LXR uboot/arch/arm/mach-imx/timer.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2007
   4 * Sascha Hauer, Pengutronix
   5 *
   6 * (C) Copyright 2009 Freescale Semiconductor, Inc.
   7 */
   8
   9#include <common.h>
  10#include <asm/io.h>
  11#include <div64.h>
  12#include <asm/arch/imx-regs.h>
  13#include <asm/arch/clock.h>
  14#include <asm/arch/sys_proto.h>
  15
  16/* General purpose timers registers */
  17struct mxc_gpt {
  18        unsigned int control;
  19        unsigned int prescaler;
  20        unsigned int status;
  21        unsigned int nouse[6];
  22        unsigned int counter;
  23};
  24
  25static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
  26
  27/* General purpose timers bitfields */
  28#define GPTCR_SWR               (1 << 15)       /* Software reset */
  29#define GPTCR_24MEN         (1 << 10)   /* Enable 24MHz clock input */
  30#define GPTCR_FRR               (1 << 9)        /* Freerun / restart */
  31#define GPTCR_CLKSOURCE_32      (4 << 6)        /* Clock source 32khz */
  32#define GPTCR_CLKSOURCE_OSC     (5 << 6)        /* Clock source OSC */
  33#define GPTCR_CLKSOURCE_PRE     (1 << 6)        /* Clock source PRECLK */
  34#define GPTCR_CLKSOURCE_MASK (0x7 << 6)
  35#define GPTCR_TEN               1               /* Timer enable */
  36
  37#define GPTPR_PRESCALER24M_SHIFT 12
  38#define GPTPR_PRESCALER24M_MASK (0xF << GPTPR_PRESCALER24M_SHIFT)
  39
  40static inline int gpt_has_clk_source_osc(void)
  41{
  42#if defined(CONFIG_MX6)
  43        if (((is_mx6dq()) && (soc_rev() > CHIP_REV_1_0)) ||
  44            is_mx6dqp() || is_mx6sdl() || is_mx6sx() || is_mx6ul() ||
  45            is_mx6ull() || is_mx6sll())
  46                return 1;
  47
  48        return 0;
  49#else
  50        return 0;
  51#endif
  52}
  53
  54static inline ulong gpt_get_clk(void)
  55{
  56#ifdef CONFIG_MXC_GPT_HCLK
  57        if (gpt_has_clk_source_osc())
  58                return MXC_HCLK >> 3;
  59        else
  60                return mxc_get_clock(MXC_IPG_PERCLK);
  61#else
  62        return MXC_CLK32;
  63#endif
  64}
  65
  66int timer_init(void)
  67{
  68        int i;
  69
  70        /* setup GP Timer 1 */
  71        __raw_writel(GPTCR_SWR, &cur_gpt->control);
  72
  73        /* We have no udelay by now */
  74        __raw_writel(0, &cur_gpt->control);
  75
  76        i = __raw_readl(&cur_gpt->control);
  77        i &= ~GPTCR_CLKSOURCE_MASK;
  78
  79#ifdef CONFIG_MXC_GPT_HCLK
  80        if (gpt_has_clk_source_osc()) {
  81                i |= GPTCR_CLKSOURCE_OSC | GPTCR_TEN;
  82
  83                /*
  84                 * For DL/S, SX, UL, ULL, SLL set 24Mhz OSC
  85                 * Enable bit and prescaler
  86                 */
  87                if (is_mx6sdl() || is_mx6sx() || is_mx6ul() || is_mx6ull() ||
  88                    is_mx6sll()) {
  89                        i |= GPTCR_24MEN;
  90
  91                        /* Produce 3Mhz clock */
  92                        __raw_writel((7 << GPTPR_PRESCALER24M_SHIFT),
  93                                     &cur_gpt->prescaler);
  94                }
  95        } else {
  96                i |= GPTCR_CLKSOURCE_PRE | GPTCR_TEN;
  97        }
  98#else
  99        __raw_writel(0, &cur_gpt->prescaler); /* 32Khz */
 100        i |= GPTCR_CLKSOURCE_32 | GPTCR_TEN;
 101#endif
 102        __raw_writel(i, &cur_gpt->control);
 103
 104        return 0;
 105}
 106
 107unsigned long timer_read_counter(void)
 108{
 109        return __raw_readl(&cur_gpt->counter); /* current tick value */
 110}
 111
 112/*
 113 * This function is derived from PowerPC code (timebase clock frequency).
 114 * On ARM it returns the number of timer ticks per second.
 115 */
 116ulong get_tbclk(void)
 117{
 118        return gpt_get_clk();
 119}
 120
 121/*
 122 * This function is intended for SHORT delays only.
 123 * It will overflow at around 10 seconds @ 400MHz,
 124 * or 20 seconds @ 200MHz.
 125 */
 126unsigned long usec2ticks(unsigned long _usec)
 127{
 128        unsigned long long usec = _usec;
 129
 130        usec *= get_tbclk();
 131        usec += 999999;
 132        do_div(usec, 1000000);
 133
 134        return usec;
 135}
 136