1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2000, 2001
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 */
6
7 #include <common.h>
8 #include <init.h>
9 #include <time.h>
10 #include <asm/io.h>
11 #include <linux/delay.h>
12
13 /* ------------------------------------------------------------------------- */
14
15 /*
16 * This function is intended for SHORT delays only.
17 * It will overflow at around 10 seconds @ 400MHz,
18 * or 20 seconds @ 200MHz.
19 */
usec2ticks(unsigned long usec)20 unsigned long usec2ticks(unsigned long usec)
21 {
22 ulong ticks;
23
24 if (usec < 1000) {
25 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
26 } else {
27 ticks = ((usec / 10) * (get_tbclk() / 100000));
28 }
29
30 return (ticks);
31 }
32
33 /* ------------------------------------------------------------------------- */
34
35 /*
36 * We implement the delay by converting the delay (the number of
37 * microseconds to wait) into a number of time base ticks; then we
38 * watch the time base until it has incremented by that amount.
39 */
__udelay(unsigned long usec)40 void __udelay(unsigned long usec)
41 {
42 ulong ticks = usec2ticks (usec);
43 wait_ticks (ticks);
44 }
45
46 /* ------------------------------------------------------------------------- */
47 #ifndef CONFIG_NAND_SPL
ticks2usec(unsigned long ticks)48 unsigned long ticks2usec(unsigned long ticks)
49 {
50 ulong tbclk = get_tbclk();
51
52 /* usec = ticks * 1000000 / tbclk
53 * Multiplication would overflow at ~4.2e3 ticks,
54 * so we break it up into
55 * usec = ( ( ticks * 1000) / tbclk ) * 1000;
56 */
57 ticks *= 1000L;
58 ticks /= tbclk;
59 ticks *= 1000L;
60
61 return ((ulong)ticks);
62 }
63 #endif
64 /* ------------------------------------------------------------------------- */
65
timer_init(void)66 int timer_init(void)
67 {
68 unsigned long temp;
69
70 /* reset */
71 asm volatile("li %0,0 ; mttbl %0 ; mttbu %0;"
72 : "=&r"(temp) );
73
74 return (0);
75 }
76 /* ------------------------------------------------------------------------- */
77