1 | // SPDX-License-Identifier: GPL-2.0-only |
---|---|
2 | /* |
3 | * OpenRISC Linux |
4 | * |
5 | * Linux architectural port borrowing liberally from similar works of |
6 | * others. All original copyrights apply as per the original source |
7 | * declaration. |
8 | * |
9 | * Modifications for the OpenRISC architecture: |
10 | * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> |
11 | * |
12 | * Precise Delay Loops |
13 | */ |
14 | |
15 | #include <linux/kernel.h> |
16 | #include <linux/export.h> |
17 | #include <linux/init.h> |
18 | #include <linux/timex.h> |
19 | #include <asm/param.h> |
20 | #include <asm/delay.h> |
21 | #include <asm/timex.h> |
22 | #include <asm/processor.h> |
23 | |
24 | int read_current_timer(unsigned long *timer_value) |
25 | { |
26 | *timer_value = get_cycles(); |
27 | return 0; |
28 | } |
29 | |
30 | void __delay(unsigned long cycles) |
31 | { |
32 | cycles_t start = get_cycles(); |
33 | |
34 | while ((get_cycles() - start) < cycles) |
35 | cpu_relax(); |
36 | } |
37 | EXPORT_SYMBOL(__delay); |
38 | |
39 | inline void __const_udelay(unsigned long xloops) |
40 | { |
41 | unsigned long long loops; |
42 | |
43 | loops = (unsigned long long)xloops * loops_per_jiffy * HZ; |
44 | |
45 | __delay(loops >> 32); |
46 | } |
47 | EXPORT_SYMBOL(__const_udelay); |
48 | |
49 | void __udelay(unsigned long usecs) |
50 | { |
51 | __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */ |
52 | } |
53 | EXPORT_SYMBOL(__udelay); |
54 | |
55 | void __ndelay(unsigned long nsecs) |
56 | { |
57 | __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */ |
58 | } |
59 | EXPORT_SYMBOL(__ndelay); |
60 |