Re: [PATCH v3 2/7] mmc: bcm2835: Add new driver for the sdhost controller.
From: Stefan Wahren
Date: Wed Mar 01 2017 - 14:31:15 EST
> Eric Anholt <eric@xxxxxxxxxx> hat am 1. MÃrz 2017 um 19:00 geschrieben:
>
>
> Gerd Hoffmann <kraxel@xxxxxxxxxx> writes:
>
> > From: Eric Anholt <eric@xxxxxxxxxx>
> >
> > The 2835 has two SD controllers: The Arasan sdhci controller (supported
> > by the iproc driver) and a custom sdhost controller. This patch adds a
> > driver for the latter.
> >
> > The sdhci controller supports both sdcard and sdio. The sdhost
> > controller supports the sdcard only, but has better performance. Also
> > note that the rpi3 has sdio wifi, so driving the sdcard with the sdhost
> > controller allows to use the sdhci controller for wifi support.
> >
> > The configuration is done by devicetree via pin muxing. Both SD
> > controller are available on the same pins (2 pin groups = pin 22 to 27 +
> > pin 48 to 53). So it's possible to use both SD controllers at the same
> > time with different pin groups.
> >
> > The code was originally written by Phil Elwell in the downstream
> > Rasbperry Pi tree, and I did a major cleanup on it (+319, -707 lines
> > out of the original 2055) for inclusion.
> >
> > Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
>
> Ulf, what do you need done to this driver patch before it can go in?
> The commit message seems like it could use some rewriting at this point
> (Personally I would drop the detailed changelogs from Stefan and Gerd,
> updating the last paragraph here to give them credit), but what's
> important to me is getting the driver in so that distros don't have to
> carry this patch for wifi support.
I'm still working on 3 small patches for this driver:
1. trivial error in a register comment
2. ignore SDCMD_FAIL_FLAG during bcm2835_finish_command (downstream [1])
3. remove unnecessary call to bcm2835_reset_internal
I plan to submit them on Friday.
[1] - https://github.com/raspberrypi/linux/commit/711cade866c9f865f9b283c9369e9486f27d1fec