hwmon: (pmbus/ltc2978) Fix temperature reporting

On LTC2978, only READ_TEMPERATURE is supported. It reports
the internal junction temperature. This register is unpaged.

On LTC3880, READ_TEMPERATURE and READ_TEMPERATURE2 are supported.
READ_TEMPERATURE is paged and reports external temperatures.
READ_TEMPERATURE2 is unpaged and reports the internal junction
temperature.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org # 3.2+
Acked-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index a58de38e23d8..6d6130752f94 100644
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -59,7 +59,7 @@ enum chips { ltc2978, ltc3880 };
 struct ltc2978_data {
         enum chips id;
         int vin_min, vin_max;
-        int temp_min, temp_max;
+        int temp_min, temp_max[2];
         int vout_min[8], vout_max[8];
         int iout_max[2];
         int temp2_max;
@@ -113,9 +113,10 @@ static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
                 ret = pmbus_read_word_data(client, page,
                                            LTC2978_MFR_TEMPERATURE_PEAK);
                 if (ret >= 0) {
-                        if (lin11_to_val(ret) > lin11_to_val(data->temp_max))
-                                data->temp_max = ret;
-                        ret = data->temp_max;
+                        if (lin11_to_val(ret)
+                            > lin11_to_val(data->temp_max[page]))
+                                data->temp_max[page] = ret;
+                        ret = data->temp_max[page];
                 }
                 break;
         case PMBUS_VIRT_RESET_VOUT_HISTORY:
@@ -266,7 +267,7 @@ static int ltc2978_write_word_data(struct i2c_client *client, int page,
                 break;
         case PMBUS_VIRT_RESET_TEMP_HISTORY:
                 data->temp_min = 0x7bff;
-                data->temp_max = 0x7c00;
+                data->temp_max[page] = 0x7c00;
                 ret = ltc2978_clear_peaks(client, page, data->id);
                 break;
         default:
@@ -323,7 +324,8 @@ static int ltc2978_probe(struct i2c_client *client,
         data->vin_min = 0x7bff;
         data->vin_max = 0x7c00;
         data->temp_min = 0x7bff;
-        data->temp_max = 0x7c00;
+        for (i = 0; i < ARRAY_SIZE(data->temp_max); i++)
+                data->temp_max[i] = 0x7c00;
         data->temp2_max = 0x7c00;
 
         switch (data->id) {