Re: atomisp kernel driver(s)

[Andy Shevchenko <andy.shevchenko@gmail.com>]

On Tue, May 12, 2020 at 1:21 PM Mauro Carvalho Chehab
<mchehab@kernel.org> wrote:
>
> Em Sat, 2 May 2020 20:33:14 +0300
> Andy Shevchenko <andy.shevchenko@gmail.com> escreveu:
>
> > On Sat, May 2, 2020 at 8:04 PM Mauro Carvalho Chehab <mchehab@kernel.org> wrote:
> > > Em Sat, 2 May 2020 19:08:36 +0300
> > > Andy Shevchenko <andy.shevchenko@gmail.com> escreveu:
>
> > > Yeah, the current issue sounds simple to solve, but I need to understand
> > > how an ACPI-based device would be calling regulator_register(). Using
> > > regulators with ACPI is new to me. I suspect that this should be done
> > > by ./arch/x86/platform/intel-mid, with of course doesn't have the needed
> > > bits for this board. Also, there is a dummy regulator driver for atomisp
> > > based boards (drivers/platform/x86/intel_atomisp2_pm.c). This one could
> > > be causing some issues too.
> > >
> > > The atomisp driver uses regulator_get() to turn on the sensors.
> >
> > It should use PMIC to get them.
>
> It took a while to make it right, but at least for PMIC TI, this is now
> working with this patch:
>
>         https://git.linuxtv.org/mchehab/experimental.git/commit/?h=atomisp_v2.1&id=6c026db444d097d6df99597e07eb3575242e680e
>
> It turns that I needed to pick some missing bits from Yocto's tree,
> as the driver at staging was missing the parts for non-regulator PMICs.
>
> I suspect that the original idea there were to use the regulator
> framework for all power management (with IMHO, makes a lot of sense).
>
> I also had to enable the PMIC ACPI OpRegion with:
>
>         CONFIG_CHT_DC_TI_PMIC_OPREGION=y
>
> And fix the PMIC region for PMIC TI.
>
> I didn't test the other types of PMIC supported by the driver.
> So, maybe some additional adjustments might be needed for
> other types.

Thanks! It makes sense.

Btw, https://git.linuxtv.org/mchehab/experimental.git/commit/?h=atomisp_v2.1&id=65608aa8d34ea274600ab2cf6f0cf54ee86d8fd1
is incorrect approach. Look closer what PCI does in case when
pcim_enable_device() has been called.


-- 
With Best Regards,
Andy Shevchenko