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
  63void reset_timer(void)
  64{
  65        lastinc = timestamp = 0;
  66
  67        __raw_writel(0,         &regs->tcr);
  68        __raw_writel(0,         &regs->tim34);
  69        __raw_writel(2 << 22,   &regs->tcr);
  70}
  71
  72static ulong get_timer_raw(void)
  73{
  74        ulong now = __raw_readl(&regs->tim34);
  75
  76        if (now >= lastinc)
  77                timestamp += now - lastinc;
  78        else
  79                timestamp += now + TIMER_LOAD_VAL - lastinc;
  80
  81        lastinc = now;
  82
  83        return timestamp;
  84}
  85
  86ulong get_timer(ulong base)
  87{
  88        return (get_timer_raw() / (TIMER_LOAD_VAL / TIM_CLK_DIV)) - base;
  89}
  90
  91void set_timer(ulong t)
  92{
  93        timestamp = t;
  94}
  95
  96unsigned long long get_ticks(void)
  97{
  98        return get_timer(0);
  99}
 100
 101void __udelay(unsigned long usec)
 102{
 103        ulong tmo;
 104        ulong endtime;
 105        signed long diff;
 106
 107        tmo = CONFIG_SYS_HZ_CLOCK / 1000;
 108        tmo *= usec;
 109        tmo /= (1000 * TIM_CLK_DIV);
 110
 111        endtime = get_timer_raw() + tmo;
 112
 113        do {
 114                ulong now = get_timer_raw();
 115                diff = endtime - now;
 116        } while (diff >= 0);
 117}
 118
 119ulong get_tbclk(void)
 120{
 121        return CONFIG_SYS_HZ;
 122}
 123