Logo Search packages:      
Sourcecode: linux version File versions  Download package

time.c

/*
 *  Copyright (C) 2001-2006 Storlink, Corp.
 *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <mach/global_reg.h>
#include <asm/mach/time.h>

/*
 * Register definitions for the timers
 */
#define TIMER_COUNT(BASE_ADDR)            (BASE_ADDR  + 0x00)
#define TIMER_LOAD(BASE_ADDR)       (BASE_ADDR  + 0x04)
#define TIMER_MATCH1(BASE_ADDR)           (BASE_ADDR  + 0x08)
#define TIMER_MATCH2(BASE_ADDR)           (BASE_ADDR  + 0x0C)
#define TIMER_CR(BASE_ADDR)         (BASE_ADDR  + 0x30)

#define TIMER_1_CR_ENABLE           (1 << 0)
#define TIMER_1_CR_CLOCK            (1 << 1)
#define TIMER_1_CR_INT              (1 << 2)
#define TIMER_2_CR_ENABLE           (1 << 3)
#define TIMER_2_CR_CLOCK            (1 << 4)
#define TIMER_2_CR_INT              (1 << 5)
#define TIMER_3_CR_ENABLE           (1 << 6)
#define TIMER_3_CR_CLOCK            (1 << 7)
#define TIMER_3_CR_INT              (1 << 8)

/*
 * IRQ handler for the timer
 */
static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id)
{
      timer_tick();

      return IRQ_HANDLED;
}

static struct irqaction gemini_timer_irq = {
      .name       = "Gemini Timer Tick",
      .flags            = IRQF_DISABLED | IRQF_TIMER,
      .handler    = gemini_timer_interrupt,
};

/*
 * Set up timer interrupt, and return the current time in seconds.
 */
void __init gemini_timer_init(void)
{
      unsigned int tick_rate, reg_v;

      reg_v = __raw_readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS));
      tick_rate = REG_TO_AHB_SPEED(reg_v) * 1000000;

      printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000);

      tick_rate /= 6;         /* APB bus run AHB*(1/6) */

      switch(reg_v & CPU_AHB_RATIO_MASK) {
      case CPU_AHB_1_1:
            printk(KERN_CONT "(1/1)\n");
            break;
      case CPU_AHB_3_2:
            printk(KERN_CONT "(3/2)\n");
            break;
      case CPU_AHB_24_13:
            printk(KERN_CONT "(24/13)\n");
            break;
      case CPU_AHB_2_1:
            printk(KERN_CONT "(2/1)\n");
            break;
      }

      /*
       * Make irqs happen for the system timer
       */
      setup_irq(IRQ_TIMER2, &gemini_timer_irq);
      /* Start the timer */
      __raw_writel(tick_rate / HZ, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));
      __raw_writel(tick_rate / HZ, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));
      __raw_writel(TIMER_2_CR_ENABLE | TIMER_2_CR_INT, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
}

Generated by  Doxygen 1.6.0   Back to index