This adds a DM video driver for U-Boot as the EFI payload. The driver
makes use of all necessary information from the passed EFI GOP info
to create a linear framebuffer device, as if it were initialized by
U-Boot itself.

Signed-off-by: Bin Meng <bmeng...@gmail.com>
Reviewed-by: Anatolij Gustschin <ag...@denx.de>
---

Changes in v2: None

 drivers/video/Kconfig  |   9 +++
 drivers/video/Makefile |   1 +
 drivers/video/efi.c    | 146 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 156 insertions(+)
 create mode 100644 drivers/video/efi.c

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 4c4d286..5ee9032 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -156,6 +156,15 @@ config VIDEO_COREBOOT
          coreboot already. This can in principle be used with any platform
          that coreboot supports.
 
+config VIDEO_EFI
+       bool "Enable EFI framebuffer driver support"
+       depends on EFI_STUB
+       help
+         Turn on this option to enable a framebuffeer driver when U-Boot is
+         loaded as a payload (see README.u-boot_on_efi) by an EFI BIOS where
+         the graphics device is configured by the EFI BIOS already. This can
+         in principle be used with any platform that has an EFI BIOS.
+
 config VIDEO_VESA
        bool "Enable VESA video driver support"
        default n
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index cf7ad28..7c89c67 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_LD9040) += ld9040.o
 obj-$(CONFIG_VIDEO_BCM2835) += bcm2835.o
 obj-$(CONFIG_VIDEO_COREBOOT) += coreboot.o
 obj-$(CONFIG_VIDEO_DA8XX) += da8xx-fb.o videomodes.o
+obj-$(CONFIG_VIDEO_EFI) += efi.o
 obj-$(CONFIG_VIDEO_LCD_ANX9804) += anx9804.o
 obj-$(CONFIG_VIDEO_LCD_HITACHI_TX18D42VM) += hitachi_tx18d42vm_lcd.o
 obj-$(CONFIG_VIDEO_LCD_SSD2828) += ssd2828.o
diff --git a/drivers/video/efi.c b/drivers/video/efi.c
new file mode 100644
index 0000000..653cb47
--- /dev/null
+++ b/drivers/video/efi.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng...@gmail.com>
+ *
+ * EFI framebuffer driver based on GOP
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <efi_api.h>
+#include <vbe.h>
+#include <video.h>
+
+struct pixel {
+       u8 pos;
+       u8 size;
+};
+
+static const struct efi_framebuffer {
+       struct pixel red;
+       struct pixel green;
+       struct pixel blue;
+       struct pixel rsvd;
+} efi_framebuffer_format_map[] = {
+       [EFI_GOT_RGBA8] = { {0, 8}, {8, 8}, {16, 8}, {24, 8} },
+       [EFI_GOT_BGRA8] = { {16, 8}, {8, 8}, {0, 8}, {24, 8} },
+};
+
+static void efi_find_pixel_bits(u32 mask, u8 *pos, u8 *size)
+{
+       u8 first, len;
+
+       first = 0;
+       len = 0;
+
+       if (mask) {
+               while (!(mask & 0x1)) {
+                       mask = mask >> 1;
+                       first++;
+               }
+
+               while (mask & 0x1) {
+                       mask = mask >> 1;
+                       len++;
+               }
+       }
+
+       *pos = first;
+       *size = len;
+}
+
+static int save_vesa_mode(struct vesa_mode_info *vesa)
+{
+       struct efi_entry_gopmode *mode;
+       const struct efi_framebuffer *fbinfo;
+       int size;
+       int ret;
+
+       ret = efi_info_get(EFIET_GOP_MODE, (void **)&mode, &size);
+       if (ret == -ENOENT) {
+               debug("efi graphics output protocol mode not found\n");
+               return -ENXIO;
+       }
+
+       vesa->phys_base_ptr = mode->fb_base;
+       vesa->x_resolution = mode->info->width;
+       vesa->y_resolution = mode->info->height;
+
+       if (mode->info->pixel_format < EFI_GOT_BITMASK) {
+               fbinfo = &efi_framebuffer_format_map[mode->info->pixel_format];
+               vesa->red_mask_size = fbinfo->red.size;
+               vesa->red_mask_pos = fbinfo->red.pos;
+               vesa->green_mask_size = fbinfo->green.size;
+               vesa->green_mask_pos = fbinfo->green.pos;
+               vesa->blue_mask_size = fbinfo->blue.size;
+               vesa->blue_mask_pos = fbinfo->blue.pos;
+               vesa->reserved_mask_size = fbinfo->rsvd.size;
+               vesa->reserved_mask_pos = fbinfo->rsvd.pos;
+
+               vesa->bits_per_pixel = 32;
+               vesa->bytes_per_scanline = mode->info->pixels_per_scanline * 4;
+       } else if (mode->info->pixel_format == EFI_GOT_BITMASK) {
+               efi_find_pixel_bits(mode->info->pixel_bitmask[0],
+                                   &vesa->red_mask_pos,
+                                   &vesa->red_mask_size);
+               efi_find_pixel_bits(mode->info->pixel_bitmask[1],
+                                   &vesa->green_mask_pos,
+                                   &vesa->green_mask_size);
+               efi_find_pixel_bits(mode->info->pixel_bitmask[2],
+                                   &vesa->blue_mask_pos,
+                                   &vesa->blue_mask_size);
+               efi_find_pixel_bits(mode->info->pixel_bitmask[3],
+                                   &vesa->reserved_mask_pos,
+                                   &vesa->reserved_mask_size);
+               vesa->bits_per_pixel = vesa->red_mask_size +
+                                      vesa->green_mask_size +
+                                      vesa->blue_mask_size +
+                                      vesa->reserved_mask_size;
+               vesa->bytes_per_scanline = (mode->info->pixels_per_scanline *
+                                           vesa->bits_per_pixel) / 8;
+       } else {
+               debug("efi set unknown framebuffer format: %d\n",
+                     mode->info->pixel_format);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int efi_video_probe(struct udevice *dev)
+{
+       struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
+       struct video_priv *uc_priv = dev_get_uclass_priv(dev);
+       struct vesa_mode_info *vesa = &mode_info.vesa;
+       int ret;
+
+       /* Initialize vesa_mode_info structure */
+       ret = save_vesa_mode(vesa);
+       if (ret)
+               goto err;
+
+       ret = vbe_setup_video_priv(vesa, uc_priv, plat);
+       if (ret)
+               goto err;
+
+       printf("Video: %dx%dx%d\n", uc_priv->xsize, uc_priv->ysize,
+              vesa->bits_per_pixel);
+
+       return 0;
+
+err:
+       printf("No video mode configured in EFI!\n");
+       return ret;
+}
+
+static const struct udevice_id efi_video_ids[] = {
+       { .compatible = "efi-fb" },
+       { }
+};
+
+U_BOOT_DRIVER(efi_video) = {
+       .name   = "efi_video",
+       .id     = UCLASS_VIDEO,
+       .of_match = efi_video_ids,
+       .probe  = efi_video_probe,
+};
-- 
2.7.4

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