1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 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> 7 */ 8 9 #include <common.h> 10 #include <div64.h> 11 #include <init.h> 12 #include <time.h> 13 #include <asm/global_data.h> 14 #include <asm/io.h> 15 #include <asm/arch/pwm.h> 16 #include <asm/arch/clk.h> 17 #include <linux/delay.h> 18 19 /* Use the old PWM interface for now */ 20 #undef CONFIG_DM_PWM 21 #include <pwm.h> 22 23 DECLARE_GLOBAL_DATA_PTR; 24 25 unsigned long get_current_tick(void); 26 static void reset_timer_masked(void); 27 28 /* macro to read the 16 bit timer */ s5p_get_base_timer(void)29static inline struct s5p_timer *s5p_get_base_timer(void) 30 { 31 return (struct s5p_timer *)samsung_get_base_timer(); 32 } 33 34 /** 35 * Read the countdown timer. 36 * 37 * This operates at 1MHz and counts downwards. It will wrap about every 38 * hour (2^32 microseconds). 39 * 40 * @return current value of timer 41 */ timer_get_us_down(void)42static unsigned long timer_get_us_down(void) 43 { 44 struct s5p_timer *const timer = s5p_get_base_timer(); 45 46 return readl(&timer->tcnto4); 47 } 48 timer_init(void)49int timer_init(void) 50 { 51 /* PWM Timer 4 */ 52 pwm_init(4, MUX_DIV_4, 0); 53 pwm_config(4, 100000, 100000); 54 pwm_enable(4); 55 56 /* Use this as the current monotonic time in us */ 57 gd->arch.timer_reset_value = 0; 58 59 /* Use this as the last timer value we saw */ 60 gd->arch.lastinc = timer_get_us_down(); 61 reset_timer_masked(); 62 63 return 0; 64 } 65 66 /* 67 * timer without interrupts 68 */ get_timer(unsigned long base)69unsigned long get_timer(unsigned long base) 70 { 71 unsigned long long time_ms; 72 73 ulong now = timer_get_us_down(); 74 75 /* 76 * Increment the time by the amount elapsed since the last read. 77 * The timer may have wrapped around, but it makes no difference to 78 * our arithmetic here. 79 */ 80 gd->arch.timer_reset_value += gd->arch.lastinc - now; 81 gd->arch.lastinc = now; 82 83 /* Divide by 1000 to convert from us to ms */ 84 time_ms = gd->arch.timer_reset_value; 85 do_div(time_ms, 1000); 86 return time_ms - base; 87 } 88 timer_get_us(void)89unsigned long __attribute__((no_instrument_function)) timer_get_us(void) 90 { 91 static unsigned long base_time_us; 92 93 struct s5p_timer *const timer = 94 (struct s5p_timer *)samsung_get_base_timer(); 95 unsigned long now_downward_us = readl(&timer->tcnto4); 96 97 if (!base_time_us) 98 base_time_us = now_downward_us; 99 100 /* Note that this timer counts downward. */ 101 return base_time_us - now_downward_us; 102 } 103 104 /* delay x useconds */ __udelay(unsigned long usec)105void __udelay(unsigned long usec) 106 { 107 unsigned long count_value; 108 109 count_value = timer_get_us_down(); 110 while ((int)(count_value - timer_get_us_down()) < (int)usec) 111 ; 112 } 113 reset_timer_masked(void)114static void reset_timer_masked(void) 115 { 116 struct s5p_timer *const timer = s5p_get_base_timer(); 117 118 /* reset time */ 119 gd->arch.lastinc = readl(&timer->tcnto4); 120 gd->arch.tbl = 0; 121 } 122 123 /* 124 * This function is derived from PowerPC code (read timebase as long long). 125 * On ARM it just returns the timer value. 126 */ get_ticks(void)127unsigned long long get_ticks(void) 128 { 129 return get_timer(0); 130 } 131 132 /* 133 * This function is derived from PowerPC code (timebase clock frequency). 134 * On ARM it returns the number of timer ticks per second. 135 */ get_tbclk(void)136unsigned long get_tbclk(void) 137 { 138 return CONFIG_SYS_HZ; 139 } 140