[PATCH 2/3] tty/serial: of_serial: add support for PXA/MMP uarts
peter at hurleysoftware.com
Wed Jan 28 09:06:09 PST 2015
On 01/28/2015 09:21 AM, Rob Herring wrote:
> On Tue, Jan 27, 2015 at 1:43 PM, Peter Hurley <peter at hurleysoftware.com> wrote:
>> On 01/27/2015 11:44 AM, Rob Herring wrote:
>>> On Tue, Jan 27, 2015 at 9:09 AM, Peter Hurley <peter at hurleysoftware.com> wrote:
>>>> On 01/27/2015 09:30 AM, Rob Herring wrote:
>>>>> On Tue, Jan 27, 2015 at 6:44 AM, Peter Hurley <peter at hurleysoftware.com> wrote:
>>>>>> On 01/26/2015 11:50 PM, Rob Herring wrote:
>> OTOH, I didn't realize that patch removed the PXA driver. That driver has
>> errata workarounds which didn't get integrated into the 8250 core; it seems
>> a shame to toss that away.
> There was some discussion on errata in the prior versions. One of them
> was deemed not needed. Another one is needed, but that's on certain
> PXA2xx. So we'll need to pickup that work-around at some point, but it
> is not yet needed here because PXA2xx is not enabled for DT.
Do you know offhand which errata? If not, nbd; I can do a little digging.
>> [ Sidebar: I did a trial split of 8250_core into a separate 8250 base module
>> and an 8250 universal driver. I keep having to rework the split but it's
>> pretty close now; the 8250 base module might be just the thing for simplifying
>> the pxa driver and getting console/earlycon/dma for free.
>> Let me see what I can do about getting that done.
> Yes, it would be nice to split the legacy ISA parts from the proper
> platform driver. There's way too many kconfig options for the 8250 as
> well IMO.
After I finish the split, I can look at making most/all of those options
dependent on the universal 8250 driver only.
> BTW, It appears that the main motivator for a separate driver was to
> add DMA support and that's what the out of tree driver adds. But now,
> we would never add the PXA DMA API support and the 8250 driver has
> learned DMA support.
Yeah, PXA should not have been forked. But I say that with the benefit
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