LXR uboot/arch/arm/cpu/armv7/stv0991/timer.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2014, STMicroelectronics - All Rights Reserved
   4 * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
   5 */
   6
   7#include <common.h>
   8#include <init.h>
   9#include <time.h>
  10#include <asm/global_data.h>
  11#include <asm/io.h>
  12#include <asm/arch-stv0991/hardware.h>
  13#include <asm/arch-stv0991/stv0991_cgu.h>
  14#include <asm/arch-stv0991/stv0991_gpt.h>
  15#include <linux/delay.h>
  16
  17static struct stv0991_cgu_regs *const stv0991_cgu_regs = \
  18                                (struct stv0991_cgu_regs *) (CGU_BASE_ADDR);
  19
  20#define READ_TIMER()    (readl(&gpt1_regs_ptr->cnt) & GPT_FREE_RUNNING)
  21#define GPT_RESOLUTION  (CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ)
  22
  23DECLARE_GLOBAL_DATA_PTR;
  24
  25#define timestamp gd->arch.tbl
  26#define lastdec gd->arch.lastinc
  27
  28static ulong get_timer_masked(void);
  29
  30int timer_init(void)
  31{
  32        /* Timer1 clock configuration */
  33        writel(TIMER1_CLK_CFG, &stv0991_cgu_regs->tim_freq);
  34        writel(readl(&stv0991_cgu_regs->cgu_enable_2) |
  35                        TIMER1_CLK_EN, &stv0991_cgu_regs->cgu_enable_2);
  36
  37        /* Stop the timer */
  38        writel(readl(&gpt1_regs_ptr->cr1) & ~GPT_CR1_CEN, &gpt1_regs_ptr->cr1);
  39        writel(GPT_PRESCALER_128, &gpt1_regs_ptr->psc);
  40        /* Configure timer for auto-reload */
  41        writel(readl(&gpt1_regs_ptr->cr1) | GPT_MODE_AUTO_RELOAD,
  42                        &gpt1_regs_ptr->cr1);
  43
  44        /* load value for free running */
  45        writel(GPT_FREE_RUNNING, &gpt1_regs_ptr->arr);
  46
  47        /* start timer */
  48        writel(readl(&gpt1_regs_ptr->cr1) | GPT_CR1_CEN,
  49                        &gpt1_regs_ptr->cr1);
  50
  51        /* Reset the timer */
  52        lastdec = READ_TIMER();
  53        timestamp = 0;
  54
  55        return 0;
  56}
  57
  58/*
  59 * timer without interrupts
  60 */
  61ulong get_timer(ulong base)
  62{
  63        return (get_timer_masked() / GPT_RESOLUTION) - base;
  64}
  65
  66void __udelay(unsigned long usec)
  67{
  68        ulong tmo;
  69        ulong start = get_timer_masked();
  70        ulong tenudelcnt = CONFIG_SYS_HZ_CLOCK / (1000 * 100);
  71        ulong rndoff;
  72
  73        rndoff = (usec % 10) ? 1 : 0;
  74
  75        /* tenudelcnt timer tick gives 10 microsecconds delay */
  76        tmo = ((usec / 10) + rndoff) * tenudelcnt;
  77
  78        while ((ulong) (get_timer_masked() - start) < tmo)
  79                ;
  80}
  81
  82static ulong get_timer_masked(void)
  83{
  84        ulong now = READ_TIMER();
  85
  86        if (now >= lastdec) {
  87                /* normal mode */
  88                timestamp += now - lastdec;
  89        } else {
  90                /* we have an overflow ... */
  91                timestamp += now + GPT_FREE_RUNNING - lastdec;
  92        }
  93        lastdec = now;
  94
  95        return timestamp;
  96}
  97
  98/*
  99 * This function is derived from PowerPC code (read timebase as long long).
 100 * On ARM it just returns the timer value.
 101 */
 102unsigned long long get_ticks(void)
 103{
 104        return get_timer(0);
 105}
 106
 107/*
 108 * This function is derived from PowerPC code (timebase clock frequency).
 109 * On ARM it returns the number of timer ticks per second.
 110 */
 111ulong get_tbclk(void)
 112{
 113        return CONFIG_SYS_HZ;
 114}
 115