1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright 2013 Freescale Semiconductor, Inc.
4  */
5 
6 #include <common.h>
7 #include <init.h>
8 #include <time.h>
9 #include <asm/global_data.h>
10 #include <asm/io.h>
11 #include <div64.h>
12 #include <asm/arch/imx-regs.h>
13 #include <asm/arch/clock.h>
14 #include <linux/delay.h>
15 
16 static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR;
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 #define TIMER_LOAD_VAL	0xffffffff
21 
tick_to_time(unsigned long long tick)22 static inline unsigned long long tick_to_time(unsigned long long tick)
23 {
24 	tick *= CONFIG_SYS_HZ;
25 	do_div(tick, mxc_get_clock(MXC_IPG_CLK));
26 
27 	return tick;
28 }
29 
us_to_tick(unsigned long long usec)30 static inline unsigned long long us_to_tick(unsigned long long usec)
31 {
32 	usec = usec * mxc_get_clock(MXC_IPG_CLK)  + 999999;
33 	do_div(usec, 1000000);
34 
35 	return usec;
36 }
37 
timer_init(void)38 int timer_init(void)
39 {
40 	__raw_writel(0, &cur_pit->mcr);
41 
42 	__raw_writel(TIMER_LOAD_VAL, &cur_pit->ldval1);
43 	__raw_writel(0, &cur_pit->tctrl1);
44 	__raw_writel(1, &cur_pit->tctrl1);
45 
46 	gd->arch.tbl = 0;
47 	gd->arch.tbu = 0;
48 
49 	return 0;
50 }
51 
get_ticks(void)52 unsigned long long get_ticks(void)
53 {
54 	ulong now = TIMER_LOAD_VAL - __raw_readl(&cur_pit->cval1);
55 
56 	/* increment tbu if tbl has rolled over */
57 	if (now < gd->arch.tbl)
58 		gd->arch.tbu++;
59 	gd->arch.tbl = now;
60 
61 	return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
62 }
63 
get_timer(ulong base)64 ulong get_timer(ulong base)
65 {
66 	return tick_to_time(get_ticks()) - base;
67 }
68 
69 /* delay x useconds AND preserve advance timstamp value */
__udelay(unsigned long usec)70 void __udelay(unsigned long usec)
71 {
72 	unsigned long long start;
73 	ulong tmo;
74 
75 	start = get_ticks();			/* get current timestamp */
76 	tmo = us_to_tick(usec);			/* convert usecs to ticks */
77 	while ((get_ticks() - start) < tmo)
78 		;				/* loop till time has passed */
79 }
80 
81 /*
82  * This function is derived from PowerPC code (timebase clock frequency).
83  * On ARM it returns the number of timer ticks per second.
84  */
get_tbclk(void)85 ulong get_tbclk(void)
86 {
87 	return mxc_get_clock(MXC_IPG_CLK);
88 }
89