/*
* 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 <asm/hardware.h>
#include <asm/io.h>
#include <asm/mach/time.h>
#include <asm/arch/netx-regs.h>
/*
* Returns number of us since last clock interrupt. Note that interrupts
* will have been disabled by do_gettimeoffset()
*/
static unsigned long netx_gettimeoffset(void)
{
return readl(NETX_GPIO_COUNTER_CURRENT(0)) / 100;
}
/*
* IRQ handler for the timer
*/
static irqreturn_t
netx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
write_seqlock(&xtime_lock);
timer_tick(regs);
write_sequnlock(&xtime_lock);
/* acknowledge interrupt */
writel(COUNTER_BIT(0), NETX_GPIO_IRQ);
return IRQ_HANDLED;
}
static struct irqaction netx_timer_irq = {
.name = "NetX Timer Tick",
.flags = SA_INTERRUPT | SA_TIMER,
.handler = netx_timer_interrupt,
};
/*
* 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);
}
struct sys_timer netx_timer = {
.init = netx_timer_init,
.offset = netx_gettimeoffset,
};
