[PATCH v3 2/7] mmc: bcm2835: Add new driver for the sdhost controller.

[Stefan Wahren]

> Eric Anholt <eric at anholt.net> hat am 1. März 2017 um 19:00 geschrieben:
> 
> 
> Gerd Hoffmann <kraxel at redhat.com> writes:
> 
> > From: Eric Anholt <eric at anholt.net>
> >
> > 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 at anholt.net>
> 
> 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