u-boot-brain/drivers/video/video-uclass.c
Simon Glass 9beac5daf7 video: Add support for copying to a hardware framebuffer
Some architectures use a cached framebuffer and flush the cache as needed
so that changes are visible. This is supported by U-Boot.

However x86 uses an uncached framebuffer with a 'write-combining' feature
to speed up writes.  Reads are permitted but they are extremely expensive.

Unfortunately, reading from the frame buffer is quite common, e.g. to
scroll it. This makes scrolling very slow.

Add a new feature which supports copying modified parts of the frame
buffer to the uncached hardware buffer. This speeds up scrolling by at
least 10x on x86 so the extra complexity cost seems worth it.

As a starting point, add the Kconfig, update the video structures to keep
track of the buffer and add a function to do the copy.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-09 12:33:24 +08:00

380 lines
9.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2015 Google, Inc
*/
#include <common.h>
#include <console.h>
#include <cpu_func.h>
#include <dm.h>
#include <log.h>
#include <malloc.h>
#include <mapmem.h>
#include <stdio_dev.h>
#include <video.h>
#include <video_console.h>
#include <asm/cache.h>
#include <dm/lists.h>
#include <dm/device-internal.h>
#include <dm/uclass-internal.h>
#ifdef CONFIG_SANDBOX
#include <asm/sdl.h>
#endif
/*
* Theory of operation:
*
* Before relocation each device is bound. The driver for each device must
* set the @align and @size values in struct video_uc_platdata. This
* information represents the requires size and alignment of the frame buffer
* for the device. The values can be an over-estimate but cannot be too
* small. The actual values will be suppled (in the same manner) by the bind()
* method after relocation.
*
* This information is then picked up by video_reserve() which works out how
* much memory is needed for all devices. This is allocated between
* gd->video_bottom and gd->video_top.
*
* After relocation the same process occurs. The driver supplies the same
* @size and @align information and this time video_post_bind() checks that
* the drivers does not overflow the allocated memory.
*
* The frame buffer address is actually set (to plat->base) in
* video_post_probe(). This function also clears the frame buffer and
* allocates a suitable text console device. This can then be used to write
* text to the video device.
*/
DECLARE_GLOBAL_DATA_PTR;
void video_set_flush_dcache(struct udevice *dev, bool flush)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
priv->flush_dcache = flush;
}
static ulong alloc_fb(struct udevice *dev, ulong *addrp)
{
struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
ulong base, align, size;
if (!plat->size)
return 0;
align = plat->align ? plat->align : 1 << 20;
base = *addrp - plat->size;
base &= ~(align - 1);
plat->base = base;
size = *addrp - base;
*addrp = base;
return size;
}
int video_reserve(ulong *addrp)
{
struct udevice *dev;
ulong size;
gd->video_top = *addrp;
for (uclass_find_first_device(UCLASS_VIDEO, &dev);
dev;
uclass_find_next_device(&dev)) {
size = alloc_fb(dev, addrp);
debug("%s: Reserving %lx bytes at %lx for video device '%s'\n",
__func__, size, *addrp, dev->name);
}
gd->video_bottom = *addrp;
gd->fb_base = *addrp;
debug("Video frame buffers from %lx to %lx\n", gd->video_bottom,
gd->video_top);
return 0;
}
int video_clear(struct udevice *dev)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
switch (priv->bpix) {
case VIDEO_BPP16:
if (IS_ENABLED(CONFIG_VIDEO_BPP16)) {
u16 *ppix = priv->fb;
u16 *end = priv->fb + priv->fb_size;
while (ppix < end)
*ppix++ = priv->colour_bg;
break;
}
case VIDEO_BPP32:
if (IS_ENABLED(CONFIG_VIDEO_BPP32)) {
u32 *ppix = priv->fb;
u32 *end = priv->fb + priv->fb_size;
while (ppix < end)
*ppix++ = priv->colour_bg;
break;
}
default:
memset(priv->fb, priv->colour_bg, priv->fb_size);
break;
}
return 0;
}
void video_set_default_colors(struct udevice *dev, bool invert)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
int fore, back;
if (CONFIG_IS_ENABLED(SYS_WHITE_ON_BLACK)) {
/* White is used when switching to bold, use light gray here */
fore = VID_LIGHT_GRAY;
back = VID_BLACK;
} else {
fore = VID_BLACK;
back = VID_WHITE;
}
if (invert) {
int temp;
temp = fore;
fore = back;
back = temp;
}
priv->fg_col_idx = fore;
priv->bg_col_idx = back;
priv->colour_fg = vid_console_color(priv, fore);
priv->colour_bg = vid_console_color(priv, back);
}
/* Flush video activity to the caches */
void video_sync(struct udevice *vid, bool force)
{
/*
* flush_dcache_range() is declared in common.h but it seems that some
* architectures do not actually implement it. Is there a way to find
* out whether it exists? For now, ARM is safe.
*/
#if defined(CONFIG_ARM) && !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
struct video_priv *priv = dev_get_uclass_priv(vid);
if (priv->flush_dcache) {
flush_dcache_range((ulong)priv->fb,
ALIGN((ulong)priv->fb + priv->fb_size,
CONFIG_SYS_CACHELINE_SIZE));
}
#elif defined(CONFIG_VIDEO_SANDBOX_SDL)
struct video_priv *priv = dev_get_uclass_priv(vid);
static ulong last_sync;
if (force || get_timer(last_sync) > 10) {
sandbox_sdl_sync(priv->fb);
last_sync = get_timer(0);
}
#endif
}
void video_sync_all(void)
{
struct udevice *dev;
for (uclass_find_first_device(UCLASS_VIDEO, &dev);
dev;
uclass_find_next_device(&dev)) {
if (device_active(dev))
video_sync(dev, true);
}
}
int video_get_xsize(struct udevice *dev)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
return priv->xsize;
}
int video_get_ysize(struct udevice *dev)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
return priv->ysize;
}
#ifdef CONFIG_VIDEO_COPY
int video_sync_copy(struct udevice *dev, void *from, void *to)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
if (priv->copy_fb) {
long offset, size;
/* Find the offset of the first byte to copy */
if ((ulong)to > (ulong)from) {
size = to - from;
offset = from - priv->fb;
} else {
size = from - to;
offset = to - priv->fb;
}
/*
* Allow a bit of leeway for valid requests somewhere near the
* frame buffer
*/
if (offset < -priv->fb_size || offset > 2 * priv->fb_size) {
#ifdef DEBUG
char str[80];
snprintf(str, sizeof(str),
"[sync_copy fb=%p, from=%p, to=%p, offset=%lx]",
priv->fb, from, to, offset);
console_puts_select_stderr(true, str);
#endif
return -EFAULT;
}
/*
* Silently crop the memcpy. This allows callers to avoid doing
* this themselves. It is common for the end pointer to go a
* few lines after the end of the frame buffer, since most of
* the update algorithms terminate a line after their last write
*/
if (offset + size > priv->fb_size) {
size = priv->fb_size - offset;
} else if (offset < 0) {
size += offset;
offset = 0;
}
memcpy(priv->copy_fb + offset, priv->fb + offset, size);
}
return 0;
}
#endif
/* Set up the colour map */
static int video_pre_probe(struct udevice *dev)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
priv->cmap = calloc(256, sizeof(ushort));
if (!priv->cmap)
return -ENOMEM;
return 0;
}
static int video_pre_remove(struct udevice *dev)
{
struct video_priv *priv = dev_get_uclass_priv(dev);
free(priv->cmap);
return 0;
}
/* Set up the display ready for use */
static int video_post_probe(struct udevice *dev)
{
struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
struct video_priv *priv = dev_get_uclass_priv(dev);
char name[30], drv[15], *str;
const char *drv_name = drv;
struct udevice *cons;
int ret;
/* Set up the line and display size */
priv->fb = map_sysmem(plat->base, plat->size);
if (!priv->line_length)
priv->line_length = priv->xsize * VNBYTES(priv->bpix);
priv->fb_size = priv->line_length * priv->ysize;
/* Set up colors */
video_set_default_colors(dev, false);
if (!CONFIG_IS_ENABLED(NO_FB_CLEAR))
video_clear(dev);
/*
* Create a text console device. For now we always do this, although
* it might be useful to support only bitmap drawing on the device
* for boards that don't need to display text. We create a TrueType
* console if enabled, a rotated console if the video driver requests
* it, otherwise a normal console.
*
* The console can be override by setting vidconsole_drv_name before
* probing this video driver, or in the probe() method.
*
* TrueType does not support rotation at present so fall back to the
* rotated console in that case.
*/
if (!priv->rot && IS_ENABLED(CONFIG_CONSOLE_TRUETYPE)) {
snprintf(name, sizeof(name), "%s.vidconsole_tt", dev->name);
strcpy(drv, "vidconsole_tt");
} else {
snprintf(name, sizeof(name), "%s.vidconsole%d", dev->name,
priv->rot);
snprintf(drv, sizeof(drv), "vidconsole%d", priv->rot);
}
str = strdup(name);
if (!str)
return -ENOMEM;
if (priv->vidconsole_drv_name)
drv_name = priv->vidconsole_drv_name;
ret = device_bind_driver(dev, drv_name, str, &cons);
if (ret) {
debug("%s: Cannot bind console driver\n", __func__);
return ret;
}
ret = device_probe(cons);
if (ret) {
debug("%s: Cannot probe console driver\n", __func__);
return ret;
}
return 0;
};
/* Post-relocation, allocate memory for the frame buffer */
static int video_post_bind(struct udevice *dev)
{
ulong addr = gd->video_top;
ulong size;
/* Before relocation there is nothing to do here */
if (!(gd->flags & GD_FLG_RELOC))
return 0;
size = alloc_fb(dev, &addr);
if (addr < gd->video_bottom) {
/* Device tree node may need the 'u-boot,dm-pre-reloc' or
* 'u-boot,dm-pre-proper' tag
*/
printf("Video device '%s' cannot allocate frame buffer memory -ensure the device is set up before relocation\n",
dev->name);
return -ENOSPC;
}
debug("%s: Claiming %lx bytes at %lx for video device '%s'\n",
__func__, size, addr, dev->name);
gd->video_bottom = addr;
return 0;
}
UCLASS_DRIVER(video) = {
.id = UCLASS_VIDEO,
.name = "video",
.flags = DM_UC_FLAG_SEQ_ALIAS,
.post_bind = video_post_bind,
.pre_probe = video_pre_probe,
.post_probe = video_post_probe,
.pre_remove = video_pre_remove,
.per_device_auto_alloc_size = sizeof(struct video_priv),
.per_device_platdata_auto_alloc_size = sizeof(struct video_uc_platdata),
};