sbtsi: Add support to get the SBTSI maximum HBM temperature

Add a new channel to support SBTSIx50 and SBTSIx54 for reporting maximum HBM temperature.

Author: bges

apml_sbtsi.c

@@ -39,6 +39,8 @@
 #define SBTSI_REG_TEMP_DEC		0x10 /* RW */
 #define SBTSI_REG_TEMP_HIGH_DEC		0x13 /* RW */
 #define SBTSI_REG_TEMP_LOW_DEC		0x14 /* RW */
+#define SBTSI_REG_MAX_HBM_INT   0x50 /* RO */
+#define SBTSI_REG_MAX_HBM_DEC   0x54 /* RO */
 
 #define SBTSI_CONFIG_READ_ORDER_SHIFT	5
 
@@ -67,6 +69,12 @@ struct apml_sbtsi_device {
 	u8 dev_static_addr;
 } __packed;
 
+enum sbtsi_channels {
+    CPU_CHANNEL,
+    HBM_CHANNEL,
+    SBTSI_NUM_CHANNELS
+};
+
 /*
  * From SB-TSI spec: CPU temperature readings and limit registers encode the
  * temperature in increments of 0.125 from 0 to 255.875. The "high byte"
@@ -118,12 +126,18 @@ static int sbtsi_read(struct device *dev, enum hwmon_sensor_types type,
 			return ret;
 
 		mutex_lock(&tsi_dev->lock);
-		if (cfg & BIT(SBTSI_CONFIG_READ_ORDER_SHIFT)) {
-			ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_DEC, &temp_dec);
-			ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_INT, &temp_int);
-		} else {
-			ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_INT, &temp_int);
-			ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_DEC, &temp_dec);
+		if (channel == HBM_CHANNEL) {
+			ret = regmap_read(tsi_dev->regmap, SBTSI_REG_MAX_HBM_INT, &temp_int);
+			ret = regmap_read(tsi_dev->regmap, SBTSI_REG_MAX_HBM_DEC, &temp_dec);
+		}
+		else {
+			if (cfg & BIT(SBTSI_CONFIG_READ_ORDER_SHIFT)) {
+				ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_DEC, &temp_dec);
+				ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_INT, &temp_int);
+			} else {
+				ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_INT, &temp_int);
+				ret = regmap_read(tsi_dev->regmap, SBTSI_REG_TEMP_DEC, &temp_dec);
+			}
 		}
 		mutex_unlock(&tsi_dev->lock);
 		break;
@@ -208,7 +222,8 @@ static umode_t sbtsi_is_visible(const void *data,
 
 static const struct hwmon_channel_info *sbtsi_info[] = {
 	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
-	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX),
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX,
+							 HWMON_T_INPUT),
 	NULL
 };