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

[Naresh Solanki]

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@xxxxxxxxxxxxx>
> >
> > Add get_status for pmbus_regulator_ops.
> >
> > Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
> > Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
> > ---
> >   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