drm: edid: add support for E-DDC
authorShirish S <s.shirish@samsung.com>
Thu, 30 Aug 2012 07:04:06 +0000 (07:04 +0000)
committerDave Airlie <airlied@redhat.com>
Thu, 13 Sep 2012 01:28:59 +0000 (11:28 +1000)
commitcd004b3f4cd4169815c82bf9e424fda06978898a
tree937c4b7676e7f375bb3cc6ad9833b17123a10c13
parent93eb58d53fb14e9eeb1b42f8c04dbd7afc09adf7
drm: edid: add support for E-DDC

The current logic for probing ddc is limited to
2 blocks (256 bytes), this patch adds support
for the 4 block (512) data.

To do this, a single 8-bit segment index is
passed to the display via the I2C address 30h.
Data from the selected segment is then immediately
read via the regular DDC2 address using a repeated
I2C 'START' signal.

Signed-off-by: Shirish S <s.shirish@samsung.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/drm_edid.c