tegra124: Add tegra_dc_i2c_aux_read to allow reading EDID.

To read EDID, we need to access I2C via DP AUX channel.

BRANCH=none
BUG=chrome-os-partner:25933
TEST=emerge-nyan coreboot chromeos-bootimage

Original-Change-Id: I2666b5d46843485b79265a537f19bd8eab5e1a26
Original-Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/188858
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
Original-Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 8f8e98ff5038b57f89332aee75573095c3933dd2)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I5b1b6ab2940c8265483059fd94a2c4db2a41144a
Reviewed-on: http://review.coreboot.org/7735
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed