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path: root/drivers/hwmon/nct7802.c
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Diffstat (limited to 'drivers/hwmon/nct7802.c')
-rw-r--r--drivers/hwmon/nct7802.c129
1 files changed, 125 insertions, 4 deletions
diff --git a/drivers/hwmon/nct7802.c b/drivers/hwmon/nct7802.c
index 604af2f6103a..d56f78327619 100644
--- a/drivers/hwmon/nct7802.c
+++ b/drivers/hwmon/nct7802.c
@@ -52,6 +52,23 @@ static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = {
#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
*/
@@ -1038,7 +1055,112 @@ static const struct regmap_config nct7802_regmap_config = {
.volatile_reg = nct7802_regmap_is_volatile,
};
-static int nct7802_init_chip(struct nct7802_data *data)
+static int nct7802_get_channel_config(struct device *dev,
+ struct device_node *node, u8 *mode_mask,
+ u8 *mode_val)
+{
+ u32 reg;
+ const char *type_str, *md_str;
+ u8 md;
+
+ if (!node->name || of_node_cmp(node->name, "channel"))
+ return 0;
+
+ if (of_property_read_u32(node, "reg", &reg)) {
+ dev_err(dev, "Could not read reg value for '%s'\n",
+ node->full_name);
+ return -EINVAL;
+ }
+
+ if (reg > 3) {
+ dev_err(dev, "Invalid reg (%u) in '%s'\n", reg,
+ node->full_name);
+ return -EINVAL;
+ }
+
+ if (reg == 0) {
+ if (!of_device_is_available(node))
+ *mode_val &= ~MODE_LTD_EN;
+ else
+ *mode_val |= MODE_LTD_EN;
+ *mode_mask |= MODE_LTD_EN;
+ return 0;
+ }
+
+ /* At this point we have reg >= 1 && reg <= 3 */
+
+ if (!of_device_is_available(node)) {
+ *mode_val &= ~(MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(reg - 1));
+ *mode_mask |= MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(reg - 1);
+ return 0;
+ }
+
+ if (of_property_read_string(node, "sensor-type", &type_str)) {
+ dev_err(dev, "No type for '%s'\n", node->full_name);
+ return -EINVAL;
+ }
+
+ 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 0;
+ }
+
+ if (strcmp(type_str, "temperature")) {
+ dev_err(dev, "Invalid type '%s' for '%s'\n", type_str,
+ node->full_name);
+ return -EINVAL;
+ }
+
+ if (reg == 3) {
+ /* RTD3 only supports thermistor mode */
+ md = RTD_MODE_THERMISTOR;
+ } else {
+ if (of_property_read_string(node, "temperature-mode",
+ &md_str)) {
+ dev_err(dev, "No mode for '%s'\n", node->full_name);
+ return -EINVAL;
+ }
+
+ 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,
+ node->full_name);
+ return -EINVAL;
+ }
+ }
+
+ *mode_val |= (md & MODE_RTD_MASK) << MODE_BIT_OFFSET_RTD(reg - 1);
+ *mode_mask |= MODE_RTD_MASK << MODE_BIT_OFFSET_RTD(reg - 1);
+
+ return 0;
+}
+
+static int nct7802_configure_channels(struct device *dev,
+ struct nct7802_data *data)
+{
+ /* Enable local temperature sensor by default */
+ u8 mode_mask = MODE_LTD_EN, mode_val = MODE_LTD_EN;
+ struct device_node *node;
+ int err;
+
+ if (dev->of_node) {
+ for_each_child_of_node(dev->of_node, node) {
+ err = nct7802_get_channel_config(dev, node, &mode_mask,
+ &mode_val);
+ if (err)
+ return err;
+ }
+ }
+
+ 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;
@@ -1047,8 +1169,7 @@ 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_channels(dev, data);
if (err)
return err;
@@ -1074,7 +1195,7 @@ 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;