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fbsplash: support non-RGB565 pixels in 16-bit mode

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function                                             old     new   delta
fbsplash_main                                        953     989     +36
fb_pixel_value                                        80     110     +30

Signed-off-by: Linus Walleij <triad@df.lth.se>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Linus Walleij 2012-09-06 16:52:31 +02:00 committed by Denys Vlasenko
parent 2dc1a97272
commit 6d463de46b
1 changed files with 22 additions and 5 deletions
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27
miscutils/fbsplash.c
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@ -50,6 +50,10 @@ struct globals {
struct fb_var_screeninfo scr_var; struct fb_var_screeninfo scr_var;
struct fb_fix_screeninfo scr_fix; struct fb_fix_screeninfo scr_fix;
unsigned bytes_per_pixel; unsigned bytes_per_pixel;
// cached (8 - scr_var.COLOR.length):
unsigned red_shift;
unsigned green_shift;
unsigned blue_shift;
}; };
#define G (*ptr_to_globals) #define G (*ptr_to_globals)
#define INIT_G() do { \ #define INIT_G() do { \
@ -139,6 +143,9 @@ static void fb_open(const char *strfb_device)
break; break;
} }
G.red_shift = 8 - G.scr_var.red.length;
G.green_shift = 8 - G.scr_var.green.length;
G.blue_shift = 8 - G.scr_var.blue.length;
G.bytes_per_pixel = (G.scr_var.bits_per_pixel + 7) >> 3; G.bytes_per_pixel = (G.scr_var.bits_per_pixel + 7) >> 3;
// map the device in memory // map the device in memory
@ -155,10 +162,13 @@ static void fb_open(const char *strfb_device)
/** /**
* Return pixel value of the passed RGB color * Return pixel value of the passed RGB color.
* This is performance critical fn.
*/ */
static unsigned fb_pixel_value(unsigned r, unsigned g, unsigned b) static unsigned fb_pixel_value(unsigned r, unsigned g, unsigned b)
{ {
/* We assume that the r,g,b values are <= 255 */
if (G.bytes_per_pixel == 1) { if (G.bytes_per_pixel == 1) {
r = r & 0xe0; // 3-bit red r = r & 0xe0; // 3-bit red
g = (g >> 3) & 0x1c; // 3-bit green g = (g >> 3) & 0x1c; // 3-bit green
@ -166,10 +176,17 @@ static unsigned fb_pixel_value(unsigned r, unsigned g, unsigned b)
return r + g + b; return r + g + b;
} }
if (G.bytes_per_pixel == 2) { if (G.bytes_per_pixel == 2) {
r = (r & 0xf8) << 8; // 5-bit red // ARM PL110 on Integrator/CP has RGBA5551 bit arrangement.
g = (g & 0xfc) << 3; // 6-bit green // We want to support bit locations like that.
b = b >> 3; // 5-bit blue //
return r + g + b; // First shift out unused bits
r = r >> G.red_shift;
g = g >> G.green_shift;
b = b >> G.blue_shift;
// Then shift the remaining bits to their offset
return (r << G.scr_var.red.offset) +
(g << G.scr_var.green.offset) +
(b << G.scr_var.blue.offset);
} }
// RGB 888 // RGB 888
return b + (g << 8) + (r << 16); return b + (g << 8) + (r << 16);