i2c/ww_ring: various driver fixes and improvements

When in development environment, some SP5 devices might not have the
LED ring attached. They are still fully functional, but when booting
up are generating massive amount of i2c error messages. This patch
prevents accesses to non-existing lp55321 devices.

When loading the program into the device the vendor recommends 1 ms
delay when accessing the program control register. This patch
separates these accesses into a function and add a delay after every
access.

Another fix - advance the program address when loading multipage
programs.

Set the global variable register 3c, not used by coreboot programs, to
a fixed value. This will allow depthcharge to avoid re-initializing
the controller when not necessary.

BRANCH=storm
BUG=chrome-os-partner:36059
TEST=booted firmware on an SP5 with no LED ring attached, no excessive
     error messages are generated, saw the default pattern displayed
     when the recovery button is pressed during reset.

Change-Id: I6a2a27968684c40dae15317540a16405b1419e30
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 5e0b4c84aca27460db594da1faf627ddee56f399
Original-Change-Id: I10f1f53cefb866d11ecf76ea48f74131d8b0ce77
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/260648
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9867
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

0 files changed, 0 insertions, 0 deletions