diff options
Diffstat (limited to 'include/asm-blackfin/delay.h')
| -rw-r--r-- | include/asm-blackfin/delay.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/include/asm-blackfin/delay.h b/include/asm-blackfin/delay.h new file mode 100644 index 000000000000..52e7a10d7ff8 --- /dev/null +++ b/include/asm-blackfin/delay.h @@ -0,0 +1,44 @@ +#ifndef _BLACKFIN_DELAY_H +#define _BLACKFIN_DELAY_H + +static inline void __delay(unsigned long loops) +{ + +/* FIXME: Currently the assembler doesn't recognize Loop Register Clobbers, + uncomment this as soon those are implemented */ +/* + __asm__ __volatile__ ( "\t LSETUP (1f,1f) LC0= %0\n\t" + "1:\t NOP;\n\t" + : :"a" (loops) + : "LT0","LB0","LC0"); + +*/ + + __asm__ __volatile__("[--SP] = LC0;\n\t" + "[--SP] = LT0;\n\t" + "[--SP] = LB0;\n\t" + "LSETUP (1f,1f) LC0 = %0;\n\t" + "1:\t NOP;\n\t" + "LB0 = [SP++];\n\t" + "LT0 = [SP++];\n\t" + "LC0 = [SP++];\n" + : + :"a" (loops)); +} + +#include <linux/param.h> /* needed for HZ */ + +/* + * Use only for very small delays ( < 1 msec). Should probably use a + * lookup table, really, as the multiplications take much too long with + * short delays. This is a "reasonable" implementation, though (and the + * first constant multiplications gets optimized away if the delay is + * a constant) + */ +static inline void udelay(unsigned long usecs) +{ + extern unsigned long loops_per_jiffy; + __delay(usecs * loops_per_jiffy / (1000000 / HZ)); +} + +#endif /* defined(_BLACKFIN_DELAY_H) */ |