hwmon: (emc1403) Add EMC1423 support

EMC1423 uses the similar register and adds a hardware shutdown pin to
protect exceed temperature. This function is set by resistor; it's not
necessary to do anything in the driver except add the emc1423 pid of 0x23.

Signed-off-by: Jekyll Lai <jekyll_lai@wistron.com>
[Updated Kconfig/comments and minor further changes asked for by the hwmon
 maintainers]
Signed-off-by: Alan Cox <alan@linux.intel.com>
[Fixed checkpatch warning]
Signed-of--by: Jean Delvare <khali@linux-fr.org>

2 files changed, 14 insertions, 6 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index bdc13d28b1ea..35f00dae3676 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -809,10 +809,10 @@ config SENSORS_DME1737
           will be called dme1737.
 
 config SENSORS_EMC1403
-        tristate "SMSC EMC1403 thermal sensor"
+        tristate "SMSC EMC1403/23 thermal sensor"
         depends on I2C
         help
-          If you say yes here you get support for the SMSC EMC1403
+          If you say yes here you get support for the SMSC EMC1403/23
           temperature monitoring chip.
 
           Threshold values can be configured using sysfs.
diff --git a/drivers/hwmon/emc1403.c b/drivers/hwmon/emc1403.c
index 8dee3f38fdfb..5dea9faa1656 100644
--- a/drivers/hwmon/emc1403.c
+++ b/drivers/hwmon/emc1403.c
@@ -269,23 +269,30 @@ static int emc1403_detect(struct i2c_client *client,
                         struct i2c_board_info *info)
 {
         int id;
-        /* Check if thermal chip is SMSC and EMC1403 */
+        /* Check if thermal chip is SMSC and EMC1403 or EMC1423 */
 
         id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
         if (id != 0x5d)
                 return -ENODEV;
 
+        id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
+        switch (id) {
+        case 0x21:
+                strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
+                break;
+        case 0x23:
+                strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
+                break;
         /* Note: 0x25 is the 1404 which is very similar and this
            driver could be extended */
-        id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
-        if (id != 0x21)
+        default:
                 return -ENODEV;
+        }
 
         id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
         if (id != 0x01)
                 return -ENODEV;
 
-        strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
         return 0;
 }
 
@@ -342,6 +349,7 @@ static const unsigned short emc1403_address_list[] = {
 
 static const struct i2c_device_id emc1403_idtable[] = {
         { "emc1403", 0 },
+        { "emc1423", 0 },
         { }
 };
 MODULE_DEVICE_TABLE(i2c, emc1403_idtable);