RE: [PATCH] spi: spi-fsl-dspi: Add ACPI support

From: Kuldip Dwivedi
Date: Wed Aug 26 2020 - 11:13:29 EST


> -----Original Message-----
> From: Vladimir Oltean <olteanv@xxxxxxxxx>
> Sent: Wednesday, August 26, 2020 8:18 PM
> To: Mark Brown <broonie@xxxxxxxxxx>
> Cc: Qiang Zhao <qiang.zhao@xxxxxxx>; kuldip dwivedi
> <kuldip.dwivedi@xxxxxxxxxxxxxxxx>; linux-spi@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Pankaj Bansal <pankaj.bansal@xxxxxxx>; Varun
Sethi
> <V.Sethi@xxxxxxx>; Tanveer Alam <tanveer.alam@xxxxxxxxxxxxxxxx>
> Subject: Re: [PATCH] spi: spi-fsl-dspi: Add ACPI support
>
> On Wed, Aug 26, 2020 at 03:23:12PM +0100, Mark Brown wrote:
> > On Wed, Aug 26, 2020 at 02:47:58PM +0300, Vladimir Oltean wrote:
> >
> > > - The compatible string plays an integral part in the functionality
of
> > > the spi-fsl-dspi driver. I want to see a solution for ACPI where
the
> > > driver knows on which SoC it's running on. Otherwise it doesn't
know
> > > what are the silicon parameters of the DSPI module (XSPI present
or
> > > not, DMA present or not, FIFO depth). I don't see that now. I just
see
> > > something hardcoded for:
> > > { "NXP0005", .driver_data =
> > > (kernel_ulong_t)&devtype_data[LS2085A], }
> >
> > Based on some other stuff I've seen with ACPI on NXP stuff it looks
> > like they're following the same scheme but only caring about that one
> > SoC for the time being.
>
> So, no argument about caring only about ACPI on one particular SoC for
the time
> being, but there's a big difference between a solution that works for
N=1 and one
> that works for N=2...
>
> Showing my ignorance here, but is there something equivalent to
> of_machine_is_compatible() for ACPI?
Just a query, Can't we use meaningful HID for different SoC just like
compatible strings in DT ?
In this way Silicon parameters can also be added in fsl_dspi_devtype_data
structure , which is
already exist in driver
>
> Thanks,
> -Vladimir