arch/arm/cpu/arm926ejs/lpc32xx/timer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2011 Vladimir Zapolskiy <vz@mleia.com>
   4  */
   5
   6 #include <common.h>
   7 #include <asm/arch/cpu.h>
   8 #include <asm/arch/clk.h>
   9 #include <asm/arch/timer.h>
  10 #include <asm/io.h>
  11
  12 static struct timer_regs  *timer0 = (struct timer_regs *)TIMER0_BASE;
  13 static struct timer_regs  *timer1 = (struct timer_regs *)TIMER1_BASE;
  14 static struct clk_pm_regs *clk    = (struct clk_pm_regs *)CLK_PM_BASE;
  15
  16 static void lpc32xx_timer_clock(u32 bit, int enable)
  17 {
  18         if (enable)
  19                 setbits_le32(&clk->timclk_ctrl1, bit);
  20         else
  21                 clrbits_le32(&clk->timclk_ctrl1, bit);
  22 }
  23
  24 static void lpc32xx_timer_reset(struct timer_regs *timer, u32 freq)
  25 {
  26         writel(TIMER_TCR_COUNTER_RESET,   &timer->tcr);
  27         writel(TIMER_TCR_COUNTER_DISABLE, &timer->tcr);
  28         writel(0, &timer->tc);
  29         writel(0, &timer->pr);
  30
  31         /* Count mode is every rising PCLK edge */
  32         writel(TIMER_CTCR_MODE_TIMER, &timer->ctcr);
  33
  34         /* Set prescale counter value */
  35         writel((get_periph_clk_rate() / freq) - 1, &timer->pr);
  36
  37         /* Ensure that the counter is not reset when matching TC */
  38         writel(0,  &timer->mcr);
  39 }
  40
  41 static void lpc32xx_timer_count(struct timer_regs *timer, int enable)
  42 {
  43         if (enable)
  44                 writel(TIMER_TCR_COUNTER_ENABLE,  &timer->tcr);
  45         else
  46                 writel(TIMER_TCR_COUNTER_DISABLE, &timer->tcr);
  47 }
  48
  49 int timer_init(void)
  50 {
  51         lpc32xx_timer_clock(CLK_TIMCLK_TIMER0, 1);
  52         lpc32xx_timer_reset(timer0, CONFIG_SYS_HZ);
  53         lpc32xx_timer_count(timer0, 1);
  54
  55         return 0;
  56 }
  57
  58 ulong get_timer(ulong base)
  59 {
  60         return readl(&timer0->tc) - base;
  61 }
  62
  63 void __udelay(unsigned long usec)
  64 {
  65         lpc32xx_timer_clock(CLK_TIMCLK_TIMER1, 1);
  66         lpc32xx_timer_reset(timer1, CONFIG_SYS_HZ * 1000);
  67         lpc32xx_timer_count(timer1, 1);
  68
  69         while (readl(&timer1->tc) < usec)
  70                 /* NOP */;
  71
  72         lpc32xx_timer_count(timer1, 0);
  73         lpc32xx_timer_clock(CLK_TIMCLK_TIMER1, 0);
  74 }
  75
  76 unsigned long long get_ticks(void)
  77 {
  78         return get_timer(0);
  79 }
  80
  81 ulong get_tbclk(void)
  82 {
  83         return CONFIG_SYS_HZ;
  84 }