diff options
Diffstat (limited to 'arch/arm26/lib/delay.S')
| -rw-r--r-- | arch/arm26/lib/delay.S | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/arm26/lib/delay.S b/arch/arm26/lib/delay.S new file mode 100644 index 0000000..66f2b68e --- /dev/null +++ b/arch/arm26/lib/delay.S @@ -0,0 +1,57 @@ +/* + * linux/arch/arm26/lib/delay.S + * + * Copyright (C) 1995, 1996 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + .text + +LC0: .word loops_per_jiffy + +/* + * 0 <= r0 <= 2000 + */ +ENTRY(udelay) + mov r2, #0x6800 + orr r2, r2, #0x00db + mul r1, r0, r2 + ldr r2, LC0 + ldr r2, [r2] + mov r1, r1, lsr #11 + mov r2, r2, lsr #11 + mul r0, r1, r2 + movs r0, r0, lsr #6 + RETINSTR(moveq,pc,lr) + +/* + * loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32 + * + * Oh, if only we had a cycle counter... + */ + +@ Delay routine +ENTRY(__delay) + subs r0, r0, #1 +#if 0 + RETINSTR(movls,pc,lr) + subs r0, r0, #1 + RETINSTR(movls,pc,lr) + subs r0, r0, #1 + RETINSTR(movls,pc,lr) + subs r0, r0, #1 + RETINSTR(movls,pc,lr) + subs r0, r0, #1 + RETINSTR(movls,pc,lr) + subs r0, r0, #1 + RETINSTR(movls,pc,lr) + subs r0, r0, #1 + RETINSTR(movls,pc,lr) + subs r0, r0, #1 +#endif + bhi __delay + RETINSTR(mov,pc,lr) |
