/*
 * linux/arch/arm/mach-omap2/timer.c
 *
 * OMAP2 GP timer support.
 *
 * Copyright (C) 2009 Nokia Corporation
 *
 * Update to use new clocksource/clockevent layers
 * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
 * Copyright (C) 2007 MontaVista Software, Inc.
 *
 * Original driver:
 * Copyright (C) 2005 Nokia Corporation
 * Author: Paul Mundt <paul.mundt@nokia.com>
 *         Juha Yrjölä <juha.yrjola@nokia.com>
 * OMAP Dual-mode timer framework support by Timo Teras
 *
 * Some parts based off of TI's 24xx code:
 *
 * Copyright (C) 2004-2009 Texas Instruments, Inc.
 *
 * Roughly modelled after the OMAP1 MPU timer code.
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/platform_data/dmtimer-omap.h>

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

#include <asm/arch_timer.h>
#include "omap_hwmod.h"
#include "omap_device.h"
#include <plat/counter-32k.h>
#include <plat/dmtimer.h>
#include "omap-pm.h"

#include "soc.h"
#include "common.h"
#include "powerdomain.h"

/* Parent clocks, eventually these will come from the clock framework */

#define OMAP2_MPU_SOURCE	"sys_ck"
#define OMAP3_MPU_SOURCE	OMAP2_MPU_SOURCE
#define OMAP4_MPU_SOURCE	"sys_clkin_ck"
#define OMAP2_32K_SOURCE	"func_32k_ck"
#define OMAP3_32K_SOURCE	"omap_32k_fck"
#define OMAP4_32K_SOURCE	"sys_32k_ck"

#define REALTIME_COUNTER_BASE				0x48243200
#define INCREMENTER_NUMERATOR_OFFSET			0x10
#define INCREMENTER_DENUMERATOR_RELOAD_OFFSET		0x14
#define NUMERATOR_DENUMERATOR_MASK			0xfffff000

/* Clockevent code */

static struct omap_dm_timer clkev;
static struct clock_event_device clockevent_gpt;

static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = &clockevent_gpt;

	__omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);

	evt->event_handler(evt);
	return IRQ_HANDLED;
}

static struct irqaction omap2_gp_timer_irq = {
	.name		= "gp_timer",
	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
	.handler	= omap2_gp_timer_interrupt,
};

static int omap2_gp_timer_set_next_event(unsigned long cycles,
					 struct clock_event_device *evt)
{
	__omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
				   0xffffffff - cycles, OMAP_TIMER_POSTED);

	return 0;
}

static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
				    struct clock_event_device *evt)
{
	u32 period;

	__omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);

	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
		period = clkev.rate / HZ;
		period -= 1;
		/* Looks like we need to first set the load value separately */
		__omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG,
				      0xffffffff - period, OMAP_TIMER_POSTED);
		__omap_dm_timer_load_start(&clkev,
					OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
					0xffffffff - period, OMAP_TIMER_POSTED);
		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 clockevent_gpt = {
	.name		= "gp_timer",
	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
	.shift		= 32,
	.rating		= 300,
	.set_next_event	= omap2_gp_timer_set_next_event,
	.set_mode	= omap2_gp_timer_set_mode,
};

static struct property device_disabled = {
	.name = "status",
	.length = sizeof("disabled"),
	.value = "disabled",
};

static struct of_device_id omap_timer_match[] __initdata = {
	{ .compatible = "ti,omap2-timer", },
	{ }
};

/**
 * omap_get_timer_dt - get a timer using device-tree
 * @match	- device-tree match structure for matching a device type
 * @property	- optional timer property to match
 *
 * Helper function to get a timer during early boot using device-tree for use
 * as kernel system timer. Optionally, the property argument can be used to
 * select a timer with a specific property. Once a timer is found then mark
 * the timer node in device-tree as disabled, to prevent the kernel from
 * registering this timer as a platform device and so no one else can use it.
 */
static struct device_node * __init omap_get_timer_dt(struct of_device_id *match,