hwmon: (max34440) Add support for 'lowest' output voltage attribute

MAX34440 and compatibles support reporting the lowest measured output voltage.
Add support for it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jean Delvare <khali@linux-fr.org>

diff --git a/Documentation/hwmon/max34440 b/Documentation/hwmon/max34440
index 8ab5153..36b335c 100644 (file)
--- a/Documentation/hwmon/max34440
+++ b/Documentation/hwmon/max34440
@@ -56,6 +56,7 @@ in[1-6]_min_alarm     Voltage low alarm. From VOLTAGE_UV_WARNING status.
 in[1-6]_max_alarm      Voltage high alarm. From VOLTAGE_OV_WARNING status.
 in[1-6]_lcrit_alarm    Voltage critical low alarm. From VOLTAGE_UV_FAULT status.
 in[1-6]_crit_alarm     Voltage critical high alarm. From VOLTAGE_OV_FAULT status.
+in[1-6]_lowest         Historical minimum voltage.
 in[1-6]_highest                Historical maximum voltage.
 in[1-6]_reset_history  Write any value to reset history.
 

diff --git a/drivers/hwmon/pmbus/max34440.c b/drivers/hwmon/pmbus/max34440.c
index 7d830c1..95ee9e1 100644 (file)
--- a/drivers/hwmon/pmbus/max34440.c
+++ b/drivers/hwmon/pmbus/max34440.c
@@ -30,6 +30,7 @@ enum chips { max34440, max34441 };
 #define MAX34440_MFR_VOUT_PEAK         0xd4
 #define MAX34440_MFR_IOUT_PEAK         0xd5
 #define MAX34440_MFR_TEMPERATURE_PEAK  0xd6
+#define MAX34440_MFR_VOUT_MIN          0xd7
 
 #define MAX34440_STATUS_OC_WARN                (1 << 0)
 #define MAX34440_STATUS_OC_FAULT       (1 << 1)
@@ -41,6 +42,10 @@ static int max34440_read_word_data(struct i2c_client *client, int page, int reg)
        int ret;
 
        switch (reg) {
+       case PMBUS_VIRT_READ_VOUT_MIN:
+               ret = pmbus_read_word_data(client, page,
+                                          MAX34440_MFR_VOUT_MIN);
+               break;
        case PMBUS_VIRT_READ_VOUT_MAX:
                ret = pmbus_read_word_data(client, page,
                                           MAX34440_MFR_VOUT_PEAK);
@@ -72,6 +77,10 @@ static int max34440_write_word_data(struct i2c_client *client, int page,
 
        switch (reg) {
        case PMBUS_VIRT_RESET_VOUT_HISTORY:
+               ret = pmbus_write_word_data(client, page,
+                                           MAX34440_MFR_VOUT_MIN, 0x7fff);
+               if (ret)
+                       break;
                ret = pmbus_write_word_data(client, page,
                                            MAX34440_MFR_VOUT_PEAK, 0);
                break;