[deliverable/linux.git] / arch / arm / mach-prima2 / timer.c

/*
 * System timer for CSR SiRFprimaII
 *
 * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
 *
 * Licensed under GPLv2 or later.
 */

#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/bitops.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <mach/map.h>
#include <asm/mach/time.h>

#define SIRFSOC_TIMER_COUNTER_LO	0x0000
#define SIRFSOC_TIMER_COUNTER_HI	0x0004
#define SIRFSOC_TIMER_MATCH_0		0x0008
#define SIRFSOC_TIMER_MATCH_1		0x000C
#define SIRFSOC_TIMER_MATCH_2		0x0010
#define SIRFSOC_TIMER_MATCH_3		0x0014
#define SIRFSOC_TIMER_MATCH_4		0x0018
#define SIRFSOC_TIMER_MATCH_5		0x001C
#define SIRFSOC_TIMER_STATUS		0x0020
#define SIRFSOC_TIMER_INT_EN		0x0024
#define SIRFSOC_TIMER_WATCHDOG_EN	0x0028
#define SIRFSOC_TIMER_DIV		0x002C
#define SIRFSOC_TIMER_LATCH		0x0030
#define SIRFSOC_TIMER_LATCHED_LO	0x0034
#define SIRFSOC_TIMER_LATCHED_HI	0x0038

#define SIRFSOC_TIMER_WDT_INDEX		5

#define SIRFSOC_TIMER_LATCH_BIT	 BIT(0)

#define SIRFSOC_TIMER_REG_CNT 11

static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = {
	SIRFSOC_TIMER_MATCH_0, SIRFSOC_TIMER_MATCH_1, SIRFSOC_TIMER_MATCH_2,
	SIRFSOC_TIMER_MATCH_3, SIRFSOC_TIMER_MATCH_4, SIRFSOC_TIMER_MATCH_5,
	SIRFSOC_TIMER_INT_EN, SIRFSOC_TIMER_WATCHDOG_EN, SIRFSOC_TIMER_DIV,
	SIRFSOC_TIMER_LATCHED_LO, SIRFSOC_TIMER_LATCHED_HI,
};

static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT];

static void __iomem *sirfsoc_timer_base;
static void __init sirfsoc_of_timer_map(void);

/* timer0 interrupt handler */
static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *ce = dev_id;

	WARN_ON(!(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_STATUS) & BIT(0)));

	/* clear timer0 interrupt */
	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);

	ce->event_handler(ce);

	return IRQ_HANDLED;
}

/* read 64-bit timer counter */
static cycle_t sirfsoc_timer_read(struct clocksource *cs)
{
	u64 cycles;

	/* latch the 64-bit timer counter */
	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
	cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_HI);
	cycles = (cycles << 32) | readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);

	return cycles;
}

static int sirfsoc_timer_set_next_event(unsigned long delta,
	struct clock_event_device *ce)
{
	unsigned long now, next;

	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
	now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
	next = now + delta;
	writel_relaxed(next, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0);
	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
	now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);

	return next - now > delta ? -ETIME : 0;
}

static void sirfsoc_timer_set_mode(enum clock_event_mode mode,
	struct clock_event_device *ce)
{
	u32 val = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
		WARN_ON(1);
		break;
	case CLOCK_EVT_MODE_ONESHOT:
		writel_relaxed(val | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
		break;
	case CLOCK_EVT_MODE_SHUTDOWN:
		writel_relaxed(val & ~BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
		break;
	case CLOCK_EVT_MODE_UNUSED:
	case CLOCK_EVT_MODE_RESUME:
		break;
	}
}

static void sirfsoc_clocksource_suspend(struct clocksource *cs)
{
	int i;

	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);

	for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
		sirfsoc_timer_reg_val[i] = readl_relaxed(sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
}

static void sirfsoc_clocksource_resume(struct clocksource *cs)
{
	int i;

	for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
		writel_relaxed(sirfsoc_timer_reg_val[i], sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);

	writel_relaxed(sirfsoc_timer_reg_val[i - 2], sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
	writel_relaxed(sirfsoc_timer_reg_val[i - 1], sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
}

static struct clock_event_device sirfsoc_clockevent = {
	.name = "sirfsoc_clockevent",
	.rating = 200,
	.features = CLOCK_EVT_FEAT_ONESHOT,
	.set_mode = sirfsoc_timer_set_mode,
	.set_next_event = sirfsoc_timer_set_next_event,
};

static struct clocksource sirfsoc_clocksource = {
	.name = "sirfsoc_clocksource",
	.rating = 200,
	.mask = CLOCKSOURCE_MASK(64),
	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
	.read = sirfsoc_timer_read,
	.suspend = sirfsoc_clocksource_suspend,
	.resume = sirfsoc_clocksource_resume,
};

static struct irqaction sirfsoc_timer_irq = {
	.name = "sirfsoc_timer0",
	.flags = IRQF_TIMER,
	.irq = 0,
	.handler = sirfsoc_timer_interrupt,
	.dev_id = &sirfsoc_clockevent,
};

/* Overwrite weak default sched_clock with more precise one */
unsigned long long notrace sched_clock(void)
{
	static int is_mapped;

	/*
	 * sched_clock is called earlier than .init of sys_timer
	 * if we map timer memory in .init of sys_timer, system
	 * will panic due to illegal memory access
	 */
	if (!is_mapped) {
		sirfsoc_of_timer_map();
		is_mapped = 1;
	}

	return sirfsoc_timer_read(NULL) * (NSEC_PER_SEC / CLOCK_TICK_RATE);
}

static void __init sirfsoc_clockevent_init(void)
{
	clockevents_calc_mult_shift(&sirfsoc_clockevent, CLOCK_TICK_RATE, 60);

	sirfsoc_clockevent.max_delta_ns =
		clockevent_delta2ns(-2, &sirfsoc_clockevent);
	sirfsoc_clockevent.min_delta_ns =
		clockevent_delta2ns(2, &sirfsoc_clockevent);

	sirfsoc_clockevent.cpumask = cpumask_of(0);
	clockevents_register_device(&sirfsoc_clockevent);
}

/* initialize the kernel jiffy timer source */
static void __init sirfsoc_timer_init(void)
{
	unsigned long rate;

	/* timer's input clock is io clock */
	struct clk *clk = clk_get_sys("io", NULL);

	BUG_ON(IS_ERR(clk));

	rate = clk_get_rate(clk);

	BUG_ON(rate < CLOCK_TICK_RATE);
	BUG_ON(rate % CLOCK_TICK_RATE);

	writel_relaxed(rate / CLOCK_TICK_RATE / 2 - 1, sirfsoc_timer_base + SIRFSOC_TIMER_DIV);
	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);

	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));

	BUG_ON(setup_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq));

	sirfsoc_clockevent_init();
}

static struct of_device_id timer_ids[] = {
	{ .compatible = "sirf,prima2-tick" },
	{},
};

static void __init sirfsoc_of_timer_map(void)
{
	struct device_node *np;
	const unsigned int *intspec;

	np = of_find_matching_node(NULL, timer_ids);
	if (!np)
		panic("unable to find compatible timer node in dtb\n");
	sirfsoc_timer_base = of_iomap(np, 0);
	if (!sirfsoc_timer_base)
		panic("unable to map timer cpu registers\n");

	/* Get the interrupts property */
	intspec = of_get_property(np, "interrupts", NULL);
	BUG_ON(!intspec);
	sirfsoc_timer_irq.irq = be32_to_cpup(intspec);

	of_node_put(np);
}

struct sys_timer sirfsoc_timer = {
	.init = sirfsoc_timer_init,
};
Commit	Line	Data
02c981c0 BD	1	/*
	2	* System timer for CSR SiRFprimaII
	3	*
	4	* Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
	5	*
	6	* Licensed under GPLv2 or later.
	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/interrupt.h>
	11	#include <linux/clockchips.h>
	12	#include <linux/clocksource.h>
	13	#include <linux/bitops.h>
	14	#include <linux/irq.h>
	15	#include <linux/clk.h>
	16	#include <linux/err.h>
	17	#include <linux/slab.h>
	18	#include <linux/of.h>
	19	#include <linux/of_address.h>
	20	#include <mach/map.h>
	21	#include <asm/mach/time.h>
	22
	23	#define SIRFSOC_TIMER_COUNTER_LO 0x0000
	24	#define SIRFSOC_TIMER_COUNTER_HI 0x0004
	25	#define SIRFSOC_TIMER_MATCH_0 0x0008
	26	#define SIRFSOC_TIMER_MATCH_1 0x000C
	27	#define SIRFSOC_TIMER_MATCH_2 0x0010
	28	#define SIRFSOC_TIMER_MATCH_3 0x0014
	29	#define SIRFSOC_TIMER_MATCH_4 0x0018
	30	#define SIRFSOC_TIMER_MATCH_5 0x001C
	31	#define SIRFSOC_TIMER_STATUS 0x0020
	32	#define SIRFSOC_TIMER_INT_EN 0x0024
	33	#define SIRFSOC_TIMER_WATCHDOG_EN 0x0028
	34	#define SIRFSOC_TIMER_DIV 0x002C
	35	#define SIRFSOC_TIMER_LATCH 0x0030
	36	#define SIRFSOC_TIMER_LATCHED_LO 0x0034
	37	#define SIRFSOC_TIMER_LATCHED_HI 0x0038
	38
	39	#define SIRFSOC_TIMER_WDT_INDEX 5
	40
	41	#define SIRFSOC_TIMER_LATCH_BIT BIT(0)
	42
e5598a85 BS	43	#define SIRFSOC_TIMER_REG_CNT 11
	44
	45	static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = {
	46	SIRFSOC_TIMER_MATCH_0, SIRFSOC_TIMER_MATCH_1, SIRFSOC_TIMER_MATCH_2,
	47	SIRFSOC_TIMER_MATCH_3, SIRFSOC_TIMER_MATCH_4, SIRFSOC_TIMER_MATCH_5,
	48	SIRFSOC_TIMER_INT_EN, SIRFSOC_TIMER_WATCHDOG_EN, SIRFSOC_TIMER_DIV,
	49	SIRFSOC_TIMER_LATCHED_LO, SIRFSOC_TIMER_LATCHED_HI,
	50	};
	51
	52	static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT];
	53
02c981c0 BD	54	static void __iomem *sirfsoc_timer_base;
	55	static void __init sirfsoc_of_timer_map(void);
	56
	57	/* timer0 interrupt handler */
	58	static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
	59	{
	60	struct clock_event_device *ce = dev_id;
	61
	62	WARN_ON(!(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_STATUS) & BIT(0)));
	63
	64	/* clear timer0 interrupt */
	65	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
	66
	67	ce->event_handler(ce);
	68
	69	return IRQ_HANDLED;
	70	}
	71
	72	/* read 64-bit timer counter */
	73	static cycle_t sirfsoc_timer_read(struct clocksource *cs)
	74	{
	75	u64 cycles;
	76
	77	/* latch the 64-bit timer counter */
	78	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
	79	cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_HI);
	80	cycles = (cycles << 32) \| readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
	81
	82	return cycles;
	83	}
	84
	85	static int sirfsoc_timer_set_next_event(unsigned long delta,
	86	struct clock_event_device *ce)
	87	{
	88	unsigned long now, next;
	89
	90	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
	91	now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
	92	next = now + delta;
	93	writel_relaxed(next, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0);
	94	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
	95	now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
	96
	97	return next - now > delta ? -ETIME : 0;
	98	}
	99
	100	static void sirfsoc_timer_set_mode(enum clock_event_mode mode,
	101	struct clock_event_device *ce)
	102	{
	103	u32 val = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
	104	switch (mode) {
	105	case CLOCK_EVT_MODE_PERIODIC:
	106	WARN_ON(1);
	107	break;
	108	case CLOCK_EVT_MODE_ONESHOT:
	109	writel_relaxed(val \| BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
	110	break;
	111	case CLOCK_EVT_MODE_SHUTDOWN:
	112	writel_relaxed(val & ~BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
	113	break;
	114	case CLOCK_EVT_MODE_UNUSED:
	115	case CLOCK_EVT_MODE_RESUME:
	116	break;
	117	}
118	}
119
e5598a85 BS	120	static void sirfsoc_clocksource_suspend(struct clocksource *cs)
	121	{
	122	int i;
	123
	124	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
	125
	126	for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
	127	sirfsoc_timer_reg_val[i] = readl_relaxed(sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
	128	}
	129
	130	static void sirfsoc_clocksource_resume(struct clocksource *cs)
	131	{
	132	int i;
	133
	134	for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
	135	writel_relaxed(sirfsoc_timer_reg_val[i], sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
	136
	137	writel_relaxed(sirfsoc_timer_reg_val[i - 2], sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
	138	writel_relaxed(sirfsoc_timer_reg_val[i - 1], sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
	139	}
	140
02c981c0 BD	141	static struct clock_event_device sirfsoc_clockevent = {
	142	.name = "sirfsoc_clockevent",
	143	.rating = 200,
	144	.features = CLOCK_EVT_FEAT_ONESHOT,
	145	.set_mode = sirfsoc_timer_set_mode,
	146	.set_next_event = sirfsoc_timer_set_next_event,
	147	};
	148
	149	static struct clocksource sirfsoc_clocksource = {
	150	.name = "sirfsoc_clocksource",
	151	.rating = 200,
	152	.mask = CLOCKSOURCE_MASK(64),
	153	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
	154	.read = sirfsoc_timer_read,
e5598a85 BS	155	.suspend = sirfsoc_clocksource_suspend,
e5598a85 BS	156	.resume = sirfsoc_clocksource_resume,
02c981c0 BD	157	};
	158
	159	static struct irqaction sirfsoc_timer_irq = {
	160	.name = "sirfsoc_timer0",
	161	.flags = IRQF_TIMER,
	162	.irq = 0,
	163	.handler = sirfsoc_timer_interrupt,
	164	.dev_id = &sirfsoc_clockevent,
	165	};
	166
	167	/* Overwrite weak default sched_clock with more precise one */
	168	unsigned long long notrace sched_clock(void)
	169	{
f70fc57e	170	static int is_mapped;
02c981c0 BD	171
	172	/*
	173	* sched_clock is called earlier than .init of sys_timer
	174	* if we map timer memory in .init of sys_timer, system
	175	* will panic due to illegal memory access
	176	*/
c6b96c54	177	if (!is_mapped) {
02c981c0 BD	178	sirfsoc_of_timer_map();
	179	is_mapped = 1;
	180	}
	181
	182	return sirfsoc_timer_read(NULL) * (NSEC_PER_SEC / CLOCK_TICK_RATE);
	183	}
	184
	185	static void __init sirfsoc_clockevent_init(void)
	186	{
	187	clockevents_calc_mult_shift(&sirfsoc_clockevent, CLOCK_TICK_RATE, 60);
	188
	189	sirfsoc_clockevent.max_delta_ns =
	190	clockevent_delta2ns(-2, &sirfsoc_clockevent);
	191	sirfsoc_clockevent.min_delta_ns =
	192	clockevent_delta2ns(2, &sirfsoc_clockevent);
	193
	194	sirfsoc_clockevent.cpumask = cpumask_of(0);
	195	clockevents_register_device(&sirfsoc_clockevent);
	196	}
	197
	198	/* initialize the kernel jiffy timer source */
	199	static void __init sirfsoc_timer_init(void)
	200	{
	201	unsigned long rate;
	202
	203	/* timer's input clock is io clock */
	204	struct clk *clk = clk_get_sys("io", NULL);
	205
	206	BUG_ON(IS_ERR(clk));
	207
	208	rate = clk_get_rate(clk);
	209
	210	BUG_ON(rate < CLOCK_TICK_RATE);
	211	BUG_ON(rate % CLOCK_TICK_RATE);
	212
	213	writel_relaxed(rate / CLOCK_TICK_RATE / 2 - 1, sirfsoc_timer_base + SIRFSOC_TIMER_DIV);
	214	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
	215	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
	216	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
	217
	218	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
	219
	220	BUG_ON(setup_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq));
	221
	222	sirfsoc_clockevent_init();
	223	}
	224
	225	static struct of_device_id timer_ids[] = {
	226	{ .compatible = "sirf,prima2-tick" },
6a53747b	227	{},
02c981c0 BD	228	};
	229
	230	static void __init sirfsoc_of_timer_map(void)
	231	{
	232	struct device_node *np;
	233	const unsigned int *intspec;
	234
	235	np = of_find_matching_node(NULL, timer_ids);
	236	if (!np)
	237	panic("unable to find compatible timer node in dtb\n");
	238	sirfsoc_timer_base = of_iomap(np, 0);
	239	if (!sirfsoc_timer_base)
	240	panic("unable to map timer cpu registers\n");
	241
	242	/* Get the interrupts property */
	243	intspec = of_get_property(np, "interrupts", NULL);
	244	BUG_ON(!intspec);
	245	sirfsoc_timer_irq.irq = be32_to_cpup(intspec);
	246
	247	of_node_put(np);
	248	}
	249
	250	struct sys_timer sirfsoc_timer = {
	251	.init = sirfsoc_timer_init,
	252	};