ARM: mmp: Change the way we use timer 0 as clockevent timer.

Instead of setting up a match interrupt for 'current_time + delta'
on ->set_next_event(), program timer 0 to count down from 'delta - 1'
and trigger an interrupt when it reaches zero.

Signed-off-by: Lennert Buytenhek <buytenh@laptop.org>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
This commit is contained in:
Lennert Buytenhek 2011-08-10 02:37:55 +08:00 коммит произвёл Eric Miao
Родитель 71c0c34140
Коммит af9dafb1dc
1 изменённых файлов: 35 добавлений и 12 удалений

Просмотреть файл

@ -75,28 +75,51 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *c = dev_id;
/* disable and clear pending interrupt status */
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0));
__raw_writel(0x1, TIMERS_VIRT_BASE + TMR_ICR(0));
/*
* Clear pending interrupt status.
*/
__raw_writel(0x01, TIMERS_VIRT_BASE + TMR_ICR(0));
/*
* Disable timer 0.
*/
__raw_writel(0x02, TIMERS_VIRT_BASE + TMR_CER);
c->event_handler(c);
return IRQ_HANDLED;
}
static int timer_set_next_event(unsigned long delta,
struct clock_event_device *dev)
{
unsigned long flags, next;
unsigned long flags;
local_irq_save(flags);
/* clear pending interrupt status and enable */
/*
* Disable timer 0.
*/
__raw_writel(0x02, TIMERS_VIRT_BASE + TMR_CER);
/*
* Clear and enable timer match 0 interrupt.
*/
__raw_writel(0x01, TIMERS_VIRT_BASE + TMR_ICR(0));
__raw_writel(0x01, TIMERS_VIRT_BASE + TMR_IER(0));
next = timer_read() + delta;
__raw_writel(next, TIMERS_VIRT_BASE + TMR_TN_MM(0, 0));
/*
* Setup new clockevent timer value.
*/
__raw_writel(delta - 1, TIMERS_VIRT_BASE + TMR_TN_MM(0, 0));
/*
* Enable timer 0.
*/
__raw_writel(0x03, TIMERS_VIRT_BASE + TMR_CER);
local_irq_restore(flags);
return 0;
}
@ -152,10 +175,10 @@ static void __init timer_config(void)
(TMR_CCR_CS_0(3) | TMR_CCR_CS_1(3));
__raw_writel(ccr, TIMERS_VIRT_BASE + TMR_CCR);
/* free-running mode */
__raw_writel(0x3, TIMERS_VIRT_BASE + TMR_CMR);
/* set timer 0 to periodic mode, and timer 1 to free-running mode */
__raw_writel(0x2, TIMERS_VIRT_BASE + TMR_CMR);
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_PLCR(0)); /* free-running */
__raw_writel(0x1, TIMERS_VIRT_BASE + TMR_PLCR(0)); /* periodic */
__raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(0)); /* clear status */
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(0));
@ -163,8 +186,8 @@ static void __init timer_config(void)
__raw_writel(0x7, TIMERS_VIRT_BASE + TMR_ICR(1)); /* clear status */
__raw_writel(0x0, TIMERS_VIRT_BASE + TMR_IER(1));
/* enable timer counter */
__raw_writel(0x3, TIMERS_VIRT_BASE + TMR_CER);
/* enable timer 1 counter */
__raw_writel(0x2, TIMERS_VIRT_BASE + TMR_CER);
}
static struct irqaction timer_irq = {