diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/lib/delay.S | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/arch/arm/lib/delay.S b/arch/arm/lib/delay.S index b3fb475b412..9183b06c0e2 100644 --- a/arch/arm/lib/delay.S +++ b/arch/arm/lib/delay.S @@ -9,28 +9,32 @@ */ #include <linux/linkage.h> #include <asm/assembler.h> +#include <asm/param.h> .text .LC0: .word loops_per_jiffy +.LC1: .word (2199023*HZ)>>11 /* - * 0 <= r0 <= 2000 + * r0 <= 2000 + * lpj <= 0x01ffffff (max. 3355 bogomips) + * HZ <= 1000 */ + ENTRY(__udelay) - mov r2, #0x6800 - orr r2, r2, #0x00db + ldr r2, .LC1 mul r0, r2, r0 -ENTRY(__const_udelay) @ 0 <= r0 <= 0x01ffffff +ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 ldr r2, .LC0 - ldr r2, [r2] @ max = 0x0fffffff - mov r0, r0, lsr #11 @ max = 0x00003fff - mov r2, r2, lsr #11 @ max = 0x0003ffff + ldr r2, [r2] @ max = 0x01ffffff + mov r0, r0, lsr #14 @ max = 0x0001ffff + mov r2, r2, lsr #10 @ max = 0x00007fff mul r0, r2, r0 @ max = 2^32-1 movs r0, r0, lsr #6 RETINSTR(moveq,pc,lr) /* - * loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32 + * loops = r0 * HZ * loops_per_jiffy / 1000000 * * Oh, if only we had a cycle counter... */ |