Re: [PATCH] hwmon: pm_bus: core: Implement regulator get_status

[Naresh Solanki <naresh.solanki@9elements.com>]

Hi Guenter,

On 18-11-2022 04:08 am, Guenter Roeck wrote:
> On Thu, Nov 17, 2022 at 08:43:51PM +0100, Naresh Solanki wrote:
>> From: Patrick Rudolph <patrick.rudolph@9elements.com>
>>
>> Add get_status for pmbus_regulator_ops.
>>
>> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>> ---
>>   drivers/hwmon/pmbus/pmbus_core.c | 78 ++++++++++++++++++++++++++++++++
>>   1 file changed, 78 insertions(+)
>>
>> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
>> index 7ec04934747e..d5e2b0662da5 100644
>> --- a/drivers/hwmon/pmbus/pmbus_core.c
>> +++ b/drivers/hwmon/pmbus/pmbus_core.c
>> @@ -2851,6 +2851,83 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
>>   	return 0;
>>   }
>>   
>> +static int pmbus_regulator_get_status(struct regulator_dev *rdev)
>> +{
>> +	struct device *dev = rdev_get_dev(rdev);
>> +	struct i2c_client *client = to_i2c_client(dev->parent);
>> +	struct pmbus_data *data = i2c_get_clientdata(client);
>> +	u8 page = rdev_get_id(rdev);
>> +	int status, status2;
>> +
>> +	mutex_lock(&data->update_lock);
>> +	status = pmbus_get_status(client, page, PMBUS_STATUS_WORD);
>> +	mutex_unlock(&data->update_lock);
>> +	if (status < 0)
>> +		 return status;
>> +
>> +	if (status & PB_STATUS_VIN_UV ||
>> +	    status & PB_STATUS_IOUT_OC ||
>> +	    status & PB_STATUS_VOUT_OV ||
>> +	    status & PB_STATUS_UNKNOWN)
>> +		 return REGULATOR_STATUS_ERROR;
> 
> 	if (status & (PB_STATUS_VIN_UV | PB_STATUS_IOUT_OC | ...))
> 
> PB_STATUS_UNKNOWN can mean anything and doesn't necessarily indicate
> an error. Not sure if it makes sense to report that as error.
I wasn't sure about this but as per spec, it still means unknown fault 
or warning. Thats why I've considered it for returning error status.
> 
>> +
>> +	if (status & PB_STATUS_VOUT_OV &&
> 
> PB_STATUS_VOUT_OV was checked above already, and the code won't get here
> if the bit is set.
Oh yes. Will change to PB_STATUS_VOUT so that other VOUT faults can be 
checked.
> 
>> +	    data->info->func[page] & PMBUS_HAVE_STATUS_VOUT) {
>> +		 mutex_lock(&data->update_lock);
>> +		 status2 = _pmbus_read_byte_data(client, page, PMBUS_STATUS_VOUT);
>> +		 mutex_unlock(&data->update_lock);
>> +		 if (status2 < 0)
>> +			  return status2;
>> +		 if (status2 & PB_VOLTAGE_OV_FAULT ||
>> +		     status2 & PB_VOLTAGE_UV_FAULT)
> 
> 		if (status2 & (...))
> 
Sure will update this way.
>> +			  return REGULATOR_STATUS_ERROR;
>> +	}
>> +	if (status & PB_STATUS_IOUT_OC &&
> 
> Same as above - this condition will never be true.
> 
Will change to PB_STATUS_IOUT_POUT so that STATUS_IOUT can be checked 
for other faults related to POUT & IOUT which aren't present in STATUS_WORD.
>> +	    data->info->func[page] & PMBUS_HAVE_STATUS_IOUT) {
>> +		 mutex_lock(&data->update_lock);
>> +		 status2 = _pmbus_read_byte_data(client, page, PMBUS_STATUS_IOUT);
>> +		 mutex_unlock(&data->update_lock);
>> +		 if (status2 < 0)
>> +			  return status2;
>> +		 if (status2 & PB_POUT_OP_FAULT ||
>> +		     status2 & PB_IOUT_UC_FAULT ||
>> +		     status2 & PB_IOUT_OC_LV_FAULT ||
>> +		     status2 & PB_IOUT_OC_FAULT)
> 
> 		if (status2 & (...))
> 
Will update accordingly.
>> +			  return REGULATOR_STATUS_ERROR;
>> +	}
>> +	if (status & PB_STATUS_VIN_UV &&
> 
> and again.
> 
Will update to PB_STATUS_INPUT.
>> +	    data->info->func[page] & PMBUS_HAVE_STATUS_INPUT) {
>> +		 mutex_lock(&data->update_lock);
>> +		 status2 = _pmbus_read_byte_data(client, page, PMBUS_STATUS_INPUT);
>> +		 mutex_unlock(&data->update_lock);
>> +		 if (status2 < 0)
>> +			  return status2;
>> +		 if (status2 & PB_IIN_OC_FAULT ||
>> +		     status2 & PB_VOLTAGE_OV_FAULT ||
>> +		     status2 & PB_VOLTAGE_UV_FAULT)
> 
> and again
> 
Will update to right way.
>> +			  return REGULATOR_STATUS_ERROR;
>> +	}
>> +	if (status & PB_STATUS_TEMPERATURE &&
>> +	    data->info->func[page] & PMBUS_HAVE_STATUS_TEMP) {
>> +		 mutex_lock(&data->update_lock);
>> +		 status2 = _pmbus_read_byte_data(client, page, PMBUS_STATUS_TEMPERATURE);
>> +		 mutex_unlock(&data->update_lock);
>> +		 if (status2 < 0)
>> +			  return status2;
>> +		 if (status2 & PB_TEMP_UT_FAULT ||
>> +		     status2 & PB_TEMP_OT_FAULT)
> 
> and again
> 
Will update.
>> +			  return REGULATOR_STATUS_ERROR;
>> +	}
>> +
>> +	if (status & PB_STATUS_OFF)
>> +		 return REGULATOR_STATUS_OFF;
>> +
>> +	if (status & PB_STATUS_POWER_GOOD_N)
>> +		 return REGULATOR_STATUS_OFF;
> 
> Wouldn't it be better to check those bits first ?
> Also, it should be
> 
> 	if (status & (PB_STATUS_OFF | PB_STATUS_POWER_GOOD_N))
> 
Yes makes sense. Will update.
>> +
>> +	return REGULATOR_STATUS_ON;
>> +}
>> +
>>   static int pmbus_regulator_get_low_margin(struct i2c_client *client, int page)
>>   {
>>   	struct pmbus_data *data = i2c_get_clientdata(client);
>> @@ -2991,6 +3068,7 @@ const struct regulator_ops pmbus_regulator_ops = {
>>   	.disable = pmbus_regulator_disable,
>>   	.is_enabled = pmbus_regulator_is_enabled,
>>   	.get_error_flags = pmbus_regulator_get_error_flags,
>> +	.get_status = pmbus_regulator_get_status,
>>   	.get_voltage = pmbus_regulator_get_voltage,
>>   	.set_voltage = pmbus_regulator_set_voltage,
>>   	.list_voltage = pmbus_regulator_list_voltage,
>>
>> base-commit: 27fea302952d8c90cafbdbee96bafeca03544401
>> -- 
>> 2.37.3
>>
Regards,
Naresh