[RFC v2 4/4] drm/mediatek: Add DRM-based framebuffer device

Philipp Zabel p.zabel at pengutronix.de
Fri Sep 18 09:12:02 PDT 2015


From: CK Hu <ck.hu at mediatek.com>

Add Mediatek legacy framebuffer support.

Signed-off-by: CK Hu <ck.hu at mediatek.com>
Signed-off-by: YT Shen <yt.shen at mediatek.com>
---
 drivers/gpu/drm/mediatek/Kconfig       |  12 +++
 drivers/gpu/drm/mediatek/mtk_drm_drv.c |  13 +++
 drivers/gpu/drm/mediatek/mtk_drm_fb.c  | 192 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/mediatek/mtk_drm_fb.h  |   1 +
 4 files changed, 218 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/Kconfig b/drivers/gpu/drm/mediatek/Kconfig
index 5343cf1..fa581fb 100644
--- a/drivers/gpu/drm/mediatek/Kconfig
+++ b/drivers/gpu/drm/mediatek/Kconfig
@@ -14,3 +14,15 @@ config DRM_MEDIATEK
 	  This driver provides kernel mode setting and
 	  buffer management to userspace.
 
+config DRM_MEDIATEK_FBDEV
+	bool "Enable legacy fbdev support for Mediatek DRM"
+	depends on DRM_MEDIATEK
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select DRM_KMS_FB_HELPER
+	help
+	  Choose this option if you have a need for the legacy
+	  fbdev support.  Note that this support also provides
+	  the Linux console on top of the Mediatek DRM mode
+	  setting driver.
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index fc071fe..b67c582 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -46,6 +46,9 @@ static const struct drm_mode_config_funcs mtk_drm_mode_config_funcs = {
 	.fb_create = mtk_drm_mode_fb_create,
 	.atomic_check = drm_atomic_helper_check,
 	.atomic_commit = mtk_atomic_commit,
+#ifdef CONFIG_DRM_MEDIATEK_FBDEV
+	.output_poll_changed = mtk_drm_mode_output_poll_changed,
+#endif
 };
 
 static const enum mtk_ddp_comp_type mtk_ddp_main[] = {
@@ -140,6 +143,12 @@ static int mtk_drm_kms_init(struct drm_device *dev)
 	drm_kms_helper_poll_init(dev);
 	drm_mode_config_reset(dev);
 
+#ifdef CONFIG_DRM_MEDIATEK_FBDEV
+	err = mtk_fbdev_create(dev);
+	if (err)
+		goto err_larb_get;
+#endif
+
 	return 0;
 
 err_larb_get:
@@ -160,6 +169,10 @@ static void mtk_drm_kms_deinit(struct drm_device *dev)
 {
 	drm_kms_helper_poll_fini(dev);
 
+#ifdef CONFIG_DRM_MEDIATEK_FBDEV
+	mtk_fbdev_destroy(dev);
+#endif
+
 	drm_vblank_cleanup(dev);
 	drm_mode_config_cleanup(dev);
 }
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_fb.c b/drivers/gpu/drm/mediatek/mtk_drm_fb.c
index dfa931b..9295ad3 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_fb.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_fb.c
@@ -102,6 +102,198 @@ static struct mtk_drm_fb *mtk_drm_framebuffer_init(struct drm_device *dev,
 	return mtk_fb;
 }
 
+#ifdef CONFIG_DRM_MEDIATEK_FBDEV
+static int mtk_drm_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	struct drm_fb_helper *helper = info->par;
+	struct mtk_drm_fb *mtk_fb = to_mtk_fb(helper->fb);
+
+	return mtk_drm_gem_mmap_buf(mtk_fb->gem_obj[0], vma);
+}
+
+static struct fb_ops mtk_fb_ops = {
+	.owner = THIS_MODULE,
+	.fb_fillrect = sys_fillrect,
+	.fb_copyarea = sys_copyarea,
+	.fb_imageblit = sys_imageblit,
+	.fb_check_var = drm_fb_helper_check_var,
+	.fb_set_par = drm_fb_helper_set_par,
+	.fb_blank = drm_fb_helper_blank,
+	.fb_pan_display = drm_fb_helper_pan_display,
+	.fb_setcmap = drm_fb_helper_setcmap,
+	.fb_mmap = mtk_drm_fb_mmap,
+};
+
+static int mtk_fbdev_probe(struct drm_fb_helper *helper,
+			   struct drm_fb_helper_surface_size *sizes)
+{
+	struct drm_device *dev = helper->dev;
+	struct drm_mode_fb_cmd2 mode = { 0 };
+	struct mtk_drm_fb *mtk_fb;
+	struct mtk_drm_gem_obj *mtk_gem;
+	struct drm_gem_object *gem;
+	struct fb_info *info;
+	struct drm_framebuffer *fb;
+	unsigned long offset;
+	size_t size;
+	int err;
+
+	mode.width = sizes->surface_width;
+	mode.height = sizes->surface_height;
+	mode.pitches[0] = sizes->surface_width * ((sizes->surface_bpp + 7) / 8);
+	mode.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
+						      sizes->surface_depth);
+
+	mode.height = mode.height;/* << 1; for fb use? */
+	size = mode.pitches[0] * mode.height;
+	dev_info(dev->dev, "mtk_fbdev_probe %dx%d bpp %d pitch %d size %zu\n",
+		 mode.width, mode.height, sizes->surface_bpp, mode.pitches[0],
+		 size);
+
+	mtk_gem = mtk_drm_gem_create(dev, size, true);
+	if (IS_ERR(mtk_gem)) {
+		err = PTR_ERR(mtk_gem);
+		goto fini;
+	}
+
+	gem = &mtk_gem->base;
+
+	mtk_fb = mtk_drm_framebuffer_init(dev, &mode, &gem);
+	if (IS_ERR(mtk_fb)) {
+		dev_err(dev->dev, "failed to allocate DRM framebuffer\n");
+		err = PTR_ERR(mtk_fb);
+		goto free;
+	}
+	fb = &mtk_fb->base;
+
+	info = framebuffer_alloc(0, dev->dev);
+	if (!info) {
+		dev_err(dev->dev, "failed to allocate framebuffer info\n");
+		err = PTR_ERR(info);
+		goto release;
+	}
+
+	helper->fb = fb;
+	helper->fbdev = info;
+
+	info->par = helper;
+	info->flags = FBINFO_FLAG_DEFAULT;
+	info->fbops = &mtk_fb_ops;
+
+	err = fb_alloc_cmap(&info->cmap, 256, 0);
+	if (err < 0) {
+		dev_err(dev->dev, "failed to allocate color map: %d\n", err);
+		goto destroy;
+	}
+
+	drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);
+	drm_fb_helper_fill_var(info, helper, fb->width, fb->height);
+
+	offset = info->var.xoffset * (fb->bits_per_pixel + 7) / 8;
+	offset += info->var.yoffset * fb->pitches[0];
+
+	strcpy(info->fix.id, "mtk");
+	/* dev->mode_config.fb_base = (resource_size_t)bo->paddr; */
+	info->var.yres = info->var.yres_virtual;/* >> 1; for fb use? */
+	info->fix.smem_start = mtk_gem->dma_addr + offset;
+	info->fix.smem_len = size;
+	info->screen_base = mtk_gem->kvaddr + offset;
+	info->screen_size = size;
+
+	return 0;
+
+destroy:
+	drm_framebuffer_unregister_private(fb);
+	mtk_drm_fb_destroy(fb);
+release:
+	framebuffer_release(info);
+free:
+	mtk_drm_gem_free_object(&mtk_gem->base);
+fini:
+	dev_err(dev->dev, "mtk_fbdev_probe fail\n");
+	return err;
+}
+
+static const struct drm_fb_helper_funcs mtk_drm_fb_helper_funcs = {
+	.fb_probe = mtk_fbdev_probe,
+};
+
+int mtk_fbdev_create(struct drm_device *dev)
+{
+	struct mtk_drm_private *priv = dev->dev_private;
+	struct drm_fb_helper *fbdev;
+	int ret;
+
+	fbdev = devm_kzalloc(dev->dev, sizeof(*fbdev), GFP_KERNEL);
+	if (!fbdev)
+		return -ENOMEM;
+
+	drm_fb_helper_prepare(dev, fbdev, &mtk_drm_fb_helper_funcs);
+
+	ret = drm_fb_helper_init(dev, fbdev, dev->mode_config.num_crtc,
+				 dev->mode_config.num_connector);
+	if (ret) {
+		dev_err(dev->dev, "failed to initialize DRM FB helper\n");
+		goto fini;
+	}
+
+	ret = drm_fb_helper_single_add_all_connectors(fbdev);
+	if (ret) {
+		dev_err(dev->dev, "failed to add connectors\n");
+		goto fini;
+	}
+
+	ret = drm_fb_helper_initial_config(fbdev, FBDEV_BPP);
+	if (ret) {
+		dev_err(dev->dev, "failed to set initial configuration\n");
+		goto fini;
+	}
+	priv->fb_helper = fbdev;
+
+	return 0;
+
+fini:
+	drm_fb_helper_fini(fbdev);
+
+	return ret;
+}
+
+void mtk_fbdev_destroy(struct drm_device *dev)
+{
+	struct mtk_drm_private *priv = dev->dev_private;
+	struct drm_fb_helper *helper = priv->fb_helper;
+	struct fb_info *info = helper->fbdev;
+
+	if (info) {
+		int err;
+
+		err = unregister_framebuffer(info);
+		if (err < 0)
+			DRM_DEBUG_KMS("failed to unregister framebuffer\n");
+
+		if (info->cmap.len)
+			fb_dealloc_cmap(&info->cmap);
+
+		framebuffer_release(info);
+	}
+
+	if (helper->fb) {
+		drm_framebuffer_unregister_private(helper->fb);
+		mtk_drm_fb_destroy(helper->fb);
+	}
+
+	drm_fb_helper_fini(helper);
+}
+
+void mtk_drm_mode_output_poll_changed(struct drm_device *dev)
+{
+	struct mtk_drm_private *priv = dev->dev_private;
+
+	if (priv->fb_helper)
+		drm_fb_helper_hotplug_event(priv->fb_helper);
+}
+#endif
+
 struct drm_framebuffer *mtk_drm_mode_fb_create(struct drm_device *dev,
 					       struct drm_file *file,
 					       struct drm_mode_fb_cmd2 *cmd)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_fb.h b/drivers/gpu/drm/mediatek/mtk_drm_fb.h
index 9ce7307..acbfecf 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_fb.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_fb.h
@@ -15,6 +15,7 @@
 #define MTK_DRM_FB_H
 
 #define MAX_FB_OBJ	3
+#define FBDEV_BPP	16
 
 struct drm_gem_object *mtk_fb_get_gem_obj(struct drm_framebuffer *fb,
 					  unsigned int plane);
-- 
2.5.1



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