Re: [PATCH] drm/mediatek: Add MTK Framebuffer-Device (mt7623)

[Daniel Vetter]

On Wed, Jan 02, 2019 at 09:49:17AM +0100, Frank Wunderlich wrote:
> From: CK Hu <ck.hu@xxxxxxxxxxxx>
> 
> This patch adds Framebuffer-Driver for Mediatek
> 
> currently tested on mt7623, maybe works on other platforms
> MTK-FBDev written by CK Hu and ported from 4.4
> 
> based on patchset drm/hdmi for 7623 v5 (except last part included in 4.20)
>   https://patchwork.kernel.org/project/linux-mediatek/list/?series=25989
> 
> depends on
>   dts-patch (resend of 5/5, parts 1-4 already in 4.20):
>     "arm: dts: mt7623: add display subsystem related device nodes"
>     https://patchwork.kernel.org/patch/10588951/
>   2 bugfix-patches from bibby hsieh
>     fix-boot-up-for-720-and-480-but-1080
>     using-different-round-rate-for-mt7623
>   1 Patch from Ryder Lee
>     http://forum.banana-pi.org/t/kernel-4-19-rc1-for-testers/6618/52
> 
> full working tree here for reference:
> https://github.com/frank-w/BPI-R2-4.14/commits/4.20-hdmiv5
> 
> Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
> Signed-off-by: Alexander Ryabchenko <d3adme4t@xxxxxxxxx>
> Signed-off-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>
> Tested-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>

Would be good to use the new generic fbdev emulation code here, for even
less code. Or at least know why this isn't possible to use for mtk (and
maybe address that in the core code). Hand-rolling fbdev code shouldn't be
needed anymore.
-Daniel
> ---
>  drivers/gpu/drm/mediatek/Makefile        |   1 +
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c   |   6 +
>  drivers/gpu/drm/mediatek/mtk_drm_drv.h   |   4 +
>  drivers/gpu/drm/mediatek/mtk_drm_fb.c    |  13 ++
>  drivers/gpu/drm/mediatek/mtk_drm_fb.h    |   3 +
>  drivers/gpu/drm/mediatek/mtk_drm_fbdev.c | 178 +++++++++++++++++++++++
>  drivers/gpu/drm/mediatek/mtk_drm_fbdev.h |  25 ++++
>  7 files changed, 230 insertions(+)
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_drm_fbdev.c
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_drm_fbdev.h
> 
> diff --git a/drivers/gpu/drm/mediatek/Makefile b/drivers/gpu/drm/mediatek/Makefile
> index 82ae49c64221..d71e57dea77a 100644
> --- a/drivers/gpu/drm/mediatek/Makefile
> +++ b/drivers/gpu/drm/mediatek/Makefile
> @@ -14,6 +14,7 @@ mediatek-drm-y := mtk_disp_color.o \
>  		  mtk_mipi_tx.o \
>  		  mtk_dpi.o
>  
> +mediatek-drm-$(CONFIG_DRM_FBDEV_EMULATION) += mtk_drm_fbdev.o
>  obj-$(CONFIG_DRM_MEDIATEK) += mediatek-drm.o
>  
>  mediatek-drm-hdmi-objs := mtk_cec.o \
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 7800822b4db1..51f1ec3412d3 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -32,6 +32,7 @@
>  #include "mtk_drm_ddp_comp.h"
>  #include "mtk_drm_drv.h"
>  #include "mtk_drm_fb.h"
> +#include "mtk_drm_fbdev.h"
>  #include "mtk_drm_gem.h"
>  
>  #define DRIVER_NAME "mediatek"
> @@ -299,6 +300,10 @@ static int mtk_drm_kms_init(struct drm_device *drm)
>  	drm_kms_helper_poll_init(drm);
>  	drm_mode_config_reset(drm);
>  
> +	ret = mtk_fbdev_init(drm);
> +	if (ret)
> +		goto err_component_unbind;
> +
>  	return 0;
>  
>  err_component_unbind:
> @@ -311,6 +316,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
>  
>  static void mtk_drm_kms_deinit(struct drm_device *drm)
>  {
> +	mtk_fbdev_fini(drm);
>  	drm_kms_helper_poll_fini(drm);
>  
>  	component_unbind_all(drm->dev, drm);
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> index 256a3ff2e66e..56129a21fb2b 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> @@ -14,6 +14,7 @@
>  #ifndef MTK_DRM_DRV_H
>  #define MTK_DRM_DRV_H
>  
> +#include <drm/drm_fb_helper.h>
>  #include <linux/io.h>
>  #include "mtk_drm_ddp_comp.h"
>  
> @@ -43,6 +44,7 @@ struct mtk_drm_private {
>  	struct drm_device *drm;
>  	struct device *dma_dev;
>  
> +	struct drm_crtc *crtc[MAX_CRTC];
>  	unsigned int num_pipes;
>  
>  	struct device_node *mutex_node;
> @@ -59,6 +61,8 @@ struct mtk_drm_private {
>  	} commit;
>  
>  	struct drm_atomic_state *suspend_state;
> +	struct drm_fb_helper fb_helper;
> +	struct drm_gem_object *fbdev_bo;
>  };
>  
>  extern struct platform_driver mtk_ddp_driver;
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_fb.c b/drivers/gpu/drm/mediatek/mtk_drm_fb.c
> index be5f6f1daf55..7533aa4733d2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_fb.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_fb.c
> @@ -56,6 +56,19 @@ static struct drm_framebuffer *mtk_drm_framebuffer_init(struct drm_device *dev,
>  	return fb;
>  }
>  
> +struct drm_framebuffer *mtk_drm_framebuffer_create(struct drm_device *dev,
> +					const struct drm_mode_fb_cmd2 *mode,
> +					struct drm_gem_object *obj)
> +{
> +	struct drm_framebuffer *mtk_fb;
> +
> +	mtk_fb = mtk_drm_framebuffer_init(dev, mode, obj);
> +	if (IS_ERR(mtk_fb))
> +		return ERR_CAST(mtk_fb);
> +
> +	return mtk_fb;
> +}
> +
>  /*
>   * Wait for any exclusive fence in fb's gem object's reservation object.
>   *
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_fb.h b/drivers/gpu/drm/mediatek/mtk_drm_fb.h
> index 7f976b196a15..e49e015380d0 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_fb.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_fb.h
> @@ -18,5 +18,8 @@ int mtk_fb_wait(struct drm_framebuffer *fb);
>  struct drm_framebuffer *mtk_drm_mode_fb_create(struct drm_device *dev,
>  					       struct drm_file *file,
>  					       const struct drm_mode_fb_cmd2 *cmd);
> +struct drm_framebuffer *mtk_drm_framebuffer_create(struct drm_device *dev,
> +		const struct drm_mode_fb_cmd2 *mode,
> +		struct drm_gem_object *obj);
>  
>  #endif /* MTK_DRM_FB_H */
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_fbdev.c b/drivers/gpu/drm/mediatek/mtk_drm_fbdev.c
> new file mode 100644
> index 000000000000..9670f50d1247
> --- /dev/null
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_fbdev.c
> @@ -0,0 +1,178 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018 MediaTek Inc.
> + * Author: CK Hu <ck.hu@xxxxxxxxxxxx>
> + */
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_gem.h>
> +
> +#include "mtk_drm_drv.h"
> +#include "mtk_drm_fb.h"
> +#include "mtk_drm_gem.h"
> +#include "mtk_drm_fbdev.h"
> +
> +#define to_drm_private(x) \
> +		container_of(x, struct mtk_drm_private, fb_helper)
> +
> +static int mtk_drm_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma)
> +{
> +	struct drm_fb_helper *helper = info->par;
> +	struct mtk_drm_private *private = to_drm_private(helper);
> +
> +	return mtk_drm_gem_mmap_buf(private->fbdev_bo, vma);
> +}
> +
> +static struct fb_ops mtk_fbdev_ops = {
> +	.owner = THIS_MODULE,
> +	DRM_FB_HELPER_DEFAULT_OPS,
> +	.fb_fillrect = drm_fb_helper_cfb_fillrect,
> +	.fb_copyarea = drm_fb_helper_cfb_copyarea,
> +	.fb_imageblit = drm_fb_helper_cfb_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_fbdev_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 mtk_drm_private *private = to_drm_private(helper);
> +	struct drm_mode_fb_cmd2 mode = { 0 };
> +	struct mtk_drm_gem_obj *mtk_gem;
> +	struct fb_info *info;
> +	struct drm_framebuffer *fb;
> +	unsigned int bytes_per_pixel;
> +	unsigned long offset;
> +	size_t size;
> +	int err = 0;
> +
> +	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);
> +
> +	mode.width = sizes->surface_width;
> +	mode.height = sizes->surface_height;
> +	mode.pitches[0] = sizes->surface_width * bytes_per_pixel;
> +	mode.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
> +						      sizes->surface_depth);
> +
> +	size = mode.pitches[0] * mode.height;
> +
> +	mtk_gem = mtk_drm_gem_create(dev, size, true);
> +	if (IS_ERR(mtk_gem))
> +		return PTR_ERR(mtk_gem);
> +
> +	private->fbdev_bo = &mtk_gem->base;
> +
> +	info = drm_fb_helper_alloc_fbi(helper);
> +	if (IS_ERR(info)) {
> +		DRM_DEV_ERROR(dev->dev,
> +			"failed to allocate framebuffer info, %d\n",
> +			err);
> +		err = PTR_ERR(info);
> +		goto out;
> +	}
> +
> +	fb = mtk_drm_framebuffer_create(dev, &mode, private->fbdev_bo);
> +	if (IS_ERR(fb)) {
> +		DRM_DEV_ERROR(dev->dev,
> +			"failed to allocate DRM framebuffer, %d\n",
> +			err);
> +		err = PTR_ERR(fb);
> +		goto out;
> +	}
> +	helper->fb = fb;
> +
> +	info->par = helper;
> +	info->flags = FBINFO_FLAG_DEFAULT;
> +	info->fbops = &mtk_fbdev_ops;
> +
> +	drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
> +	drm_fb_helper_fill_var(info, helper, sizes->fb_width, sizes->fb_height);
> +
> +	offset = info->var.xoffset * bytes_per_pixel;
> +	offset += info->var.yoffset * fb->pitches[0];
> +
> +	dev->mode_config.fb_base = 0;
> +	info->screen_base = mtk_gem->kvaddr + offset;
> +	info->screen_size = size;
> +	info->fix.smem_len = size;
> +
> +	DRM_DEBUG_KMS("FB [%ux%u]-%u offset=%lu size=%zd\n",
> +		      fb->width, fb->height, fb->format->depth, offset, size);
> +
> +	info->skip_vt_switch = true;
> +
> +	return 0;
> +
> +out:
> +
> +
> +	mtk_drm_gem_free_object(&mtk_gem->base);
> +	return err;
> +}
> +
> +static const struct drm_fb_helper_funcs mtk_drm_fb_helper_funcs = {
> +	.fb_probe = mtk_fbdev_probe,
> +};
> +
> +int mtk_fbdev_init(struct drm_device *dev)
> +{
> +	struct mtk_drm_private *priv = dev->dev_private;
> +	struct drm_fb_helper *helper = &priv->fb_helper;
> +	int ret;
> +
> +	if (!dev->mode_config.num_crtc || !dev->mode_config.num_connector)
> +		return -EINVAL;
> +
> +	drm_fb_helper_prepare(dev, helper, &mtk_drm_fb_helper_funcs);
> +
> +	ret = drm_fb_helper_init(dev, helper, dev->mode_config.num_connector);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(dev->dev,
> +			"failed to initialize DRM FB helper, %d\n",
> +			ret);
> +//		goto fini;
> +		return ret;
> +	}
> +
> +	ret = drm_fb_helper_single_add_all_connectors(helper);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(dev->dev, "failed to add connectors, %d\n", ret);
> +		goto fini;
> +	}
> +
> +	ret = drm_fb_helper_initial_config(helper, 32);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(dev->dev,
> +			"failed to set initial configuration, %d\n",
> +			ret);
> +		goto fini;
> +	}
> +
> +	return 0;
> +
> +fini:
> +	drm_fb_helper_fini(helper);
> +	return ret;
> +}
> +
> +void mtk_fbdev_fini(struct drm_device *dev)
> +{
> +	struct mtk_drm_private *priv = dev->dev_private;
> +	struct drm_fb_helper *helper = &priv->fb_helper;
> +
> +	drm_fb_helper_unregister_fbi(helper);
> +
> +	if (helper->fb) {
> +		drm_framebuffer_unregister_private(helper->fb);
> +		drm_framebuffer_remove(helper->fb);
> +	}
> +
> +	drm_fb_helper_fini(helper);
> +}
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_fbdev.h b/drivers/gpu/drm/mediatek/mtk_drm_fbdev.h
> new file mode 100644
> index 000000000000..45717b642dc5
> --- /dev/null
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_fbdev.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2018 MediaTek Inc.
> + * Author: CK Hu <ck.hu@xxxxxxxxxxxx>
> + */
> +
> +#ifndef MTK_DRM_FBDEV_H
> +#define MTK_DRM_FBDEV_H
> +
> +#ifdef CONFIG_DRM_FBDEV_EMULATION
> +int mtk_fbdev_init(struct drm_device *dev);
> +void mtk_fbdev_fini(struct drm_device *dev);
> +#else
> +int mtk_fbdev_init(struct drm_device *dev)
> +{
> +	return 0;
> +}
> +
> +void mtk_fbdev_fini(struct drm_device *dev)
> +{
> +
> +}
> +#endif /* CONFIG_DRM_FBDEV_EMULATION */
> +
> +#endif /* MTK_DRM_FBDEV_H */
> -- 
> 2.17.1
> 

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