MLK-16986-3: drm: mxsfb: fix connector handling

Since the MXSFB initially was just a simple display pipe using a
drm_panel, the drm_connector was created "in-house", by mxsfb driver.
But, with latest changes, mxsfb also supports a bridge. In case of a
drm_bridge, the the connector is created and initialized by that bridge.
So, for a proper initialization during start-up, we need to take into
consideration that connector, instead of our "in-house" connector.
The connector created and initialized by mxsfb will be used only when
this driver will have a panel.

Signed-off-by: Robert Chiras <robert.chiras@nxp.com>
Reviewed-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>

4 files changed, 48 insertions, 13 deletions

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index a940e22fae8e..1ac03213f1c8 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -96,8 +96,11 @@ static void mxsfb_set_bus_fmt(struct mxsfb_drm_private *mxsfb)
 
 	reg = readl(mxsfb->base + LCDC_CTRL);
 
-	if (mxsfb->connector.display_info.num_bus_formats)
-		bus_format = mxsfb->connector.display_info.bus_formats[0];
+	if (mxsfb->connector->display_info.num_bus_formats)
+		bus_format = mxsfb->connector->display_info.bus_formats[0];
+
+	DRM_DEV_DEBUG_DRIVER(mxsfb->dev,
+		"Using bus_format: 0x%08X\n", bus_format);
 
 	reg &= ~CTRL_BUS_WIDTH_MASK;
 	switch (bus_format) {
@@ -174,7 +177,7 @@ static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 {
 	struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode;
-	const u32 bus_flags = mxsfb->connector.display_info.bus_flags;
+	const u32 bus_flags = mxsfb->connector->display_info.bus_flags;
 	u32 hbp = m->crtc_hblank_end - m->crtc_hsync_end;
 	u32 vbp = m->crtc_vblank_end - m->crtc_vsync_end;
 	u32 vdctrl0, vsync_pulse_len, hsync_pulse_len;
@@ -196,6 +199,11 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 
 	clk_set_rate(mxsfb->clk, m->crtc_clock * 1000);
 
+	DRM_DEV_DEBUG_DRIVER(mxsfb->dev,
+		"Connector bus_flags: 0x%08X\n", bus_flags);
+	DRM_DEV_DEBUG_DRIVER(mxsfb->dev,
+		"Mode flags: 0x%08X\n", m->flags);
+
 	writel(TRANSFER_COUNT_SET_VCOUNT(m->crtc_vdisplay) |
 	       TRANSFER_COUNT_SET_HCOUNT(m->crtc_hdisplay),
 	       mxsfb->base + mxsfb->devdata->transfer_count);
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
index 4ec6d311cd31..f37dd51a9f25 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
@@ -104,8 +104,23 @@ static const struct drm_mode_config_funcs mxsfb_mode_config_funcs = {
 static void mxsfb_pipe_enable(struct drm_simple_display_pipe *pipe,
 			      struct drm_crtc_state *crtc_state)
 {
+	struct drm_device *drm = pipe->encoder.dev;
+	struct drm_connector *connector;
 	struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe);
 
+	if (!mxsfb->connector) {
+		drm_for_each_connector(connector, drm)
+			if (connector->encoder == &(mxsfb->pipe.encoder)) {
+				mxsfb->connector = connector;
+				break;
+			}
+	}
+
+	if (!mxsfb->connector) {
+		dev_warn(drm->dev, "No connector attached, using default\n");
+		mxsfb->connector = &mxsfb->panel_connector;
+	}
+
 	mxsfb_crtc_enable(mxsfb);
 	pm_runtime_get_sync(mxsfb->dev);
 }
@@ -116,6 +131,9 @@ static void mxsfb_pipe_disable(struct drm_simple_display_pipe *pipe)
 
 	mxsfb_crtc_disable(mxsfb);
 	pm_runtime_put_sync(mxsfb->dev);
+
+	if (mxsfb->connector != &mxsfb->panel_connector)
+		mxsfb->connector = NULL;
 }
 
 static void mxsfb_pipe_update(struct drm_simple_display_pipe *pipe,
@@ -200,15 +218,22 @@ static int mxsfb_load(struct drm_device *drm, unsigned long flags)
 
 	ret = drm_simple_display_pipe_init(drm, &mxsfb->pipe, &mxsfb_funcs,
 			mxsfb_formats, ARRAY_SIZE(mxsfb_formats),
-			&mxsfb->connector);
+			mxsfb->connector);
 	if (ret < 0) {
 		dev_err(drm->dev, "Cannot setup simple display pipe\n");
 		goto err_vblank;
 	}
 
-	/* Attach panel only if there is one */
+	/*
+	 * Attach panel only if there is one.
+	 * If there is no panel attach, it must be a bridge. In this case, we
+	 * need a reference to its connector for a proper initialization.
+	 * We will do this check in pipe->enable(), since the connector won't
+	 * be attached to an encoder until then.
+	 */
+
 	if (mxsfb->panel) {
-		ret = drm_panel_attach(mxsfb->panel, &mxsfb->connector);
+		ret = drm_panel_attach(mxsfb->panel, mxsfb->connector);
 		if (ret) {
 			dev_err(drm->dev, "Cannot connect panel\n");
 			goto err_vblank;
@@ -220,7 +245,6 @@ static int mxsfb_load(struct drm_device *drm, unsigned long flags)
 			dev_err(drm->dev, "Cannot connect bridge\n");
 			goto err_vblank;
 		}
-
 	}
 
 	drm->mode_config.min_width	= MXSFB_MIN_XRES;
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.h b/drivers/gpu/drm/mxsfb/mxsfb_drv.h
index 71e62b0267da..baf35b35049a 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h
@@ -37,7 +37,8 @@ struct mxsfb_drm_private {
 	struct clk			*clk_disp_axi;
 
 	struct drm_simple_display_pipe	pipe;
-	struct drm_connector		connector;
+	struct drm_connector		panel_connector;
+	struct drm_connector		*connector;
 	struct drm_panel		*panel;
 	struct drm_bridge		*bridge;
 	struct drm_fbdev_cma		*fbdev;
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_out.c b/drivers/gpu/drm/mxsfb/mxsfb_out.c
index cecbd08dcacb..5587341862ab 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_out.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_out.c
@@ -29,7 +29,8 @@
 static struct mxsfb_drm_private *
 drm_connector_to_mxsfb_drm_private(struct drm_connector *connector)
 {
-	return container_of(connector, struct mxsfb_drm_private, connector);
+	return container_of(connector, struct mxsfb_drm_private,
+			    panel_connector);
 }
 
 static int mxsfb_panel_get_modes(struct drm_connector *connector)
@@ -99,11 +100,12 @@ static int mxsfb_attach_endpoint(struct drm_device *drm,
 		return -EPROBE_DEFER;
 
 	if (mxsfb->panel) {
-		mxsfb->connector.dpms = DRM_MODE_DPMS_OFF;
-		mxsfb->connector.polled = 0;
-		drm_connector_helper_add(&mxsfb->connector,
+		mxsfb->connector = &mxsfb->panel_connector;
+		mxsfb->connector->dpms = DRM_MODE_DPMS_OFF;
+		mxsfb->connector->polled = 0;
+		drm_connector_helper_add(mxsfb->connector,
 				&mxsfb_panel_connector_helper_funcs);
-		ret = drm_connector_init(drm, &mxsfb->connector,
+		ret = drm_connector_init(drm, mxsfb->connector,
 					 &mxsfb_panel_connector_funcs,
 					 DRM_MODE_CONNECTOR_Unknown);
 	}