[deliverable/linux.git] / drivers / clocksource / samsung_pwm_timer.c

/*
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com/
 *
 * samsung - Common hr-timer support (s3c and s5p)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sched_clock.h>

#include <clocksource/samsung_pwm.h>


/*
 * Clocksource driver
 */

#define REG_TCFG0			0x00
#define REG_TCFG1			0x04
#define REG_TCON			0x08
#define REG_TINT_CSTAT			0x44

#define REG_TCNTB(chan)			(0x0c + 12 * (chan))
#define REG_TCMPB(chan)			(0x10 + 12 * (chan))

#define TCFG0_PRESCALER_MASK		0xff
#define TCFG0_PRESCALER1_SHIFT		8

#define TCFG1_SHIFT(x)	  		((x) * 4)
#define TCFG1_MUX_MASK	  		0xf

/*
 * Each channel occupies 4 bits in TCON register, but there is a gap of 4
 * bits (one channel) after channel 0, so channels have different numbering
 * when accessing TCON register.
 *
 * In addition, the location of autoreload bit for channel 4 (TCON channel 5)
 * in its set of bits is 2 as opposed to 3 for other channels.
 */
#define TCON_START(chan)		(1 << (4 * (chan) + 0))
#define TCON_MANUALUPDATE(chan)		(1 << (4 * (chan) + 1))
#define TCON_INVERT(chan)		(1 << (4 * (chan) + 2))
#define _TCON_AUTORELOAD(chan)		(1 << (4 * (chan) + 3))
#define _TCON_AUTORELOAD4(chan)		(1 << (4 * (chan) + 2))
#define TCON_AUTORELOAD(chan)		\
	((chan < 5) ? _TCON_AUTORELOAD(chan) : _TCON_AUTORELOAD4(chan))

DEFINE_SPINLOCK(samsung_pwm_lock);
EXPORT_SYMBOL(samsung_pwm_lock);

struct samsung_pwm_clocksource {
	void __iomem *base;
	void __iomem *source_reg;
	unsigned int irq[SAMSUNG_PWM_NUM];
	struct samsung_pwm_variant variant;

	struct clk *timerclk;

	unsigned int event_id;
	unsigned int source_id;
	unsigned int tcnt_max;
	unsigned int tscaler_div;
	unsigned int tdiv;

	unsigned long clock_count_per_tick;
};

static struct samsung_pwm_clocksource pwm;

static void samsung_timer_set_prescale(unsigned int channel, u16 prescale)
{
	unsigned long flags;
	u8 shift = 0;
	u32 reg;

	if (channel >= 2)
		shift = TCFG0_PRESCALER1_SHIFT;

	spin_lock_irqsave(&samsung_pwm_lock, flags);

	reg = readl(pwm.base + REG_TCFG0);
	reg &= ~(TCFG0_PRESCALER_MASK << shift);
	reg |= (prescale - 1) << shift;
	writel(reg, pwm.base + REG_TCFG0);

	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
}

static void samsung_timer_set_divisor(unsigned int channel, u8 divisor)
{
	u8 shift = TCFG1_SHIFT(channel);
	unsigned long flags;
	u32 reg;
	u8 bits;

	bits = (fls(divisor) - 1) - pwm.variant.div_base;

	spin_lock_irqsave(&samsung_pwm_lock, flags);

	reg = readl(pwm.base + REG_TCFG1);
	reg &= ~(TCFG1_MUX_MASK << shift);
	reg |= bits << shift;
	writel(reg, pwm.base + REG_TCFG1);

	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
}

static void samsung_time_stop(unsigned int channel)
{
	unsigned long tcon;
	unsigned long flags;

	if (channel > 0)
		++channel;

	spin_lock_irqsave(&samsung_pwm_lock, flags);

	tcon = __raw_readl(pwm.base + REG_TCON);
	tcon &= ~TCON_START(channel);
	__raw_writel(tcon, pwm.base + REG_TCON);

	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
}

static void samsung_time_setup(unsigned int channel, unsigned long tcnt)
{
	unsigned long tcon;
	unsigned long flags;
	unsigned int tcon_chan = channel;

	if (tcon_chan > 0)
		++tcon_chan;

	spin_lock_irqsave(&samsung_pwm_lock, flags);

	tcon = __raw_readl(pwm.base + REG_TCON);

	tcon &= ~(TCON_START(tcon_chan) | TCON_AUTORELOAD(tcon_chan));
	tcon |= TCON_MANUALUPDATE(tcon_chan);

	__raw_writel(tcnt, pwm.base + REG_TCNTB(channel));
	__raw_writel(tcnt, pwm.base + REG_TCMPB(channel));
	__raw_writel(tcon, pwm.base + REG_TCON);

	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
}

static void samsung_time_start(unsigned int channel, bool periodic)
{
	unsigned long tcon;
	unsigned long flags;

	if (channel > 0)
		++channel;

	spin_lock_irqsave(&samsung_pwm_lock, flags);

	tcon = __raw_readl(pwm.base + REG_TCON);

	tcon &= ~TCON_MANUALUPDATE(channel);
	tcon |= TCON_START(channel);

	if (periodic)
		tcon |= TCON_AUTORELOAD(channel);
	else
		tcon &= ~TCON_AUTORELOAD(channel);

	__raw_writel(tcon, pwm.base + REG_TCON);

	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
}

static int samsung_set_next_event(unsigned long cycles,
				struct clock_event_device *evt)
{
	/*
	 * This check is needed to account for internal rounding
	 * errors inside clockevents core, which might result in
	 * passing cycles = 0, which in turn would not generate any
	 * timer interrupt and hang the system.
	 *
	 * Another solution would be to set up the clockevent device
	 * with min_delta = 2, but this would unnecessarily increase
	 * the minimum sleep period.
	 */
	if (!cycles)
		cycles = 1;

	samsung_time_setup(pwm.event_id, cycles);
	samsung_time_start(pwm.event_id, false);

	return 0;
}

static void samsung_set_mode(enum clock_event_mode mode,
				struct clock_event_device *evt)
{
	samsung_time_stop(pwm.event_id);

	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
		samsung_time_setup(pwm.event_id, pwm.clock_count_per_tick - 1);
		samsung_time_start(pwm.event_id, true);
		break;

	case CLOCK_EVT_MODE_ONESHOT:
		break;

	case CLOCK_EVT_MODE_UNUSED:
	case CLOCK_EVT_MODE_SHUTDOWN:
	case CLOCK_EVT_MODE_RESUME:
		break;
	}
}

static void samsung_clockevent_resume(struct clock_event_device *cev)
{
	samsung_timer_set_prescale(pwm.event_id, pwm.tscaler_div);
	samsung_timer_set_divisor(pwm.event_id, pwm.tdiv);

	if (pwm.variant.has_tint_cstat) {
		u32 mask = (1 << pwm.event_id);
		writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT);
	}
}

static struct clock_event_device time_event_device = {
	.name		= "samsung_event_timer",
	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
	.rating		= 200,
	.set_next_event	= samsung_set_next_event,
	.set_mode	= samsung_set_mode,
	.resume		= samsung_clockevent_resume,
};

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

	if (pwm.variant.has_tint_cstat) {
		u32 mask = (1 << pwm.event_id);
		writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT);
	}

	evt->event_handler(evt);

	return IRQ_HANDLED;
}

static struct irqaction samsung_clock_event_irq = {
	.name		= "samsung_time_irq",
	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
	.handler	= samsung_clock_event_isr,
	.dev_id		= &time_event_device,
};

static void __init samsung_clockevent_init(void)
{
	unsigned long pclk;
	unsigned long clock_rate;
	unsigned int irq_number;

	pclk = clk_get_rate(pwm.timerclk);

	samsung_timer_set_prescale(pwm.event_id, pwm.tscaler_div);
	samsung_timer_set_divisor(pwm.event_id, pwm.tdiv);

	clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv);
	pwm.clock_count_per_tick = clock_rate / HZ;

	time_event_device.cpumask = cpumask_of(0);
	clockevents_config_and_register(&time_event_device,
						clock_rate, 1, pwm.tcnt_max);

	irq_number = pwm.irq[pwm.event_id];
	setup_irq(irq_number, &samsung_clock_event_irq);

	if (pwm.variant.has_tint_cstat) {
		u32 mask = (1 << pwm.event_id);
		writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT);
	}
}

static void samsung_clocksource_suspend(struct clocksource *cs)
{
	samsung_time_stop(pwm.source_id);
}

static void samsung_clocksource_resume(struct clocksource *cs)
{
	samsung_timer_set_prescale(pwm.source_id, pwm.tscaler_div);
	samsung_timer_set_divisor(pwm.source_id, pwm.tdiv);

	samsung_time_setup(pwm.source_id, pwm.tcnt_max);
	samsung_time_start(pwm.source_id, true);
}

static cycle_t samsung_clocksource_read(struct clocksource *c)
{
	return ~readl_relaxed(pwm.source_reg);
}

static struct clocksource samsung_clocksource = {
	.name		= "samsung_clocksource_timer",
	.rating		= 250,
	.read		= samsung_clocksource_read,
	.suspend	= samsung_clocksource_suspend,
	.resume		= samsung_clocksource_resume,
	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
};

/*
 * Override the global weak sched_clock symbol with this
 * local implementation which uses the clocksource to get some
 * better resolution when scheduling the kernel. We accept that
 * this wraps around for now, since it is just a relative time
 * stamp. (Inspired by U300 implementation.)
 */
static u32 notrace samsung_read_sched_clock(void)
{
	return samsung_clocksource_read(NULL);
}

static void __init samsung_clocksource_init(void)
{
	unsigned long pclk;
	unsigned long clock_rate;
	int ret;

	pclk = clk_get_rate(pwm.timerclk);

	samsung_timer_set_prescale(pwm.source_id, pwm.tscaler_div);
	samsung_timer_set_divisor(pwm.source_id, pwm.tdiv);

	clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv);

	samsung_time_setup(pwm.source_id, pwm.tcnt_max);
	samsung_time_start(pwm.source_id, true);

	if (pwm.source_id == 4)
		pwm.source_reg = pwm.base + 0x40;
	else
		pwm.source_reg = pwm.base + pwm.source_id * 0x0c + 0x14;

	setup_sched_clock(samsung_read_sched_clock,
						pwm.variant.bits, clock_rate);

	samsung_clocksource.mask = CLOCKSOURCE_MASK(pwm.variant.bits);
	ret = clocksource_register_hz(&samsung_clocksource, clock_rate);
	if (ret)
		panic("samsung_clocksource_timer: can't register clocksource\n");
}

static void __init samsung_timer_resources(void)
{
	clk_prepare_enable(pwm.timerclk);

	pwm.tcnt_max = (1UL << pwm.variant.bits) - 1;
	if (pwm.variant.bits == 16) {
		pwm.tscaler_div = 25;
		pwm.tdiv = 2;
	} else {
		pwm.tscaler_div = 2;
		pwm.tdiv = 1;
	}
}

/*
 * PWM master driver
 */
static void __init _samsung_pwm_clocksource_init(void)
{
	u8 mask;
	int channel;

	mask = ~pwm.variant.output_mask & ((1 << SAMSUNG_PWM_NUM) - 1);
	channel = fls(mask) - 1;
	if (channel < 0)
		panic("failed to find PWM channel for clocksource");
	pwm.source_id = channel;

	mask &= ~(1 << channel);
	channel = fls(mask) - 1;
	if (channel < 0)
		panic("failed to find PWM channel for clock event");
	pwm.event_id = channel;

	samsung_timer_resources();
	samsung_clockevent_init();
	samsung_clocksource_init();
}

void __init samsung_pwm_clocksource_init(void __iomem *base,
			unsigned int *irqs, struct samsung_pwm_variant *variant)
{
	pwm.base = base;
	memcpy(&pwm.variant, variant, sizeof(pwm.variant));
	memcpy(pwm.irq, irqs, SAMSUNG_PWM_NUM * sizeof(*irqs));

	pwm.timerclk = clk_get(NULL, "timers");
	if (IS_ERR(pwm.timerclk))
		panic("failed to get timers clock for timer");

	_samsung_pwm_clocksource_init();
}

#ifdef CONFIG_CLKSRC_OF
static void __init samsung_pwm_alloc(struct device_node *np,
				     const struct samsung_pwm_variant *variant)
{
	struct property *prop;
	const __be32 *cur;
	u32 val;
	int i;

	memcpy(&pwm.variant, variant, sizeof(pwm.variant));
	for (i = 0; i < SAMSUNG_PWM_NUM; ++i)
		pwm.irq[i] = irq_of_parse_and_map(np, i);

	of_property_for_each_u32(np, "samsung,pwm-outputs", prop, cur, val) {
		if (val >= SAMSUNG_PWM_NUM) {
			pr_warning("%s: invalid channel index in samsung,pwm-outputs property\n",
								__func__);
			continue;
		}
		pwm.variant.output_mask |= 1 << val;
	}

	pwm.base = of_iomap(np, 0);
	if (!pwm.base) {
		pr_err("%s: failed to map PWM registers\n", __func__);
		return;
	}

	pwm.timerclk = of_clk_get_by_name(np, "timers");
	if (IS_ERR(pwm.timerclk))
		panic("failed to get timers clock for timer");

	_samsung_pwm_clocksource_init();
}

static const struct samsung_pwm_variant s3c24xx_variant = {
	.bits		= 16,
	.div_base	= 1,
	.has_tint_cstat	= false,
	.tclk_mask	= (1 << 4),
};

static void __init s3c2410_pwm_clocksource_init(struct device_node *np)
{
	samsung_pwm_alloc(np, &s3c24xx_variant);
}
CLOCKSOURCE_OF_DECLARE(s3c2410_pwm, "samsung,s3c2410-pwm", s3c2410_pwm_clocksource_init);

static const struct samsung_pwm_variant s3c64xx_variant = {
	.bits		= 32,
	.div_base	= 0,
	.has_tint_cstat	= true,
	.tclk_mask	= (1 << 7) | (1 << 6) | (1 << 5),
};

static void __init s3c64xx_pwm_clocksource_init(struct device_node *np)
{
	samsung_pwm_alloc(np, &s3c64xx_variant);
}
CLOCKSOURCE_OF_DECLARE(s3c6400_pwm, "samsung,s3c6400-pwm", s3c64xx_pwm_clocksource_init);

static const struct samsung_pwm_variant s5p64x0_variant = {
	.bits		= 32,
	.div_base	= 0,
	.has_tint_cstat	= true,
	.tclk_mask	= 0,
};

static void __init s5p64x0_pwm_clocksource_init(struct device_node *np)
{
	samsung_pwm_alloc(np, &s5p64x0_variant);
}
CLOCKSOURCE_OF_DECLARE(s5p6440_pwm, "samsung,s5p6440-pwm", s5p64x0_pwm_clocksource_init);

static const struct samsung_pwm_variant s5p_variant = {
	.bits		= 32,
	.div_base	= 0,
	.has_tint_cstat	= true,
	.tclk_mask	= (1 << 5),
};

static void __init s5p_pwm_clocksource_init(struct device_node *np)
{
	samsung_pwm_alloc(np, &s5p_variant);
}
CLOCKSOURCE_OF_DECLARE(s5pc100_pwm, "samsung,s5pc100-pwm", s5p_pwm_clocksource_init);
#endif
Commit	Line	Data
	1	/*
	2	* Copyright (c) 2011 Samsung Electronics Co., Ltd.
	3	* http://www.samsung.com/
	4	*
	5	* samsung - Common hr-timer support (s3c and s5p)
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/interrupt.h>
	13	#include <linux/irq.h>
	14	#include <linux/err.h>
	15	#include <linux/clk.h>
	16	#include <linux/clockchips.h>
	17	#include <linux/list.h>
	18	#include <linux/module.h>
	19	#include <linux/of.h>
	20	#include <linux/of_address.h>
	21	#include <linux/of_irq.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/slab.h>
	24	#include <linux/sched_clock.h>
	25
	26	#include <clocksource/samsung_pwm.h>
	27
	28
	29	/*
	30	* Clocksource driver
	31	*/
	32
	33	#define REG_TCFG0 0x00
	34	#define REG_TCFG1 0x04
	35	#define REG_TCON 0x08
	36	#define REG_TINT_CSTAT 0x44
	37
	38	#define REG_TCNTB(chan) (0x0c + 12 * (chan))
	39	#define REG_TCMPB(chan) (0x10 + 12 * (chan))
	40
	41	#define TCFG0_PRESCALER_MASK 0xff
	42	#define TCFG0_PRESCALER1_SHIFT 8
	43
	44	#define TCFG1_SHIFT(x) ((x) * 4)
	45	#define TCFG1_MUX_MASK 0xf
	46
	47	/*
	48	* Each channel occupies 4 bits in TCON register, but there is a gap of 4
	49	* bits (one channel) after channel 0, so channels have different numbering
	50	* when accessing TCON register.
	51	*
	52	* In addition, the location of autoreload bit for channel 4 (TCON channel 5)
	53	* in its set of bits is 2 as opposed to 3 for other channels.
	54	*/
	55	#define TCON_START(chan) (1 << (4 * (chan) + 0))
	56	#define TCON_MANUALUPDATE(chan) (1 << (4 * (chan) + 1))
	57	#define TCON_INVERT(chan) (1 << (4 * (chan) + 2))
	58	#define _TCON_AUTORELOAD(chan) (1 << (4 * (chan) + 3))
	59	#define _TCON_AUTORELOAD4(chan) (1 << (4 * (chan) + 2))
	60	#define TCON_AUTORELOAD(chan) \
	61	((chan < 5) ? _TCON_AUTORELOAD(chan) : _TCON_AUTORELOAD4(chan))
	62
	63	DEFINE_SPINLOCK(samsung_pwm_lock);
	64	EXPORT_SYMBOL(samsung_pwm_lock);
	65
	66	struct samsung_pwm_clocksource {
	67	void __iomem *base;
	68	void __iomem *source_reg;
	69	unsigned int irq[SAMSUNG_PWM_NUM];
	70	struct samsung_pwm_variant variant;
	71
	72	struct clk *timerclk;
	73
	74	unsigned int event_id;
	75	unsigned int source_id;
	76	unsigned int tcnt_max;
	77	unsigned int tscaler_div;
	78	unsigned int tdiv;
	79
	80	unsigned long clock_count_per_tick;
	81	};
	82
	83	static struct samsung_pwm_clocksource pwm;
	84
	85	static void samsung_timer_set_prescale(unsigned int channel, u16 prescale)
	86	{
	87	unsigned long flags;
	88	u8 shift = 0;
	89	u32 reg;
	90
	91	if (channel >= 2)
	92	shift = TCFG0_PRESCALER1_SHIFT;
	93
	94	spin_lock_irqsave(&samsung_pwm_lock, flags);
	95
	96	reg = readl(pwm.base + REG_TCFG0);
	97	reg &= ~(TCFG0_PRESCALER_MASK << shift);
	98	reg \|= (prescale - 1) << shift;
	99	writel(reg, pwm.base + REG_TCFG0);
	100
	101	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
	102	}
	103
	104	static void samsung_timer_set_divisor(unsigned int channel, u8 divisor)
	105	{
	106	u8 shift = TCFG1_SHIFT(channel);
	107	unsigned long flags;
	108	u32 reg;
	109	u8 bits;
	110
	111	bits = (fls(divisor) - 1) - pwm.variant.div_base;
	112
	113	spin_lock_irqsave(&samsung_pwm_lock, flags);
	114
	115	reg = readl(pwm.base + REG_TCFG1);
	116	reg &= ~(TCFG1_MUX_MASK << shift);
	117	reg \|= bits << shift;
	118	writel(reg, pwm.base + REG_TCFG1);
	119
	120	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
	121	}
	122
	123	static void samsung_time_stop(unsigned int channel)
	124	{
	125	unsigned long tcon;
	126	unsigned long flags;
	127
	128	if (channel > 0)
	129	++channel;
	130
	131	spin_lock_irqsave(&samsung_pwm_lock, flags);
	132
	133	tcon = __raw_readl(pwm.base + REG_TCON);
	134	tcon &= ~TCON_START(channel);
	135	__raw_writel(tcon, pwm.base + REG_TCON);
	136
	137	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
	138	}
	139
	140	static void samsung_time_setup(unsigned int channel, unsigned long tcnt)
	141	{
	142	unsigned long tcon;
	143	unsigned long flags;
	144	unsigned int tcon_chan = channel;
	145
	146	if (tcon_chan > 0)
	147	++tcon_chan;
	148
	149	spin_lock_irqsave(&samsung_pwm_lock, flags);
	150
	151	tcon = __raw_readl(pwm.base + REG_TCON);
	152
	153	tcon &= ~(TCON_START(tcon_chan) \| TCON_AUTORELOAD(tcon_chan));
	154	tcon \|= TCON_MANUALUPDATE(tcon_chan);
	155
	156	__raw_writel(tcnt, pwm.base + REG_TCNTB(channel));
	157	__raw_writel(tcnt, pwm.base + REG_TCMPB(channel));
	158	__raw_writel(tcon, pwm.base + REG_TCON);
	159
	160	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
	161	}
	162
	163	static void samsung_time_start(unsigned int channel, bool periodic)
	164	{
	165	unsigned long tcon;
	166	unsigned long flags;
	167
	168	if (channel > 0)
	169	++channel;
	170
	171	spin_lock_irqsave(&samsung_pwm_lock, flags);
	172
	173	tcon = __raw_readl(pwm.base + REG_TCON);
	174
	175	tcon &= ~TCON_MANUALUPDATE(channel);
	176	tcon \|= TCON_START(channel);
	177
	178	if (periodic)
	179	tcon \|= TCON_AUTORELOAD(channel);
	180	else
	181	tcon &= ~TCON_AUTORELOAD(channel);
	182
	183	__raw_writel(tcon, pwm.base + REG_TCON);
	184
	185	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
	186	}
	187
	188	static int samsung_set_next_event(unsigned long cycles,
	189	struct clock_event_device *evt)
	190	{
	191	/*
	192	* This check is needed to account for internal rounding
	193	* errors inside clockevents core, which might result in
	194	* passing cycles = 0, which in turn would not generate any
	195	* timer interrupt and hang the system.
	196	*
	197	* Another solution would be to set up the clockevent device
	198	* with min_delta = 2, but this would unnecessarily increase
	199	* the minimum sleep period.
	200	*/
	201	if (!cycles)
	202	cycles = 1;
	203
	204	samsung_time_setup(pwm.event_id, cycles);
	205	samsung_time_start(pwm.event_id, false);
	206
	207	return 0;
	208	}
	209
	210	static void samsung_set_mode(enum clock_event_mode mode,
	211	struct clock_event_device *evt)
	212	{
	213	samsung_time_stop(pwm.event_id);
	214
	215	switch (mode) {
	216	case CLOCK_EVT_MODE_PERIODIC:
	217	samsung_time_setup(pwm.event_id, pwm.clock_count_per_tick - 1);
	218	samsung_time_start(pwm.event_id, true);
	219	break;
	220
	221	case CLOCK_EVT_MODE_ONESHOT:
	222	break;
	223
	224	case CLOCK_EVT_MODE_UNUSED:
	225	case CLOCK_EVT_MODE_SHUTDOWN:
	226	case CLOCK_EVT_MODE_RESUME:
	227	break;
	228	}
	229	}
	230
	231	static void samsung_clockevent_resume(struct clock_event_device *cev)
	232	{
	233	samsung_timer_set_prescale(pwm.event_id, pwm.tscaler_div);
	234	samsung_timer_set_divisor(pwm.event_id, pwm.tdiv);
	235
	236	if (pwm.variant.has_tint_cstat) {
	237	u32 mask = (1 << pwm.event_id);
	238	writel(mask \| (mask << 5), pwm.base + REG_TINT_CSTAT);
	239	}
	240	}
	241
	242	static struct clock_event_device time_event_device = {
	243	.name = "samsung_event_timer",
	244	.features = CLOCK_EVT_FEAT_PERIODIC \| CLOCK_EVT_FEAT_ONESHOT,
	245	.rating = 200,
	246	.set_next_event = samsung_set_next_event,
	247	.set_mode = samsung_set_mode,
	248	.resume = samsung_clockevent_resume,
	249	};
	250
	251	static irqreturn_t samsung_clock_event_isr(int irq, void *dev_id)
	252	{
	253	struct clock_event_device *evt = dev_id;
	254
	255	if (pwm.variant.has_tint_cstat) {
	256	u32 mask = (1 << pwm.event_id);
	257	writel(mask \| (mask << 5), pwm.base + REG_TINT_CSTAT);
	258	}
	259
	260	evt->event_handler(evt);
	261
	262	return IRQ_HANDLED;
	263	}
	264
	265	static struct irqaction samsung_clock_event_irq = {
	266	.name = "samsung_time_irq",
	267	.flags = IRQF_DISABLED \| IRQF_TIMER \| IRQF_IRQPOLL,
	268	.handler = samsung_clock_event_isr,
	269	.dev_id = &time_event_device,
	270	};
	271
	272	static void __init samsung_clockevent_init(void)
	273	{
	274	unsigned long pclk;
	275	unsigned long clock_rate;
	276	unsigned int irq_number;
	277
	278	pclk = clk_get_rate(pwm.timerclk);
	279
	280	samsung_timer_set_prescale(pwm.event_id, pwm.tscaler_div);
	281	samsung_timer_set_divisor(pwm.event_id, pwm.tdiv);
	282
	283	clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv);
	284	pwm.clock_count_per_tick = clock_rate / HZ;
	285
	286	time_event_device.cpumask = cpumask_of(0);
	287	clockevents_config_and_register(&time_event_device,
	288	clock_rate, 1, pwm.tcnt_max);
	289
	290	irq_number = pwm.irq[pwm.event_id];
	291	setup_irq(irq_number, &samsung_clock_event_irq);
	292
	293	if (pwm.variant.has_tint_cstat) {
	294	u32 mask = (1 << pwm.event_id);
	295	writel(mask \| (mask << 5), pwm.base + REG_TINT_CSTAT);
	296	}
	297	}
	298
	299	static void samsung_clocksource_suspend(struct clocksource *cs)
	300	{
	301	samsung_time_stop(pwm.source_id);
	302	}
	303
	304	static void samsung_clocksource_resume(struct clocksource *cs)
	305	{
	306	samsung_timer_set_prescale(pwm.source_id, pwm.tscaler_div);
	307	samsung_timer_set_divisor(pwm.source_id, pwm.tdiv);
	308
	309	samsung_time_setup(pwm.source_id, pwm.tcnt_max);
	310	samsung_time_start(pwm.source_id, true);
	311	}
	312
	313	static cycle_t samsung_clocksource_read(struct clocksource *c)
	314	{
	315	return ~readl_relaxed(pwm.source_reg);
	316	}
	317
	318	static struct clocksource samsung_clocksource = {
	319	.name = "samsung_clocksource_timer",
	320	.rating = 250,
	321	.read = samsung_clocksource_read,
	322	.suspend = samsung_clocksource_suspend,
	323	.resume = samsung_clocksource_resume,
	324	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
	325	};
	326
	327	/*
	328	* Override the global weak sched_clock symbol with this
	329	* local implementation which uses the clocksource to get some
	330	* better resolution when scheduling the kernel. We accept that
	331	* this wraps around for now, since it is just a relative time
	332	* stamp. (Inspired by U300 implementation.)
	333	*/
	334	static u32 notrace samsung_read_sched_clock(void)
	335	{
	336	return samsung_clocksource_read(NULL);
	337	}
	338
	339	static void __init samsung_clocksource_init(void)
	340	{
	341	unsigned long pclk;
	342	unsigned long clock_rate;
	343	int ret;
	344
	345	pclk = clk_get_rate(pwm.timerclk);
	346
	347	samsung_timer_set_prescale(pwm.source_id, pwm.tscaler_div);
	348	samsung_timer_set_divisor(pwm.source_id, pwm.tdiv);
	349
	350	clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv);
	351
	352	samsung_time_setup(pwm.source_id, pwm.tcnt_max);
	353	samsung_time_start(pwm.source_id, true);
	354
	355	if (pwm.source_id == 4)
	356	pwm.source_reg = pwm.base + 0x40;
	357	else
	358	pwm.source_reg = pwm.base + pwm.source_id * 0x0c + 0x14;
	359
	360	setup_sched_clock(samsung_read_sched_clock,
	361	pwm.variant.bits, clock_rate);
	362
	363	samsung_clocksource.mask = CLOCKSOURCE_MASK(pwm.variant.bits);
	364	ret = clocksource_register_hz(&samsung_clocksource, clock_rate);
	365	if (ret)
	366	panic("samsung_clocksource_timer: can't register clocksource\n");
	367	}
	368
	369	static void __init samsung_timer_resources(void)
	370	{
	371	clk_prepare_enable(pwm.timerclk);
	372
	373	pwm.tcnt_max = (1UL << pwm.variant.bits) - 1;
	374	if (pwm.variant.bits == 16) {
	375	pwm.tscaler_div = 25;
	376	pwm.tdiv = 2;
	377	} else {
	378	pwm.tscaler_div = 2;
	379	pwm.tdiv = 1;
	380	}
	381	}
	382
	383	/*
	384	* PWM master driver
	385	*/
	386	static void __init _samsung_pwm_clocksource_init(void)
	387	{
	388	u8 mask;
	389	int channel;
	390
	391	mask = ~pwm.variant.output_mask & ((1 << SAMSUNG_PWM_NUM) - 1);
	392	channel = fls(mask) - 1;
	393	if (channel < 0)
	394	panic("failed to find PWM channel for clocksource");
	395	pwm.source_id = channel;
	396
	397	mask &= ~(1 << channel);
	398	channel = fls(mask) - 1;
	399	if (channel < 0)
	400	panic("failed to find PWM channel for clock event");
	401	pwm.event_id = channel;
	402
	403	samsung_timer_resources();
	404	samsung_clockevent_init();
	405	samsung_clocksource_init();
	406	}
	407
	408	void __init samsung_pwm_clocksource_init(void __iomem *base,
	409	unsigned int irqs, struct samsung_pwm_variant variant)
	410	{
	411	pwm.base = base;
	412	memcpy(&pwm.variant, variant, sizeof(pwm.variant));
	413	memcpy(pwm.irq, irqs, SAMSUNG_PWM_NUM * sizeof(*irqs));
	414
	415	pwm.timerclk = clk_get(NULL, "timers");
	416	if (IS_ERR(pwm.timerclk))
	417	panic("failed to get timers clock for timer");
	418
	419	_samsung_pwm_clocksource_init();
	420	}
	421
	422	#ifdef CONFIG_CLKSRC_OF
	423	static void __init samsung_pwm_alloc(struct device_node *np,
	424	const struct samsung_pwm_variant *variant)
	425	{
	426	struct property *prop;
	427	const __be32 *cur;
	428	u32 val;
	429	int i;
	430
	431	memcpy(&pwm.variant, variant, sizeof(pwm.variant));
	432	for (i = 0; i < SAMSUNG_PWM_NUM; ++i)
	433	pwm.irq[i] = irq_of_parse_and_map(np, i);
	434
	435	of_property_for_each_u32(np, "samsung,pwm-outputs", prop, cur, val) {
	436	if (val >= SAMSUNG_PWM_NUM) {
	437	pr_warning("%s: invalid channel index in samsung,pwm-outputs property\n",
	438	__func__);
	439	continue;
	440	}
	441	pwm.variant.output_mask \|= 1 << val;
	442	}
	443
	444	pwm.base = of_iomap(np, 0);
	445	if (!pwm.base) {
	446	pr_err("%s: failed to map PWM registers\n", __func__);
	447	return;
	448	}
	449
	450	pwm.timerclk = of_clk_get_by_name(np, "timers");
	451	if (IS_ERR(pwm.timerclk))
	452	panic("failed to get timers clock for timer");
	453
	454	_samsung_pwm_clocksource_init();
	455	}
	456
	457	static const struct samsung_pwm_variant s3c24xx_variant = {
	458	.bits = 16,
	459	.div_base = 1,
	460	.has_tint_cstat = false,
	461	.tclk_mask = (1 << 4),
	462	};
	463
	464	static void __init s3c2410_pwm_clocksource_init(struct device_node *np)
	465	{
	466	samsung_pwm_alloc(np, &s3c24xx_variant);
	467	}
	468	CLOCKSOURCE_OF_DECLARE(s3c2410_pwm, "samsung,s3c2410-pwm", s3c2410_pwm_clocksource_init);
	469
	470	static const struct samsung_pwm_variant s3c64xx_variant = {
	471	.bits = 32,
	472	.div_base = 0,
	473	.has_tint_cstat = true,
	474	.tclk_mask = (1 << 7) \| (1 << 6) \| (1 << 5),
	475	};
	476
	477	static void __init s3c64xx_pwm_clocksource_init(struct device_node *np)
	478	{
	479	samsung_pwm_alloc(np, &s3c64xx_variant);
	480	}
	481	CLOCKSOURCE_OF_DECLARE(s3c6400_pwm, "samsung,s3c6400-pwm", s3c64xx_pwm_clocksource_init);
	482
	483	static const struct samsung_pwm_variant s5p64x0_variant = {
	484	.bits = 32,
	485	.div_base = 0,
	486	.has_tint_cstat = true,
	487	.tclk_mask = 0,
	488	};
	489
	490	static void __init s5p64x0_pwm_clocksource_init(struct device_node *np)
	491	{
	492	samsung_pwm_alloc(np, &s5p64x0_variant);
	493	}
	494	CLOCKSOURCE_OF_DECLARE(s5p6440_pwm, "samsung,s5p6440-pwm", s5p64x0_pwm_clocksource_init);
	495
	496	static const struct samsung_pwm_variant s5p_variant = {
	497	.bits = 32,
	498	.div_base = 0,
	499	.has_tint_cstat = true,
	500	.tclk_mask = (1 << 5),
	501	};
	502
	503	static void __init s5p_pwm_clocksource_init(struct device_node *np)
	504	{
	505	samsung_pwm_alloc(np, &s5p_variant);
	506	}
	507	CLOCKSOURCE_OF_DECLARE(s5pc100_pwm, "samsung,s5pc100-pwm", s5p_pwm_clocksource_init);
	508	#endif