From: Thierry Reding Date: Thu, 28 Nov 2013 10:31:00 +0000 (+0100) Subject: drm/dp: Add AUX channel infrastructure X-Git-Tag: v3.15-rc1~51^2~63^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c197db75ff5c1d4f015c7668a3715e230a5d7e27;p=pandora-kernel.git drm/dp: Add AUX channel infrastructure This is a superset of the current i2c_dp_aux bus functionality and can be used to transfer native AUX in addition to I2C-over-AUX messages. Helpers are provided to read and write the DPCD, either blockwise or byte-wise. Many of the existing helpers for DisplayPort take a copy of a portion of the DPCD and operate on that, without a way to write data back to the DPCD (e.g. for configuration of the link). Subsequent patches will build upon this infrastructure to provide common functionality in a generic way. Reviewed-by: Alex Deucher Reviewed-by: Jani Nikula Signed-off-by: Thierry Reding --- Changes in v5: - move comments partially to struct drm_dp_aux_msg in header file - return -EPROTO on short reads in DPCD helpers Changes in v4: - fix a typo in a comment Changes in v3: - reorder drm_dp_dpcd_writeb() arguments to be more intuitive - return number of bytes transferred in drm_dp_dpcd_write() - factor out drm_dp_dpcd_access() - describe error codes --- Reading git-diff-tree failed