[PATCH 1/2] drm/dp: Add HBR3 support in existing DRM DP helpers

Manasi Navare
2018-01-22T22:43:10Z

Existing helpers add support upto HBR2. This patch
adds support for HBR3 rate (8.1 Gbps) introduced as
part of DP 1.4 specification.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
---
drivers/gpu/drm/drm_dp_helper.c | 4 ++++
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
include/drm/drm_dp_helper.h | 1 +
3 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index adf79be..ffe14ec 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -146,6 +146,8 @@ u8 drm_dp_link_rate_to_bw_code(int link_rate)
return DP_LINK_BW_2_7;
case 540000:
return DP_LINK_BW_5_4;
+ case 810000:
+ return DP_LINK_BW_8_1;
}
}
EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code);
@@ -161,6 +163,8 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw)
return 270000;
case DP_LINK_BW_5_4:
return 540000;
+ case DP_LINK_BW_8_1:
+ return 810000;
}
}
EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 70dcfa5..36df7df 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2087,6 +2087,9 @@ static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
case DP_LINK_BW_5_4:
*out = 10 * dp_link_count;
break;
+ case DP_LINK_BW_8_1:
+ *out = 15 * dp_link_count;
+ break;
}
return true;
}
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 9d3ce3b..c80fa92 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -334,6 +334,7 @@
# define DP_LINK_BW_1_62 0x06
# define DP_LINK_BW_2_7 0x0a
# define DP_LINK_BW_5_4 0x14 /* 1.2 */
+# define DP_LINK_BW_8_1 0x1e /* 1.4 */

#define DP_LANE_COUNT_SET 0x101
# define DP_LANE_COUNT_MASK 0x0f
--
2.7.4