| /* | |
| * linux/arch/unicore32/lib/delay.S | |
| * | |
| * Code specific to PKUnity SoC and UniCore ISA | |
| * | |
| * Copyright (C) 2001-2010 GUAN Xue-tao | |
| * | |
| * 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> | |
| #include <asm/param.h> | |
| .text | |
| .LC0: .word loops_per_jiffy | |
| .LC1: .word (2199023*HZ)>>11 | |
| /* | |
| * r0 <= 2000 | |
| * lpj <= 0x01ffffff (max. 3355 bogomips) | |
| * HZ <= 1000 | |
| */ | |
| ENTRY(__udelay) | |
| ldw r2, .LC1 | |
| mul r0, r2, r0 | |
| ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 | |
| ldw r2, .LC0 | |
| ldw r2, [r2] @ max = 0x01ffffff | |
| mov r0, r0 >> #14 @ max = 0x0001ffff | |
| mov r2, r2 >> #10 @ max = 0x00007fff | |
| mul r0, r2, r0 @ max = 2^32-1 | |
| mov.a r0, r0 >> #6 | |
| cmoveq pc, lr | |
| /* | |
| * loops = r0 * HZ * loops_per_jiffy / 1000000 | |
| * | |
| * Oh, if only we had a cycle counter... | |
| */ | |
| @ Delay routine | |
| ENTRY(__delay) | |
| sub.a r0, r0, #2 | |
| bua __delay | |
| mov pc, lr | |
| ENDPROC(__udelay) | |
| ENDPROC(__const_udelay) | |
| ENDPROC(__delay) |