[U-Boot] [PATCH] serial: 16550: Add JZ47xx support

[Paul Burton]

On Thu, May 26, 2016 at 02:05:07PM +0200, Marek Vasut wrote:
> > Interesting :) May I ask which platform/SoC you're working with? Have
> > you seen the (unfortunately currently out of tree) port we did for the
> > JZ4780-based Ci20? I recall the pain of squeezing SPL down to a small
> > enough size well...
> 
> I bought the CI20, yeah. I started with that tree and am now getting it
> into mainline shape. I actually managed to optimize the SPL, so it does
> not overflow. One of the things which helped a lot was removing slop[1]
> from the structures and using appropriate data types in them (like don't
> use u32 to store an 8bit number). I also tinified the MMC stack, so that
> it won't pull in too much useless code.
> 
> At this point, I have a u-boot running from SD card and the SD driver in
> full U-Boot is already probing from DT and using DM. I sent Daniel the
> updated patches, but they are still work in progress. Nonetheless, if
> you want me forward that to you as well, let me know.
> 
> I plan to get this CI20 submitted at some point this or next week, so it
> can land in 2016.07 (I hope!) and then debian and fedora-mips (and other
> distros) can pick it up and package proper. That's how I see it.

That sounds great :) I'd be interested in seeing them but probably won't
have any time to look at them for a few weeks anyway (busy with other
work things & then getting married & going off on honeymoon!). So
hopefully by the time I'd get round to having a look they'll be in
mainline :)

> btw. what is the linux support status of the ci20 ? Is anyone working
> on that? I saw the DTS in Linux, but it's pretty bare-bones.

Yeah the support in mainline Linux is a bit basic at the moment. The
biggest holdup is pinctrl support which I need to do some work on - the
DT bindings are more complicated than they need to be, and the driver
should probably be made more generic to cover other Ingenic SoCs before
it goes into mainline.

> btw2. can I get the ci40 anywhere or is that just unobtainium board ?

I'll email you separately about that.

Thanks,
    Paul