Re: [PATCH v2 5/7] mfd: Add RTL8231 core device

From: Sander Vanheule
Date: Mon May 24 2021 - 04:04:47 EST


On Mon, 2021-05-24 at 10:55 +0300, Andy Shevchenko wrote:
> On Mon, May 24, 2021 at 10:50 AM Sander Vanheule <sander@xxxxxxxxxxxxx> wrote:
> > On Tue, 2021-05-18 at 00:18 +0300, Andy Shevchenko wrote:
> > > On Mon, May 17, 2021 at 10:28 PM Sander Vanheule <sander@xxxxxxxxxxxxx>
> > > wrote:
> > > > +       err = regmap_read(map, RTL8231_REG_FUNC1, &v);
> > >
> > > > +       ready_code = FIELD_GET(RTL8231_FUNC1_READY_CODE_MASK, v);
> > >
> > > If we got an error why we need a read_core, what for?
> >
> > The chip has a static 5-bit field in register 0x01, called READY_CODE
> > according
> > to the datasheet. If a device is present, and a read from register 0x01
> > succeeds, I still check that this field has the correct value. For the
> > RTL8231,
> > it should return 0x37. If this isn't the case, I assume this isn't an
> > RTL8231,
> > so the driver probe stops and returns an error value.
>
> Right. And why do you get ready_code if you know that there is an error?

This has changed in v3. I now check if there was an error reading the register,
and return if there was. Only if there wasn't an error, the code continues to
extract and verify the READY_CODE value.

Best,
Sander