drm/rcar-du: Add FBDEV emulation support

Use the FB CMA helpers to implement FBDEV emulation support. The VGA
connector status must be reported as connector_status_connected instead
of connector_status_unknown to be usable by the emulation layer.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

drivers/gpu/drm/rcar-du/rcar_du_drv.c

@@ -21,6 +21,7 @@
 
 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 
 #include "rcar_du_crtc.h"
@@ -34,6 +35,11 @@
 
 static int rcar_du_unload(struct drm_device *dev)
 {
+	struct rcar_du_device *rcdu = dev->dev_private;
+
+	if (rcdu->fbdev)
+		drm_fbdev_cma_fini(rcdu->fbdev);
+
 	drm_kms_helper_poll_fini(dev);
 	drm_mode_config_cleanup(dev);
 	drm_vblank_cleanup(dev);
@@ -109,6 +115,13 @@ static void rcar_du_preclose(struct drm_device *dev, struct drm_file *file)
 		rcar_du_crtc_cancel_page_flip(&rcdu->crtcs[i], file);
 }
 
+static void rcar_du_lastclose(struct drm_device *dev)
+{
+	struct rcar_du_device *rcdu = dev->dev_private;
+
+	drm_fbdev_cma_restore_mode(rcdu->fbdev);
+}
+
 static int rcar_du_enable_vblank(struct drm_device *dev, int crtc)
 {
 	struct rcar_du_device *rcdu = dev->dev_private;
@@ -145,6 +158,7 @@ static struct drm_driver rcar_du_driver = {
 	.load			= rcar_du_load,
 	.unload			= rcar_du_unload,
 	.preclose		= rcar_du_preclose,
+	.lastclose		= rcar_du_lastclose,
 	.get_vblank_counter	= drm_vblank_count,
 	.enable_vblank		= rcar_du_enable_vblank,
 	.disable_vblank		= rcar_du_disable_vblank,

drivers/gpu/drm/rcar-du/rcar_du_drv.h

@@ -23,6 +23,7 @@
 struct clk;
 struct device;
 struct drm_device;
+struct drm_fbdev_cma;
 struct rcar_du_device;
 struct rcar_du_lvdsenc;
 
@@ -66,6 +67,7 @@ struct rcar_du_device {
 	void __iomem *mmio;
 
 	struct drm_device *ddev;
+	struct drm_fbdev_cma *fbdev;
 
 	struct rcar_du_crtc crtcs[3];
 	unsigned int num_crtcs;

drivers/gpu/drm/rcar-du/rcar_du_kms.c

@@ -167,8 +167,16 @@ rcar_du_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 	return drm_fb_cma_create(dev, file_priv, mode_cmd);
 }
 
+static void rcar_du_output_poll_changed(struct drm_device *dev)
+{
+	struct rcar_du_device *rcdu = dev->dev_private;
+
+	drm_fbdev_cma_hotplug_event(rcdu->fbdev);
+}
+
 static const struct drm_mode_config_funcs rcar_du_mode_config_funcs = {
 	.fb_create = rcar_du_fb_create,
+	.output_poll_changed = rcar_du_output_poll_changed,
 };
 
 int rcar_du_modeset_init(struct rcar_du_device *rcdu)
@@ -179,17 +187,18 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 
 	struct drm_device *dev = rcdu->ddev;
 	struct drm_encoder *encoder;
+	struct drm_fbdev_cma *fbdev;
 	unsigned int num_groups;
 	unsigned int i;
 	int ret;
 
-	drm_mode_config_init(rcdu->ddev);
+	drm_mode_config_init(dev);
 
-	rcdu->ddev->mode_config.min_width = 0;
-	rcdu->ddev->mode_config.min_height = 0;
-	rcdu->ddev->mode_config.max_width = 4095;
-	rcdu->ddev->mode_config.max_height = 2047;
-	rcdu->ddev->mode_config.funcs = &rcar_du_mode_config_funcs;
+	dev->mode_config.min_width = 0;
+	dev->mode_config.min_height = 0;
+	dev->mode_config.max_width = 4095;
+	dev->mode_config.max_height = 2047;
+	dev->mode_config.funcs = &rcar_du_mode_config_funcs;
 
 	rcdu->num_crtcs = rcdu->info->num_crtcs;
 
@@ -262,9 +271,20 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 			return ret;
 	}
 
-	drm_kms_helper_poll_init(rcdu->ddev);
+	drm_kms_helper_poll_init(dev);
+
+	drm_helper_disable_unused_functions(dev);
+
+	fbdev = drm_fbdev_cma_init(dev, 32, dev->mode_config.num_crtc,
+				   dev->mode_config.num_connector);
+	if (IS_ERR(fbdev))
+		return PTR_ERR(fbdev);
+
+#ifndef CONFIG_FRAMEBUFFER_CONSOLE
+	drm_fbdev_cma_restore_mode(fbdev);
+#endif
 
-	drm_helper_disable_unused_functions(rcdu->ddev);
+	rcdu->fbdev = fbdev;
 
 	return 0;
 }

drivers/gpu/drm/rcar-du/rcar_du_vgacon.c

@@ -46,7 +46,7 @@ static void rcar_du_vga_connector_destroy(struct drm_connector *connector)
 static enum drm_connector_status
 rcar_du_vga_connector_detect(struct drm_connector *connector, bool force)
 {
-	return connector_status_unknown;
+	return connector_status_connected;
 }
 
 static const struct drm_connector_funcs connector_funcs = {