drm/cma-helper: Use the generic fbdev emulation

This switches the CMA helper drivers that use its fbdev emulation over
to the generic fbdev emulation. It's the first phase of using generic
fbdev. A later phase will use DRM client callbacks for the
lastclose/hotplug/remove callbacks.

There are currently 2 fbdev init/fini functions:
- drm_fb_cma_fbdev_init/drm_fb_cma_fbdev_fini
- drm_fbdev_cma_init/drm_fbdev_cma_fini

This is because the work on generic fbdev came up during a fbdev
refactoring and thus wasn't completed. No point in completing that
refactoring when drivers will soon move to drm_fb_helper_generic_probe().

tinydrm uses drm_fb_cma_fbdev_init_with_funcs().

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180703160354.59955-5-noralf@tronnes.org

drivers/gpu/drm/drm_fb_cma_helper.c

@@ -18,6 +18,7 @@
  */
 
 #include <drm/drmP.h>
+#include <drm/drm_client.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_gem_cma_helper.h>
@@ -26,11 +27,8 @@
 #include <drm/drm_print.h>
 #include <linux/module.h>
 
-#define DEFAULT_FBDEFIO_DELAY_MS 50
-
 struct drm_fbdev_cma {
 	struct drm_fb_helper	fb_helper;
-	const struct drm_framebuffer_funcs *fb_funcs;
 };
 
 /**
@@ -44,36 +42,6 @@ struct drm_fbdev_cma {
  *
  * An fbdev framebuffer backed by cma is also available by calling
  * drm_fb_cma_fbdev_init(). drm_fb_cma_fbdev_fini() tears it down.
- * If the &drm_framebuffer_funcs.dirty callback is set, fb_deferred_io will be
- * set up automatically. &drm_framebuffer_funcs.dirty is called by
- * drm_fb_helper_deferred_io() in process context (&struct delayed_work).
- *
- * Example fbdev deferred io code::
- *
- *     static int driver_fb_dirty(struct drm_framebuffer *fb,
- *                                struct drm_file *file_priv,
- *                                unsigned flags, unsigned color,
- *                                struct drm_clip_rect *clips,
- *                                unsigned num_clips)
- *     {
- *         struct drm_gem_cma_object *cma = drm_fb_cma_get_gem_obj(fb, 0);
- *         ... push changes ...
- *         return 0;
- *     }
- *
- *     static struct drm_framebuffer_funcs driver_fb_funcs = {
- *         .destroy       = drm_gem_fb_destroy,
- *         .create_handle = drm_gem_fb_create_handle,
- *         .dirty         = driver_fb_dirty,
- *     };
- *
- * Initialize::
- *
- *     fbdev = drm_fb_cma_fbdev_init_with_funcs(dev, 16,
- *                                           dev->mode_config.num_crtc,
- *                                           dev->mode_config.num_connector,
- *                                           &driver_fb_funcs);
- *
  */
 
 static inline struct drm_fbdev_cma *to_fbdev_cma(struct drm_fb_helper *helper)
@@ -131,153 +99,6 @@ dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb,
 }
 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_addr);
 
-static int drm_fb_cma_mmap(struct fb_info *info, struct vm_area_struct *vma)
-{
-	return dma_mmap_writecombine(info->device, vma, info->screen_base,
-				     info->fix.smem_start, info->fix.smem_len);
-}
-
-static struct fb_ops drm_fbdev_cma_ops = {
-	.owner		= THIS_MODULE,
-	DRM_FB_HELPER_DEFAULT_OPS,
-	.fb_fillrect	= drm_fb_helper_sys_fillrect,
-	.fb_copyarea	= drm_fb_helper_sys_copyarea,
-	.fb_imageblit	= drm_fb_helper_sys_imageblit,
-	.fb_mmap	= drm_fb_cma_mmap,
-};
-
-static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info,
-					  struct vm_area_struct *vma)
-{
-	fb_deferred_io_mmap(info, vma);
-	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
-
-	return 0;
-}
-
-static int drm_fbdev_cma_defio_init(struct fb_info *fbi,
-				    struct drm_gem_cma_object *cma_obj)
-{
-	struct fb_deferred_io *fbdefio;
-	struct fb_ops *fbops;
-
-	/*
-	 * Per device structures are needed because:
-	 * fbops: fb_deferred_io_cleanup() clears fbops.fb_mmap
-	 * fbdefio: individual delays
-	 */
-	fbdefio = kzalloc(sizeof(*fbdefio), GFP_KERNEL);
-	fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
-	if (!fbdefio || !fbops) {
-		kfree(fbdefio);
-		kfree(fbops);
-		return -ENOMEM;
-	}
-
-	/* can't be offset from vaddr since dirty() uses cma_obj */
-	fbi->screen_buffer = cma_obj->vaddr;
-	/* fb_deferred_io_fault() needs a physical address */
-	fbi->fix.smem_start = page_to_phys(virt_to_page(fbi->screen_buffer));
-
-	*fbops = *fbi->fbops;
-	fbi->fbops = fbops;
-
-	fbdefio->delay = msecs_to_jiffies(DEFAULT_FBDEFIO_DELAY_MS);
-	fbdefio->deferred_io = drm_fb_helper_deferred_io;
-	fbi->fbdefio = fbdefio;
-	fb_deferred_io_init(fbi);
-	fbi->fbops->fb_mmap = drm_fbdev_cma_deferred_io_mmap;
-
-	return 0;
-}
-
-static void drm_fbdev_cma_defio_fini(struct fb_info *fbi)
-{
-	if (!fbi->fbdefio)
-		return;
-
-	fb_deferred_io_cleanup(fbi);
-	kfree(fbi->fbdefio);
-	kfree(fbi->fbops);
-}
-
-static int
-drm_fbdev_cma_create(struct drm_fb_helper *helper,
-	struct drm_fb_helper_surface_size *sizes)
-{
-	struct drm_fbdev_cma *fbdev_cma = to_fbdev_cma(helper);
-	struct drm_device *dev = helper->dev;
-	struct drm_gem_cma_object *obj;
-	struct drm_framebuffer *fb;
-	unsigned int bytes_per_pixel;
-	unsigned long offset;
-	struct fb_info *fbi;
-	size_t size;
-	int ret;
-
-	DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d)\n",
-			sizes->surface_width, sizes->surface_height,
-			sizes->surface_bpp);
-
-	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
-	size = sizes->surface_width * sizes->surface_height * bytes_per_pixel;
-	obj = drm_gem_cma_create(dev, size);
-	if (IS_ERR(obj))
-		return -ENOMEM;
-
-	fbi = drm_fb_helper_alloc_fbi(helper);
-	if (IS_ERR(fbi)) {
-		ret = PTR_ERR(fbi);
-		goto err_gem_free_object;
-	}
-
-	fb = drm_gem_fbdev_fb_create(dev, sizes, 0, &obj->base,
-				     fbdev_cma->fb_funcs);
-	if (IS_ERR(fb)) {
-		dev_err(dev->dev, "Failed to allocate DRM framebuffer.\n");
-		ret = PTR_ERR(fb);
-		goto err_fb_info_destroy;
-	}
-
-	helper->fb = fb;
-
-	fbi->par = helper;
-	fbi->flags = FBINFO_FLAG_DEFAULT;
-	fbi->fbops = &drm_fbdev_cma_ops;
-
-	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->format->depth);
-	drm_fb_helper_fill_var(fbi, helper, sizes->fb_width, sizes->fb_height);
-
-	offset = fbi->var.xoffset * bytes_per_pixel;
-	offset += fbi->var.yoffset * fb->pitches[0];
-
-	dev->mode_config.fb_base = (resource_size_t)obj->paddr;
-	fbi->screen_base = obj->vaddr + offset;
-	fbi->fix.smem_start = (unsigned long)(obj->paddr + offset);
-	fbi->screen_size = size;
-	fbi->fix.smem_len = size;
-
-	if (fb->funcs->dirty) {
-		ret = drm_fbdev_cma_defio_init(fbi, obj);
-		if (ret)
-			goto err_cma_destroy;
-	}
-
-	return 0;
-
-err_cma_destroy:
-	drm_framebuffer_remove(fb);
-err_fb_info_destroy:
-	drm_fb_helper_fini(helper);
-err_gem_free_object:
-	drm_gem_object_put_unlocked(&obj->base);
-	return ret;
-}
-
-static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
-	.fb_probe = drm_fbdev_cma_create,
-};
-
 /**
  * drm_fb_cma_fbdev_init_with_funcs() - Allocate and initialize fbdev emulation
  * @dev: DRM device
@@ -295,53 +116,7 @@ int drm_fb_cma_fbdev_init_with_funcs(struct drm_device *dev,
 	unsigned int preferred_bpp, unsigned int max_conn_count,
 	const struct drm_framebuffer_funcs *funcs)
 {
-	struct drm_fbdev_cma *fbdev_cma;
-	struct drm_fb_helper *fb_helper;
-	int ret;
-
-	if (!preferred_bpp)
-		preferred_bpp = dev->mode_config.preferred_depth;
-	if (!preferred_bpp)
-		preferred_bpp = 32;
-
-	if (!max_conn_count)
-		max_conn_count = dev->mode_config.num_connector;
-
-	fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
-	if (!fbdev_cma)
-		return -ENOMEM;
-
-	fbdev_cma->fb_funcs = funcs;
-	fb_helper = &fbdev_cma->fb_helper;
-
-	drm_fb_helper_prepare(dev, fb_helper, &drm_fb_cma_helper_funcs);
-
-	ret = drm_fb_helper_init(dev, fb_helper, max_conn_count);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev->dev, "Failed to initialize fbdev helper.\n");
-		goto err_free;
-	}
-
-	ret = drm_fb_helper_single_add_all_connectors(fb_helper);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev->dev, "Failed to add connectors.\n");
-		goto err_drm_fb_helper_fini;
-	}
-
-	ret = drm_fb_helper_initial_config(fb_helper, preferred_bpp);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev->dev, "Failed to set fbdev configuration.\n");
-		goto err_drm_fb_helper_fini;
-	}
-
-	return 0;
-
-err_drm_fb_helper_fini:
-	drm_fb_helper_fini(fb_helper);
-err_free:
-	kfree(fbdev_cma);
-
-	return ret;
+	return drm_fb_cma_fbdev_init(dev, preferred_bpp, max_conn_count);
 }
 EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_init_with_funcs);
 
@@ -359,8 +134,14 @@ EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_init_with_funcs);
 int drm_fb_cma_fbdev_init(struct drm_device *dev, unsigned int preferred_bpp,
 			  unsigned int max_conn_count)
 {
-	return drm_fb_cma_fbdev_init_with_funcs(dev, preferred_bpp,
-						max_conn_count, NULL);
+	struct drm_fbdev_cma *fbdev_cma;
+
+	/* dev->fb_helper will indirectly point to fbdev_cma after this call */
+	fbdev_cma = drm_fbdev_cma_init(dev, preferred_bpp, max_conn_count);
+	if (IS_ERR(fbdev_cma))
+		return PTR_ERR(fbdev_cma);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_init);
 
@@ -370,104 +151,54 @@ EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_init);
  */
 void drm_fb_cma_fbdev_fini(struct drm_device *dev)
 {
-	struct drm_fb_helper *fb_helper = dev->fb_helper;
-
-	if (!fb_helper)
-		return;
-
-	/* Unregister if it hasn't been done already */
-	if (fb_helper->fbdev && fb_helper->fbdev->dev)
-		drm_fb_helper_unregister_fbi(fb_helper);
-
-	if (fb_helper->fbdev)
-		drm_fbdev_cma_defio_fini(fb_helper->fbdev);
-
-	if (fb_helper->fb)
-		drm_framebuffer_remove(fb_helper->fb);
-
-	drm_fb_helper_fini(fb_helper);
-	kfree(to_fbdev_cma(fb_helper));
+	if (dev->fb_helper)
+		drm_fbdev_cma_fini(to_fbdev_cma(dev->fb_helper));
 }
 EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_fini);
 
+static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
+	.fb_probe = drm_fb_helper_generic_probe,
+};
+
 /**
- * drm_fbdev_cma_init_with_funcs() - Allocate and initializes a drm_fbdev_cma struct
+ * drm_fbdev_cma_init() - Allocate and initializes a drm_fbdev_cma struct
  * @dev: DRM device
  * @preferred_bpp: Preferred bits per pixel for the device
  * @max_conn_count: Maximum number of connectors
- * @funcs: fb helper functions, in particular a custom dirty() callback
  *
  * Returns a newly allocated drm_fbdev_cma struct or a ERR_PTR.
  */
-struct drm_fbdev_cma *drm_fbdev_cma_init_with_funcs(struct drm_device *dev,
-	unsigned int preferred_bpp, unsigned int max_conn_count,
-	const struct drm_framebuffer_funcs *funcs)
+struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
+	unsigned int preferred_bpp, unsigned int max_conn_count)
 {
 	struct drm_fbdev_cma *fbdev_cma;
-	struct drm_fb_helper *helper;
+	struct drm_fb_helper *fb_helper;
 	int ret;
 
 	fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
-	if (!fbdev_cma) {
-		dev_err(dev->dev, "Failed to allocate drm fbdev.\n");
+	if (!fbdev_cma)
 		return ERR_PTR(-ENOMEM);
-	}
-	fbdev_cma->fb_funcs = funcs;
-
-	helper = &fbdev_cma->fb_helper;
 
-	drm_fb_helper_prepare(dev, helper, &drm_fb_cma_helper_funcs);
+	fb_helper = &fbdev_cma->fb_helper;
 
-	ret = drm_fb_helper_init(dev, helper, max_conn_count);
-	if (ret < 0) {
-		dev_err(dev->dev, "Failed to initialize drm fb helper.\n");
+	ret = drm_client_new(dev, &fb_helper->client, "fbdev", NULL);
+	if (ret)
 		goto err_free;
-	}
 
-	ret = drm_fb_helper_single_add_all_connectors(helper);
-	if (ret < 0) {
-		dev_err(dev->dev, "Failed to add connectors.\n");
-		goto err_drm_fb_helper_fini;
-
-	}
-
-	ret = drm_fb_helper_initial_config(helper, preferred_bpp);
-	if (ret < 0) {
-		dev_err(dev->dev, "Failed to set initial hw configuration.\n");
-		goto err_drm_fb_helper_fini;
-	}
+	ret = drm_fb_helper_fbdev_setup(dev, fb_helper, &drm_fb_cma_helper_funcs,
+					preferred_bpp, max_conn_count);
+	if (ret)
+		goto err_client_put;
 
 	return fbdev_cma;
 
-err_drm_fb_helper_fini:
-	drm_fb_helper_fini(helper);
+err_client_put:
+	drm_client_release(&fb_helper->client);
 err_free:
 	kfree(fbdev_cma);
 
 	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(drm_fbdev_cma_init_with_funcs);
-
-static const struct drm_framebuffer_funcs drm_fb_cma_funcs = {
-	.destroy	= drm_gem_fb_destroy,
-	.create_handle	= drm_gem_fb_create_handle,
-};
-
-/**
- * drm_fbdev_cma_init() - Allocate and initializes a drm_fbdev_cma struct
- * @dev: DRM device
- * @preferred_bpp: Preferred bits per pixel for the device
- * @max_conn_count: Maximum number of connectors
- *
- * Returns a newly allocated drm_fbdev_cma struct or a ERR_PTR.
- */
-struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
-	unsigned int preferred_bpp, unsigned int max_conn_count)
-{
-	return drm_fbdev_cma_init_with_funcs(dev, preferred_bpp,
-					     max_conn_count,
-					     &drm_fb_cma_funcs);
-}
 EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
 
 /**
@@ -477,14 +208,7 @@ EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
 void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
 {
 	drm_fb_helper_unregister_fbi(&fbdev_cma->fb_helper);
-	if (fbdev_cma->fb_helper.fbdev)
-		drm_fbdev_cma_defio_fini(fbdev_cma->fb_helper.fbdev);
-
-	if (fbdev_cma->fb_helper.fb)
-		drm_framebuffer_remove(fbdev_cma->fb_helper.fb);
-
-	drm_fb_helper_fini(&fbdev_cma->fb_helper);
-	kfree(fbdev_cma);
+	/* All resources have now been freed by drm_fbdev_fb_destroy() */
 }
 EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
 

include/drm/drm_fb_cma_helper.h

@@ -23,9 +23,6 @@ int drm_fb_cma_fbdev_init(struct drm_device *dev, unsigned int preferred_bpp,
 			  unsigned int max_conn_count);
 void drm_fb_cma_fbdev_fini(struct drm_device *dev);
 
-struct drm_fbdev_cma *drm_fbdev_cma_init_with_funcs(struct drm_device *dev,
-	unsigned int preferred_bpp, unsigned int max_conn_count,
-	const struct drm_framebuffer_funcs *funcs);
 struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
 	unsigned int preferred_bpp, unsigned int max_conn_count);
 void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma);