arch/arm/mach-tegra/timer.c - linux - Git at Google

 /*
  * 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/err.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 <asm/mach/time.h>
 #include <asm/smp_twd.h>
 #include <asm/sched_clock.h>

 #include <mach/iomap.h>
 #include <mach/irqs.h>

 #include "board.h"
 #include "clock.h"

 #define RTC_SECONDS            0x08
 #define RTC_SHADOW_SECONDS     0x0c
 #define RTC_MILLISECONDS       0x10

 #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

 static void __iomem *timer_reg_base = IO_ADDRESS(TEGRA_TMR1_BASE);
 static void __iomem *rtc_base = IO_ADDRESS(TEGRA_RTC_BASE);

 static struct timespec persistent_ts;
 static u64 persistent_ms, last_persistent_ms;

 #define timer_writel(value, reg) \
 	__raw_writel(value, timer_reg_base + (reg))
 #define timer_readl(reg) \
 	__raw_readl(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 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 u32 notrace tegra_read_sched_clock(void)
 {
 	return timer_readl(TIMERUS_CNTR_1US);
 }

 /*
  * tegra_rtc_read - Reads the Tegra RTC registers
  * Care must be taken that this funciton is not called while the
  * tegra_rtc driver could be executing to avoid race conditions
  * on the RTC shadow register
  */
 static u64 tegra_rtc_read_ms(void)
 {
 	u32 ms = readl(rtc_base + RTC_MILLISECONDS);
 	u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
 	return (u64)s * MSEC_PER_SEC + ms;
 }

 /*
  * tegra_read_persistent_clock -  Return time from a persistent clock.
  *
  * Reads the time from a source which isn't disabled during PM, the
  * 32k sync timer.  Convert the cycles elapsed since last read into
  * nsecs and adds to a monotonically increasing timespec.
  * Care must be taken that this funciton is not called while the
  * tegra_rtc driver could be executing to avoid race conditions
  * on the RTC shadow register
  */
 static void tegra_read_persistent_clock(struct timespec *ts)
 {
 	u64 delta;
 	struct timespec *tsp = &persistent_ts;

 	last_persistent_ms = persistent_ms;
 	persistent_ms = tegra_rtc_read_ms();
 	delta = persistent_ms - last_persistent_ms;

 	timespec_add_ns(tsp, delta * NSEC_PER_MSEC);
 	*ts = *tsp;
 }

 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,
 };

 #ifdef CONFIG_HAVE_ARM_TWD
 static DEFINE_TWD_LOCAL_TIMER(twd_local_timer,
 			      TEGRA_ARM_PERIF_BASE + 0x600,
 			      IRQ_LOCALTIMER);

 static void __init tegra_twd_init(void)
 {
 	int err = twd_local_timer_register(&twd_local_timer);
 	if (err)
 		pr_err("twd_local_timer_register failed %d\n", err);
 }
 #else
 #define tegra_twd_init()	do {} while(0)
 #endif

 static void __init tegra_init_timer(void)
 {
 	struct clk *clk;
 	unsigned long rate;
 	int ret;

 	clk = clk_get_sys("timer", NULL);
 	if (IS_ERR(clk)) {
 		pr_warn("Unable to get timer clock."
 			" Assuming 12Mhz input clock.\n");
 		rate = 12000000;
 	} else {
 		clk_prepare_enable(clk);
 		rate = clk_get_rate(clk);
 	}

 	/*
 	 * rtc registers are used by read_persistent_clock, keep the rtc clock
 	 * enabled
 	 */
 	clk = clk_get_sys("rtc-tegra", NULL);
 	if (IS_ERR(clk))
 		pr_warn("Unable to get rtc-tegra clock\n");
 	else
 		clk_prepare_enable(clk);

 	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");
 	}

 	setup_sched_clock(tegra_read_sched_clock, 32, 1000000);

 	if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
 		"timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) {
 		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);
 	tegra_twd_init();
 	register_persistent_clock(NULL, tegra_read_persistent_clock);
 }

 struct sys_timer tegra_timer = {
 	.init = tegra_init_timer,
 };

 #ifdef CONFIG_PM
 static u32 usec_config;

 void tegra_timer_suspend(void)
 {
 	usec_config = timer_readl(TIMERUS_USEC_CFG);
 }

 void tegra_timer_resume(void)
 {
 	timer_writel(usec_config, TIMERUS_USEC_CFG);
 }
 #endif
	/*
	* 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/err.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 <asm/mach/time.h>
	#include <asm/smp_twd.h>
	#include <asm/sched_clock.h>

	#include <mach/iomap.h>
	#include <mach/irqs.h>

	#include "board.h"
	#include "clock.h"

	#define RTC_SECONDS 0x08
	#define RTC_SHADOW_SECONDS 0x0c
	#define RTC_MILLISECONDS 0x10

	#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

	static void __iomem *timer_reg_base = IO_ADDRESS(TEGRA_TMR1_BASE);
	static void __iomem *rtc_base = IO_ADDRESS(TEGRA_RTC_BASE);

	static struct timespec persistent_ts;
	static u64 persistent_ms, last_persistent_ms;

	#define timer_writel(value, reg) \
	__raw_writel(value, timer_reg_base + (reg))
	#define timer_readl(reg) \
	__raw_readl(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 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 u32 notrace tegra_read_sched_clock(void)
	{
	return timer_readl(TIMERUS_CNTR_1US);
	}

	/*
	* tegra_rtc_read - Reads the Tegra RTC registers
	* Care must be taken that this funciton is not called while the
	* tegra_rtc driver could be executing to avoid race conditions
	* on the RTC shadow register
	*/
	static u64 tegra_rtc_read_ms(void)
	{
	u32 ms = readl(rtc_base + RTC_MILLISECONDS);
	u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
	return (u64)s * MSEC_PER_SEC + ms;
	}

	/*
	* tegra_read_persistent_clock - Return time from a persistent clock.
	*
	* Reads the time from a source which isn't disabled during PM, the
	* 32k sync timer. Convert the cycles elapsed since last read into
	* nsecs and adds to a monotonically increasing timespec.
	* Care must be taken that this funciton is not called while the
	* tegra_rtc driver could be executing to avoid race conditions
	* on the RTC shadow register
	*/
	static void tegra_read_persistent_clock(struct timespec *ts)
	{
	u64 delta;
	struct timespec *tsp = &persistent_ts;

	last_persistent_ms = persistent_ms;
	persistent_ms = tegra_rtc_read_ms();
	delta = persistent_ms - last_persistent_ms;

	timespec_add_ns(tsp, delta * NSEC_PER_MSEC);
	ts = tsp;
	}

	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,
	};

	#ifdef CONFIG_HAVE_ARM_TWD
	static DEFINE_TWD_LOCAL_TIMER(twd_local_timer,
	TEGRA_ARM_PERIF_BASE + 0x600,
	IRQ_LOCALTIMER);

	static void __init tegra_twd_init(void)
	{
	int err = twd_local_timer_register(&twd_local_timer);
	if (err)
	pr_err("twd_local_timer_register failed %d\n", err);
	}
	#else
	#define tegra_twd_init() do {} while(0)
	#endif

	static void __init tegra_init_timer(void)
	{
	struct clk *clk;
	unsigned long rate;
	int ret;

	clk = clk_get_sys("timer", NULL);
	if (IS_ERR(clk)) {
	pr_warn("Unable to get timer clock."
	" Assuming 12Mhz input clock.\n");
	rate = 12000000;
	} else {
	clk_prepare_enable(clk);
	rate = clk_get_rate(clk);
	}

	/*
	* rtc registers are used by read_persistent_clock, keep the rtc clock
	* enabled
	*/
	clk = clk_get_sys("rtc-tegra", NULL);
	if (IS_ERR(clk))
	pr_warn("Unable to get rtc-tegra clock\n");
	else
	clk_prepare_enable(clk);

	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");
	}

	setup_sched_clock(tegra_read_sched_clock, 32, 1000000);

	if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
	"timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) {
	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);
	tegra_twd_init();
	register_persistent_clock(NULL, tegra_read_persistent_clock);
	}

	struct sys_timer tegra_timer = {
	.init = tegra_init_timer,
	};

	#ifdef CONFIG_PM
	static u32 usec_config;

	void tegra_timer_suspend(void)
	{
	usec_config = timer_readl(TIMERUS_USEC_CFG);
	}

	void tegra_timer_resume(void)
	{
	timer_writel(usec_config, TIMERUS_USEC_CFG);
	}
	#endif