[PATCH] hwmon: (pmbus) Add Vin unit off handling

[Brandon Wyman <bjwyman@gmail.com>]

If there is an input undervoltage fault, reported in STATUS_INPUT
command response, there is quite likely a "Unit Off For Insufficient
Input Voltage" condition as well.

Add a constant for bit 3 of STATUS_INPUT. Update the Vin limit
attributes to include both bits in the mask for clearing faults.

If an input undervoltage fault occurs, causing a unit off for
insufficient input voltage, but the unit is off bit is not cleared, the
STATUS_WORD will not be updated to clear the input fault condition.
Including the unit is off bit (bit 3) allows for the input fault
condition to completely clear.

Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
---
 drivers/hwmon/pmbus/pmbus.h      | 1 +
 drivers/hwmon/pmbus/pmbus_core.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index e0aa8aa46d8c..ef3a8ecde4df 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -319,6 +319,7 @@ enum pmbus_fan_mode { percent = 0, rpm };
 /*
  * STATUS_VOUT, STATUS_INPUT
  */
+#define PB_VOLTAGE_VIN_OFF		BIT(3)
 #define PB_VOLTAGE_UV_FAULT		BIT(4)
 #define PB_VOLTAGE_UV_WARNING		BIT(5)
 #define PB_VOLTAGE_OV_WARNING		BIT(6)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index ac2fbee1ba9c..a0d899dc81f0 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1373,7 +1373,7 @@ static const struct pmbus_limit_attr vin_limit_attrs[] = {
 		.reg = PMBUS_VIN_UV_FAULT_LIMIT,
 		.attr = "lcrit",
 		.alarm = "lcrit_alarm",
-		.sbit = PB_VOLTAGE_UV_FAULT,
+		.sbit = (PB_VOLTAGE_UV_FAULT | PB_VOLTAGE_VIN_OFF),
 	}, {
 		.reg = PMBUS_VIN_OV_WARN_LIMIT,
 		.attr = "max",
-- 
2.25.1