Logo Search packages:      
Sourcecode: linux version File versions

time.c

/*
 * arch/arm/mach-netx/time.c
 *
 * Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clocksource.h>

#include <mach/hardware.h>
#include <asm/io.h>
#include <asm/mach/time.h>
#include <mach/netx-regs.h>

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

      /* acknowledge interrupt */
      writel(COUNTER_BIT(0), NETX_GPIO_IRQ);

      return IRQ_HANDLED;
}

static struct irqaction netx_timer_irq = {
      .name           = "NetX Timer Tick",
      .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
      .handler        = netx_timer_interrupt,
};

cycle_t netx_get_cycles(void)
{
      return readl(NETX_GPIO_COUNTER_CURRENT(1));
}

static struct clocksource clocksource_netx = {
      .name             = "netx_timer",
      .rating           = 200,
      .read       = netx_get_cycles,
      .mask       = CLOCKSOURCE_MASK(32),
      .shift            = 20,
      .flags            = CLOCK_SOURCE_IS_CONTINUOUS,
};

/*
 * Set up timer interrupt
 */
static void __init netx_timer_init(void)
{
      /* disable timer initially */
      writel(0, NETX_GPIO_COUNTER_CTRL(0));

      /* Reset the timer value to zero */
      writel(0, NETX_GPIO_COUNTER_CURRENT(0));

      writel(LATCH, NETX_GPIO_COUNTER_MAX(0));

      /* acknowledge interrupt */
      writel(COUNTER_BIT(0), NETX_GPIO_IRQ);

      /* Enable the interrupt in the specific timer register and start timer */
      writel(COUNTER_BIT(0), NETX_GPIO_IRQ_ENABLE);
      writel(NETX_GPIO_COUNTER_CTRL_IRQ_EN | NETX_GPIO_COUNTER_CTRL_RUN,
            NETX_GPIO_COUNTER_CTRL(0));

      setup_irq(NETX_IRQ_TIMER0, &netx_timer_irq);

      /* Setup timer one for clocksource */
        writel(0, NETX_GPIO_COUNTER_CTRL(1));
        writel(0, NETX_GPIO_COUNTER_CURRENT(1));
        writel(0xFFFFFFFF, NETX_GPIO_COUNTER_MAX(1));

        writel(NETX_GPIO_COUNTER_CTRL_RUN,
                NETX_GPIO_COUNTER_CTRL(1));

      clocksource_netx.mult =
            clocksource_hz2mult(CLOCK_TICK_RATE, clocksource_netx.shift);
      clocksource_register(&clocksource_netx);
}

struct sys_timer netx_timer = {
      .init       = netx_timer_init,
};

Generated by  Doxygen 1.6.0   Back to index