LXR uboot/arch/arm/cpu/armv7/s5p-common/timer.c

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