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

[Guenter Roeck]

On Thu, Mar 17, 2022 at 11:21:23PM +0000, Brandon Wyman wrote:
> 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 at gmail.com>

Applied.

Thanks,
Guenter

> ---
>  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",