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drm/tegra: dp: Read eDP version from DPCD

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

Signed-off-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Thierry Reding 2015-07-07 20:59:22 +02:00
parent 4ff9ba5674
commit 7aa3cc540d
2 changed files with 18 additions and 2 deletions
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18
drivers/gpu/drm/tegra/dp.c
View File

@ -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;

2
drivers/gpu/drm/tegra/dp.h
View File

@ -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;