drm/vc4: Make DSI call into the bridge after the DSI link is enabled.

This allows panels or bridges that need to send DSI commands during
pre_enable() to successfully send them. We delay DISP0 (aka the
actual display) enabling until after pre_enable so that pixels aren't
streaming before then.

v2: Just clear out the encoder->bridge value to disable the midlayer
calls (idea by Andrzej Hajda).

Signed-off-by: Eric Anholt <[e-mail]>
Cc: Andrzej Hajda <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Reviewed-by: Andrzej Hajda <[e-mail]>

drivers/gpu/drm/vc4/vc4_dsi.c

···
 	struct vc4_dsi *dsi = vc4_encoder->dsi;
 	struct device *dev = &dsi->pdev->dev;
 
+	drm_bridge_disable(dsi->bridge);
 	vc4_dsi_ulps(dsi, true);
+	drm_bridge_post_disable(dsi->bridge);
 
 	clk_disable_unprepare(dsi->pll_phy_clock);
 	clk_disable_unprepare(dsi->escape_clock);
···
 	/* Display reset sequence timeout */
 	DSI_PORT_WRITE(PR_TO_CNT, 100000);
 
-	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
-		DSI_PORT_WRITE(DISP0_CTRL,
-			       VC4_SET_FIELD(dsi->divider,
-					     DSI_DISP0_PIX_CLK_DIV) |
-			       VC4_SET_FIELD(dsi->format, DSI_DISP0_PFORMAT) |
-			       VC4_SET_FIELD(DSI_DISP0_LP_STOP_PERFRAME,
-					     DSI_DISP0_LP_STOP_CTRL) |
-			       DSI_DISP0_ST_END |
-			       DSI_DISP0_ENABLE);
-	} else {
-		DSI_PORT_WRITE(DISP0_CTRL,
-			       DSI_DISP0_COMMAND_MODE |
-			       DSI_DISP0_ENABLE);
-	}
-
 	/* Set up DISP1 for transferring long command payloads through
 	 * the pixfifo.
 	 */
···
 	}
 
 	vc4_dsi_ulps(dsi, false);
+
+	drm_bridge_pre_enable(dsi->bridge);
+
+	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
+		DSI_PORT_WRITE(DISP0_CTRL,
+			       VC4_SET_FIELD(dsi->divider,
+					     DSI_DISP0_PIX_CLK_DIV) |
+			       VC4_SET_FIELD(dsi->format, DSI_DISP0_PFORMAT) |
+			       VC4_SET_FIELD(DSI_DISP0_LP_STOP_PERFRAME,
+					     DSI_DISP0_LP_STOP_CTRL) |
+			       DSI_DISP0_ST_END |
+			       DSI_DISP0_ENABLE);
+	} else {
+		DSI_PORT_WRITE(DISP0_CTRL,
+			       DSI_DISP0_COMMAND_MODE |
+			       DSI_DISP0_ENABLE);
+	}
+
+	drm_bridge_enable(dsi->bridge);
 
 	if (debug_dump_regs) {
 		DRM_INFO("DSI regs after:\n");
···
 		dev_err(dev, "bridge attach failed: %d\n", ret);
 		return ret;
 	}
+	/* Disable the atomic helper calls into the bridge.  We
+	 * manually call the bridge pre_enable / enable / etc. calls
+	 * from our driver, since we need to sequence them within the
+	 * encoder's enable/disable paths.
+	 */
+	dsi->encoder->bridge = NULL;
 
 	pm_runtime_enable(dev);