Re: [PATCH 3/9] regulator: mt6380: Add support for MT6380

[Sean Wang]

On Fri, 2017-06-23 at 17:14 +0100, Mark Brown wrote:
> On Fri, Jun 23, 2017 at 11:56:05PM +0800, Sean Wang wrote:
> > On Tue, 2017-06-06 at 19:22 +0100, Mark Brown wrote:
> 
> > > > +	return (regval & info->desc.enable_mask) ?
> > > > +		REGULATOR_STATUS_ON : REGULATOR_STATUS_OFF;
> 
> > > This isn't really a get_status() operation - it's just showing the
> > > status of the enable we set.  The get_status() operation is for hardware
> > > that has a mechanism for reading back the current physical status of the
> > > regulator, usually including things like if it's in regulation or not.
> 
> > > Also please write normal conditional statements, it helps people read
> > > the code.
> 
> > for the hardware, the way for reflect the current physical physical 
> > has to depend on the bit reading as the bit we enable. It indeed tends
> > to confuse other users and developers, we maybe can add some comments
> > for this to avoid.
> 
> It's OK to just not have a get_status() operation - a lot of regulators
> just can't do this and that's fine, the subsystem will cope.
> 

understood. it seems to be better with subsystem coping. we'll remove
get_status callback.

> > > > +static const struct of_device_id mt6380_of_match[] = {
> > > > +	{ .compatible = "mediatek,mt6380-regulator", },
> > > > +	{ /* sentinel */ },
> > > > +};
> > > > +MODULE_DEVICE_TABLE(of, mt6380_of_match);
> 
> > > Given that this driver is entirely specific to the parent PMIC there
> > > should be no need for a separate compatible string, it's redundant.
> 
> > the parent of pmic is MediaTek pwrap which is possibly being used with
> > various pmics such as MT6323, MT6797, MT6380 and so on. So extra
> > matching we thought is required to identify which pmic is actually being
> > connected. 
> 
> > For those opinions, maybe we didn't get your exact point. If something
> > is wrong, please kindly guide us to the right place.
> 
> It sounds like pwrap should be a bus rather than using a platform device
> here?  But I guess that's how things are for now so OK.

yes, it is a bus , a proprietary bus,  which is something like
encapsulation of spi and there's some protocol running on this 
between master/slave.