1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2009 Samsung Electronics
4 * Heungjun Kim <riverful.kim@samsung.com>
5 * Inki Dae <inki.dae@samsung.com>
6 * Minkyu Kang <mk7.kang@samsung.com>
14 #include <asm/arch/pwm.h>
15 #include <asm/arch/clk.h>
16 #include <linux/delay.h>
18 /* Use the old PWM interface for now */
22 DECLARE_GLOBAL_DATA_PTR;
24 unsigned long get_current_tick(void);
25 static void reset_timer_masked(void);
27 /* macro to read the 16 bit timer */
28 static inline struct s5p_timer *s5p_get_base_timer(void)
30 return (struct s5p_timer *)samsung_get_base_timer();
34 * Read the countdown timer.
36 * This operates at 1MHz and counts downwards. It will wrap about every
37 * hour (2^32 microseconds).
39 * @return current value of timer
41 static unsigned long timer_get_us_down(void)
43 struct s5p_timer *const timer = s5p_get_base_timer();
45 return readl(&timer->tcnto4);
51 pwm_init(4, MUX_DIV_4, 0);
52 pwm_config(4, 100000, 100000);
55 /* Use this as the current monotonic time in us */
56 gd->arch.timer_reset_value = 0;
58 /* Use this as the last timer value we saw */
59 gd->arch.lastinc = timer_get_us_down();
66 * timer without interrupts
68 unsigned long get_timer(unsigned long base)
70 unsigned long long time_ms;
72 ulong now = timer_get_us_down();
75 * Increment the time by the amount elapsed since the last read.
76 * The timer may have wrapped around, but it makes no difference to
77 * our arithmetic here.
79 gd->arch.timer_reset_value += gd->arch.lastinc - now;
80 gd->arch.lastinc = now;
82 /* Divide by 1000 to convert from us to ms */
83 time_ms = gd->arch.timer_reset_value;
84 do_div(time_ms, 1000);
85 return time_ms - base;
88 unsigned long __attribute__((no_instrument_function)) timer_get_us(void)
90 static unsigned long base_time_us;
92 struct s5p_timer *const timer =
93 (struct s5p_timer *)samsung_get_base_timer();
94 unsigned long now_downward_us = readl(&timer->tcnto4);
97 base_time_us = now_downward_us;
99 /* Note that this timer counts downward. */
100 return base_time_us - now_downward_us;
103 /* delay x useconds */
104 void __udelay(unsigned long usec)
106 unsigned long count_value;
108 count_value = timer_get_us_down();
109 while ((int)(count_value - timer_get_us_down()) < (int)usec)
113 static void reset_timer_masked(void)
115 struct s5p_timer *const timer = s5p_get_base_timer();
118 gd->arch.lastinc = readl(&timer->tcnto4);
123 * This function is derived from PowerPC code (read timebase as long long).
124 * On ARM it just returns the timer value.
126 unsigned long long get_ticks(void)
132 * This function is derived from PowerPC code (timebase clock frequency).
133 * On ARM it returns the number of timer ticks per second.
135 unsigned long get_tbclk(void)
137 return CONFIG_SYS_HZ;