1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2009 Samsung Electronics 4 * Heungjun Kim <riverful.kim (at) samsung.com> 5 * Inki Dae <inki.dae (at) samsung.com> 6 * Minkyu Kang <mk7.kang (at) samsung.com> 7 */ 8 9 #include <common.h> 10 #include <div64.h> 11 #include <asm/io.h> 12 #include <asm/arch/pwm.h> 13 #include <asm/arch/clk.h> 14 15 /* Use the old PWM interface for now */ 16 #undef CONFIG_DM_PWM 17 #include <pwm.h> 18 19 DECLARE_GLOBAL_DATA_PTR; 20 21 unsigned long get_current_tick(void); 22 23 /* macro to read the 16 bit timer */ 24 static inline struct s5p_timer *s5p_get_base_timer(void) 25 { 26 return (struct s5p_timer *)samsung_get_base_timer(); 27 } 28 29 /** 30 * Read the countdown timer. 31 * 32 * This operates at 1MHz and counts downwards. It will wrap about every 33 * hour (2^32 microseconds). 34 * 35 * @return current value of timer 36 */ 37 static unsigned long timer_get_us_down(void) 38 { 39 struct s5p_timer *const timer = s5p_get_base_timer(); 40 41 return readl(&timer->tcnto4); 42 } 43 44 int timer_init(void) 45 { 46 /* PWM Timer 4 */ 47 pwm_init(4, MUX_DIV_4, 0); 48 pwm_config(4, 100000, 100000); 49 pwm_enable(4); 50 51 /* Use this as the current monotonic time in us */ 52 gd->arch.timer_reset_value = 0; 53 54 /* Use this as the last timer value we saw */ 55 gd->arch.lastinc = timer_get_us_down(); 56 reset_timer_masked(); 57 58 return 0; 59 } 60 61 /* 62 * timer without interrupts 63 */ 64 unsigned long get_timer(unsigned long base) 65 { 66 unsigned long long time_ms; 67 68 ulong now = timer_get_us_down(); 69 70 /* 71 * Increment the time by the amount elapsed since the last read. 72 * The timer may have wrapped around, but it makes no difference to 73 * our arithmetic here. 74 */ 75 gd->arch.timer_reset_value += gd->arch.lastinc - now; 76 gd->arch.lastinc = now; 77 78 /* Divide by 1000 to convert from us to ms */ 79 time_ms = gd->arch.timer_reset_value; 80 do_div(time_ms, 1000); 81 return time_ms - base; 82 } 83 84 unsigned long __attribute__((no_instrument_function)) timer_get_us(void) 85 { 86 static unsigned long base_time_us; 87 88 struct s5p_timer *const timer = 89 (struct s5p_timer *)samsung_get_base_timer(); 90 unsigned long now_downward_us = readl(&timer->tcnto4); 91 92 if (!base_time_us) 93 base_time_us = now_downward_us; 94 95 /* Note that this timer counts downward. */ 96 return base_time_us - now_downward_us; 97 } 98 99 /* delay x useconds */ 100 void __udelay(unsigned long usec) 101 { 102 unsigned long count_value; 103 104 count_value = timer_get_us_down(); 105 while ((int)(count_value - timer_get_us_down()) < (int)usec) 106 ; 107 } 108 109 void reset_timer_masked(void) 110 { 111 struct s5p_timer *const timer = s5p_get_base_timer(); 112 113 /* reset time */ 114 gd->arch.lastinc = readl(&timer->tcnto4); 115 gd->arch.tbl = 0; 116 } 117 118 /* 119 * This function is derived from PowerPC code (read timebase as long long). 120 * On ARM it just returns the timer value. 121 */ 122 unsigned long long get_ticks(void) 123 { 124 return get_timer(0); 125 } 126 127 /* 128 * This function is derived from PowerPC code (timebase clock frequency). 129 * On ARM it returns the number of timer ticks per second. 130 */ 131 unsigned long get_tbclk(void) 132 { 133 return CONFIG_SYS_HZ; 134 } 135