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

[Frank Wunderlich <frank-w@public-files.de>]

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

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@mediatek.com>
Signed-off-by: Alexander Ryabchenko <d3adme4t@gmail.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Tested-by: Frank Wunderlich <frank-w@public-files.de>
---
 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@mediatek.com>
+ */
+
+#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@mediatek.com>
+ */
+
+#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