Commit 7aa3cc54 authored by Thierry Reding's avatar Thierry Reding
Browse files

drm/tegra: dp: Read eDP version from DPCD 



If the sink supports eDP, read the eDP revision from it's DPCD.

Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 4ff9ba56

drivers/gpu/drm/tegra/dp.c

+16 −2
Original line number Diff line number Diff line
@@ -5,9 +5,12 @@ 
 */



#include <drm/drm_dp_helper.h>

#include <drm/drm_print.h>



#include "dp.h"



static const u8 drm_dp_edp_revisions[] = { 0x11, 0x12, 0x13, 0x14 };



static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)

{

	caps->enhanced_framing = false;
@@ -37,6 +40,7 @@ static void drm_dp_link_reset(struct drm_dp_link *link) 
	link->max_lanes = 0;



	drm_dp_link_caps_reset(&link->caps);

	link->edp = 0;



	link->rate = 0;

	link->lanes = 0;
@@ -55,7 +59,7 @@ static void drm_dp_link_reset(struct drm_dp_link *link) 
 */

int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)

{

	u8 dpcd[DP_RECEIVER_CAP_SIZE];

	u8 dpcd[DP_RECEIVER_CAP_SIZE], value;

	int err;



	drm_dp_link_reset(link);
@@ -73,9 +77,19 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link) 
	link->caps.fast_training = drm_dp_fast_training_cap(dpcd);

	link->caps.channel_coding = drm_dp_channel_coding_supported(dpcd);



	if (drm_dp_alternate_scrambler_reset_cap(dpcd))

	if (drm_dp_alternate_scrambler_reset_cap(dpcd)) {

		link->caps.alternate_scrambler_reset = true;



		err = drm_dp_dpcd_readb(aux, DP_EDP_DPCD_REV, &value);

		if (err < 0)

			return err;



		if (value >= ARRAY_SIZE(drm_dp_edp_revisions))

			DRM_ERROR("unsupported eDP version: %02x\n", value);

		else

			link->edp = drm_dp_edp_revisions[value];

	}



	link->rate = link->max_rate;

	link->lanes = link->max_lanes;

drivers/gpu/drm/tegra/dp.h

+2 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest, 
 * @max_rate: maximum clock rate supported on the link

 * @max_lanes: maximum number of lanes supported on the link

 * @caps: capabilities supported on the link (see &drm_dp_link_caps)

 * @edp: eDP revision (0x11: eDP 1.1, 0x12: eDP 1.2, ...)

 * @rate: currently configured link rate

 * @lanes: currently configured number of lanes

 */
@@ -69,6 +70,7 @@ struct drm_dp_link { 
	unsigned int max_lanes;



	struct drm_dp_link_caps caps;

	unsigned char edp;



	unsigned int rate;

	unsigned int lanes;