From f9309086600f7689b61f38bb53ac00e45bb45f8f Mon Sep 17 00:00:00 2001
From: Greg Hackmann <ghackmann@google.com>
Date: Tue, 9 Jul 2013 13:07:26 -0700
Subject: [PATCH] video: adf: add fbdev compatibility helper

Change-Id: I2b82bb625f805e8edb27799743b290dda5befb97
Signed-off-by: Greg Hackmann <ghackmann@google.com>
---
 drivers/video/adf/Kconfig     |   5 +
 drivers/video/adf/Makefile    |   2 +
 drivers/video/adf/adf_fbdev.c | 651 ++++++++++++++++++++++++++++++++++
 include/video/adf_fbdev.h     |  59 +++
 4 files changed, 717 insertions(+)
 create mode 100644 drivers/video/adf/adf_fbdev.c
 create mode 100644 include/video/adf_fbdev.h

diff --git a/drivers/video/adf/Kconfig b/drivers/video/adf/Kconfig
index fcd725fb93d8..33858b73d8bb 100644
--- a/drivers/video/adf/Kconfig
+++ b/drivers/video/adf/Kconfig
@@ -3,6 +3,11 @@ menuconfig ADF
 	depends on DMA_SHARED_BUFFER
 	tristate "Atomic Display Framework"
 
+menuconfig ADF_FBDEV
+	depends on ADF
+	depends on FB
+	tristate "Helper for implementing the fbdev API in ADF drivers"
+
 menuconfig ADF_MEMBLOCK
 	depends on ADF
 	depends on HAVE_MEMBLOCK
diff --git a/drivers/video/adf/Makefile b/drivers/video/adf/Makefile
index 4118f324f654..78d0915122f4 100644
--- a/drivers/video/adf/Makefile
+++ b/drivers/video/adf/Makefile
@@ -10,4 +10,6 @@ obj-$(CONFIG_ADF) += adf.o \
 
 obj-$(CONFIG_COMPAT) += adf_fops32.o
 
+obj-$(CONFIG_ADF_FBDEV) += adf_fbdev.o
+
 obj-$(CONFIG_ADF_MEMBLOCK) += adf_memblock.o
diff --git a/drivers/video/adf/adf_fbdev.c b/drivers/video/adf/adf_fbdev.c
new file mode 100644
index 000000000000..477abd63ccc2
--- /dev/null
+++ b/drivers/video/adf/adf_fbdev.c
@@ -0,0 +1,651 @@
+/*
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/vmalloc.h>
+
+#include <video/adf.h>
+#include <video/adf_client.h>
+#include <video/adf_fbdev.h>
+#include <video/adf_format.h>
+
+#include "adf.h"
+
+struct adf_fbdev_format {
+	u32 fourcc;
+	u32 bpp;
+	u32 r_length;
+	u32 g_length;
+	u32 b_length;
+	u32 a_length;
+	u32 r_offset;
+	u32 g_offset;
+	u32 b_offset;
+	u32 a_offset;
+};
+
+static const struct adf_fbdev_format format_table[] = {
+	{DRM_FORMAT_RGB332, 8, 3, 3, 2, 0, 5, 2, 0, 0},
+	{DRM_FORMAT_BGR233, 8, 3, 3, 2, 0, 0, 3, 5, 0},
+
+	{DRM_FORMAT_XRGB4444, 16, 4, 4, 4, 0, 8, 4, 0, 0},
+	{DRM_FORMAT_XBGR4444, 16, 4, 4, 4, 0, 0, 4, 8, 0},
+	{DRM_FORMAT_RGBX4444, 16, 4, 4, 4, 0, 12, 8, 4, 0},
+	{DRM_FORMAT_BGRX4444, 16, 4, 4, 4, 0, 0, 4, 8, 0},
+
+	{DRM_FORMAT_ARGB4444, 16, 4, 4, 4, 4, 8, 4, 0, 12},
+	{DRM_FORMAT_ABGR4444, 16, 4, 4, 4, 4, 0, 4, 8, 12},
+	{DRM_FORMAT_RGBA4444, 16, 4, 4, 4, 4, 12, 8, 4, 0},
+	{DRM_FORMAT_BGRA4444, 16, 4, 4, 4, 4, 0, 4, 8, 0},
+
+	{DRM_FORMAT_XRGB1555, 16, 5, 5, 5, 0, 10, 5, 0, 0},
+	{DRM_FORMAT_XBGR1555, 16, 5, 5, 5, 0, 0, 5, 10, 0},
+	{DRM_FORMAT_RGBX5551, 16, 5, 5, 5, 0, 11, 6, 1, 0},
+	{DRM_FORMAT_BGRX5551, 16, 5, 5, 5, 0, 1, 6, 11, 0},
+
+	{DRM_FORMAT_ARGB1555, 16, 5, 5, 5, 1, 10, 5, 0, 15},
+	{DRM_FORMAT_ABGR1555, 16, 5, 5, 5, 1, 0, 5, 10, 15},
+	{DRM_FORMAT_RGBA5551, 16, 5, 5, 5, 1, 11, 6, 1, 0},
+	{DRM_FORMAT_BGRA5551, 16, 5, 5, 5, 1, 1, 6, 11, 0},
+
+	{DRM_FORMAT_RGB565, 16, 5, 6, 5, 0, 11, 5, 0, 0},
+	{DRM_FORMAT_BGR565, 16, 5, 6, 5, 0, 0, 5, 11, 0},
+
+	{DRM_FORMAT_RGB888, 24, 8, 8, 8, 0, 16, 8, 0, 0},
+	{DRM_FORMAT_BGR888, 24, 8, 8, 8, 0, 0, 8, 16, 0},
+
+	{DRM_FORMAT_XRGB8888, 32, 8, 8, 8, 0, 16, 8, 0, 0},
+	{DRM_FORMAT_XBGR8888, 32, 8, 8, 8, 0, 0, 8, 16, 0},
+	{DRM_FORMAT_RGBX8888, 32, 8, 8, 8, 0, 24, 16, 8, 0},
+	{DRM_FORMAT_BGRX8888, 32, 8, 8, 8, 0, 8, 16, 24, 0},
+
+	{DRM_FORMAT_ARGB8888, 32, 8, 8, 8, 8, 16, 8, 0, 24},
+	{DRM_FORMAT_ABGR8888, 32, 8, 8, 8, 8, 0, 8, 16, 24},
+	{DRM_FORMAT_RGBA8888, 32, 8, 8, 8, 8, 24, 16, 8, 0},
+	{DRM_FORMAT_BGRA8888, 32, 8, 8, 8, 8, 8, 16, 24, 0},
+
+	{DRM_FORMAT_XRGB2101010, 32, 10, 10, 10, 0, 20, 10, 0, 0},
+	{DRM_FORMAT_XBGR2101010, 32, 10, 10, 10, 0, 0, 10, 20, 0},
+	{DRM_FORMAT_RGBX1010102, 32, 10, 10, 10, 0, 22, 12, 2, 0},
+	{DRM_FORMAT_BGRX1010102, 32, 10, 10, 10, 0, 2, 12, 22, 0},
+
+	{DRM_FORMAT_ARGB2101010, 32, 10, 10, 10, 2, 20, 10, 0, 30},
+	{DRM_FORMAT_ABGR2101010, 32, 10, 10, 10, 2, 0, 10, 20, 30},
+	{DRM_FORMAT_RGBA1010102, 32, 10, 10, 10, 2, 22, 12, 2, 0},
+	{DRM_FORMAT_BGRA1010102, 32, 10, 10, 10, 2, 2, 12, 22, 0},
+};
+
+static u32 drm_fourcc_from_fb_var(struct fb_var_screeninfo *var)
+{
+	size_t i;
+	for (i = 0; i < ARRAY_SIZE(format_table); i++) {
+		const struct adf_fbdev_format *f = &format_table[i];
+		if (var->red.length == f->r_length &&
+			var->red.offset == f->r_offset &&
+			var->green.length == f->g_length &&
+			var->green.offset == f->g_offset &&
+			var->blue.length == f->b_length &&
+			var->blue.offset == f->b_offset &&
+			var->transp.length == f->a_length &&
+			(var->transp.length == 0 ||
+					var->transp.offset == f->a_offset))
+			return f->fourcc;
+	}
+
+	return 0;
+}
+
+static const struct adf_fbdev_format *fbdev_format_info(u32 format)
+{
+	size_t i;
+	for (i = 0; i < ARRAY_SIZE(format_table); i++) {
+		const struct adf_fbdev_format *f = &format_table[i];
+		if (f->fourcc == format)
+			return f;
+	}
+
+	BUG();
+}
+
+void adf_modeinfo_to_fb_videomode(const struct drm_mode_modeinfo *mode,
+		struct fb_videomode *vmode)
+{
+	memset(vmode, 0, sizeof(*vmode));
+
+	vmode->refresh = mode->vrefresh;
+
+	vmode->xres = mode->hdisplay;
+	vmode->yres = mode->vdisplay;
+
+	vmode->pixclock = mode->clock ? KHZ2PICOS(mode->clock) : 0;
+	vmode->left_margin = mode->htotal - mode->hsync_end;
+	vmode->right_margin = mode->hsync_start - mode->hdisplay;
+	vmode->upper_margin = mode->vtotal - mode->vsync_end;
+	vmode->lower_margin = mode->vsync_start - mode->vdisplay;
+	vmode->hsync_len = mode->hsync_end - mode->hsync_start;
+	vmode->vsync_len = mode->vsync_end - mode->vsync_start;
+
+	vmode->sync = 0;
+	if (mode->flags | DRM_MODE_FLAG_PHSYNC)
+		vmode->sync |= FB_SYNC_HOR_HIGH_ACT;
+	if (mode->flags | DRM_MODE_FLAG_PVSYNC)
+		vmode->sync |= FB_SYNC_VERT_HIGH_ACT;
+	if (mode->flags | DRM_MODE_FLAG_PCSYNC)
+		vmode->sync |= FB_SYNC_COMP_HIGH_ACT;
+	if (mode->flags | DRM_MODE_FLAG_BCAST)
+		vmode->sync |= FB_SYNC_BROADCAST;
+
+	vmode->vmode = 0;
+	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+		vmode->vmode |= FB_VMODE_INTERLACED;
+	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+		vmode->vmode |= FB_VMODE_DOUBLE;
+}
+EXPORT_SYMBOL(adf_modeinfo_to_fb_videomode);
+
+void adf_modeinfo_from_fb_videomode(const struct fb_videomode *vmode,
+		struct drm_mode_modeinfo *mode)
+{
+	memset(mode, 0, sizeof(*mode));
+
+	mode->hdisplay = vmode->xres;
+	mode->hsync_start = mode->hdisplay + vmode->right_margin;
+	mode->hsync_end = mode->hsync_start + vmode->hsync_len;
+	mode->htotal = mode->hsync_end + vmode->left_margin;
+
+	mode->vdisplay = vmode->yres;
+	mode->vsync_start = mode->vdisplay + vmode->lower_margin;
+	mode->vsync_end = mode->vsync_start + vmode->vsync_len;
+	mode->vtotal = mode->vsync_end + vmode->upper_margin;
+
+	mode->clock = vmode->pixclock ? PICOS2KHZ(vmode->pixclock) : 0;
+
+	mode->flags = 0;
+	if (vmode->sync & FB_SYNC_HOR_HIGH_ACT)
+		mode->flags |= DRM_MODE_FLAG_PHSYNC;
+	if (vmode->sync & FB_SYNC_VERT_HIGH_ACT)
+		mode->flags |= DRM_MODE_FLAG_PVSYNC;
+	if (vmode->sync & FB_SYNC_COMP_HIGH_ACT)
+		mode->flags |= DRM_MODE_FLAG_PCSYNC;
+	if (vmode->sync & FB_SYNC_BROADCAST)
+		mode->flags |= DRM_MODE_FLAG_BCAST;
+	if (vmode->vmode & FB_VMODE_INTERLACED)
+		mode->flags |= DRM_MODE_FLAG_INTERLACE;
+	if (vmode->vmode & FB_VMODE_DOUBLE)
+		mode->flags |= DRM_MODE_FLAG_DBLSCAN;
+
+	if (vmode->refresh)
+		mode->vrefresh = vmode->refresh;
+	else
+		adf_modeinfo_set_vrefresh(mode);
+
+	if (vmode->name)
+		strlcpy(mode->name, vmode->name, sizeof(mode->name));
+	else
+		adf_modeinfo_set_name(mode);
+}
+EXPORT_SYMBOL(adf_modeinfo_from_fb_videomode);
+
+static int adf_fbdev_post(struct adf_fbdev *fbdev)
+{
+	struct adf_buffer buf;
+	struct sync_fence *complete_fence;
+	int ret = 0;
+
+	memset(&buf, 0, sizeof(buf));
+	buf.overlay_engine = fbdev->eng;
+	buf.w = fbdev->info->var.xres;
+	buf.h = fbdev->info->var.yres;
+	buf.format = fbdev->format;
+	buf.dma_bufs[0] = fbdev->dma_buf;
+	buf.offset[0] = fbdev->offset +
+			fbdev->info->var.yoffset * fbdev->pitch +
+			fbdev->info->var.xoffset *
+			(fbdev->info->var.bits_per_pixel / 8);
+	buf.pitch[0] = fbdev->pitch;
+	buf.n_planes = 1;
+
+	complete_fence = adf_interface_simple_post(fbdev->intf, &buf);
+	if (IS_ERR(complete_fence)) {
+		ret = PTR_ERR(complete_fence);
+		goto done;
+	}
+
+	sync_fence_put(complete_fence);
+done:
+	return ret;
+}
+
+static const u16 vga_palette[][3] = {
+	{0x0000, 0x0000, 0x0000},
+	{0x0000, 0x0000, 0xAAAA},
+	{0x0000, 0xAAAA, 0x0000},
+	{0x0000, 0xAAAA, 0xAAAA},
+	{0xAAAA, 0x0000, 0x0000},
+	{0xAAAA, 0x0000, 0xAAAA},
+	{0xAAAA, 0x5555, 0x0000},
+	{0xAAAA, 0xAAAA, 0xAAAA},
+	{0x5555, 0x5555, 0x5555},
+	{0x5555, 0x5555, 0xFFFF},
+	{0x5555, 0xFFFF, 0x5555},
+	{0x5555, 0xFFFF, 0xFFFF},
+	{0xFFFF, 0x5555, 0x5555},
+	{0xFFFF, 0x5555, 0xFFFF},
+	{0xFFFF, 0xFFFF, 0x5555},
+	{0xFFFF, 0xFFFF, 0xFFFF},
+};
+
+static int adf_fb_alloc(struct adf_fbdev *fbdev)
+{
+	int ret;
+
+	ret = adf_interface_simple_buffer_alloc(fbdev->intf,
+			fbdev->default_xres_virtual,
+			fbdev->default_yres_virtual,
+			fbdev->default_format,
+			&fbdev->dma_buf, &fbdev->offset, &fbdev->pitch);
+	if (ret < 0) {
+		dev_err(fbdev->info->dev, "allocating fb failed: %d\n", ret);
+		return ret;
+	}
+
+	fbdev->vaddr = dma_buf_vmap(fbdev->dma_buf);
+	if (!fbdev->vaddr) {
+		ret = -ENOMEM;
+		dev_err(fbdev->info->dev, "vmapping fb failed\n");
+		goto err_vmap;
+	}
+	fbdev->info->fix.line_length = fbdev->pitch;
+	fbdev->info->var.xres_virtual = fbdev->default_xres_virtual;
+	fbdev->info->var.yres_virtual = fbdev->default_yres_virtual;
+	fbdev->info->fix.smem_len = fbdev->dma_buf->size;
+	fbdev->info->screen_base = fbdev->vaddr;
+
+	return 0;
+
+err_vmap:
+	dma_buf_put(fbdev->dma_buf);
+	return ret;
+}
+
+static void adf_fb_destroy(struct adf_fbdev *fbdev)
+{
+	dma_buf_vunmap(fbdev->dma_buf, fbdev->vaddr);
+	dma_buf_put(fbdev->dma_buf);
+}
+
+static void adf_fbdev_set_format(struct adf_fbdev *fbdev, u32 format)
+{
+	size_t i;
+	const struct adf_fbdev_format *info = fbdev_format_info(format);
+	for (i = 0; i < ARRAY_SIZE(vga_palette); i++) {
+		u16 r = vga_palette[i][0];
+		u16 g = vga_palette[i][1];
+		u16 b = vga_palette[i][2];
+
+		r >>= (16 - info->r_length);
+		g >>= (16 - info->g_length);
+		b >>= (16 - info->b_length);
+
+		fbdev->pseudo_palette[i] =
+			(r << info->r_offset) |
+			(g << info->g_offset) |
+			(b << info->b_offset);
+
+		if (info->a_length) {
+			u16 a = BIT(info->a_length) - 1;
+			fbdev->pseudo_palette[i] |= (a << info->a_offset);
+		}
+	}
+
+	fbdev->info->var.bits_per_pixel = adf_format_bpp(format);
+	fbdev->info->var.red.length = info->r_length;
+	fbdev->info->var.red.offset = info->r_offset;
+	fbdev->info->var.green.length = info->g_length;
+	fbdev->info->var.green.offset = info->g_offset;
+	fbdev->info->var.blue.length = info->b_length;
+	fbdev->info->var.blue.offset = info->b_offset;
+	fbdev->info->var.transp.length = info->a_length;
+	fbdev->info->var.transp.offset = info->a_offset;
+	fbdev->format = format;
+}
+
+static void adf_fbdev_fill_modelist(struct adf_fbdev *fbdev)
+{
+	struct drm_mode_modeinfo *modelist;
+	struct fb_videomode fbmode;
+	size_t n_modes, i;
+	int ret = 0;
+
+	n_modes = adf_interface_modelist(fbdev->intf, NULL, 0);
+	modelist = kzalloc(sizeof(modelist[0]) * n_modes, GFP_KERNEL);
+	if (!modelist) {
+		dev_warn(fbdev->info->dev, "allocating new modelist failed; keeping old modelist\n");
+		return;
+	}
+	adf_interface_modelist(fbdev->intf, modelist, n_modes);
+
+	fb_destroy_modelist(&fbdev->info->modelist);
+
+	for (i = 0; i < n_modes; i++) {
+		adf_modeinfo_to_fb_videomode(&modelist[i], &fbmode);
+		ret = fb_add_videomode(&fbmode, &fbdev->info->modelist);
+		if (ret < 0)
+			dev_warn(fbdev->info->dev, "adding mode %s to modelist failed: %d\n",
+					modelist[i].name, ret);
+	}
+
+	kfree(modelist);
+}
+
+/**
+ * adf_fbdev_open - default implementation of fbdev open op
+ */
+int adf_fbdev_open(struct fb_info *info, int user)
+{
+	struct adf_fbdev *fbdev = info->par;
+	int ret;
+
+	if (!fbdev->open) {
+		struct drm_mode_modeinfo mode;
+		struct fb_videomode fbmode;
+		struct adf_device *dev = adf_interface_parent(fbdev->intf);
+
+		ret = adf_device_attach(dev, fbdev->eng, fbdev->intf);
+		if (ret < 0 && ret != -EALREADY)
+			return ret;
+
+		ret = adf_fb_alloc(fbdev);
+		if (ret < 0)
+			return ret;
+
+		adf_interface_current_mode(fbdev->intf, &mode);
+		adf_modeinfo_to_fb_videomode(&mode, &fbmode);
+		fb_videomode_to_var(&fbdev->info->var, &fbmode);
+
+		adf_fbdev_set_format(fbdev, fbdev->default_format);
+		adf_fbdev_fill_modelist(fbdev);
+	}
+
+	ret = adf_fbdev_post(fbdev);
+	if (ret < 0) {
+		if (!fbdev->open)
+			adf_fb_destroy(fbdev);
+		return ret;
+	}
+
+	fbdev->open = true;
+	return 0;
+}
+EXPORT_SYMBOL(adf_fbdev_open);
+
+/**
+ * adf_fbdev_release - default implementation of fbdev release op
+ */
+int adf_fbdev_release(struct fb_info *info, int user)
+{
+	struct adf_fbdev *fbdev = info->par;
+	adf_fb_destroy(fbdev);
+	fbdev->open = false;
+	return 0;
+}
+EXPORT_SYMBOL(adf_fbdev_release);
+
+/**
+ * adf_fbdev_check_var - default implementation of fbdev check_var op
+ */
+int adf_fbdev_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
+{
+	struct adf_fbdev *fbdev = info->par;
+	bool valid_format = true;
+	u32 format = drm_fourcc_from_fb_var(var);
+	u32 pitch = var->xres_virtual * var->bits_per_pixel / 8;
+
+	if (!format) {
+		dev_dbg(info->dev, "%s: unrecognized format\n", __func__);
+		valid_format = false;
+	}
+
+	if (valid_format && var->grayscale) {
+		dev_dbg(info->dev, "%s: grayscale modes not supported\n",
+				__func__);
+		valid_format = false;
+	}
+
+	if (valid_format && var->nonstd) {
+		dev_dbg(info->dev, "%s: nonstandard formats not supported\n",
+				__func__);
+		valid_format = false;
+	}
+
+	if (valid_format && !adf_overlay_engine_supports_format(fbdev->eng,
+			format)) {
+		char format_str[ADF_FORMAT_STR_SIZE];
+		adf_format_str(format, format_str);
+		dev_dbg(info->dev, "%s: format %s not supported by overlay engine %s\n",
+				__func__, format_str, fbdev->eng->base.name);
+		valid_format = false;
+	}
+
+	if (valid_format && pitch > fbdev->pitch) {
+		dev_dbg(info->dev, "%s: fb pitch too small for var (pitch = %u, xres_virtual = %u, bits_per_pixel = %u)\n",
+				__func__, fbdev->pitch, var->xres_virtual,
+				var->bits_per_pixel);
+		valid_format = false;
+	}
+
+	if (valid_format && var->yres_virtual > fbdev->default_yres_virtual) {
+		dev_dbg(info->dev, "%s: fb height too small for var (h = %u, yres_virtual = %u)\n",
+				__func__, fbdev->default_yres_virtual,
+				var->yres_virtual);
+		valid_format = false;
+	}
+
+	if (valid_format) {
+		var->activate = info->var.activate;
+		var->height = info->var.height;
+		var->width = info->var.width;
+		var->accel_flags = info->var.accel_flags;
+		var->rotate = info->var.rotate;
+		var->colorspace = info->var.colorspace;
+		/* userspace can't change these */
+	} else {
+		/* if any part of the format is invalid then fixing it up is
+		   impractical, so save just the modesetting bits and
+		   overwrite everything else */
+		struct fb_videomode mode;
+		fb_var_to_videomode(&mode, var);
+		memcpy(var, &info->var, sizeof(*var));
+		fb_videomode_to_var(var, &mode);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(adf_fbdev_check_var);
+
+/**
+ * adf_fbdev_set_par - default implementation of fbdev set_par op
+ */
+int adf_fbdev_set_par(struct fb_info *info)
+{
+	struct adf_fbdev *fbdev = info->par;
+	struct adf_interface *intf = fbdev->intf;
+	struct fb_videomode vmode;
+	struct drm_mode_modeinfo mode;
+	int ret;
+	u32 format = drm_fourcc_from_fb_var(&info->var);
+
+	fb_var_to_videomode(&vmode, &info->var);
+	adf_modeinfo_from_fb_videomode(&vmode, &mode);
+	ret = adf_interface_set_mode(intf, &mode);
+	if (ret < 0)
+		return ret;
+
+	ret = adf_fbdev_post(fbdev);
+	if (ret < 0)
+		return ret;
+
+	if (format != fbdev->format)
+		adf_fbdev_set_format(fbdev, format);
+
+	return 0;
+}
+EXPORT_SYMBOL(adf_fbdev_set_par);
+
+/**
+ * adf_fbdev_blank - default implementation of fbdev blank op
+ */
+int adf_fbdev_blank(int blank, struct fb_info *info)
+{
+	struct adf_fbdev *fbdev = info->par;
+	struct adf_interface *intf = fbdev->intf;
+	u8 dpms_state;
+
+	switch (blank) {
+	case FB_BLANK_UNBLANK:
+		dpms_state = DRM_MODE_DPMS_ON;
+		break;
+	case FB_BLANK_NORMAL:
+		dpms_state = DRM_MODE_DPMS_STANDBY;
+		break;
+	case FB_BLANK_VSYNC_SUSPEND:
+		dpms_state = DRM_MODE_DPMS_STANDBY;
+		break;
+	case FB_BLANK_HSYNC_SUSPEND:
+		dpms_state = DRM_MODE_DPMS_SUSPEND;
+		break;
+	case FB_BLANK_POWERDOWN:
+		dpms_state = DRM_MODE_DPMS_OFF;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return adf_interface_blank(intf, dpms_state);
+}
+EXPORT_SYMBOL(adf_fbdev_blank);
+
+/**
+ * adf_fbdev_pan_display - default implementation of fbdev pan_display op
+ */
+int adf_fbdev_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
+{
+	struct adf_fbdev *fbdev = info->par;
+	return adf_fbdev_post(fbdev);
+}
+EXPORT_SYMBOL(adf_fbdev_pan_display);
+
+/**
+ * adf_fbdev_mmap - default implementation of fbdev mmap op
+ */
+int adf_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	struct adf_fbdev *fbdev = info->par;
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	return dma_buf_mmap(fbdev->dma_buf, vma, 0);
+}
+EXPORT_SYMBOL(adf_fbdev_mmap);
+
+/**
+ * adf_fbdev_init - initialize helper to wrap ADF device in fbdev API
+ *
+ * @fbdev: the fbdev helper
+ * @interface: the ADF interface that will display the framebuffer
+ * @eng: the ADF overlay engine that will scan out the framebuffer
+ * @xres_virtual: the virtual width of the framebuffer
+ * @yres_virtual: the virtual height of the framebuffer
+ * @format: the format of the framebuffer
+ * @fbops: the device's fbdev ops
+ * @fmt: formatting for the framebuffer identification string
+ * @...: variable arguments
+ *
+ * @format must be a standard, non-indexed RGB format, i.e.,
+ * adf_format_is_rgb(@format) && @format != @DRM_FORMAT_C8.
+ *
+ * Returns 0 on success or -errno on failure.
+ */
+int adf_fbdev_init(struct adf_fbdev *fbdev, struct adf_interface *interface,
+		struct adf_overlay_engine *eng,
+		u16 xres_virtual, u16 yres_virtual, u32 format,
+		struct fb_ops *fbops, const char *fmt, ...)
+{
+	struct adf_device *parent = adf_interface_parent(interface);
+	struct device *dev = &parent->base.dev;
+	u16 width_mm, height_mm;
+	va_list args;
+	int ret;
+
+	if (!adf_format_is_rgb(format) ||
+			format == DRM_FORMAT_C8) {
+		dev_err(dev, "fbdev helper does not support format %u\n",
+				format);
+		return -EINVAL;
+	}
+
+	memset(fbdev, 0, sizeof(*fbdev));
+	fbdev->intf = interface;
+	fbdev->eng = eng;
+	fbdev->info = framebuffer_alloc(0, dev);
+	if (!fbdev->info) {
+		dev_err(dev, "allocating framebuffer device failed\n");
+		return -ENOMEM;
+	}
+	fbdev->default_xres_virtual = xres_virtual;
+	fbdev->default_yres_virtual = yres_virtual;
+	fbdev->default_format = format;
+
+	fbdev->info->flags = FBINFO_FLAG_DEFAULT;
+	ret = adf_interface_get_screen_size(interface, &width_mm, &height_mm);
+	if (ret < 0) {
+		width_mm = 0;
+		height_mm = 0;
+	}
+	fbdev->info->var.width = width_mm;
+	fbdev->info->var.height = height_mm;
+	fbdev->info->var.activate = FB_ACTIVATE_VBL;
+	va_start(args, fmt);
+	vsnprintf(fbdev->info->fix.id, sizeof(fbdev->info->fix.id), fmt, args);
+	va_end(args);
+	fbdev->info->fix.type = FB_TYPE_PACKED_PIXELS;
+	fbdev->info->fix.visual = FB_VISUAL_TRUECOLOR;
+	fbdev->info->fix.xpanstep = 1;
+	fbdev->info->fix.ypanstep = 1;
+	INIT_LIST_HEAD(&fbdev->info->modelist);
+	fbdev->info->fbops = fbops;
+	fbdev->info->pseudo_palette = fbdev->pseudo_palette;
+	fbdev->info->par = fbdev;
+
+	ret = register_framebuffer(fbdev->info);
+	if (ret < 0) {
+		dev_err(dev, "registering framebuffer failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(adf_fbdev_init);
+
+/**
+ * adf_fbdev_destroy - destroy helper to wrap ADF device in fbdev API
+ *
+ * @fbdev: the fbdev helper
+ */
+void adf_fbdev_destroy(struct adf_fbdev *fbdev)
+{
+	unregister_framebuffer(fbdev->info);
+	if (WARN_ON(fbdev->open))
+		adf_fb_destroy(fbdev);
+	framebuffer_release(fbdev->info);
+}
+EXPORT_SYMBOL(adf_fbdev_destroy);
diff --git a/include/video/adf_fbdev.h b/include/video/adf_fbdev.h
new file mode 100644
index 000000000000..9c349144b5cd
--- /dev/null
+++ b/include/video/adf_fbdev.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _VIDEO_ADF_FBDEV_H_
+#define _VIDEO_ADF_FBDEV_H_
+
+#include <linux/fb.h>
+#include <video/adf.h>
+
+struct adf_fbdev {
+	struct adf_interface *intf;
+	struct adf_overlay_engine *eng;
+	struct fb_info *info;
+	u32 pseudo_palette[16];
+
+	bool open;
+
+	struct dma_buf *dma_buf;
+	u32 offset;
+	u32 pitch;
+	void *vaddr;
+	u32 format;
+
+	u16 default_xres_virtual;
+	u16 default_yres_virtual;
+	u32 default_format;
+};
+
+void adf_modeinfo_to_fb_videomode(const struct drm_mode_modeinfo *mode,
+		struct fb_videomode *vmode);
+void adf_modeinfo_from_fb_videomode(const struct fb_videomode *vmode,
+		struct drm_mode_modeinfo *mode);
+
+int adf_fbdev_init(struct adf_fbdev *fbdev, struct adf_interface *interface,
+		struct adf_overlay_engine *eng,
+		u16 xres_virtual, u16 yres_virtual, u32 format,
+		struct fb_ops *fbops, const char *fmt, ...);
+void adf_fbdev_destroy(struct adf_fbdev *fbdev);
+
+int adf_fbdev_open(struct fb_info *info, int user);
+int adf_fbdev_release(struct fb_info *info, int user);
+int adf_fbdev_check_var(struct fb_var_screeninfo *var, struct fb_info *info);
+int adf_fbdev_set_par(struct fb_info *info);
+int adf_fbdev_blank(int blank, struct fb_info *info);
+int adf_fbdev_pan_display(struct fb_var_screeninfo *var, struct fb_info *info);
+int adf_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma);
+
+#endif /* _VIDEO_ADF_FBDEV_H_ */
-- 
2.34.1