dt-bindings: hwmon: Add nct7802 bindings

index 604af2f6103a..515c081c2506 100644
@@ -51,6 +51,23 @@ static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = {
 #define REG_CHIP_ID		0xfe
 #define REG_VERSION_ID		0xff
 
+/*
+ * Resistance temperature detector (RTD) modes according to 7.2.32 Mode
+ * Selection Register
+ */
+#define RTD_MODE_CURRENT	0x1
+#define RTD_MODE_THERMISTOR	0x2
+#define RTD_MODE_VOLTAGE	0x3
+
+#define MODE_RTD_MASK		0x3
+#define MODE_LTD_EN		0x40
+
+/*
+ * Bit offset for sensors modes in REG_MODE.
+ * Valid for index 0..2, indicating RTD1..3.
+ */
+#define MODE_BIT_OFFSET_RTD(index) ((index) * 2)
+
 /*
  * Data structures and manipulation thereof
  */

@@ -74,7 +91,9 @@ static ssize_t temp_type_show(struct device *dev,
 	if (ret < 0)
 		return ret;
 
-	return sprintf(buf, "%u\n", (mode >> (2 * sattr->index) & 3) + 2);
+	return sprintf(buf, "%u\n",
+			((mode >> MODE_BIT_OFFSET_RTD(sattr->index)) &
+				MODE_RTD_MASK) + 2);
 }
 
 static ssize_t temp_type_store(struct device *dev,

@@ -94,7 +113,8 @@ static ssize_t temp_type_store(struct device *dev,
 	if (type < 3 || type > 4)
 		return -EINVAL;
 	err = regmap_update_bits(data->regmap, REG_MODE,
-			3 << 2 * sattr->index, (type - 2) << 2 * sattr->index);
+			MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(sattr->index),
+			(type - 2) << MODE_BIT_OFFSET_RTD(sattr->index));
 	return err ? : count;
 }
 

@@ -682,24 +702,24 @@ static umode_t nct7802_temp_is_visible(struct kobject *kobj,
 	struct device *dev = kobj_to_dev(kobj);
 	struct nct7802_data *data = dev_get_drvdata(dev);
 	unsigned int reg;
+	unsigned int rtd_mode;
 	int err;
 
 	err = regmap_read(data->regmap, REG_MODE, &reg);
 	if (err < 0)
 		return 0;
 
-	if (index < 10 &&
-	    (reg & 03) != 0x01 && (reg & 0x03) != 0x02)		/* RD1 */
+	rtd_mode = (reg >> MODE_BIT_OFFSET_RTD(index / 10)) & MODE_RTD_MASK;
+	if (index >= 0 && index < 20 &&				/* RD1, RD 2*/
+	    rtd_mode != 0x01 && rtd_mode != 0x02)
 		return 0;
 
-	if (index >= 10 && index < 20 &&
-	    (reg & 0x0c) != 0x04 && (reg & 0x0c) != 0x08)	/* RD2 */
-		return 0;
-	if (index >= 20 && index < 30 && (reg & 0x30) != 0x20)	/* RD3 */
+	if (index >= 20 && index < 30 && rtd_mode != 0x02)	/* RD3 */
 		return 0;
 
-	if (index >= 30 && index < 38)				/* local */
-		return attr->mode;
+	if (index >= 30 && index < 38 &&			/* local */
+	    (reg & MODE_LTD_EN) != MODE_LTD_EN)
+		return 0;
 
 	err = regmap_read(data->regmap, REG_PECI_ENABLE, &reg);
 	if (err < 0)

@@ -1038,7 +1058,118 @@ static const struct regmap_config nct7802_regmap_config = {
 	.volatile_reg = nct7802_regmap_is_volatile,
 };
 
-static int nct7802_init_chip(struct nct7802_data *data)
+static bool nct7802_get_input_config(struct device *dev,
+	struct device_node *input, u8 *mode_mask, u8 *mode_val)
+{
+	u32 reg;
+	const char *type_str, *md_str;
+	u8 md;
+
+	if (!input->name || of_node_cmp(input->name, "input"))
+		return false;
+
+	if (of_property_read_u32(input, "reg", &reg)) {
+		dev_err(dev, "Could not read reg value for '%s'\n",
+			input->full_name);
+		return false;
+	}
+
+	if (reg > 3) {
+		dev_err(dev,
+			"Invalid reg (%u) in '%s'\n", reg, input->full_name);
+		return false;
+	}
+
+	if (reg == 0) {
+		if (!of_device_is_available(input))
+			*mode_val &= ~MODE_LTD_EN;
+		else
+			*mode_val |= MODE_LTD_EN;
+		*mode_mask |= MODE_LTD_EN;
+		return true;
+	}
+
+	if (reg >= 1 && reg <= 3 && !of_device_is_available(input)) {
+		*mode_val &= ~(MODE_RTD_MASK
+			<< MODE_BIT_OFFSET_RTD(reg-1));
+		*mode_mask |= MODE_RTD_MASK
+			<< MODE_BIT_OFFSET_RTD(reg-1);
+		return true;
+	}
+
+	if (of_property_read_string(input, "sensor-type", &type_str)) {
+		dev_err(dev, "No type for '%s'\n", input->full_name);
+		return false;
+	}
+
+	if (!strcmp(type_str, "voltage")) {
+		*mode_val |= (RTD_MODE_VOLTAGE & MODE_RTD_MASK)
+			<< MODE_BIT_OFFSET_RTD(reg-1);
+		*mode_mask |= MODE_RTD_MASK
+			<< MODE_BIT_OFFSET_RTD(reg-1);
+		return true;
+	}
+
+	if (strcmp(type_str, "temperature")) {
+		dev_err(dev, "Invalid type '%s' for '%s'\n", type_str,
+			input->full_name);
+		return false;
+	}
+
+	if (reg == 3) {
+		/* RTD3 only supports thermistor mode */
+		md = RTD_MODE_THERMISTOR;
+	} else {
+		if (of_property_read_string(input, "temperature-mode",
+								&md_str)) {
+			dev_err(dev, "No mode for '%s'\n", input->full_name);
+			return false;
+		}
+
+		if (!strcmp(md_str, "thermal-diode"))
+			md = RTD_MODE_CURRENT;
+		else if (!strcmp(md_str, "thermistor"))
+			md = RTD_MODE_THERMISTOR;
+		else {
+			dev_err(dev, "Invalid mode '%s' for '%s'\n", md_str,
+				input->full_name);
+			return false;
+		}
+	}
+
+	*mode_val |= (md & MODE_RTD_MASK)
+		<< MODE_BIT_OFFSET_RTD(reg-1);
+	*mode_mask |= MODE_RTD_MASK
+		<< MODE_BIT_OFFSET_RTD(reg-1);
+
+	return true;
+}
+
+static int nct7802_configure_inputs(struct device *dev,
+	struct nct7802_data *data)
+{
+	bool found_input_config = false;
+	u8 mode_mask = 0, mode_val = 0;
+	struct device_node *input;
+
+	if (dev->of_node) {
+		for_each_child_of_node(dev->of_node, input) {
+			if (nct7802_get_input_config(dev, input, &mode_mask,
+					&mode_val))
+				found_input_config = true;
+		}
+	}
+
+	if (!found_input_config) {
+		/* Enable local temperature sensor by default */
+		mode_val |= MODE_LTD_EN;
+		mode_mask |= MODE_LTD_EN;
+	}
+
+	return regmap_update_bits(data->regmap, REG_MODE, mode_mask, mode_val);
+}
+
+static int nct7802_init_chip(struct device *dev, struct nct7802_data *data)
 {
 	int err;
 

@@ -1047,12 +1178,11 @@ static int nct7802_init_chip(struct nct7802_data *data)
 	if (err)
 		return err;
 
-	/* Enable local temperature sensor */
-	err = regmap_update_bits(data->regmap, REG_MODE, 0x40, 0x40);
+	err = nct7802_configure_inputs(dev, data);
 	if (err)
 		return err;
 
-	/* Enable Vcore and VCC voltage monitoring */
+	/* Enable Vcore and VCC voltage monit, struct nct7802_data *dataoring */
 	return regmap_update_bits(data->regmap, REG_VMON_ENABLE, 0x03, 0x03);
 }
 

@@ -1074,7 +1204,7 @@ static int nct7802_probe(struct i2c_client *client)
 	mutex_init(&data->access_lock);
 	mutex_init(&data->in_alarm_lock);
 
-	ret = nct7802_init_chip(data);
+	ret = nct7802_init_chip(dev, data);
 	if (ret < 0)
 		return ret;