drm/msm: edp: Avoid drm_dp_link helpers

During the discussion of patches that enhance the drm_dp_link helpers it
was concluded that these helpers aren't very useful to begin with. Start
pushing the equivalent code into individual drivers to ultimately remove
them.

Signed-off-by: Thierry Reding <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/msm/edp/edp_ctrl.c

···
 	/* edid raw data */
 	struct edid *edid;
 
-	struct drm_dp_link dp_link;
 	struct drm_dp_aux *drm_aux;
 
 	/* dpcd raw data */
···
 	u32 prate;
 	u32 lrate;
 	u32 bpp;
-	u8 max_lane = ctrl->dp_link.num_lanes;
+	u8 max_lane = drm_dp_max_lane_count(ctrl->dpcd);
 	u8 lane;
 
 	prate = ctrl->pixel_rate;
···
 	 * By default, use the maximum link rate and minimum lane count,
 	 * so that we can do rate down shift during link training.
 	 */
-	ctrl->link_rate = drm_dp_link_rate_to_bw_code(ctrl->dp_link.rate);
+	ctrl->link_rate = ctrl->dpcd[DP_MAX_LINK_RATE];
 
 	prate *= bpp;
 	prate /= 8; /* in kByte */
···
 
 	data = EDP_CONFIGURATION_CTRL_LANES(ctrl->lane_cnt - 1);
 
-	if (ctrl->dp_link.capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
+	if (drm_dp_enhanced_frame_cap(ctrl->dpcd))
 		data |= EDP_CONFIGURATION_CTRL_ENHANCED_FRAMING;
 
 	depth = EDP_6BIT;
···
 
 	rate = ctrl->link_rate;
 	lane = ctrl->lane_cnt;
-	max_lane = ctrl->dp_link.num_lanes;
+	max_lane = drm_dp_max_lane_count(ctrl->dpcd);
 
 	bpp = ctrl->color_depth * 3;
 	prate = ctrl->pixel_rate;
···
 
 static int edp_do_link_train(struct edp_ctrl *ctrl)
 {
+	u8 values[2];
 	int ret;
-	struct drm_dp_link dp_link;
 
 	DBG("");
 	/*
 	 * Set the current link rate and lane cnt to panel. They may have been
 	 * adjusted and the values are different from them in DPCD CAP
 	 */
-	dp_link.num_lanes = ctrl->lane_cnt;
-	dp_link.rate = drm_dp_bw_code_to_link_rate(ctrl->link_rate);
-	dp_link.capabilities = ctrl->dp_link.capabilities;
-	if (drm_dp_link_configure(ctrl->drm_aux, &dp_link) < 0)
+	values[0] = ctrl->lane_cnt;
+	values[1] = ctrl->link_rate;
+
+	if (drm_dp_enhanced_frame_cap(ctrl->dpcd))
+		values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
+
+	if (drm_dp_dpcd_write(ctrl->drm_aux, DP_LINK_BW_SET, values,
+			      sizeof(values)) < 0)
 		return EDP_TRAIN_FAIL;
 
 	ctrl->v_level = 0; /* start from default level */
···
 {
 	struct edp_ctrl *ctrl = container_of(
 				work, struct edp_ctrl, on_work);
+	u8 value;
 	int ret;
 
 	mutex_lock(&ctrl->dev_mutex);
···
 	edp_ctrl_link_enable(ctrl, 1);
 
 	edp_ctrl_irq_enable(ctrl, 1);
-	ret = drm_dp_link_power_up(ctrl->drm_aux, &ctrl->dp_link);
-	if (ret)
-		goto fail;
+
+	/* DP_SET_POWER register is only available on DPCD v1.1 and later */
+	if (ctrl->dpcd[DP_DPCD_REV] >= 0x11) {
+		ret = drm_dp_dpcd_readb(ctrl->drm_aux, DP_SET_POWER, &value);
+		if (ret < 0)
+			goto fail;
+
+		value &= ~DP_SET_POWER_MASK;
+		value |= DP_SET_POWER_D0;
+
+		ret = drm_dp_dpcd_writeb(ctrl->drm_aux, DP_SET_POWER, value);
+		if (ret < 0)
+			goto fail;
+
+		/*
+		 * According to the DP 1.1 specification, a "Sink Device must
+		 * exit the power saving state within 1 ms" (Section 2.5.3.1,
+		 * Table 5-52, "Sink Control Field" (register 0x600).
+		 */
+		usleep_range(1000, 2000);
+	}
 
 	ctrl->power_on = true;
 
···
 
 	edp_state_ctrl(ctrl, 0);
 
-	drm_dp_link_power_down(ctrl->drm_aux, &ctrl->dp_link);
+	/* DP_SET_POWER register is only available on DPCD v1.1 and later */
+	if (ctrl->dpcd[DP_DPCD_REV] >= 0x11) {
+		u8 value;
+		int ret;
+
+		ret = drm_dp_dpcd_readb(ctrl->drm_aux, DP_SET_POWER, &value);
+		if (ret > 0) {
+			value &= ~DP_SET_POWER_MASK;
+			value |= DP_SET_POWER_D3;
+
+			drm_dp_dpcd_writeb(ctrl->drm_aux, DP_SET_POWER, value);
+		}
+	}
 
 	edp_ctrl_irq_enable(ctrl, 0);
 
···
 		edp_ctrl_irq_enable(ctrl, 1);
 	}
 
-	ret = drm_dp_link_probe(ctrl->drm_aux, &ctrl->dp_link);
-	if (ret) {
-		pr_err("%s: read dpcd cap failed, %d\n", __func__, ret);
-		goto disable_ret;
-	}
-
 	/* Initialize link rate as panel max link rate */
-	ctrl->link_rate = drm_dp_link_rate_to_bw_code(ctrl->dp_link.rate);
+	ctrl->link_rate = ctrl->dpcd[DP_MAX_LINK_RATE];
 
 	ctrl->edid = drm_get_edid(connector, &ctrl->drm_aux->ddc);
 	if (!ctrl->edid) {