[linux-2.6-block.git] / drivers / clocksource / tegra20_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 <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>
#include <linux/delay.h>

#include <asm/mach/time.h>
#include <asm/smp_twd.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;
static void __iomem *rtc_base;

static struct timespec64 persistent_ts;
static u64 persistent_ms, last_persistent_ms;

static struct delay_timer tegra_delay_timer;

#define timer_writel(value, reg) \
	writel_relaxed(value, timer_reg_base + (reg))
#define timer_readl(reg) \
	readl_relaxed(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 inline void timer_shutdown(struct clock_event_device *evt)
{
	timer_writel(0, TIMER3_BASE + TIMER_PTV);
}

static int tegra_timer_shutdown(struct clock_event_device *evt)
{
	timer_shutdown(evt);
	return 0;
}

static int tegra_timer_set_periodic(struct clock_event_device *evt)
{
	u32 reg = 0xC0000000 | ((1000000 / HZ) - 1);

	timer_shutdown(evt);
	timer_writel(reg, TIMER3_BASE + TIMER_PTV);
	return 0;
}

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_state_shutdown	= tegra_timer_shutdown,
	.set_state_periodic	= tegra_timer_set_periodic,
	.set_state_oneshot	= tegra_timer_shutdown,
	.tick_resume		= tegra_timer_shutdown,
};

static u64 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_clock64 -  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 timespec64.
 * 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_clock64(struct timespec64 *ts)
{
	u64 delta;

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

	timespec64_add_ns(&persistent_ts, delta * NSEC_PER_MSEC);
	*ts = persistent_ts;
}

static unsigned long tegra_delay_timer_read_counter_long(void)
{
	return readl(timer_reg_base + TIMERUS_CNTR_1US);
}

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_TIMER | IRQF_TRIGGER_HIGH,
	.handler	= tegra_timer_interrupt,
	.dev_id		= &tegra_clockevent,
};

static void __init tegra20_init_timer(struct device_node *np)
{
	struct clk *clk;
	unsigned long rate;
	int ret;

	timer_reg_base = of_iomap(np, 0);
	if (!timer_reg_base) {
		pr_err("Can't map timer registers\n");
		BUG();
	}

	tegra_timer_irq.irq = irq_of_parse_and_map(np, 2);
	if (tegra_timer_irq.irq <= 0) {
		pr_err("Failed to map timer IRQ\n");
		BUG();
	}

	clk = of_clk_get(np, 0);
	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);
	}

	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");
	}

	sched_clock_register(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)) {
		pr_err("Failed to register clocksource\n");
		BUG();
	}

	tegra_delay_timer.read_current_timer =
			tegra_delay_timer_read_counter_long;
	tegra_delay_timer.freq = 1000000;
	register_current_timer_delay(&tegra_delay_timer);

	ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
	if (ret) {
		pr_err("Failed to register timer IRQ: %d\n", ret);
		BUG();
	}

	tegra_clockevent.cpumask = cpu_all_mask;
	tegra_clockevent.irq = tegra_timer_irq.irq;
	clockevents_config_and_register(&tegra_clockevent, 1000000,
					0x1, 0x1fffffff);
}
CLOCKSOURCE_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra20_init_timer);

static void __init tegra20_init_rtc(struct device_node *np)
{
	struct clk *clk;

	rtc_base = of_iomap(np, 0);
	if (!rtc_base) {
		pr_err("Can't map RTC registers");
		BUG();
	}

	/*
	 * rtc registers are used by read_persistent_clock, keep the rtc clock
	 * enabled
	 */
	clk = of_clk_get(np, 0);
	if (IS_ERR(clk))
		pr_warn("Unable to get rtc-tegra clock\n");
	else
		clk_prepare_enable(clk);

	register_persistent_clock(NULL, tegra_read_persistent_clock64);
}
CLOCKSOURCE_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);

#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
Commit	Line	Data
2d5cd9a3	1	/*
2d5cd9a3 CC	2	* Copyright (C) 2010 Google, Inc.
	3	*
	4	* Author:
	5	* Colin Cross <ccross@google.com>
	6	*
	7	* This software is licensed under the terms of the GNU General Public
	8	* License version 2, as published by the Free Software Foundation, and
	9	* may be copied, distributed, and modified under those terms.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	*/
	17
	18	#include <linux/init.h>
62248ae8	19	#include <linux/err.h>
2d5cd9a3 CC	20	#include <linux/time.h>
	21	#include <linux/interrupt.h>
	22	#include <linux/irq.h>
	23	#include <linux/clockchips.h>
	24	#include <linux/clocksource.h>
	25	#include <linux/clk.h>
	26	#include <linux/io.h>
3a04931e	27	#include <linux/of_address.h>
56415480	28	#include <linux/of_irq.h>
38ff87f7	29	#include <linux/sched_clock.h>
0ff36b4f	30	#include <linux/delay.h>
2d5cd9a3	31
2d5cd9a3	32	#include <asm/mach/time.h>
1fcf3a6e	33	#include <asm/smp_twd.h>
2d5cd9a3	34
09361785 CC	35	#define RTC_SECONDS 0x08
	36	#define RTC_SHADOW_SECONDS 0x0c
	37	#define RTC_MILLISECONDS 0x10
	38
2d5cd9a3 CC	39	#define TIMERUS_CNTR_1US 0x10
	40	#define TIMERUS_USEC_CFG 0x14
	41	#define TIMERUS_CNTR_FREEZE 0x4c
	42
	43	#define TIMER1_BASE 0x0
	44	#define TIMER2_BASE 0x8
	45	#define TIMER3_BASE 0x50
	46	#define TIMER4_BASE 0x58
	47
	48	#define TIMER_PTV 0x0
	49	#define TIMER_PCR 0x4
	50
3a04931e SW	51	static void __iomem *timer_reg_base;
3a04931e SW	52	static void __iomem *rtc_base;
09361785	53
a0c2998f	54	static struct timespec64 persistent_ts;
09361785	55	static u64 persistent_ms, last_persistent_ms;
2d5cd9a3	56
0ff36b4f PDS	57	static struct delay_timer tegra_delay_timer;
0ff36b4f PDS	58
2d5cd9a3	59	#define timer_writel(value, reg) \
59196bce	60	writel_relaxed(value, timer_reg_base + (reg))
2d5cd9a3	61	#define timer_readl(reg) \
59196bce	62	readl_relaxed(timer_reg_base + (reg))
2d5cd9a3 CC	63
	64	static int tegra_timer_set_next_event(unsigned long cycles,
	65	struct clock_event_device *evt)
	66	{
	67	u32 reg;
	68
	69	reg = 0x80000000 \| ((cycles > 1) ? (cycles-1) : 0);
	70	timer_writel(reg, TIMER3_BASE + TIMER_PTV);
	71
	72	return 0;
	73	}
	74
4134d29b	75	static inline void timer_shutdown(struct clock_event_device *evt)
2d5cd9a3	76	{
2d5cd9a3	77	timer_writel(0, TIMER3_BASE + TIMER_PTV);
4134d29b	78	}
2d5cd9a3	79
4134d29b VK	80	static int tegra_timer_shutdown(struct clock_event_device *evt)
	81	{
	82	timer_shutdown(evt);
	83	return 0;
	84	}
	85
	86	static int tegra_timer_set_periodic(struct clock_event_device *evt)
	87	{
	88	u32 reg = 0xC0000000 \| ((1000000 / HZ) - 1);
	89
	90	timer_shutdown(evt);
	91	timer_writel(reg, TIMER3_BASE + TIMER_PTV);
	92	return 0;
2d5cd9a3 CC	93	}
2d5cd9a3 CC	94
2d5cd9a3	95	static struct clock_event_device tegra_clockevent = {
4134d29b VK	96	.name = "timer0",
	97	.rating = 300,
	98	.features = CLOCK_EVT_FEAT_ONESHOT \|
	99	CLOCK_EVT_FEAT_PERIODIC,
	100	.set_next_event = tegra_timer_set_next_event,
	101	.set_state_shutdown = tegra_timer_shutdown,
	102	.set_state_periodic = tegra_timer_set_periodic,
	103	.set_state_oneshot = tegra_timer_shutdown,
	104	.tick_resume = tegra_timer_shutdown,
2d5cd9a3 CC	105	};
2d5cd9a3 CC	106
35702999	107	static u64 notrace tegra_read_sched_clock(void)
e3f4c0ab	108	{
2f0778af	109	return timer_readl(TIMERUS_CNTR_1US);
2d5cd9a3 CC	110	}
2d5cd9a3 CC	111
09361785 CC	112	/*
	113	* tegra_rtc_read - Reads the Tegra RTC registers
	114	* Care must be taken that this funciton is not called while the
	115	* tegra_rtc driver could be executing to avoid race conditions
	116	* on the RTC shadow register
	117	*/
b28fba2a	118	static u64 tegra_rtc_read_ms(void)
09361785 CC	119	{
	120	u32 ms = readl(rtc_base + RTC_MILLISECONDS);
	121	u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
	122	return (u64)s * MSEC_PER_SEC + ms;
	123	}
	124
	125	/*
a0c2998f	126	* tegra_read_persistent_clock64 - Return time from a persistent clock.
09361785 CC	127	*
	128	* Reads the time from a source which isn't disabled during PM, the
	129	* 32k sync timer. Convert the cycles elapsed since last read into
a0c2998f	130	* nsecs and adds to a monotonically increasing timespec64.
09361785 CC	131	* Care must be taken that this funciton is not called while the
	132	* tegra_rtc driver could be executing to avoid race conditions
	133	* on the RTC shadow register
	134	*/
a0c2998f	135	static void tegra_read_persistent_clock64(struct timespec64 *ts)
09361785 CC	136	{
09361785 CC	137	u64 delta;
09361785 CC	138
	139	last_persistent_ms = persistent_ms;
	140	persistent_ms = tegra_rtc_read_ms();
	141	delta = persistent_ms - last_persistent_ms;
	142
a0c2998f XP	143	timespec64_add_ns(&persistent_ts, delta * NSEC_PER_MSEC);
	144	*ts = persistent_ts;
	145	}
	146
0ff36b4f PDS	147	static unsigned long tegra_delay_timer_read_counter_long(void)
	148	{
	149	return readl(timer_reg_base + TIMERUS_CNTR_1US);
	150	}
	151
2d5cd9a3 CC	152	static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)
	153	{
	154	struct clock_event_device evt = (struct clock_event_device )dev_id;
	155	timer_writel(1<<30, TIMER3_BASE + TIMER_PCR);
	156	evt->event_handler(evt);
	157	return IRQ_HANDLED;
	158	}
	159
	160	static struct irqaction tegra_timer_irq = {
	161	.name = "timer0",
39304fad	162	.flags = IRQF_TIMER \| IRQF_TRIGGER_HIGH,
2d5cd9a3 CC	163	.handler = tegra_timer_interrupt,
2d5cd9a3 CC	164	.dev_id = &tegra_clockevent,
2d5cd9a3 CC	165	};
2d5cd9a3 CC	166
effbfdd7	167	static void __init tegra20_init_timer(struct device_node *np)
2d5cd9a3	168	{
62248ae8	169	struct clk *clk;
8e4fab2c	170	unsigned long rate;
2d5cd9a3 CC	171	int ret;
2d5cd9a3 CC	172
3a04931e SW	173	timer_reg_base = of_iomap(np, 0);
3a04931e SW	174	if (!timer_reg_base) {
37340866	175	pr_err("Can't map timer registers\n");
3a04931e SW	176	BUG();
	177	}
	178
56415480 SW	179	tegra_timer_irq.irq = irq_of_parse_and_map(np, 2);
	180	if (tegra_timer_irq.irq <= 0) {
	181	pr_err("Failed to map timer IRQ\n");
	182	BUG();
	183	}
	184
6f88fb8a	185	clk = of_clk_get(np, 0);
8e4fab2c	186	if (IS_ERR(clk)) {
58664f90	187	pr_warn("Unable to get timer clock. Assuming 12Mhz input clock.\n");
8e4fab2c PDS	188	rate = 12000000;
8e4fab2c PDS	189	} else {
6a5278d0	190	clk_prepare_enable(clk);
8e4fab2c PDS	191	rate = clk_get_rate(clk);
8e4fab2c PDS	192	}
62248ae8	193
2d5cd9a3 CC	194	switch (rate) {
	195	case 12000000:
	196	timer_writel(0x000b, TIMERUS_USEC_CFG);
	197	break;
	198	case 13000000:
	199	timer_writel(0x000c, TIMERUS_USEC_CFG);
	200	break;
	201	case 19200000:
	202	timer_writel(0x045f, TIMERUS_USEC_CFG);
	203	break;
	204	case 26000000:
	205	timer_writel(0x0019, TIMERUS_USEC_CFG);
	206	break;
	207	default:
	208	WARN(1, "Unknown clock rate");
	209	}
	210
35702999	211	sched_clock_register(tegra_read_sched_clock, 32, 1000000);
e3f4c0ab	212
234b6ced RK	213	if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
234b6ced RK	214	"timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) {
58664f90	215	pr_err("Failed to register clocksource\n");
2d5cd9a3 CC	216	BUG();
	217	}
	218
0ff36b4f PDS	219	tegra_delay_timer.read_current_timer =
	220	tegra_delay_timer_read_counter_long;
	221	tegra_delay_timer.freq = 1000000;
	222	register_current_timer_delay(&tegra_delay_timer);
	223
2d5cd9a3 CC	224	ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
2d5cd9a3 CC	225	if (ret) {
58664f90	226	pr_err("Failed to register timer IRQ: %d\n", ret);
2d5cd9a3 CC	227	BUG();
	228	}
	229
2d5cd9a3 CC	230	tegra_clockevent.cpumask = cpu_all_mask;
2d5cd9a3 CC	231	tegra_clockevent.irq = tegra_timer_irq.irq;
838a2ae8 SG	232	clockevents_config_and_register(&tegra_clockevent, 1000000,
838a2ae8 SG	233	0x1, 0x1fffffff);
1d16cfb3 RH	234	}
	235	CLOCKSOURCE_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra20_init_timer);
	236
	237	static void __init tegra20_init_rtc(struct device_node *np)
	238	{
	239	struct clk *clk;
	240
	241	rtc_base = of_iomap(np, 0);
	242	if (!rtc_base) {
	243	pr_err("Can't map RTC registers");
	244	BUG();
	245	}
	246
	247	/*
	248	* rtc registers are used by read_persistent_clock, keep the rtc clock
	249	* enabled
	250	*/
8024206d	251	clk = of_clk_get(np, 0);
1d16cfb3 RH	252	if (IS_ERR(clk))
	253	pr_warn("Unable to get rtc-tegra clock\n");
	254	else
	255	clk_prepare_enable(clk);
	256
cb850717	257	register_persistent_clock(NULL, tegra_read_persistent_clock64);
2d5cd9a3	258	}
1d16cfb3	259	CLOCKSOURCE_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);
2d5cd9a3	260
09361785 CC	261	#ifdef CONFIG_PM
	262	static u32 usec_config;
	263
	264	void tegra_timer_suspend(void)
	265	{
	266	usec_config = timer_readl(TIMERUS_USEC_CFG);
	267	}
	268
	269	void tegra_timer_resume(void)
	270	{
	271	timer_writel(usec_config, TIMERUS_USEC_CFG);
	272	}
	273	#endif