Re: [PATCH v2 0/8] ARM64: Initial Marvell IAP140 enablement

["Andreas Färber" <afaerber@suse.de>]

Am 22.02.2017 um 17:43 schrieb Andreas Färber:
> Hi Rob,
> 
> Am 22.02.2017 um 14:34 schrieb Rob Herring:
>> On Tue, Feb 21, 2017 at 8:29 PM, Andreas Färber <afaerber@suse.de> wrote:
>>> One limitation is currently the lack of an IAP140 clk driver. Patch 4/4 works
>>> around that for UART0 with a fixed-clock.
>>
>> The PXA1928 clock driver should be close to what you need. They are
>> supposed to be very similar.
> 
> Where do you see that in mainline? Not in drivers/clk/pxa/ at least. I'm
> certain the acorn-marvell tree has a PXA1908 clk driver somewhere, too,
> I just haven't ported it yet.
> 
>>> Andreas Färber (8):
>>>   Documentation: arm: Marvell: Document IAP140
>>>   tty: serial: Suppress deprecated SERIAL_PXA on arm64
>>>   tty: serial: 8250_pxa: Implement mmp earlycon
>>
>> You should not use the pxa serial driver. AFAICT, it was separate to
>> add DMA support, but now the base 8250 driver supports DMA. The base
>> 8250 driver works with the PXA1928 and should also work with the
>> PXA1908.
> 
> Do you personally have one? I didn't spot a pxa1928 DT in mainline.
> 
> So, by my reading both 8250_of.c and 8250_pxa.c list "mrvl,mmp-uart" for
> the platform driver. Is that really intentional?
> 
> What the early_pxa earlycon does is set the register shift and then
> reuse the 8250 core - that looks perfectly valid to me. Are you possibly
> mixing that up with the non-8250 pxa serial driver that I am already
> suppressing one patch earlier?

Hit send too early: There's also 8250_early.c, but that does not appear
to use the reg-shift property (which is not mentioned in the
mrvl,mmp-uart binding) and thus omap has a custom earlycon driver there,
similar to what is in 8250_pxa.c.

> 
> While at it, are you aware that we have two drivers, one pxa and one
> mmp, that bind to "marvell,pdma-1.0"? That seemed wrong to me, too.
> 
> Regards,
> Andreas
> 


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