52e405eaa9
The irgflags consolidation did conflict with the ARM to generic IRQ conversion and was not applied for ARM. Fix it up. Use the new IRQF_ constants and remove the SA_INTERRUPT define Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
141 lines
3.8 KiB
C
141 lines
3.8 KiB
C
/*
|
|
* linux/arch/arm/mach-at91rm9200/at91rm9200_time.c
|
|
*
|
|
* Copyright (C) 2003 SAN People
|
|
* Copyright (C) 2003 ATMEL
|
|
*
|
|
* 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.
|
|
*
|
|
* 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/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/time.h>
|
|
|
|
#include <asm/hardware.h>
|
|
#include <asm/io.h>
|
|
#include <asm/mach/time.h>
|
|
|
|
static unsigned long last_crtr;
|
|
|
|
/*
|
|
* The ST_CRTR is updated asynchronously to the master clock. It is therefore
|
|
* necessary to read it twice (with the same value) to ensure accuracy.
|
|
*/
|
|
static inline unsigned long read_CRTR(void) {
|
|
unsigned long x1, x2;
|
|
|
|
do {
|
|
x1 = at91_sys_read(AT91_ST_CRTR);
|
|
x2 = at91_sys_read(AT91_ST_CRTR);
|
|
} while (x1 != x2);
|
|
|
|
return x1;
|
|
}
|
|
|
|
/*
|
|
* Returns number of microseconds since last timer interrupt. Note that interrupts
|
|
* will have been disabled by do_gettimeofday()
|
|
* 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy.
|
|
* 'tick' is usecs per jiffy (linux/timex.h).
|
|
*/
|
|
static unsigned long at91rm9200_gettimeoffset(void)
|
|
{
|
|
unsigned long elapsed;
|
|
|
|
elapsed = (read_CRTR() - last_crtr) & AT91_ST_ALMV;
|
|
|
|
return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH;
|
|
}
|
|
|
|
/*
|
|
* IRQ handler for the timer.
|
|
*/
|
|
static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
|
|
{
|
|
if (at91_sys_read(AT91_ST_SR) & AT91_ST_PITS) { /* This is a shared interrupt */
|
|
write_seqlock(&xtime_lock);
|
|
|
|
while (((read_CRTR() - last_crtr) & AT91_ST_ALMV) >= LATCH) {
|
|
timer_tick(regs);
|
|
last_crtr = (last_crtr + LATCH) & AT91_ST_ALMV;
|
|
}
|
|
|
|
write_sequnlock(&xtime_lock);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
else
|
|
return IRQ_NONE; /* not handled */
|
|
}
|
|
|
|
static struct irqaction at91rm9200_timer_irq = {
|
|
.name = "at91_tick",
|
|
.flags = IRQF_SHARED | IRQF_DISABLED | IRQF_TIMER,
|
|
.handler = at91rm9200_timer_interrupt
|
|
};
|
|
|
|
void at91rm9200_timer_reset(void)
|
|
{
|
|
last_crtr = 0;
|
|
|
|
/* Real time counter incremented every 30.51758 microseconds */
|
|
at91_sys_write(AT91_ST_RTMR, 1);
|
|
|
|
/* Set Period Interval timer */
|
|
at91_sys_write(AT91_ST_PIMR, LATCH);
|
|
|
|
/* Enable Period Interval Timer interrupt */
|
|
at91_sys_write(AT91_ST_IER, AT91_ST_PITS);
|
|
}
|
|
|
|
/*
|
|
* Set up timer interrupt.
|
|
*/
|
|
void __init at91rm9200_timer_init(void)
|
|
{
|
|
/* Disable all timer interrupts */
|
|
at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
|
|
(void) at91_sys_read(AT91_ST_SR); /* Clear any pending interrupts */
|
|
|
|
/* Make IRQs happen for the system timer */
|
|
setup_irq(AT91_ID_SYS, &at91rm9200_timer_irq);
|
|
|
|
/* Change the kernel's 'tick' value to 10009 usec. (the default is 10000) */
|
|
tick_usec = (LATCH * 1000000) / CLOCK_TICK_RATE;
|
|
|
|
/* Initialize and enable the timer interrupt */
|
|
at91rm9200_timer_reset();
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static void at91rm9200_timer_suspend(void)
|
|
{
|
|
/* disable Period Interval Timer interrupt */
|
|
at91_sys_write(AT91_ST_IDR, AT91_ST_PITS);
|
|
}
|
|
#else
|
|
#define at91rm9200_timer_suspend NULL
|
|
#endif
|
|
|
|
struct sys_timer at91rm9200_timer = {
|
|
.init = at91rm9200_timer_init,
|
|
.offset = at91rm9200_gettimeoffset,
|
|
.suspend = at91rm9200_timer_suspend,
|
|
.resume = at91rm9200_timer_reset,
|
|
};
|
|
|