[patch 3/6] fbdev: c2p - Cleanups

Geert Uytterhoeven
2008-12-21T15:02:00Z

[-- Attachment #1: c2p-prepare.diff --]
[-- Type: text/plain, Size: 6382 bytes --]

- Improve comments and naming
- Use void * for arbitrary pointers
- Use a union to represent pixels/words, to avoid casts

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
drivers/video/c2p.c | 80 +++++++++++++++++++++++++++-------------------------
drivers/video/c2p.h | 6 +--
2 files changed, 45 insertions(+), 41 deletions(-)

--- a/drivers/video/c2p.c
+++ b/drivers/video/c2p.c
@@ -54,7 +54,7 @@ static inline u32 get_mask(int n)
return 0;
}

-#define transp_nx1(d, n) \
+#define transp8_nx1(d, n) \
do { \
u32 mask = get_mask(n); \
/* First block */ \
@@ -67,7 +67,7 @@ static inline u32 get_mask(int n)
_transp(d, 6, 7, n, mask); \
} while (0)

-#define transp_nx2(d, n) \
+#define transp8_nx2(d, n) \
do { \
u32 mask = get_mask(n); \
/* First block */ \
@@ -78,40 +78,41 @@ static inline u32 get_mask(int n)
_transp(d, 5, 7, n, mask); \
} while (0)

-#define transp_nx4(d, n) \
+#define transp8_nx4(d, n) \
do { \
u32 mask = get_mask(n); \
+ /* Single block */ \
_transp(d, 0, 4, n, mask); \
_transp(d, 1, 5, n, mask); \
_transp(d, 2, 6, n, mask); \
_transp(d, 3, 7, n, mask); \
} while (0)

-#define transp(d, n, m) transp_nx ## m(d, n)
+#define transp8(d, n, m) transp8_nx ## m(d, n)

/*
* Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words
* containing
* - 32 8-bit chunky pixels on input
- * - permuted planar data on output
+ * - permutated planar data (1 plane per 32-bit word) on output
*/

-static void c2p_8bpp(u32 d[8])
+static void c2p_32x8(u32 d[8])
{
- transp(d, 16, 4);
- transp(d, 8, 2);
- transp(d, 4, 1);
- transp(d, 2, 4);
- transp(d, 1, 2);
+ transp8(d, 16, 4);
+ transp8(d, 8, 2);
+ transp8(d, 4, 1);
+ transp8(d, 2, 4);
+ transp8(d, 1, 2);
}

/*
- * Array containing the permution indices of the planar data after c2p
+ * Array containing the permutation indices of the planar data after c2p
*/

-static const int perm_c2p_8bpp[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };
+static const int perm_c2p_32x8[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };

/*
@@ -130,12 +131,12 @@ static inline unsigned long comp(unsigne
* Store a full block of planar data after c2p conversion
*/

-static inline void store_planar(char *dst, u32 dst_inc, u32 bpp, u32 d[8])
+static inline void store_planar(void *dst, u32 dst_inc, u32 bpp, u32 d[8])
{
int i;

for (i = 0; i < bpp; i++, dst += dst_inc)
- *(u32 *)dst = d[perm_c2p_8bpp[i]];
+ *(u32 *)dst = d[perm_c2p_32x8[i]];
}

@@ -143,13 +144,13 @@ static inline void store_planar(char *ds
* Store a partial block of planar data after c2p conversion
*/

-static inline void store_planar_masked(char *dst, u32 dst_inc, u32 bpp,
+static inline void store_planar_masked(void *dst, u32 dst_inc, u32 bpp,
u32 d[8], u32 mask)
{
int i;

for (i = 0; i < bpp; i++, dst += dst_inc)
- *(u32 *)dst = comp(d[perm_c2p_8bpp[i]], *(u32 *)dst, mask);
+ *(u32 *)dst = comp(d[perm_c2p_32x8[i]], *(u32 *)dst, mask);
}

@@ -166,18 +167,21 @@ static inline void store_planar_masked(c
* @bpp: Bits per pixel of the planar frame buffer (1-8)
*/

-void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height,
+void c2p(void *dst, const void *src, u32 dx, u32 dy, u32 width, u32 height,
u32 dst_nextline, u32 dst_nextplane, u32 src_nextline, u32 bpp)
{
- int dst_idx;
- u32 d[8], first, last, w;
+ union {
+ u8 pixels[32];
+ u32 words[8];
+ } d;
+ u32 dst_idx, first, last, w;
const u8 *c;
- u8 *p;
+ void *p;

dst += dy*dst_nextline+(dx & ~31);
dst_idx = dx % 32;
- first = ~0UL >> dst_idx;
- last = ~(~0UL >> ((dst_idx+width) % 32));
+ first = 0xffffffffU >> dst_idx;
+ last = ~(0xffffffffU >> ((dst_idx+width) % 32));
while (height--) {
c = src;
p = dst;
@@ -185,11 +189,11 @@ void c2p(u8 *dst, const u8 *src, u32 dx,
if (dst_idx+width <= 32) {
/* Single destination word */
first &= last;
- memset(d, 0, sizeof(d));
- memcpy((u8 *)d+dst_idx, c, width);
+ memset(d.pixels, 0, sizeof(d));
+ memcpy(d.pixels+dst_idx, c, width);
c += width;
- c2p_8bpp(d);
- store_planar_masked(p, dst_nextplane, bpp, d, first);
+ c2p_32x8(d.words);
+ store_planar_masked(p, dst_nextplane, bpp, d.words, first);
p += 4;
} else {
/* Multiple destination words */
@@ -197,30 +201,30 @@ void c2p(u8 *dst, const u8 *src, u32 dx,
/* Leading bits */
if (dst_idx) {
w = 32 - dst_idx;
- memset(d, 0, dst_idx);
- memcpy((u8 *)d+dst_idx, c, w);
+ memset(d.pixels, 0, dst_idx);
+ memcpy(d.pixels+dst_idx, c, w);
c += w;
- c2p_8bpp(d);
- store_planar_masked(p, dst_nextplane, bpp, d, first);
+ c2p_32x8(d.words);
+ store_planar_masked(p, dst_nextplane, bpp, d.words, first);
p += 4;
w = width-w;
}
/* Main chunk */
while (w >= 32) {
- memcpy(d, c, 32);
+ memcpy(d.pixels, c, 32);
c += 32;
- c2p_8bpp(d);
- store_planar(p, dst_nextplane, bpp, d);
+ c2p_32x8(d.words);
+ store_planar(p, dst_nextplane, bpp, d.words);
p += 4;
w -= 32;
}
/* Trailing bits */
w %= 32;
if (w > 0) {
- memcpy(d, c, w);
- memset((u8 *)d+w, 0, 32-w);
- c2p_8bpp(d);
- store_planar_masked(p, dst_nextplane, bpp, d, last);
+ memcpy(d.pixels, c, w);
+ memset(d.pixels+w, 0, 32-w);
+ c2p_32x8(d.words);
+ store_planar_masked(p, dst_nextplane, bpp, d.words, last);
}
}
src += src_nextline;
--- a/drivers/video/c2p.h
+++ b/drivers/video/c2p.h
@@ -10,7 +10,7 @@

#include <linux/types.h>

-extern void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height,
- u32 dst_nextline, u32 dst_nextplane, u32 src_nextline,
- u32 bpp);
+extern void c2p(void *dst, const void *src, u32 dx, u32 dy, u32 width,
+ u32 height, u32 dst_nextline, u32 dst_nextplane,
+ u32 src_nextline, u32 bpp);