* external diode 4 low byte */
+	case 0x43:	/* external diode 5 high byte */
+	case 0x44:	/* external diode 5 low byte */
+	case 0x45:	/* external diode 6 high byte */
+	case 0x46:	/* external diode 6 low byte */
+	case 0x47:	/* external diode 7 high byte */
+	case 0x48:	/* external diode 7 low byte */
 		return true;
 	default:
 		return false;
···
 		[temp_crit] = 0x30,
 		[temp_input] = 0x2a,
 	},
+	[4] = {
+		[temp_min] = 0x51,
+		[temp_max] = 0x50,
+		[temp_crit] = 0x64,
+		[temp_input] = 0x41,
+	},
+	[5] = {
+		[temp_min] = 0x55,
+		[temp_max] = 0x54,
+		[temp_crit] = 0x65,
+		[temp_input] = 0x43
+	},
+	[6] = {
+		[temp_min] = 0x59,
+		[temp_max] = 0x58,
+		[temp_crit] = 0x66,
+		[temp_input] = 0x45,
+	},
+	[7] = {
+		[temp_min] = 0x5d,
+		[temp_max] = 0x5c,
+		[temp_crit] = 0x67,
+		[temp_input] = 0x47,
+	},
 };
 
 static s8 emc1403_temp_regs_low[][4] = {
···
 		[temp_crit] = -1,
 		[temp_input] = 0x2b,
 	},
+	[4] = {
+		[temp_min] = 0x53,
+		[temp_max] = 0x52,
+		[temp_crit] = -1,
+		[temp_input] = 0x42,
+	},
+	[5] = {
+		[temp_min] = 0x57,
+		[temp_max] = 0x56,
+		[temp_crit] = -1,
+		[temp_input] = 0x44,
+	},
+	[6] = {
+		[temp_min] = 0x5b,
+		[temp_max] = 0x5a,
+		[temp_crit] = -1,
+		[temp_input] = 0x46,
+	},
+	[7] = {
+		[temp_min] = 0x5f,
+		[temp_max] = 0x5e,
+		[temp_crit] = -1,
+		[temp_input] = 0x48,
+	},
 };
 
 static int __emc1403_get_temp(struct thermal_data *data, int channel,
 			      enum emc1403_reg_map map, long *val)
 {
-	unsigned int regval;
+	unsigned int regvalh;
+	unsigned int regvall = 0;
 	int ret;
 	s8 reg;
 
-	ret = regmap_read(data->regmap, emc1403_temp_regs[channel][map], &regval);
+	ret = regmap_read(data->regmap, emc1403_temp_regs[channel][map], &regvalh);
 	if (ret < 0)
 		return ret;
-	*val = regval * 1000;
 
 	reg = emc1403_temp_regs_low[channel][map];
 	if (reg >= 0) {
-		ret = regmap_read(data->regmap, reg, &regval);
+		ret = regmap_read(data->regmap, reg, &regvall);
 		if (ret < 0)
 			return ret;
-		*val += (regval >> 5) * 125;
 	}
+
+	if (data->chip == emc1428)
+		*val = sign_extend32((regvalh << 3) | (regvall >> 5), 10) * 125;
+	else
+		*val = ((regvalh << 3) | (regvall >> 5)) * 125;
+
 	return 0;
 }
 
···
 	int hyst, ret;
 	long limit;
 
-	val = clamp_val(val, 0, 255000);
+	if (data->chip == emc1428)
+		val = clamp_val(val, -128000, 127000);
+	else
+		val = clamp_val(val, 0, 255000);
 
 	mutex_lock(&data->mutex);
 	ret = __emc1403_get_temp(data, 0, temp_crit, &limit);
···
 		goto unlock;
 
 	hyst = limit - val;
-	hyst = clamp_val(DIV_ROUND_CLOSEST(hyst, 1000), 0, 255);
+	if (data->chip == emc1428)
+		hyst = clamp_val(DIV_ROUND_CLOSEST(hyst, 1000), 0, 127);
+	else
+		hyst = clamp_val(DIV_ROUND_CLOSEST(hyst, 1000), 0, 255);
 	ret = regmap_write(data->regmap, 0x21, hyst);
 unlock:
 	mutex_unlock(&data->mutex);
···
 
 	mutex_lock(&data->mutex);
 	if (regl >= 0) {
-		val = clamp_val(val, 0, 255875);
+		if (data->chip == emc1428)
+			val = clamp_val(val, -128000, 127875);
+		else
+			val = clamp_val(val, 0, 255875);
 		regval = DIV_ROUND_CLOSEST(val, 125);
-		ret = regmap_write(data->regmap, regh, regval >> 3);
+		ret = regmap_write(data->regmap, regh, (regval >> 3) & 0xff);
 		if (ret < 0)
 			goto unlock;
 		ret = regmap_write(data->regmap, regl, (regval & 0x07) << 5);
 	} else {
-		val = clamp_val(val, 0, 255000);
+		if (data->chip == emc1428)
+			val = clamp_val(val, -128000, 127000);
+		else
+			val = clamp_val(val, 0, 255000);
 		regval = DIV_ROUND_CLOSEST(val, 1000);
 		ret = regmap_write(data->regmap, regh, regval);
 	}
···
 		return 0;
 	if (data->chip == emc1403 && channel > 2)
 		return 0;
+	if (data->chip != emc1428 && channel > 3)
+		return 0;
 
 	switch (attr) {
 	case hwmon_temp_input:
···
 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
 			   HWMON_T_CRIT | HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_CRIT | HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
+			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_CRIT | HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
+			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_CRIT | HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
+			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
+			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
+			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+			   HWMON_T_CRIT | HWMON_T_MIN_HYST | HWMON_T_MAX_HYST |
+			   HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT
 			   ),
 	NULL
···
 	{ "emc1422", emc1402 },
 	{ "emc1423", emc1403 },
 	{ "emc1424", emc1404 },
+	{ "emc1428", emc1428 },
+	{ "emc1438", emc1428 },
 	{ "emc1442", emc1402 },
 	{ }
 };