linux/drivers/video/fbdev/core/fb_logo.c

// SPDX-License-Identifier: GPL-2.0

#include <linux/fb.h>
#include <linux/linux_logo.h>

#include "fb_internal.h"

bool fb_center_logo __read_mostly;
int fb_logo_count __read_mostly = …;

static inline unsigned int safe_shift(unsigned int d, int n)
{ … }

static void fb_set_logocmap(struct fb_info *info,
				   const struct linux_logo *logo)
{ … }

static void  fb_set_logo_truepalette(struct fb_info *info,
					    const struct linux_logo *logo,
					    u32 *palette)
{ … }

static void fb_set_logo_directpalette(struct fb_info *info,
					     const struct linux_logo *logo,
					     u32 *palette)
{ … }

static void fb_set_logo(struct fb_info *info,
			       const struct linux_logo *logo, u8 *dst,
			       int depth)
{ … }

/*
 * Three (3) kinds of logo maps exist.  linux_logo_clut224 (>16 colors),
 * linux_logo_vga16 (16 colors) and linux_logo_mono (2 colors).  Depending on
 * the visual format and color depth of the framebuffer, the DAC, the
 * pseudo_palette, and the logo data will be adjusted accordingly.
 *
 * Case 1 - linux_logo_clut224:
 * Color exceeds the number of console colors (16), thus we set the hardware DAC
 * using fb_set_cmap() appropriately.  The "needs_cmapreset"  flag will be set.
 *
 * For visuals that require color info from the pseudo_palette, we also construct
 * one for temporary use. The "needs_directpalette" or "needs_truepalette" flags
 * will be set.
 *
 * Case 2 - linux_logo_vga16:
 * The number of colors just matches the console colors, thus there is no need
 * to set the DAC or the pseudo_palette.  However, the bitmap is packed, ie,
 * each byte contains color information for two pixels (upper and lower nibble).
 * To be consistent with fb_imageblit() usage, we therefore separate the two
 * nibbles into separate bytes. The "depth" flag will be set to 4.
 *
 * Case 3 - linux_logo_mono:
 * This is similar with Case 2.  Each byte contains information for 8 pixels.
 * We isolate each bit and expand each into a byte. The "depth" flag will
 * be set to 1.
 */
static struct logo_data { … } fb_logo __read_mostly;

static void fb_rotate_logo_ud(const u8 *in, u8 *out, u32 width, u32 height)
{ … }

static void fb_rotate_logo_cw(const u8 *in, u8 *out, u32 width, u32 height)
{ … }

static void fb_rotate_logo_ccw(const u8 *in, u8 *out, u32 width, u32 height)
{ … }

static void fb_rotate_logo(struct fb_info *info, u8 *dst,
			   struct fb_image *image, int rotate)
{ … }

static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
			    int rotate, unsigned int num)
{ … }

static int fb_show_logo_line(struct fb_info *info, int rotate,
			     const struct linux_logo *logo, int y,
			     unsigned int n)
{ … }

#ifdef CONFIG_FB_LOGO_EXTRA

#define FB_LOGO_EX_NUM_MAX …
static struct logo_data_extra {
	const struct linux_logo *logo;
	unsigned int n;
} fb_logo_ex[FB_LOGO_EX_NUM_MAX];
static unsigned int fb_logo_ex_num;

void fb_append_extra_logo(const struct linux_logo *logo, unsigned int n)
{
	if (!n || fb_logo_ex_num == FB_LOGO_EX_NUM_MAX)
		return;

	fb_logo_ex[fb_logo_ex_num].logo = logo;
	fb_logo_ex[fb_logo_ex_num].n = n;
	fb_logo_ex_num++;
}

static int fb_prepare_extra_logos(struct fb_info *info, unsigned int height,
				  unsigned int yres)
{
	unsigned int i;

	/* FIXME: logo_ex supports only truecolor fb. */
	if (info->fix.visual != FB_VISUAL_TRUECOLOR)
		fb_logo_ex_num = 0;

	for (i = 0; i < fb_logo_ex_num; i++) {
		if (fb_logo_ex[i].logo->type != fb_logo.logo->type) {
			fb_logo_ex[i].logo = NULL;
			continue;
		}
		height += fb_logo_ex[i].logo->height;
		if (height > yres) {
			height -= fb_logo_ex[i].logo->height;
			fb_logo_ex_num = i;
			break;
		}
	}
	return height;
}

static int fb_show_extra_logos(struct fb_info *info, int y, int rotate)
{
	unsigned int i;

	for (i = 0; i < fb_logo_ex_num; i++)
		y = fb_show_logo_line(info, rotate,
				      fb_logo_ex[i].logo, y, fb_logo_ex[i].n);

	return y;
}
#endif /* CONFIG_FB_LOGO_EXTRA */

int fb_prepare_logo(struct fb_info *info, int rotate)
{ … }

int fb_show_logo(struct fb_info *info, int rotate)
{ … }