1 /*
2  * Copyright (C) 2009 Samsung Electronics
3  * Heungjun Kim <riverful.kim@samsung.com>
4  * Inki Dae <inki.dae@samsung.com>
5  * Minkyu Kang <mk7.kang@samsung.com>
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <common.h>
11 #include <div64.h>
12 #include <asm/io.h>
13 #include <asm/arch/pwm.h>
14 #include <asm/arch/clk.h>
15 #include <pwm.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 unsigned long get_current_tick(void);
20 
21 /* macro to read the 16 bit timer */
22 static inline struct s5p_timer *s5p_get_base_timer(void)
23 {
24 	return (struct s5p_timer *)samsung_get_base_timer();
25 }
26 
27 /**
28  * Read the countdown timer.
29  *
30  * This operates at 1MHz and counts downwards. It will wrap about every
31  * hour (2^32 microseconds).
32  *
33  * @return current value of timer
34  */
35 static unsigned long timer_get_us_down(void)
36 {
37 	struct s5p_timer *const timer = s5p_get_base_timer();
38 
39 	return readl(&timer->tcnto4);
40 }
41 
42 int timer_init(void)
43 {
44 	/* PWM Timer 4 */
45 	pwm_init(4, MUX_DIV_4, 0);
46 	pwm_config(4, 100000, 100000);
47 	pwm_enable(4);
48 
49 	/* Use this as the current monotonic time in us */
50 	gd->arch.timer_reset_value = 0;
51 
52 	/* Use this as the last timer value we saw */
53 	gd->arch.lastinc = timer_get_us_down();
54 	reset_timer_masked();
55 
56 	return 0;
57 }
58 
59 /*
60  * timer without interrupts
61  */
62 unsigned long get_timer(unsigned long base)
63 {
64 	unsigned long long time_ms;
65 
66 	ulong now = timer_get_us_down();
67 
68 	/*
69 	 * Increment the time by the amount elapsed since the last read.
70 	 * The timer may have wrapped around, but it makes no difference to
71 	 * our arithmetic here.
72 	 */
73 	gd->arch.timer_reset_value += gd->arch.lastinc - now;
74 	gd->arch.lastinc = now;
75 
76 	/* Divide by 1000 to convert from us to ms */
77 	time_ms = gd->arch.timer_reset_value;
78 	do_div(time_ms, 1000);
79 	return time_ms - base;
80 }
81 
82 unsigned long __attribute__((no_instrument_function)) timer_get_us(void)
83 {
84 	static unsigned long base_time_us;
85 
86 	struct s5p_timer *const timer =
87 		(struct s5p_timer *)samsung_get_base_timer();
88 	unsigned long now_downward_us = readl(&timer->tcnto4);
89 
90 	if (!base_time_us)
91 		base_time_us = now_downward_us;
92 
93 	/* Note that this timer counts downward. */
94 	return base_time_us - now_downward_us;
95 }
96 
97 /* delay x useconds */
98 void __udelay(unsigned long usec)
99 {
100 	unsigned long count_value;
101 
102 	count_value = timer_get_us_down();
103 	while ((int)(count_value - timer_get_us_down()) < (int)usec)
104 		;
105 }
106 
107 void reset_timer_masked(void)
108 {
109 	struct s5p_timer *const timer = s5p_get_base_timer();
110 
111 	/* reset time */
112 	gd->arch.lastinc = readl(&timer->tcnto4);
113 	gd->arch.tbl = 0;
114 }
115 
116 /*
117  * This function is derived from PowerPC code (read timebase as long long).
118  * On ARM it just returns the timer value.
119  */
120 unsigned long long get_ticks(void)
121 {
122 	return get_timer(0);
123 }
124 
125 /*
126  * This function is derived from PowerPC code (timebase clock frequency).
127  * On ARM it returns the number of timer ticks per second.
128  */
129 unsigned long get_tbclk(void)
130 {
131 	return CONFIG_SYS_HZ;
132 }
133