- 根目录:
- arch
- arm
- mach-omap1
- time.c
/*
* linux/arch/arm/mach-omap1/time.c
*
* OMAP Timers
*
* Copyright (C) 2004 Nokia Corporation
* Partial timer rewrite and additional dynamic tick timer support by
* Tony Lindgen <tony@atomide.com> and
* Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
*
* MPU timer code based on the older MPU timer code for OMAP
* Copyright (C) 2000 RidgeRun, Inc.
* Author: Greg Lonnon <glonnon@ridgerun.com>
*
* 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 SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <asm/sched_clock.h>
#include <mach/hardware.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include "iomap.h"
#include "common.h"
#ifdef CONFIG_OMAP_MPU_TIMER
#define OMAP_MPU_TIMER_BASE OMAP_MPU_TIMER1_BASE
#define OMAP_MPU_TIMER_OFFSET 0x100
typedef struct {
u32 cntl; /* CNTL_TIMER, R/W */
u32 load_tim; /* LOAD_TIM, W */
u32 read_tim; /* READ_TIM, R */
} omap_mpu_timer_regs_t;
#define omap_mpu_timer_base(n) \
((omap_mpu_timer_regs_t __iomem *)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE + \
(n)*OMAP_MPU_TIMER_OFFSET))
static inline unsigned long notrace omap_mpu_timer_read(int nr)
{
omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
return readl(&timer->read_tim);
}
static inline void omap_mpu_set_autoreset(int nr)
{
omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
writel(readl(&timer->cntl) | MPU_TIMER_AR, &timer->cntl);
}
static inline void omap_mpu_remove_autoreset(int nr)
{
omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
writel(readl(&timer->cntl) & ~MPU_TIMER_AR, &timer->cntl);
}
static inline void omap_mpu_timer_start(int nr, unsigned long load_val,
int autoreset)
{
omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
unsigned int timerflags = MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST;
if (autoreset)
timerflags |= MPU_TIMER_AR;
writel(MPU_TIMER_CLOCK_ENABLE, &timer->cntl);
udelay(1);
writel(load_val, &timer->load_tim);
udelay(1);
writel(timerflags, &timer->cntl);
}
static inline void omap_mpu_timer_stop(int nr)
{
omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
writel(readl(&timer->cntl) & ~MPU_TIMER_ST, &timer->cntl);
}
/*
* ---------------------------------------------------------------------------
* MPU timer 1 ... count down to zero, interrupt, reload
* ---------------------------------------------------------------------------
*/
static int omap_mpu_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
omap_mpu_timer_start(0, cycles, 0);
return 0;
}
static void omap_mpu_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
omap_mpu_set_autoreset(0);
break;
case CLOCK_EVT_MODE_ONESHOT:
omap_mpu_timer_stop(0);
omap_mpu_remove_autoreset(0);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
break;
}
}
static struct clock_event_device clockevent_mpu_timer1 = {
.name = "mpu_timer1",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = omap_mpu_set_next_event,
.set_mode = omap_mpu_set_mode,
};
static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &clockevent_mpu_timer1;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction omap_mpu_timer1_irq = {
.name = "mpu_timer1",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = omap_mpu_timer1_interrupt,
};
static __init void omap_init_mpu_timer(unsigned long rate)
{
setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
omap_mpu_timer_start(0, (rate / HZ) - 1, 1);
clockevent_mpu_timer1.cpumask = cpumask_of(0);
clockevents_config_and_register(&clockevent_mpu_timer1, rate,
1, -1);
}
/*
* ---------------------------------------------------------------------------
* MPU timer 2 ... free running 32-bit clock source and scheduler clock
* ---------------------------------------------------------------------------
*/
static u32 notrace omap_mpu_read_sched_clock(void)
{
return ~omap_mpu_timer_read(1);
}
static void __init omap_init_clocksource(unsigned long rate)
{
omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(1);
static char err[] __initdata = KERN_ERR
"%s: can't register clocksource!\n";
omap_mpu_timer_start(1, ~0, 1);
setup_sched_clock(omap_mpu_read_sched_clock, 32, rate);
if (clocksource_mmio_init(&timer->read_tim, "mpu_timer2", rate,
300, 32, clocksource_mmio_readl_down))
printk(err, "mpu_timer2");
}
static void __init omap_mpu_timer_init(void)
{
struct clk *ck_ref = clk_get(NULL, "ck_ref");
unsigned long rate;
BUG_ON(IS_ERR(ck_ref));
rate = clk_get_rate(ck_ref);
clk_put(ck_ref);
/* PTV = 0 */
rate /= 2;
omap_init_mpu_timer(rate);
omap_init_clocksource(rate);
}
#else
static inline void omap_mpu_timer_init(void)
{
pr_err("Bogus timer, should not happen\n");
}
#endif /* CONFIG_OMAP_MPU_TIMER */
/*
* ---------------------------------------------------------------------------
* Timer initialization
* ---------------------------------------------------------------------------
*/
void __init omap1_timer_init(void)
{
if (omap_32k_timer_init() != 0)
omap_mpu_timer_init();
}