Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 932 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
new file mode 100644
index 000000000..3ee59bae9
--- /dev/null
+++ b/drivers/gpu/drm/drm_format_helper.c
@@ -0,0 +1,932 @@
+// SPDX-License-Identifier: GPL-2.0 or MIT
+/*
+ * Copyright (C) 2016 Noralf Trønnes
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/io.h>
+#include <linux/iosys-map.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <drm/drm_device.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_print.h>
+#include <drm/drm_rect.h>
+
+static unsigned int clip_offset(const struct drm_rect *clip, unsigned int pitch, unsigned int cpp)
+{
+	return clip->y1 * pitch + clip->x1 * cpp;
+}
+
+/**
+ * drm_fb_clip_offset - Returns the clipping rectangles byte-offset in a framebuffer
+ * @pitch: Framebuffer line pitch in byte
+ * @format: Framebuffer format
+ * @clip: Clip rectangle
+ *
+ * Returns:
+ * The byte offset of the clip rectangle's top-left corner within the framebuffer.
+ */
+unsigned int drm_fb_clip_offset(unsigned int pitch, const struct drm_format_info *format,
+				const struct drm_rect *clip)
+{
+	return clip_offset(clip, pitch, format->cpp[0]);
+}
+EXPORT_SYMBOL(drm_fb_clip_offset);
+
+/* TODO: Make this function work with multi-plane formats. */
+static int __drm_fb_xfrm(void *dst, unsigned long dst_pitch, unsigned long dst_pixsize,
+			 const void *vaddr, const struct drm_framebuffer *fb,
+			 const struct drm_rect *clip, bool vaddr_cached_hint,
+			 void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels))
+{
+	unsigned long linepixels = drm_rect_width(clip);
+	unsigned long lines = drm_rect_height(clip);
+	size_t sbuf_len = linepixels * fb->format->cpp[0];
+	void *stmp = NULL;
+	unsigned long i;
+	const void *sbuf;
+
+	/*
+	 * Some source buffers, such as DMA memory, use write-combine
+	 * caching, so reads are uncached. Speed up access by fetching
+	 * one line at a time.
+	 */
+	if (!vaddr_cached_hint) {
+		stmp = kmalloc(sbuf_len, GFP_KERNEL);
+		if (!stmp)
+			return -ENOMEM;
+	}
+
+	if (!dst_pitch)
+		dst_pitch = drm_rect_width(clip) * dst_pixsize;
+	vaddr += clip_offset(clip, fb->pitches[0], fb->format->cpp[0]);
+
+	for (i = 0; i < lines; ++i) {
+		if (stmp)
+			sbuf = memcpy(stmp, vaddr, sbuf_len);
+		else
+			sbuf = vaddr;
+		xfrm_line(dst, sbuf, linepixels);
+		vaddr += fb->pitches[0];
+		dst += dst_pitch;
+	}
+
+	kfree(stmp);
+
+	return 0;
+}
+
+/* TODO: Make this function work with multi-plane formats. */
+static int __drm_fb_xfrm_toio(void __iomem *dst, unsigned long dst_pitch, unsigned long dst_pixsize,
+			      const void *vaddr, const struct drm_framebuffer *fb,
+			      const struct drm_rect *clip, bool vaddr_cached_hint,
+			      void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels))
+{
+	unsigned long linepixels = drm_rect_width(clip);
+	unsigned long lines = drm_rect_height(clip);
+	size_t dbuf_len = linepixels * dst_pixsize;
+	size_t stmp_off = round_up(dbuf_len, ARCH_KMALLOC_MINALIGN); /* for sbuf alignment */
+	size_t sbuf_len = linepixels * fb->format->cpp[0];
+	void *stmp = NULL;
+	unsigned long i;
+	const void *sbuf;
+	void *dbuf;
+
+	if (vaddr_cached_hint) {
+		dbuf = kmalloc(dbuf_len, GFP_KERNEL);
+	} else {
+		dbuf = kmalloc(stmp_off + sbuf_len, GFP_KERNEL);
+		stmp = dbuf + stmp_off;
+	}
+	if (!dbuf)
+		return -ENOMEM;
+
+	if (!dst_pitch)
+		dst_pitch = linepixels * dst_pixsize;
+	vaddr += clip_offset(clip, fb->pitches[0], fb->format->cpp[0]);
+
+	for (i = 0; i < lines; ++i) {
+		if (stmp)
+			sbuf = memcpy(stmp, vaddr, sbuf_len);
+		else
+			sbuf = vaddr;
+		xfrm_line(dbuf, sbuf, linepixels);
+		memcpy_toio(dst, dbuf, dbuf_len);
+		vaddr += fb->pitches[0];
+		dst += dst_pitch;
+	}
+
+	kfree(dbuf);
+
+	return 0;
+}
+
+/* TODO: Make this function work with multi-plane formats. */
+static int drm_fb_xfrm(struct iosys_map *dst,
+		       const unsigned int *dst_pitch, const u8 *dst_pixsize,
+		       const struct iosys_map *src, const struct drm_framebuffer *fb,
+		       const struct drm_rect *clip, bool vaddr_cached_hint,
+		       void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels))
+{
+	static const unsigned int default_dst_pitch[DRM_FORMAT_MAX_PLANES] = {
+		0, 0, 0, 0
+	};
+
+	if (!dst_pitch)
+		dst_pitch = default_dst_pitch;
+
+	/* TODO: handle src in I/O memory here */
+	if (dst[0].is_iomem)
+		return __drm_fb_xfrm_toio(dst[0].vaddr_iomem, dst_pitch[0], dst_pixsize[0],
+					  src[0].vaddr, fb, clip, vaddr_cached_hint, xfrm_line);
+	else
+		return __drm_fb_xfrm(dst[0].vaddr, dst_pitch[0], dst_pixsize[0],
+				     src[0].vaddr, fb, clip, vaddr_cached_hint, xfrm_line);
+}
+
+/**
+ * drm_fb_memcpy - Copy clip buffer
+ * @dst: Array of destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * This function copies parts of a framebuffer to display memory. Destination and
+ * framebuffer formats must match. No conversion takes place. The parameters @dst,
+ * @dst_pitch and @src refer to arrays. Each array must have at least as many entries
+ * as there are planes in @fb's format. Each entry stores the value for the format's
+ * respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ */
+void drm_fb_memcpy(struct iosys_map *dst, const unsigned int *dst_pitch,
+		   const struct iosys_map *src, const struct drm_framebuffer *fb,
+		   const struct drm_rect *clip)
+{
+	static const unsigned int default_dst_pitch[DRM_FORMAT_MAX_PLANES] = {
+		0, 0, 0, 0
+	};
+
+	const struct drm_format_info *format = fb->format;
+	unsigned int i, y, lines = drm_rect_height(clip);
+
+	if (!dst_pitch)
+		dst_pitch = default_dst_pitch;
+
+	for (i = 0; i < format->num_planes; ++i) {
+		unsigned int bpp_i = drm_format_info_bpp(format, i);
+		unsigned int cpp_i = DIV_ROUND_UP(bpp_i, 8);
+		size_t len_i = DIV_ROUND_UP(drm_rect_width(clip) * bpp_i, 8);
+		unsigned int dst_pitch_i = dst_pitch[i];
+		struct iosys_map dst_i = dst[i];
+		struct iosys_map src_i = src[i];
+
+		if (!dst_pitch_i)
+			dst_pitch_i = len_i;
+
+		iosys_map_incr(&src_i, clip_offset(clip, fb->pitches[i], cpp_i));
+		for (y = 0; y < lines; y++) {
+			/* TODO: handle src_i in I/O memory here */
+			iosys_map_memcpy_to(&dst_i, 0, src_i.vaddr, len_i);
+			iosys_map_incr(&src_i, fb->pitches[i]);
+			iosys_map_incr(&dst_i, dst_pitch_i);
+		}
+	}
+}
+EXPORT_SYMBOL(drm_fb_memcpy);
+
+static void drm_fb_swab16_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u16 *dbuf16 = dbuf;
+	const u16 *sbuf16 = sbuf;
+	const u16 *send16 = sbuf16 + pixels;
+
+	while (sbuf16 < send16)
+		*dbuf16++ = swab16(*sbuf16++);
+}
+
+static void drm_fb_swab32_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u32 *dbuf32 = dbuf;
+	const u32 *sbuf32 = sbuf;
+	const u32 *send32 = sbuf32 + pixels;
+
+	while (sbuf32 < send32)
+		*dbuf32++ = swab32(*sbuf32++);
+}
+
+/**
+ * drm_fb_swab - Swap bytes into clip buffer
+ * @dst: Array of destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ * @cached: Source buffer is mapped cached (eg. not write-combined)
+ *
+ * This function copies parts of a framebuffer to display memory and swaps per-pixel
+ * bytes during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index. If @cached is
+ * false a temporary buffer is used to cache one pixel line at a time to speed up
+ * slow uncached reads.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ */
+void drm_fb_swab(struct iosys_map *dst, const unsigned int *dst_pitch,
+		 const struct iosys_map *src, const struct drm_framebuffer *fb,
+		 const struct drm_rect *clip, bool cached)
+{
+	const struct drm_format_info *format = fb->format;
+	u8 cpp = DIV_ROUND_UP(drm_format_info_bpp(format, 0), 8);
+	void (*swab_line)(void *dbuf, const void *sbuf, unsigned int npixels);
+
+	switch (cpp) {
+	case 4:
+		swab_line = drm_fb_swab32_line;
+		break;
+	case 2:
+		swab_line = drm_fb_swab16_line;
+		break;
+	default:
+		drm_warn_once(fb->dev, "Format %p4cc has unsupported pixel size.\n",
+			      &format->format);
+		return;
+	}
+
+	drm_fb_xfrm(dst, dst_pitch, &cpp, src, fb, clip, cached, swab_line);
+}
+EXPORT_SYMBOL(drm_fb_swab);
+
+static void drm_fb_xrgb8888_to_rgb332_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u8 *dbuf8 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		dbuf8[x] = ((pix & 0x00e00000) >> 16) |
+			   ((pix & 0x0000e000) >> 11) |
+			   ((pix & 0x000000c0) >> 6);
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_rgb332 - Convert XRGB8888 to RGB332 clip buffer
+ * @dst: Array of RGB332 destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of XRGB8888 source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * Drivers can use this function for RGB332 devices that don't support XRGB8888 natively.
+ */
+void drm_fb_xrgb8888_to_rgb332(struct iosys_map *dst, const unsigned int *dst_pitch,
+			       const struct iosys_map *src, const struct drm_framebuffer *fb,
+			       const struct drm_rect *clip)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		1,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
+		    drm_fb_xrgb8888_to_rgb332_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb332);
+
+static void drm_fb_xrgb8888_to_rgb565_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u16 *dbuf16 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u16 val16;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		val16 = ((pix & 0x00F80000) >> 8) |
+			((pix & 0x0000FC00) >> 5) |
+			((pix & 0x000000F8) >> 3);
+		dbuf16[x] = val16;
+	}
+}
+
+static void drm_fb_xrgb8888_to_rgb565_swab_line(void *dbuf, const void *sbuf,
+						unsigned int pixels)
+{
+	u16 *dbuf16 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u16 val16;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		val16 = ((pix & 0x00F80000) >> 8) |
+			((pix & 0x0000FC00) >> 5) |
+			((pix & 0x000000F8) >> 3);
+		dbuf16[x] = swab16(val16);
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_rgb565 - Convert XRGB8888 to RGB565 clip buffer
+ * @dst: Array of RGB565 destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of XRGB8888 source buffer
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ * @swab: Swap bytes
+ *
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * Drivers can use this function for RGB565 devices that don't support XRGB8888 natively.
+ */
+void drm_fb_xrgb8888_to_rgb565(struct iosys_map *dst, const unsigned int *dst_pitch,
+			       const struct iosys_map *src, const struct drm_framebuffer *fb,
+			       const struct drm_rect *clip, bool swab)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		2,
+	};
+
+	void (*xfrm_line)(void *dbuf, const void *sbuf, unsigned int npixels);
+
+	if (swab)
+		xfrm_line = drm_fb_xrgb8888_to_rgb565_swab_line;
+	else
+		xfrm_line = drm_fb_xrgb8888_to_rgb565_line;
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false, xfrm_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565);
+
+static void drm_fb_xrgb8888_to_rgb888_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u8 *dbuf8 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		*dbuf8++ = (pix & 0x000000FF) >>  0;
+		*dbuf8++ = (pix & 0x0000FF00) >>  8;
+		*dbuf8++ = (pix & 0x00FF0000) >> 16;
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_rgb888 - Convert XRGB8888 to RGB888 clip buffer
+ * @dst: Array of RGB888 destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of XRGB8888 source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * Drivers can use this function for RGB888 devices that don't natively
+ * support XRGB8888.
+ */
+void drm_fb_xrgb8888_to_rgb888(struct iosys_map *dst, const unsigned int *dst_pitch,
+			       const struct iosys_map *src, const struct drm_framebuffer *fb,
+			       const struct drm_rect *clip)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		3,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
+		    drm_fb_xrgb8888_to_rgb888_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888);
+
+static void drm_fb_rgb565_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	__le32 *dbuf32 = dbuf;
+	const __le16 *sbuf16 = sbuf;
+	unsigned int x;
+
+	for (x = 0; x < pixels; x++) {
+		u16 val16 = le16_to_cpu(sbuf16[x]);
+		u32 val32 = ((val16 & 0xf800) << 8) |
+			    ((val16 & 0x07e0) << 5) |
+			    ((val16 & 0x001f) << 3);
+		val32 = 0xff000000 | val32 |
+			((val32 >> 3) & 0x00070007) |
+			((val32 >> 2) & 0x00000300);
+		dbuf32[x] = cpu_to_le32(val32);
+	}
+}
+
+static void drm_fb_rgb565_to_xrgb8888(struct iosys_map *dst, const unsigned int *dst_pitch,
+				      const struct iosys_map *src,
+				      const struct drm_framebuffer *fb,
+				      const struct drm_rect *clip)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		4,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
+		    drm_fb_rgb565_to_xrgb8888_line);
+}
+
+static void drm_fb_rgb888_to_xrgb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	__le32 *dbuf32 = dbuf;
+	const u8 *sbuf8 = sbuf;
+	unsigned int x;
+
+	for (x = 0; x < pixels; x++) {
+		u8 r = *sbuf8++;
+		u8 g = *sbuf8++;
+		u8 b = *sbuf8++;
+		u32 pix = 0xff000000 | (r << 16) | (g << 8) | b;
+		dbuf32[x] = cpu_to_le32(pix);
+	}
+}
+
+static void drm_fb_rgb888_to_xrgb8888(struct iosys_map *dst, const unsigned int *dst_pitch,
+				      const struct iosys_map *src,
+				      const struct drm_framebuffer *fb,
+				      const struct drm_rect *clip)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		4,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
+		    drm_fb_rgb888_to_xrgb8888_line);
+}
+
+static void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	__le32 *dbuf32 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+	u32 val32;
+	u32 pix;
+
+	for (x = 0; x < pixels; x++) {
+		pix = le32_to_cpu(sbuf32[x]);
+		val32 = ((pix & 0x000000FF) << 2) |
+			((pix & 0x0000FF00) << 4) |
+			((pix & 0x00FF0000) << 6);
+		pix = val32 | ((val32 >> 8) & 0x00300C03);
+		*dbuf32++ = cpu_to_le32(pix);
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_xrgb2101010 - Convert XRGB8888 to XRGB2101010 clip buffer
+ * @dst: Array of XRGB2101010 destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of XRGB8888 source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * Drivers can use this function for XRGB2101010 devices that don't support XRGB8888
+ * natively.
+ */
+void drm_fb_xrgb8888_to_xrgb2101010(struct iosys_map *dst, const unsigned int *dst_pitch,
+				    const struct iosys_map *src, const struct drm_framebuffer *fb,
+				    const struct drm_rect *clip)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		4,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
+		    drm_fb_xrgb8888_to_xrgb2101010_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010);
+
+static void drm_fb_xrgb8888_to_gray8_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u8 *dbuf8 = dbuf;
+	const __le32 *sbuf32 = sbuf;
+	unsigned int x;
+
+	for (x = 0; x < pixels; x++) {
+		u32 pix = le32_to_cpu(sbuf32[x]);
+		u8 r = (pix & 0x00ff0000) >> 16;
+		u8 g = (pix & 0x0000ff00) >> 8;
+		u8 b =  pix & 0x000000ff;
+
+		/* ITU BT.601: Y = 0.299 R + 0.587 G + 0.114 B */
+		*dbuf8++ = (3 * r + 6 * g + b) / 10;
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_gray8 - Convert XRGB8888 to grayscale
+ * @dst: Array of 8-bit grayscale destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of XRGB8888 source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * DRM doesn't have native monochrome or grayscale support. Drivers can use this
+ * function for grayscale devices that don't support XRGB8888 natively.Such
+ * drivers can announce the commonly supported XR24 format to userspace and use
+ * this function to convert to the native format. Monochrome drivers will use the
+ * most significant bit, where 1 means foreground color and 0 background color.
+ * ITU BT.601 is being used for the RGB -> luma (brightness) conversion.
+ */
+void drm_fb_xrgb8888_to_gray8(struct iosys_map *dst, const unsigned int *dst_pitch,
+			      const struct iosys_map *src, const struct drm_framebuffer *fb,
+			      const struct drm_rect *clip)
+{
+	static const u8 dst_pixsize[DRM_FORMAT_MAX_PLANES] = {
+		1,
+	};
+
+	drm_fb_xfrm(dst, dst_pitch, dst_pixsize, src, fb, clip, false,
+		    drm_fb_xrgb8888_to_gray8_line);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_gray8);
+
+/**
+ * drm_fb_blit - Copy parts of a framebuffer to display memory
+ * @dst:	Array of display-memory addresses to copy to
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @dst_format:	FOURCC code of the display's color format
+ * @src:	The framebuffer memory to copy from
+ * @fb:		The framebuffer to copy from
+ * @clip:	Clip rectangle area to copy
+ *
+ * This function copies parts of a framebuffer to display memory. If the
+ * formats of the display and the framebuffer mismatch, the blit function
+ * will attempt to convert between them during the process. The parameters @dst,
+ * @dst_pitch and @src refer to arrays. Each array must have at least as many
+ * entries as there are planes in @dst_format's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * Returns:
+ * 0 on success, or
+ * -EINVAL if the color-format conversion failed, or
+ * a negative error code otherwise.
+ */
+int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t dst_format,
+		const struct iosys_map *src, const struct drm_framebuffer *fb,
+		const struct drm_rect *clip)
+{
+	uint32_t fb_format = fb->format->format;
+
+	/* treat alpha channel like filler bits */
+	if (fb_format == DRM_FORMAT_ARGB8888)
+		fb_format = DRM_FORMAT_XRGB8888;
+	if (dst_format == DRM_FORMAT_ARGB8888)
+		dst_format = DRM_FORMAT_XRGB8888;
+	if (fb_format == DRM_FORMAT_ARGB2101010)
+		fb_format = DRM_FORMAT_XRGB2101010;
+	if (dst_format == DRM_FORMAT_ARGB2101010)
+		dst_format = DRM_FORMAT_XRGB2101010;
+
+	if (dst_format == fb_format) {
+		drm_fb_memcpy(dst, dst_pitch, src, fb, clip);
+		return 0;
+
+	} else if (dst_format == DRM_FORMAT_RGB565) {
+		if (fb_format == DRM_FORMAT_XRGB8888) {
+			drm_fb_xrgb8888_to_rgb565(dst, dst_pitch, src, fb, clip, false);
+			return 0;
+		}
+	} else if (dst_format == DRM_FORMAT_RGB888) {
+		if (fb_format == DRM_FORMAT_XRGB8888) {
+			drm_fb_xrgb8888_to_rgb888(dst, dst_pitch, src, fb, clip);
+			return 0;
+		}
+	} else if (dst_format == DRM_FORMAT_XRGB8888) {
+		if (fb_format == DRM_FORMAT_RGB888) {
+			drm_fb_rgb888_to_xrgb8888(dst, dst_pitch, src, fb, clip);
+			return 0;
+		} else if (fb_format == DRM_FORMAT_RGB565) {
+			drm_fb_rgb565_to_xrgb8888(dst, dst_pitch, src, fb, clip);
+			return 0;
+		}
+	} else if (dst_format == DRM_FORMAT_XRGB2101010) {
+		if (fb_format == DRM_FORMAT_XRGB8888) {
+			drm_fb_xrgb8888_to_xrgb2101010(dst, dst_pitch, src, fb, clip);
+			return 0;
+		}
+	}
+
+	drm_warn_once(fb->dev, "No conversion helper from %p4cc to %p4cc found.\n",
+		      &fb_format, &dst_format);
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(drm_fb_blit);
+
+static void drm_fb_gray8_to_mono_line(void *dbuf, const void *sbuf, unsigned int pixels)
+{
+	u8 *dbuf8 = dbuf;
+	const u8 *sbuf8 = sbuf;
+
+	while (pixels) {
+		unsigned int i, bits = min(pixels, 8U);
+		u8 byte = 0;
+
+		for (i = 0; i < bits; i++, pixels--) {
+			if (*sbuf8++ >= 128)
+				byte |= BIT(i);
+		}
+		*dbuf8++ = byte;
+	}
+}
+
+/**
+ * drm_fb_xrgb8888_to_mono - Convert XRGB8888 to monochrome
+ * @dst: Array of monochrome destination buffers (0=black, 1=white)
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @src: Array of XRGB8888 source buffers
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ *
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @src refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner). The first pixel (upper left corner of the clip rectangle) will
+ * be converted and copied to the first bit (LSB) in the first byte of the monochrome
+ * destination buffer. If the caller requires that the first pixel in a byte must
+ * be located at an x-coordinate that is a multiple of 8, then the caller must take
+ * care itself of supplying a suitable clip rectangle.
+ *
+ * DRM doesn't have native monochrome support. Drivers can use this function for
+ * monochrome devices that don't support XRGB8888 natively. Such drivers can
+ * announce the commonly supported XR24 format to userspace and use this function
+ * to convert to the native format.
+ *
+ * This function uses drm_fb_xrgb8888_to_gray8() to convert to grayscale and
+ * then the result is converted from grayscale to monochrome.
+ */
+void drm_fb_xrgb8888_to_mono(struct iosys_map *dst, const unsigned int *dst_pitch,
+			     const struct iosys_map *src, const struct drm_framebuffer *fb,
+			     const struct drm_rect *clip)
+{
+	static const unsigned int default_dst_pitch[DRM_FORMAT_MAX_PLANES] = {
+		0, 0, 0, 0
+	};
+	unsigned int linepixels = drm_rect_width(clip);
+	unsigned int lines = drm_rect_height(clip);
+	unsigned int cpp = fb->format->cpp[0];
+	unsigned int len_src32 = linepixels * cpp;
+	struct drm_device *dev = fb->dev;
+	void *vaddr = src[0].vaddr;
+	unsigned int dst_pitch_0;
+	unsigned int y;
+	u8 *mono = dst[0].vaddr, *gray8;
+	u32 *src32;
+
+	if (drm_WARN_ON(dev, fb->format->format != DRM_FORMAT_XRGB8888))
+		return;
+
+	if (!dst_pitch)
+		dst_pitch = default_dst_pitch;
+	dst_pitch_0 = dst_pitch[0];
+
+	/*
+	 * The mono destination buffer contains 1 bit per pixel
+	 */
+	if (!dst_pitch_0)
+		dst_pitch_0 = DIV_ROUND_UP(linepixels, 8);
+
+	/*
+	 * The dma memory is write-combined so reads are uncached.
+	 * Speed up by fetching one line at a time.
+	 *
+	 * Also, format conversion from XR24 to monochrome are done
+	 * line-by-line but are converted to 8-bit grayscale as an
+	 * intermediate step.
+	 *
+	 * Allocate a buffer to be used for both copying from the cma
+	 * memory and to store the intermediate grayscale line pixels.
+	 */
+	src32 = kmalloc(len_src32 + linepixels, GFP_KERNEL);
+	if (!src32)
+		return;
+
+	gray8 = (u8 *)src32 + len_src32;
+
+	vaddr += clip_offset(clip, fb->pitches[0], cpp);
+	for (y = 0; y < lines; y++) {
+		src32 = memcpy(src32, vaddr, len_src32);
+		drm_fb_xrgb8888_to_gray8_line(gray8, src32, linepixels);
+		drm_fb_gray8_to_mono_line(mono, gray8, linepixels);
+		vaddr += fb->pitches[0];
+		mono += dst_pitch_0;
+	}
+
+	kfree(src32);
+}
+EXPORT_SYMBOL(drm_fb_xrgb8888_to_mono);
+
+static bool is_listed_fourcc(const uint32_t *fourccs, size_t nfourccs, uint32_t fourcc)
+{
+	const uint32_t *fourccs_end = fourccs + nfourccs;
+
+	while (fourccs < fourccs_end) {
+		if (*fourccs == fourcc)
+			return true;
+		++fourccs;
+	}
+	return false;
+}
+
+static const uint32_t conv_from_xrgb8888[] = {
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ARGB8888,
+	DRM_FORMAT_XRGB2101010,
+	DRM_FORMAT_ARGB2101010,
+	DRM_FORMAT_RGB565,
+	DRM_FORMAT_RGB888,
+};
+
+static const uint32_t conv_from_rgb565_888[] = {
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ARGB8888,
+};
+
+static bool is_conversion_supported(uint32_t from, uint32_t to)
+{
+	switch (from) {
+	case DRM_FORMAT_XRGB8888:
+	case DRM_FORMAT_ARGB8888:
+		return is_listed_fourcc(conv_from_xrgb8888, ARRAY_SIZE(conv_from_xrgb8888), to);
+	case DRM_FORMAT_RGB565:
+	case DRM_FORMAT_RGB888:
+		return is_listed_fourcc(conv_from_rgb565_888, ARRAY_SIZE(conv_from_rgb565_888), to);
+	case DRM_FORMAT_XRGB2101010:
+		return to == DRM_FORMAT_ARGB2101010;
+	case DRM_FORMAT_ARGB2101010:
+		return to == DRM_FORMAT_XRGB2101010;
+	default:
+		return false;
+	}
+}
+
+/**
+ * drm_fb_build_fourcc_list - Filters a list of supported color formats against
+ *                            the device's native formats
+ * @dev: DRM device
+ * @native_fourccs: 4CC codes of natively supported color formats
+ * @native_nfourccs: The number of entries in @native_fourccs
+ * @driver_fourccs: 4CC codes of all driver-supported color formats
+ * @driver_nfourccs: The number of entries in @driver_fourccs
+ * @fourccs_out: Returns 4CC codes of supported color formats
+ * @nfourccs_out: The number of available entries in @fourccs_out
+ *
+ * This function create a list of supported color format from natively
+ * supported formats and the emulated formats.
+ * At a minimum, most userspace programs expect at least support for
+ * XRGB8888 on the primary plane. Devices that have to emulate the
+ * format, and possibly others, can use drm_fb_build_fourcc_list() to
+ * create a list of supported color formats. The returned list can
+ * be handed over to drm_universal_plane_init() et al. Native formats
+ * will go before emulated formats. Other heuristics might be applied
+ * to optimize the order. Formats near the beginning of the list are
+ * usually preferred over formats near the end of the list. Formats
+ * without conversion helpers will be skipped. New drivers should only
+ * pass in XRGB8888 and avoid exposing additional emulated formats.
+ *
+ * Returns:
+ * The number of color-formats 4CC codes returned in @fourccs_out.
+ */
+size_t drm_fb_build_fourcc_list(struct drm_device *dev,
+				const u32 *native_fourccs, size_t native_nfourccs,
+				const u32 *driver_fourccs, size_t driver_nfourccs,
+				u32 *fourccs_out, size_t nfourccs_out)
+{
+	u32 *fourccs = fourccs_out;
+	const u32 *fourccs_end = fourccs_out + nfourccs_out;
+	uint32_t native_format = 0;
+	size_t i;
+
+	/*
+	 * The device's native formats go first.
+	 */
+
+	for (i = 0; i < native_nfourccs; ++i) {
+		u32 fourcc = native_fourccs[i];
+
+		if (is_listed_fourcc(fourccs_out, fourccs - fourccs_out, fourcc)) {
+			continue; /* skip duplicate entries */
+		} else if (fourccs == fourccs_end) {
+			drm_warn(dev, "Ignoring native format %p4cc\n", &fourcc);
+			continue; /* end of available output buffer */
+		}
+
+		drm_dbg_kms(dev, "adding native format %p4cc\n", &fourcc);
+
+		/*
+		 * There should only be one native format with the current API.
+		 * This API needs to be refactored to correctly support arbitrary
+		 * sets of native formats, since it needs to report which native
+		 * format to use for each emulated format.
+		 */
+		if (!native_format)
+			native_format = fourcc;
+		*fourccs = fourcc;
+		++fourccs;
+	}
+
+	/*
+	 * The extra formats, emulated by the driver, go second.
+	 */
+
+	for (i = 0; (i < driver_nfourccs) && (fourccs < fourccs_end); ++i) {
+		u32 fourcc = driver_fourccs[i];
+
+		if (is_listed_fourcc(fourccs_out, fourccs - fourccs_out, fourcc)) {
+			continue; /* skip duplicate and native entries */
+		} else if (fourccs == fourccs_end) {
+			drm_warn(dev, "Ignoring emulated format %p4cc\n", &fourcc);
+			continue; /* end of available output buffer */
+		} else if (!is_conversion_supported(fourcc, native_format)) {
+			drm_dbg_kms(dev, "Unsupported emulated format %p4cc\n", &fourcc);
+			continue; /* format is not supported for conversion */
+		}
+
+		drm_dbg_kms(dev, "adding emulated format %p4cc\n", &fourcc);
+
+		*fourccs = fourcc;
+		++fourccs;
+	}
+
+	return fourccs - fourccs_out;
+}
+EXPORT_SYMBOL(drm_fb_build_fourcc_list);