mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 08:31:55 +00:00
b200eff6d1
Add clocksource and clockevent support for the timer/counter unit on JZ4740 SoCs. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/1397/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
145 lines
3.8 KiB
C
145 lines
3.8 KiB
C
/*
|
|
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
|
|
* JZ4740 platform time support
|
|
*
|
|
* 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.
|
|
*
|
|
* 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/interrupt.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/time.h>
|
|
|
|
#include <linux/clockchips.h>
|
|
|
|
#include <asm/mach-jz4740/irq.h>
|
|
#include <asm/time.h>
|
|
|
|
#include "clock.h"
|
|
#include "timer.h"
|
|
|
|
#define TIMER_CLOCKEVENT 0
|
|
#define TIMER_CLOCKSOURCE 1
|
|
|
|
static uint16_t jz4740_jiffies_per_tick;
|
|
|
|
static cycle_t jz4740_clocksource_read(struct clocksource *cs)
|
|
{
|
|
return jz4740_timer_get_count(TIMER_CLOCKSOURCE);
|
|
}
|
|
|
|
static struct clocksource jz4740_clocksource = {
|
|
.name = "jz4740-timer",
|
|
.rating = 200,
|
|
.read = jz4740_clocksource_read,
|
|
.mask = CLOCKSOURCE_MASK(16),
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
};
|
|
|
|
static irqreturn_t jz4740_clockevent_irq(int irq, void *devid)
|
|
{
|
|
struct clock_event_device *cd = devid;
|
|
|
|
jz4740_timer_ack_full(TIMER_CLOCKEVENT);
|
|
|
|
if (cd->mode != CLOCK_EVT_MODE_PERIODIC)
|
|
jz4740_timer_disable(TIMER_CLOCKEVENT);
|
|
|
|
cd->event_handler(cd);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static void jz4740_clockevent_set_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *cd)
|
|
{
|
|
switch (mode) {
|
|
case CLOCK_EVT_MODE_PERIODIC:
|
|
jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
|
|
jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
|
|
case CLOCK_EVT_MODE_RESUME:
|
|
jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
|
|
jz4740_timer_enable(TIMER_CLOCKEVENT);
|
|
break;
|
|
case CLOCK_EVT_MODE_ONESHOT:
|
|
case CLOCK_EVT_MODE_SHUTDOWN:
|
|
jz4740_timer_disable(TIMER_CLOCKEVENT);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int jz4740_clockevent_set_next(unsigned long evt,
|
|
struct clock_event_device *cd)
|
|
{
|
|
jz4740_timer_set_count(TIMER_CLOCKEVENT, 0);
|
|
jz4740_timer_set_period(TIMER_CLOCKEVENT, evt);
|
|
jz4740_timer_enable(TIMER_CLOCKEVENT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct clock_event_device jz4740_clockevent = {
|
|
.name = "jz4740-timer",
|
|
.features = CLOCK_EVT_FEAT_PERIODIC,
|
|
.set_next_event = jz4740_clockevent_set_next,
|
|
.set_mode = jz4740_clockevent_set_mode,
|
|
.rating = 200,
|
|
.irq = JZ4740_IRQ_TCU0,
|
|
};
|
|
|
|
static struct irqaction timer_irqaction = {
|
|
.handler = jz4740_clockevent_irq,
|
|
.flags = IRQF_PERCPU | IRQF_TIMER,
|
|
.name = "jz4740-timerirq",
|
|
.dev_id = &jz4740_clockevent,
|
|
};
|
|
|
|
void __init plat_time_init(void)
|
|
{
|
|
int ret;
|
|
uint32_t clk_rate;
|
|
uint16_t ctrl;
|
|
|
|
jz4740_timer_init();
|
|
|
|
clk_rate = jz4740_clock_bdata.ext_rate >> 4;
|
|
jz4740_jiffies_per_tick = DIV_ROUND_CLOSEST(clk_rate, HZ);
|
|
|
|
clockevent_set_clock(&jz4740_clockevent, clk_rate);
|
|
jz4740_clockevent.min_delta_ns = clockevent_delta2ns(100, &jz4740_clockevent);
|
|
jz4740_clockevent.max_delta_ns = clockevent_delta2ns(0xffff, &jz4740_clockevent);
|
|
jz4740_clockevent.cpumask = cpumask_of(0);
|
|
|
|
clockevents_register_device(&jz4740_clockevent);
|
|
|
|
clocksource_set_clock(&jz4740_clocksource, clk_rate);
|
|
ret = clocksource_register(&jz4740_clocksource);
|
|
|
|
if (ret)
|
|
printk(KERN_ERR "Failed to register clocksource: %d\n", ret);
|
|
|
|
setup_irq(JZ4740_IRQ_TCU0, &timer_irqaction);
|
|
|
|
ctrl = JZ_TIMER_CTRL_PRESCALE_16 | JZ_TIMER_CTRL_SRC_EXT;
|
|
|
|
jz4740_timer_set_ctrl(TIMER_CLOCKEVENT, ctrl);
|
|
jz4740_timer_set_ctrl(TIMER_CLOCKSOURCE, ctrl);
|
|
|
|
jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick);
|
|
jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT);
|
|
|
|
jz4740_timer_set_period(TIMER_CLOCKSOURCE, 0xffff);
|
|
|
|
jz4740_timer_enable(TIMER_CLOCKEVENT);
|
|
jz4740_timer_enable(TIMER_CLOCKSOURCE);
|
|
}
|