xref: /rk3399_rockchip-uboot/arch/powerpc/lib/time.c (revision f0eda3cb89813c49d90fec7ee5fa69d3fe3d6daa)
1a47a12beSStefan Roese /*
2a47a12beSStefan Roese  * (C) Copyright 2000, 2001
3a47a12beSStefan Roese  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4a47a12beSStefan Roese  *
51a459660SWolfgang Denk  * SPDX-License-Identifier:	GPL-2.0+
6a47a12beSStefan Roese  */
7a47a12beSStefan Roese 
8a47a12beSStefan Roese #include <common.h>
9ba3da734SChristophe Leroy #include <asm/io.h>
10a47a12beSStefan Roese 
11a47a12beSStefan Roese /* ------------------------------------------------------------------------- */
12a47a12beSStefan Roese 
13a47a12beSStefan Roese /*
14a47a12beSStefan Roese  * This function is intended for SHORT delays only.
15a47a12beSStefan Roese  * It will overflow at around 10 seconds @ 400MHz,
16a47a12beSStefan Roese  * or 20 seconds @ 200MHz.
17a47a12beSStefan Roese  */
usec2ticks(unsigned long usec)18a47a12beSStefan Roese unsigned long usec2ticks(unsigned long usec)
19a47a12beSStefan Roese {
20a47a12beSStefan Roese 	ulong ticks;
21a47a12beSStefan Roese 
22a47a12beSStefan Roese 	if (usec < 1000) {
23a47a12beSStefan Roese 		ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
24a47a12beSStefan Roese 	} else {
25a47a12beSStefan Roese 		ticks = ((usec / 10) * (get_tbclk() / 100000));
26a47a12beSStefan Roese 	}
27a47a12beSStefan Roese 
28a47a12beSStefan Roese 	return (ticks);
29a47a12beSStefan Roese }
30a47a12beSStefan Roese 
31a47a12beSStefan Roese /* ------------------------------------------------------------------------- */
32a47a12beSStefan Roese 
33a47a12beSStefan Roese /*
34a47a12beSStefan Roese  * We implement the delay by converting the delay (the number of
35a47a12beSStefan Roese  * microseconds to wait) into a number of time base ticks; then we
36a47a12beSStefan Roese  * watch the time base until it has incremented by that amount.
37a47a12beSStefan Roese  */
__udelay(unsigned long usec)38a47a12beSStefan Roese void __udelay(unsigned long usec)
39a47a12beSStefan Roese {
40a47a12beSStefan Roese 	ulong ticks = usec2ticks (usec);
41a47a12beSStefan Roese 	wait_ticks (ticks);
42a47a12beSStefan Roese }
43a47a12beSStefan Roese 
44a47a12beSStefan Roese /* ------------------------------------------------------------------------- */
45a47a12beSStefan Roese #ifndef CONFIG_NAND_SPL
ticks2usec(unsigned long ticks)46a47a12beSStefan Roese unsigned long ticks2usec(unsigned long ticks)
47a47a12beSStefan Roese {
48a47a12beSStefan Roese 	ulong tbclk = get_tbclk();
49a47a12beSStefan Roese 
50a47a12beSStefan Roese 	/* usec = ticks * 1000000 / tbclk
51a47a12beSStefan Roese 	 * Multiplication would overflow at ~4.2e3 ticks,
52a47a12beSStefan Roese 	 * so we break it up into
53a47a12beSStefan Roese 	 * usec = ( ( ticks * 1000) / tbclk ) * 1000;
54a47a12beSStefan Roese 	 */
55a47a12beSStefan Roese 	ticks *= 1000L;
56a47a12beSStefan Roese 	ticks /= tbclk;
57a47a12beSStefan Roese 	ticks *= 1000L;
58a47a12beSStefan Roese 
59a47a12beSStefan Roese 	return ((ulong)ticks);
60a47a12beSStefan Roese }
61a47a12beSStefan Roese #endif
62a47a12beSStefan Roese /* ------------------------------------------------------------------------- */
63a47a12beSStefan Roese 
timer_init(void)6470e2aaf3SSimon Glass int timer_init(void)
65a47a12beSStefan Roese {
6696805a52STimur Tabi 	unsigned long temp;
6796805a52STimur Tabi 
68a47a12beSStefan Roese 	/* reset */
69*f0eda3cbSChristophe Leroy 	asm volatile("li %0,0 ; mttbl %0 ; mttbu %0;"
7096805a52STimur Tabi 	     : "=&r"(temp) );
71a47a12beSStefan Roese 
72a47a12beSStefan Roese 	return (0);
73a47a12beSStefan Roese }
74a47a12beSStefan Roese /* ------------------------------------------------------------------------- */
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