drm: extract drm_dp_max_lane_count helper

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_dp.c

@@ -124,19 +124,6 @@ intel_edp_target_clock(struct intel_encoder *intel_encoder,
 		return mode->clock;
 }
 
-static int
-intel_dp_max_lane_count(struct intel_dp *intel_dp)
-{
-	int max_lane_count = intel_dp->dpcd[DP_MAX_LANE_COUNT] & 0x1f;
-	switch (max_lane_count) {
-	case 1: case 2: case 4:
-		break;
-	default:
-		max_lane_count = 4;
-	}
-	return max_lane_count;
-}
-
 static int
 intel_dp_max_link_bw(struct intel_dp *intel_dp)
 {
@@ -197,7 +184,7 @@ intel_dp_adjust_dithering(struct intel_dp *intel_dp,
 			  bool adjust_mode)
 {
 	int max_link_clock = intel_dp_link_clock(intel_dp_max_link_bw(intel_dp));
-	int max_lanes = intel_dp_max_lane_count(intel_dp);
+	int max_lanes = drm_dp_max_lane_count(intel_dp->dpcd);
 	int max_rate, mode_rate;
 
 	mode_rate = intel_dp_link_required(mode->clock, 24);
@@ -699,7 +686,7 @@ intel_dp_mode_fixup(struct drm_encoder *encoder,
 	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 	struct intel_connector *intel_connector = intel_dp->attached_connector;
 	int lane_count, clock;
-	int max_lane_count = intel_dp_max_lane_count(intel_dp);
+	int max_lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
 	int max_clock = intel_dp_max_link_bw(intel_dp) == DP_LINK_BW_2_7 ? 1 : 0;
 	int bpp, mode_rate;
 	static int bws[2] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7 };

drivers/gpu/drm/radeon/atombios_dp.c

@@ -347,11 +347,6 @@ static int dp_get_max_dp_pix_clock(int link_rate,
 	return (link_rate * lane_num * 8) / bpp;
 }
 
-static u8 dp_get_max_lane_number(u8 dpcd[DP_DPCD_SIZE])
-{
-	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
-}
-
 /***** radeon specific DP functions *****/
 
 /* First get the min lane# when low rate is used according to pixel clock
@@ -364,7 +359,7 @@ static int radeon_dp_get_dp_lane_number(struct drm_connector *connector,
 {
 	int bpp = convert_bpc_to_bpp(radeon_get_monitor_bpc(connector));
 	int max_link_rate = drm_dp_max_link_rate(dpcd);
-	int max_lane_num = dp_get_max_lane_number(dpcd);
+	int max_lane_num = drm_dp_max_lane_count(dpcd);
 	int lane_num;
 	int max_dp_pix_clock;
 

include/drm/drm_dp_helper.h

@@ -346,4 +346,11 @@ drm_dp_max_link_rate(u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {
 	return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
 }
+
+static inline u8
+drm_dp_max_lane_count(u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
+}
+
 #endif /* _DRM_DP_HELPER_H_ */