LXR uboot/arch/arm/cpu/arm1176/tnetv107x/timer.c

   1/*
   2 * TNETV107X: Timer implementation
   3 *
   4 * See file CREDITS for list of people who contributed to this
   5 * project.
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License as published by
   9 * the Free Software Foundation; either version 2 of the License, or
  10 * (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22#include <common.h>
  23#include <asm/io.h>
  24#include <asm/arch/clock.h>
  25
  26struct timer_regs {
  27        u_int32_t pid12;
  28        u_int32_t pad[3];
  29        u_int32_t tim12;
  30        u_int32_t tim34;
  31        u_int32_t prd12;
  32        u_int32_t prd34;
  33        u_int32_t tcr;
  34        u_int32_t tgcr;
  35        u_int32_t wdtcr;
  36};
  37
  38#define regs ((struct timer_regs *)CONFIG_SYS_TIMERBASE)
  39
  40#define TIMER_LOAD_VAL  (CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ)
  41#define TIM_CLK_DIV     16
  42
  43static ulong timestamp;
  44static ulong lastinc;
  45
  46int timer_init(void)
  47{
  48        clk_enable(TNETV107X_LPSC_TIMER0);
  49
  50        lastinc = timestamp = 0;
  51
  52        /* We are using timer34 in unchained 32-bit mode, full speed */
  53        __raw_writel(0x0, &regs->tcr);
  54        __raw_writel(0x0, &regs->tgcr);
  55        __raw_writel(0x06 | ((TIM_CLK_DIV - 1) << 8), &regs->tgcr);
  56        __raw_writel(0x0, &regs->tim34);
  57        __raw_writel(TIMER_LOAD_VAL, &regs->prd34);
  58        __raw_writel(2 << 22, &regs->tcr);
  59
  60        return 0;
  61}
  62
  63static ulong get_timer_raw(void)
  64{
  65        ulong now = __raw_readl(&regs->tim34);
  66
  67        if (now >= lastinc)
  68                timestamp += now - lastinc;
  69        else
  70                timestamp += now + TIMER_LOAD_VAL - lastinc;
  71
  72        lastinc = now;
  73
  74        return timestamp;
  75}
  76
  77ulong get_timer(ulong base)
  78{
  79        return (get_timer_raw() / (TIMER_LOAD_VAL / TIM_CLK_DIV)) - base;
  80}
  81
  82unsigned long long get_ticks(void)
  83{
  84        return get_timer(0);
  85}
  86
  87void __udelay(unsigned long usec)
  88{
  89        ulong tmo;
  90        ulong endtime;
  91        signed long diff;
  92
  93        tmo = CONFIG_SYS_HZ_CLOCK / 1000;
  94        tmo *= usec;
  95        tmo /= (1000 * TIM_CLK_DIV);
  96
  97        endtime = get_timer_raw() + tmo;
  98
  99        do {
 100                ulong now = get_timer_raw();
 101                diff = endtime - now;
 102        } while (diff >= 0);
 103}
 104
 105ulong get_tbclk(void)
 106{
 107        return CONFIG_SYS_HZ;
 108}
 109