Eric Anholt [off-list ref] hat am 1. M?rz 2017 um 20:31 geschrieben:


Stefan Wahren [off-list ref] writes:

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Eric Anholt [off-list ref] hat am 1. M?rz 2017 um 19:00 geschrieben:


Gerd Hoffmann [off-list ref] writes:

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From: Eric Anholt <redacted>

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 <redacted>

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

Should any of those changes block merging the current code, though? 

No, but the recursion about bcm2835_finish_command() and bcm2835_transfer_complete() is still there.