openwrt/target/linux/xburst/files-2.6.32/arch/mips/jz4740/time.c

257 lines
7.2 KiB
C

/*
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 platform timer 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/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/clockchips.h>
#include <linux/clk.h>
#include <asm/mach-jz4740/irq.h>
#include <asm/mach-jz4740/jz4740.h>
#include <asm/time.h>
#include "clock.h"
#define JZ_REG_TIMER_STOP 0x1C
#define JZ_REG_TIMER_STOP_SET 0x2C
#define JZ_REG_TIMER_STOP_CLEAR 0x3C
#define JZ_REG_TIMER_ENABLE 0x10
#define JZ_REG_TIMER_ENABLE_SET 0x14
#define JZ_REG_TIMER_ENABLE_CLEAR 0x18
#define JZ_REG_TIMER_FLAG 0x20
#define JZ_REG_TIMER_FLAG_SET 0x24
#define JZ_REG_TIMER_FLAG_CLEAR 0x28
#define JZ_REG_TIMER_MASK 0x30
#define JZ_REG_TIMER_MASK_SET 0x34
#define JZ_REG_TIMER_MASK_CLEAR 0x38
#define JZ_REG_TIMER_DFR(x) (((x) * 0x10) + 0x40)
#define JZ_REG_TIMER_DHR(x) (((x) * 0x10) + 0x44)
#define JZ_REG_TIMER_CNT(x) (((x) * 0x10) + 0x48)
#define JZ_REG_TIMER_CTRL(x) (((x) * 0x10) + 0x4C)
#define JZ_TIMER_IRQ_HALF(x) BIT((x) + 0x10)
#define JZ_TIMER_IRQ_FULL(x) BIT(x)
#define JZ_TIMER_CTRL_PWM_ACTIVE_LOW BIT(8)
#define JZ_TIMER_CTRL_PWM_ENABLE BIT(7)
#define JZ_TIMER_CTRL_PRESCALE_MASK 0x1c
#define JZ_TIMER_CTRL_PRESCALE_OFFSET 0x3
#define JZ_TIMER_CTRL_PRESCALE_1 (0 << 3)
#define JZ_TIMER_CTRL_PRESCALE_4 (1 << 3)
#define JZ_TIMER_CTRL_PRESCALE_16 (2 << 3)
#define JZ_TIMER_CTRL_PRESCALE_64 (3 << 3)
#define JZ_TIMER_CTRL_PRESCALE_256 (4 << 3)
#define JZ_TIMER_CTRL_PRESCALE_1024 (5 << 3)
#define JZ_TIMER_CTRL_SRC_EXT BIT(2)
#define JZ_TIMER_CTRL_SRC_RTC BIT(1)
#define JZ_TIMER_CTRL_SRC_PCLK BIT(0)
static void __iomem *jz4740_timer_base;
static uint16_t jz4740_jiffies_per_tick;
void jz4740_timer_enable_watchdog(void)
{
writel(BIT(16), jz4740_timer_base + JZ_REG_TIMER_STOP_CLEAR);
}
void jz4740_timer_disable_watchdog(void)
{
writel(BIT(16), jz4740_timer_base + JZ_REG_TIMER_STOP_SET);
}
static inline void jz4740_timer_set_period(unsigned int timer, uint16_t period)
{
writew(period, jz4740_timer_base + JZ_REG_TIMER_DFR(timer));
}
static inline void jz4740_timer_set_duty(unsigned int timer, uint16_t duty)
{
writew(duty, jz4740_timer_base + JZ_REG_TIMER_DHR(timer));
}
static void jz4740_init_timer(void)
{
uint16_t val = 0;
val |= JZ_TIMER_CTRL_PRESCALE_16;
val |= JZ_TIMER_CTRL_SRC_EXT;
writew(val, jz4740_timer_base + JZ_REG_TIMER_CTRL(0));
writew(0xffff, jz4740_timer_base + JZ_REG_TIMER_DFR(0));
writew(val, jz4740_timer_base + JZ_REG_TIMER_CTRL(1));
writew(0xffff, jz4740_timer_base + JZ_REG_TIMER_DFR(1));
}
static void jz4740_timer_enable(unsigned int timer)
{
writel(BIT(timer), jz4740_timer_base + JZ_REG_TIMER_STOP_CLEAR);
writeb(BIT(timer), jz4740_timer_base + JZ_REG_TIMER_ENABLE_SET);
}
static void jz4740_timer_disable(unsigned int timer)
{
writeb(BIT(timer), jz4740_timer_base + JZ_REG_TIMER_ENABLE_CLEAR);
writel(BIT(timer), jz4740_timer_base + JZ_REG_TIMER_STOP_SET);
}
static void jz4740_timer_irq_full_enable(unsigned int timer)
{
writel(JZ_TIMER_IRQ_FULL(timer), jz4740_timer_base + JZ_REG_TIMER_FLAG_CLEAR);
writel(JZ_TIMER_IRQ_FULL(timer), jz4740_timer_base + JZ_REG_TIMER_MASK_CLEAR);
}
static int jz4740_timer_irq_full_is_enabled(unsigned int timer)
{
return !(readl(jz4740_timer_base + JZ_REG_TIMER_MASK) &
JZ_TIMER_IRQ_FULL(timer));
}
static void jz4740_timer_irq_full_disable(unsigned int timer)
{
writel(JZ_TIMER_IRQ_FULL(timer), jz4740_timer_base + JZ_REG_TIMER_MASK_SET);
}
static void jz4740_timer_irq_half_enable(unsigned int timer)
{
writel(JZ_TIMER_IRQ_HALF(timer), jz4740_timer_base + JZ_REG_TIMER_FLAG_CLEAR);
writel(JZ_TIMER_IRQ_HALF(timer), jz4740_timer_base + JZ_REG_TIMER_MASK_CLEAR);
}
static void jz4740_timer_irq_half_disable(unsigned int timer)
{
writel(JZ_TIMER_IRQ_HALF(timer), jz4740_timer_base + JZ_REG_TIMER_MASK_SET);
}
static cycle_t jz4740_clocksource_read(struct clocksource *cs)
{
uint16_t val;
val = readw(jz4740_timer_base + JZ_REG_TIMER_CNT(1));
return val;
}
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;
writel(JZ_TIMER_IRQ_FULL(0), jz4740_timer_base + JZ_REG_TIMER_FLAG_CLEAR);
if (cd->mode != CLOCK_EVT_MODE_PERIODIC) {
jz4740_timer_disable(0);
cd->event_handler(cd);
} else {
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:
writew(0x0, jz4740_timer_base + JZ_REG_TIMER_CNT(0));
writew(jz4740_jiffies_per_tick, jz4740_timer_base + JZ_REG_TIMER_DFR(0));
case CLOCK_EVT_MODE_RESUME:
jz4740_timer_irq_full_enable(0);
jz4740_timer_enable(0);
break;
case CLOCK_EVT_MODE_ONESHOT:
case CLOCK_EVT_MODE_SHUTDOWN:
jz4740_timer_disable(0);
break;
default:
break;
}
}
static int jz4740_clockevent_set_next(unsigned long evt, struct
clock_event_device *cd)
{
writew(0x0, jz4740_timer_base + JZ_REG_TIMER_CNT(0));
writew(evt, jz4740_timer_base + JZ_REG_TIMER_DFR(0));
jz4740_timer_enable(0);
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 = JZ_IRQ_TCU0,
};
static struct irqaction jz_irqaction = {
.handler = jz4740_clockevent_irq,
.flags = IRQF_PERCPU | IRQF_TIMER | IRQF_DISABLED,
.name = "jz4740-timerirq",
.dev_id = &jz4740_clockevent,
};
void __init plat_time_init(void)
{
int ret;
uint32_t clk_rate;
jz4740_timer_base = ioremap(CPHYSADDR(TCU_BASE), 0x100);
if (!jz4740_timer_base) {
printk(KERN_ERR "Failed to ioremap timer registers");
return;
}
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(JZ_IRQ_TCU0, &jz_irqaction);
jz4740_init_timer();
writew(jz4740_jiffies_per_tick, jz4740_timer_base + JZ_REG_TIMER_DFR(0));
jz4740_timer_irq_half_disable(0);
jz4740_timer_irq_full_enable(0);
jz4740_timer_enable(0);
jz4740_timer_irq_half_disable(1);
jz4740_timer_irq_full_disable(1);
jz4740_timer_enable(1);
}