| /* |
| * 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) |
