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

[Daniel Vetter <daniel@ffwll.ch>]

On Fri, Sep 18, 2015 at 06:12:02PM +0200, Philipp Zabel wrote:
> From: CK Hu <ck.hu@mediatek.com>
> 
> Add Mediatek legacy framebuffer support.
> 
> Signed-off-by: CK Hu <ck.hu@mediatek.com>
> Signed-off-by: YT Shen <yt.shen@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.

With the new Kconfig for fbdev emulation in 4.3 and the module option to
disable it queued up for 4.4 driver-private Kconfig entries for fbdev
aren't needed any more.
-Daniel

> 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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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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