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/*
* arch/arch/mach-tegra/timer.c
*
* Copyright (C) 2010 Google, Inc.
*
* Author:
* Colin Cross <ccross@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/cnt32_to_63.h>
#include <asm/mach/time.h>
#include <asm/localtimer.h>
#include <mach/iomap.h>
#include <mach/irqs.h>
#include "board.h"
#include "clock.h"
#define TIMERUS_CNTR_1US 0x10
#define TIMERUS_USEC_CFG 0x14
#define TIMERUS_CNTR_FREEZE 0x4c
#define TIMER1_BASE 0x0
#define TIMER2_BASE 0x8
#define TIMER3_BASE 0x50
#define TIMER4_BASE 0x58
#define TIMER_PTV 0x0
#define TIMER_PCR 0x4
struct tegra_timer;
static void __iomem *timer_reg_base = IO_ADDRESS(TEGRA_TMR1_BASE);
#define timer_writel(value, reg) \
__raw_writel(value, (u32)timer_reg_base + (reg))
#define timer_readl(reg) \
__raw_readl((u32)timer_reg_base + (reg))
static int tegra_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
u32 reg;
reg = 0x80000000 | ((cycles > 1) ? (cycles-1) : 0);
timer_writel(reg, TIMER3_BASE + TIMER_PTV);
return 0;
}
static void tegra_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
u32 reg;
timer_writel(0, TIMER3_BASE + TIMER_PTV);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
reg = 0xC0000000 | ((1000000/HZ)-1);
timer_writel(reg, TIMER3_BASE + TIMER_PTV);
break;
case CLOCK_EVT_MODE_ONESHOT:
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
break;
}
}
static cycle_t tegra_clocksource_read(struct clocksource *cs)
{
return timer_readl(TIMERUS_CNTR_1US);
}
static struct clock_event_device tegra_clockevent = {
.name = "timer0",
.rating = 300,
.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
.set_next_event = tegra_timer_set_next_event,
.set_mode = tegra_timer_set_mode,
};
static struct clocksource tegra_clocksource = {
.name = "timer_us",
.rating = 300,
.read = tegra_clocksource_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
unsigned long long sched_clock(void)
{
return cnt32_to_63(timer_readl(TIMERUS_CNTR_1US)) * 1000;
}
static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = (struct clock_event_device *)dev_id;
timer_writel(1<<30, TIMER3_BASE + TIMER_PCR);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction tegra_timer_irq = {
.name = "timer0",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_HIGH,
.handler = tegra_timer_interrupt,
.dev_id = &tegra_clockevent,
.irq = INT_TMR3,
};
static void __init tegra_init_timer(void)
{
unsigned long rate = clk_measure_input_freq();
int ret;
#ifdef CONFIG_HAVE_ARM_TWD
twd_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE + 0x600);
#endif
switch (rate) {
case 12000000:
timer_writel(0x000b, TIMERUS_USEC_CFG);
break;
case 13000000:
timer_writel(0x000c, TIMERUS_USEC_CFG);
break;
case 19200000:
timer_writel(0x045f, TIMERUS_USEC_CFG);
break;
case 26000000:
timer_writel(0x0019, TIMERUS_USEC_CFG);
break;
default:
WARN(1, "Unknown clock rate");
}
if (clocksource_register_hz(&tegra_clocksource, 1000000)) {
printk(KERN_ERR "Failed to register clocksource\n");
BUG();
}
ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
if (ret) {
printk(KERN_ERR "Failed to register timer IRQ: %d\n", ret);
BUG();
}
clockevents_calc_mult_shift(&tegra_clockevent, 1000000, 5);
tegra_clockevent.max_delta_ns =
clockevent_delta2ns(0x1fffffff, &tegra_clockevent);
tegra_clockevent.min_delta_ns =
clockevent_delta2ns(0x1, &tegra_clockevent);
tegra_clockevent.cpumask = cpu_all_mask;
tegra_clockevent.irq = tegra_timer_irq.irq;
clockevents_register_device(&tegra_clockevent);
return;
}
struct sys_timer tegra_timer = {
.init = tegra_init_timer,
};
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