projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 96cf5185 G |
1 | /* |
| 2 | * linux/arch/unicore32/lib/delay.S | |
| 3 | * | |
| 4 | * Code specific to PKUnity SoC and UniCore ISA | |
| 5 | * | |
| 6 | * Copyright (C) 2001-2010 GUAN Xue-tao | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | */ | |
| 12 | #include <linux/linkage.h> | |
| 13 | #include <asm/assembler.h> | |
| 14 | #include <asm/param.h> | |
| 15 | .text | |
| 16 | ||
| 17 | .LC0: .word loops_per_jiffy | |
| 18 | .LC1: .word (2199023*HZ)>>11 | |
| 19 | ||
| 20 | /* | |
| 21 | * r0 <= 2000 | |
| 22 | * lpj <= 0x01ffffff (max. 3355 bogomips) | |
| 23 | * HZ <= 1000 | |
| 24 | */ | |
| 25 | ||
| 26 | ENTRY(__udelay) | |
| 27 | ldw r2, .LC1 | |
| 28 | mul r0, r2, r0 | |
| 29 | ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 | |
| 30 | ldw r2, .LC0 | |
| 31 | ldw r2, [r2] @ max = 0x01ffffff | |
| 32 | mov r0, r0 >> #14 @ max = 0x0001ffff | |
| 33 | mov r2, r2 >> #10 @ max = 0x00007fff | |
| 34 | mul r0, r2, r0 @ max = 2^32-1 | |
| 35 | mov.a r0, r0 >> #6 | |
| 36 | cmoveq pc, lr | |
| 37 | ||
| 38 | /* | |
| 39 | * loops = r0 * HZ * loops_per_jiffy / 1000000 | |
| 40 | * | |
| 41 | * Oh, if only we had a cycle counter... | |
| 42 | */ | |
| 43 | ||
| 44 | @ Delay routine | |
| 45 | ENTRY(__delay) | |
| 46 | sub.a r0, r0, #2 | |
| 47 | bua __delay | |
| 48 | mov pc, lr | |
| 49 | ENDPROC(__udelay) | |
| 50 | ENDPROC(__const_udelay) | |
| 51 | ENDPROC(__delay) |