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