fbmem.c

/*
 *  linux/drivers/video/fbmem.c
 *
 *  Copyright (C) 1994 Martin Schaller
 *
 *	2001 - Documented with DocBook
 *	- Brad Douglas <brad@neruo.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/module.h>

#include <linux/compat.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/vt.h>
#include <linux/init.h>
#include <linux/linux_logo.h>
#include <linux/proc_fs.h>
#include <linux/console.h>
#ifdef CONFIG_KMOD
#include <linux/kmod.h>
#endif
#include <linux/err.h>
#include <linux/device.h>
#include <linux/efi.h>

#if defined(__mc68000__) || defined(CONFIG_APUS)
#include <asm/setup.h>
#endif

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>

#include <linux/fb.h>

    /*
     *  Frame buffer device initialization and setup routines
     */

#define FBPIXMAPSIZE	(1024 * 8)

struct fb_info *registered_fb[FB_MAX];
int num_registered_fb;

/*
 * Helpers
 */

int fb_get_color_depth(struct fb_var_screeninfo *var,
		       struct fb_fix_screeninfo *fix)
{
	int depth = 0;

	if (fix->visual == FB_VISUAL_MONO01 ||
	    fix->visual == FB_VISUAL_MONO10)
		depth = 1;
	else {
		if (var->green.length == var->blue.length &&
		    var->green.length == var->red.length &&
		    var->green.offset == var->blue.offset &&
		    var->green.offset == var->red.offset)
			depth = var->green.length;
		else
			depth = var->green.length + var->red.length +
				var->blue.length;
	}

	return depth;
}
EXPORT_SYMBOL(fb_get_color_depth);

/*
 * Data padding functions.
 */
void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 s_pitch, u32 height)
{
	__fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, height);
}
EXPORT_SYMBOL(fb_pad_aligned_buffer);

void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx, u32 height,
				u32 shift_high, u32 shift_low, u32 mod)
{
	u8 mask = (u8) (0xfff << shift_high), tmp;
	int i, j;

	for (i = height; i--; ) {
		for (j = 0; j < idx; j++) {
			tmp = dst[j];
			tmp &= mask;
			tmp |= *src >> shift_low;
			dst[j] = tmp;
			tmp = *src << shift_high;
			dst[j+1] = tmp;
			src++;
		}
		tmp = dst[idx];
		tmp &= mask;
		tmp |= *src >> shift_low;
		dst[idx] = tmp;
		if (shift_high < mod) {
			tmp = *src << shift_high;
			dst[idx+1] = tmp;
		}
		src++;
		dst += d_pitch;
	}
}
EXPORT_SYMBOL(fb_pad_unaligned_buffer);

/*
 * we need to lock this section since fb_cursor
 * may use fb_imageblit()
 */
char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size)
{
	u32 align = buf->buf_align - 1, offset;
	char *addr = buf->addr;

	/* If IO mapped, we need to sync before access, no sharing of
	 * the pixmap is done
	 */
	if (buf->flags & FB_PIXMAP_IO) {
		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
			info->fbops->fb_sync(info);
		return addr;
	}

	/* See if we fit in the remaining pixmap space */
	offset = buf->offset + align;
	offset &= ~align;
	if (offset + size > buf->size) {
		/* We do not fit. In order to be able to re-use the buffer,
		 * we must ensure no asynchronous DMA'ing or whatever operation
		 * is in progress, we sync for that.
		 */
		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
			info->fbops->fb_sync(info);
		offset = 0;
	}
	buf->offset = offset + size;
	addr += offset;

	return addr;
}

#ifdef CONFIG_LOGO

static inline unsigned safe_shift(unsigned d, int n)
{
	return n < 0 ? d >> -n : d << n;
}

static void fb_set_logocmap(struct fb_info *info,
				   const struct linux_logo *logo)
{
	struct fb_cmap palette_cmap;
	u16 palette_green[16];
	u16 palette_blue[16];
	u16 palette_red[16];
	int i, j, n;
	const unsigned char *clut = logo->clut;

	palette_cmap.start = 0;
	palette_cmap.len = 16;
	palette_cmap.red = palette_red;
	palette_cmap.green = palette_green;
	palette_cmap.blue = palette_blue;
	palette_cmap.transp = NULL;

	for (i = 0; i < logo->clutsize; i += n) {
		n = logo->clutsize - i;
		/* palette_cmap provides space for only 16 colors at once */
		if (n > 16)
			n = 16;
		palette_cmap.start = 32 + i;
		palette_cmap.len = n;
		for (j = 0; j < n; ++j) {
			palette_cmap.red[j] = clut[0] << 8 | clut[0];
			palette_cmap.green[j] = clut[1] << 8 | clut[1];
			palette_cmap.blue[j] = clut[2] << 8 | clut[2];
			clut += 3;
		}
		fb_set_cmap(&palette_cmap, info);
	}
}