| 1 | // SPDX-License-Identifier: GPL-2.0-only |
|---|---|
| 2 | /* |
| 3 | * Copyright (C) 2011 Richard Weinberger <richrd@nod.at> |
| 4 | * Mostly copied from arch/x86/lib/delay.c |
| 5 | */ |
| 6 | |
| 7 | #include <linux/export.h> |
| 8 | #include <linux/kernel.h> |
| 9 | #include <linux/delay.h> |
| 10 | #include <asm/param.h> |
| 11 | |
| 12 | void __delay(unsigned long loops) |
| 13 | { |
| 14 | asm volatile( |
| 15 | "test %0,%0\n" |
| 16 | "jz 3f\n" |
| 17 | "jmp 1f\n" |
| 18 | |
| 19 | ".align 16\n" |
| 20 | "1: jmp 2f\n" |
| 21 | |
| 22 | ".align 16\n" |
| 23 | "2: dec %0\n" |
| 24 | " jnz 2b\n" |
| 25 | "3: dec %0\n" |
| 26 | |
| 27 | : /* we don't need output */ |
| 28 | : "a"(loops) |
| 29 | ); |
| 30 | } |
| 31 | EXPORT_SYMBOL(__delay); |
| 32 | |
| 33 | inline void __const_udelay(unsigned long xloops) |
| 34 | { |
| 35 | int d0; |
| 36 | |
| 37 | xloops *= 4; |
| 38 | asm("mull %%edx" |
| 39 | : "=d"(xloops), "=&a"(d0) |
| 40 | : "1"(xloops), "0" |
| 41 | (loops_per_jiffy * (HZ/4))); |
| 42 | |
| 43 | __delay(++xloops); |
| 44 | } |
| 45 | EXPORT_SYMBOL(__const_udelay); |
| 46 | |
| 47 | void __udelay(unsigned long usecs) |
| 48 | { |
| 49 | __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ |
| 50 | } |
| 51 | EXPORT_SYMBOL(__udelay); |
| 52 | |
| 53 | void __ndelay(unsigned long nsecs) |
| 54 | { |
| 55 | __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ |
| 56 | } |
| 57 | EXPORT_SYMBOL(__ndelay); |
| 58 |