linux/drivers/video/fb_draw.h
Benjamin Herrenschmidt 3f6a558046 fbdev: Make pixel_to_pat() failure mode more friendly
If we accidentally pass an incorrect bpp value to pixel_to_pat(),
it panics. This is pretty useless, as we generally have the various
console locks held at that point, so nothing will be displayed,
and there is no reason to make this a fatal event.

Let's WARN instead.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
2012-07-29 12:25:06 +00:00

186 lines
4.4 KiB
C

#ifndef _FB_DRAW_H
#define _FB_DRAW_H
#include <asm/types.h>
#include <linux/fb.h>
#include <linux/bug.h>
/*
* Compose two values, using a bitmask as decision value
* This is equivalent to (a & mask) | (b & ~mask)
*/
static inline unsigned long
comp(unsigned long a, unsigned long b, unsigned long mask)
{
return ((a ^ b) & mask) ^ b;
}
/*
* Create a pattern with the given pixel's color
*/
#if BITS_PER_LONG == 64
static inline unsigned long
pixel_to_pat( u32 bpp, u32 pixel)
{
switch (bpp) {
case 1:
return 0xfffffffffffffffful*pixel;
case 2:
return 0x5555555555555555ul*pixel;
case 4:
return 0x1111111111111111ul*pixel;
case 8:
return 0x0101010101010101ul*pixel;
case 12:
return 0x1001001001001001ul*pixel;
case 16:
return 0x0001000100010001ul*pixel;
case 24:
return 0x0001000001000001ul*pixel;
case 32:
return 0x0000000100000001ul*pixel;
default:
WARN(1, "pixel_to_pat(): unsupported pixelformat %d\n", bpp);
return 0;
}
}
#else
static inline unsigned long
pixel_to_pat( u32 bpp, u32 pixel)
{
switch (bpp) {
case 1:
return 0xfffffffful*pixel;
case 2:
return 0x55555555ul*pixel;
case 4:
return 0x11111111ul*pixel;
case 8:
return 0x01010101ul*pixel;
case 12:
return 0x01001001ul*pixel;
case 16:
return 0x00010001ul*pixel;
case 24:
return 0x01000001ul*pixel;
case 32:
return 0x00000001ul*pixel;
default:
WARN(1, "pixel_to_pat(): unsupported pixelformat %d\n", bpp);
return 0;
}
}
#endif
#ifdef CONFIG_FB_CFB_REV_PIXELS_IN_BYTE
#if BITS_PER_LONG == 64
#define REV_PIXELS_MASK1 0x5555555555555555ul
#define REV_PIXELS_MASK2 0x3333333333333333ul
#define REV_PIXELS_MASK4 0x0f0f0f0f0f0f0f0ful
#else
#define REV_PIXELS_MASK1 0x55555555ul
#define REV_PIXELS_MASK2 0x33333333ul
#define REV_PIXELS_MASK4 0x0f0f0f0ful
#endif
static inline unsigned long fb_rev_pixels_in_long(unsigned long val,
u32 bswapmask)
{
if (bswapmask & 1)
val = comp(val >> 1, val << 1, REV_PIXELS_MASK1);
if (bswapmask & 2)
val = comp(val >> 2, val << 2, REV_PIXELS_MASK2);
if (bswapmask & 3)
val = comp(val >> 4, val << 4, REV_PIXELS_MASK4);
return val;
}
static inline u32 fb_shifted_pixels_mask_u32(struct fb_info *p, u32 index,
u32 bswapmask)
{
u32 mask;
if (!bswapmask) {
mask = FB_SHIFT_HIGH(p, ~(u32)0, index);
} else {
mask = 0xff << FB_LEFT_POS(p, 8);
mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
#if defined(__i386__) || defined(__x86_64__)
/* Shift argument is limited to 0 - 31 on x86 based CPU's */
if(index + bswapmask < 32)
#endif
mask |= FB_SHIFT_HIGH(p, ~(u32)0,
(index + bswapmask) & ~(bswapmask));
}
return mask;
}
static inline unsigned long fb_shifted_pixels_mask_long(struct fb_info *p,
u32 index,
u32 bswapmask)
{
unsigned long mask;
if (!bswapmask) {
mask = FB_SHIFT_HIGH(p, ~0UL, index);
} else {
mask = 0xff << FB_LEFT_POS(p, 8);
mask = FB_SHIFT_LOW(p, mask, index & (bswapmask)) & mask;
mask = FB_SHIFT_HIGH(p, mask, index & ~(bswapmask));
#if defined(__i386__) || defined(__x86_64__)
/* Shift argument is limited to 0 - 31 on x86 based CPU's */
if(index + bswapmask < BITS_PER_LONG)
#endif
mask |= FB_SHIFT_HIGH(p, ~0UL,
(index + bswapmask) & ~(bswapmask));
}
return mask;
}
static inline u32 fb_compute_bswapmask(struct fb_info *info)
{
u32 bswapmask = 0;
unsigned bpp = info->var.bits_per_pixel;
if ((bpp < 8) && (info->var.nonstd & FB_NONSTD_REV_PIX_IN_B)) {
/*
* Reversed order of pixel layout in bytes
* works only for 1, 2 and 4 bpp
*/
bswapmask = 7 - bpp + 1;
}
return bswapmask;
}
#else /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
static inline unsigned long fb_rev_pixels_in_long(unsigned long val,
u32 bswapmask)
{
return val;
}
#define fb_shifted_pixels_mask_u32(p, i, b) FB_SHIFT_HIGH((p), ~(u32)0, (i))
#define fb_shifted_pixels_mask_long(p, i, b) FB_SHIFT_HIGH((p), ~0UL, (i))
#define fb_compute_bswapmask(...) 0
#endif /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */
#define cpu_to_le_long _cpu_to_le_long(BITS_PER_LONG)
#define _cpu_to_le_long(x) __cpu_to_le_long(x)
#define __cpu_to_le_long(x) cpu_to_le##x
#define le_long_to_cpu _le_long_to_cpu(BITS_PER_LONG)
#define _le_long_to_cpu(x) __le_long_to_cpu(x)
#define __le_long_to_cpu(x) le##x##_to_cpu
static inline unsigned long rolx(unsigned long word, unsigned int shift, unsigned int x)
{
return (word << shift) | (word >> (x - shift));
}
#endif /* FB_DRAW_H */