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

/*
 *  linux/drivers/clocksource/arm_arch_timer.c
 *
 *  Copyright (C) 2011 ARM Ltd.
 *  All Rights Reserved
 *
 * 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/init.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/io.h>

#include <asm/arch_timer.h>
#include <asm/virt.h>

#include <clocksource/arm_arch_timer.h>

static u32 arch_timer_rate;

enum ppi_nr {
	PHYS_SECURE_PPI,
	PHYS_NONSECURE_PPI,
	VIRT_PPI,
	HYP_PPI,
	MAX_TIMER_PPI
};

static int arch_timer_ppi[MAX_TIMER_PPI];

static struct clock_event_device __percpu *arch_timer_evt;

static bool arch_timer_use_virtual = true;

/*
 * Architected system timer support.
 */

static inline irqreturn_t timer_handler(const int access,
					struct clock_event_device *evt)
{
	unsigned long ctrl;
	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
	if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
		ctrl |= ARCH_TIMER_CTRL_IT_MASK;
		arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
		evt->event_handler(evt);
		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

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

	return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
}

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

	return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
}

static inline void timer_set_mode(const int access, int mode)
{
	unsigned long ctrl;
	switch (mode) {
	case CLOCK_EVT_MODE_UNUSED:
	case CLOCK_EVT_MODE_SHUTDOWN:
		ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
		ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
		arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
		break;
	default:
		break;
	}
}

static void arch_timer_set_mode_virt(enum clock_event_mode mode,
				     struct clock_event_device *clk)
{
	timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode);
}

static void arch_timer_set_mode_phys(enum clock_event_mode mode,
				     struct clock_event_device *clk)
{
	timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode);
}

static inline void set_next_event(const int access, unsigned long evt)
{
	unsigned long ctrl;
	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
	ctrl |= ARCH_TIMER_CTRL_ENABLE;
	ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
	arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
}

static int arch_timer_set_next_event_virt(unsigned long evt,
					  struct clock_event_device *unused)
{
	set_next_event(ARCH_TIMER_VIRT_ACCESS, evt);
	return 0;
}

static int arch_timer_set_next_event_phys(unsigned long evt,
					  struct clock_event_device *unused)
{
	set_next_event(ARCH_TIMER_PHYS_ACCESS, evt);
	return 0;
}

static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
{
	clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
	clk->name = "arch_sys_timer";
	clk->rating = 450;
	if (arch_timer_use_virtual) {
		clk->irq = arch_timer_ppi[VIRT_PPI];
		clk->set_mode = arch_timer_set_mode_virt;
		clk->set_next_event = arch_timer_set_next_event_virt;
	} else {
		clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
		clk->set_mode = arch_timer_set_mode_phys;
		clk->set_next_event = arch_timer_set_next_event_phys;
	}

	clk->cpumask = cpumask_of(smp_processor_id());

	clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);

	clockevents_config_and_register(clk, arch_timer_rate,
					0xf, 0x7fffffff);

	if (arch_timer_use_virtual)
		enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
	else {
		enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
		if (arch_timer_ppi[PHYS_NONSECURE_PPI])
			enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
	}

	arch_counter_set_user_access();

	return 0;
}

static int arch_timer_available(void)
{
	u32 freq;

	if (arch_timer_rate == 0) {
		freq = arch_timer_get_cntfrq();

		/* Check the timer frequency. */
		if (freq == 0) {
			pr_warn("Architected timer frequency not available\n");
			return -EINVAL;
		}

		arch_timer_rate = freq;
	}

	pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n",
		     (unsigned long)arch_timer_rate / 1000000,
		     (unsigned long)(arch_timer_rate / 10000) % 100,
		     arch_timer_use_virtual ? "virt" : "phys");
	return 0;
}

u32 arch_timer_get_rate(void)
{
	return arch_timer_rate;
}

/*
 * Some external users of arch_timer_read_counter (e.g. sched_clock) may try to
 * call it before it has been initialised. Rather than incur a performance
 * penalty checking for initialisation, provide a default implementation that
 * won't lead to time appearing to jump backwards.
 */
static u64 arch_timer_read_zero(void)
{
	return 0;
}

u64 (*arch_timer_read_counter)(void) = arch_timer_read_zero;

static cycle_t arch_counter_read(struct clocksource *cs)
{
	return arch_timer_read_counter();
}

static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
{
	return arch_timer_read_counter();
}

static struct clocksource clocksource_counter = {
	.name	= "arch_sys_counter",
	.rating	= 400,
	.read	= arch_counter_read,
	.mask	= CLOCKSOURCE_MASK(56),
	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
};

static struct cyclecounter cyclecounter = {
	.read	= arch_counter_read_cc,
	.mask	= CLOCKSOURCE_MASK(56),
};

static struct timecounter timecounter;

struct timecounter *arch_timer_get_timecounter(void)
{
	return &timecounter;
}

static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
{
	pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
		 clk->irq, smp_processor_id());

	if (arch_timer_use_virtual)
		disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
	else {
		disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
		if (arch_timer_ppi[PHYS_NONSECURE_PPI])
			disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
	}

	clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
}

static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
					   unsigned long action, void *hcpu)
{
	struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt);

	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_STARTING:
		arch_timer_setup(evt);
		break;
	case CPU_DYING:
		arch_timer_stop(evt);
		break;
	}

	return NOTIFY_OK;
}

static struct notifier_block arch_timer_cpu_nb __cpuinitdata = {
	.notifier_call = arch_timer_cpu_notify,
};

static int __init arch_timer_register(void)
{
	int err;
	int ppi;

	err = arch_timer_available();
	if (err)
		goto out;

	arch_timer_evt = alloc_percpu(struct clock_event_device);
	if (!arch_timer_evt) {
		err = -ENOMEM;
		goto out;
	}

	clocksource_register_hz(&clocksource_counter, arch_timer_rate);
	cyclecounter.mult = clocksource_counter.mult;
	cyclecounter.shift = clocksource_counter.shift;
	timecounter_init(&timecounter, &cyclecounter,
			 arch_counter_get_cntpct());

	if (arch_timer_use_virtual) {
		ppi = arch_timer_ppi[VIRT_PPI];
		err = request_percpu_irq(ppi, arch_timer_handler_virt,
					 "arch_timer", arch_timer_evt);
	} else {
		ppi = arch_timer_ppi[PHYS_SECURE_PPI];
		err = request_percpu_irq(ppi, arch_timer_handler_phys,
					 "arch_timer", arch_timer_evt);
		if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
			ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
			err = request_percpu_irq(ppi, arch_timer_handler_phys,
						 "arch_timer", arch_timer_evt);
			if (err)
				free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
						arch_timer_evt);
		}
	}

	if (err) {
		pr_err("arch_timer: can't register interrupt %d (%d)\n",
		       ppi, err);
		goto out_free;
	}

	err = register_cpu_notifier(&arch_timer_cpu_nb);
	if (err)
		goto out_free_irq;

	/* Immediately configure the timer on the boot CPU */
	arch_timer_setup(this_cpu_ptr(arch_timer_evt));

	return 0;

out_free_irq:
	if (arch_timer_use_virtual)
		free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
	else {
		free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
				arch_timer_evt);
		if (arch_timer_ppi[PHYS_NONSECURE_PPI])
			free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
					arch_timer_evt);
	}

out_free:
	free_percpu(arch_timer_evt);
out:
	return err;
}

static const struct of_device_id arch_timer_of_match[] __initconst = {
	{ .compatible	= "arm,armv7-timer",	},
	{ .compatible	= "arm,armv8-timer",	},
	{},
};

int __init arch_timer_init(void)
{
	struct device_node *np;
	u32 freq;
	int i;

	np = of_find_matching_node(NULL, arch_timer_of_match);
	if (!np) {
		pr_err("arch_timer: can't find DT node\n");
		return -ENODEV;
	}

	/* Try to determine the frequency from the device tree or CNTFRQ */
	if (!of_property_read_u32(np, "clock-frequency", &freq))
		arch_timer_rate = freq;

	for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
		arch_timer_ppi[i] = irq_of_parse_and_map(np, i);

	of_node_put(np);

	/*
	 * If HYP mode is available, we know that the physical timer
	 * has been configured to be accessible from PL1. Use it, so
	 * that a guest can use the virtual timer instead.
	 *
	 * If no interrupt provided for virtual timer, we'll have to
	 * stick to the physical timer. It'd better be accessible...
	 */
	if (is_hyp_mode_available() || !arch_timer_ppi[VIRT_PPI]) {
		arch_timer_use_virtual = false;

		if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
		    !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
			pr_warn("arch_timer: No interrupt available, giving up\n");
			return -EINVAL;
		}
	}

	if (arch_timer_use_virtual)
		arch_timer_read_counter = arch_counter_get_cntvct;
	else
		arch_timer_read_counter = arch_counter_get_cntpct;

	return arch_timer_register();
}
Commit	Line	Data
8a4da6e3 MR	1	/*
	2	* linux/drivers/clocksource/arm_arch_timer.c
	3	*
	4	* Copyright (C) 2011 ARM Ltd.
	5	* All Rights Reserved
	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	#include <linux/init.h>
	12	#include <linux/kernel.h>
	13	#include <linux/device.h>
	14	#include <linux/smp.h>
	15	#include <linux/cpu.h>
	16	#include <linux/clockchips.h>
	17	#include <linux/interrupt.h>
	18	#include <linux/of_irq.h>
	19	#include <linux/io.h>
	20
	21	#include <asm/arch_timer.h>
8266891e	22	#include <asm/virt.h>
8a4da6e3 MR	23
	24	#include <clocksource/arm_arch_timer.h>
	25
	26	static u32 arch_timer_rate;
	27
	28	enum ppi_nr {
	29	PHYS_SECURE_PPI,
	30	PHYS_NONSECURE_PPI,
	31	VIRT_PPI,
	32	HYP_PPI,
	33	MAX_TIMER_PPI
	34	};
	35
	36	static int arch_timer_ppi[MAX_TIMER_PPI];
	37
	38	static struct clock_event_device __percpu *arch_timer_evt;
	39
	40	static bool arch_timer_use_virtual = true;
	41
	42	/*
	43	* Architected system timer support.
	44	*/
	45
	46	static inline irqreturn_t timer_handler(const int access,
	47	struct clock_event_device *evt)
	48	{
	49	unsigned long ctrl;
	50	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
	51	if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
	52	ctrl \|= ARCH_TIMER_CTRL_IT_MASK;
	53	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
	54	evt->event_handler(evt);
	55	return IRQ_HANDLED;
	56	}
	57
	58	return IRQ_NONE;
	59	}
	60
	61	static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
	62	{
	63	struct clock_event_device *evt = dev_id;
	64
	65	return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
	66	}
	67
	68	static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
	69	{
	70	struct clock_event_device *evt = dev_id;
	71
	72	return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
	73	}
	74
	75	static inline void timer_set_mode(const int access, int mode)
	76	{
	77	unsigned long ctrl;
	78	switch (mode) {
	79	case CLOCK_EVT_MODE_UNUSED:
	80	case CLOCK_EVT_MODE_SHUTDOWN:
	81	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
	82	ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
	83	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
	84	break;
	85	default:
	86	break;
87	}
88	}
89
90	static void arch_timer_set_mode_virt(enum clock_event_mode mode,
91	struct clock_event_device *clk)
92	{
93	timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode);
94	}
95
96	static void arch_timer_set_mode_phys(enum clock_event_mode mode,
97	struct clock_event_device *clk)
98	{
99	timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode);
100	}
101
102	static inline void set_next_event(const int access, unsigned long evt)
103	{
104	unsigned long ctrl;
105	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
106	ctrl \|= ARCH_TIMER_CTRL_ENABLE;
107	ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
108	arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
109	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
110	}
111
112	static int arch_timer_set_next_event_virt(unsigned long evt,
113	struct clock_event_device *unused)
114	{
115	set_next_event(ARCH_TIMER_VIRT_ACCESS, evt);
116	return 0;
117	}
118
119	static int arch_timer_set_next_event_phys(unsigned long evt,
120	struct clock_event_device *unused)
121	{
122	set_next_event(ARCH_TIMER_PHYS_ACCESS, evt);
123	return 0;
124	}
125
126	static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
127	{
128	clk->features = CLOCK_EVT_FEAT_ONESHOT \| CLOCK_EVT_FEAT_C3STOP;
129	clk->name = "arch_sys_timer";
130	clk->rating = 450;
131	if (arch_timer_use_virtual) {
132	clk->irq = arch_timer_ppi[VIRT_PPI];
133	clk->set_mode = arch_timer_set_mode_virt;
134	clk->set_next_event = arch_timer_set_next_event_virt;
135	} else {
136	clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
137	clk->set_mode = arch_timer_set_mode_phys;
138	clk->set_next_event = arch_timer_set_next_event_phys;
139	}
140
141	clk->cpumask = cpumask_of(smp_processor_id());
142
143	clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);
144
145	clockevents_config_and_register(clk, arch_timer_rate,
146	0xf, 0x7fffffff);
147
148	if (arch_timer_use_virtual)
149	enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
150	else {
151	enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
152	if (arch_timer_ppi[PHYS_NONSECURE_PPI])
153	enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
154	}
155
156	arch_counter_set_user_access();
157
158	return 0;
159	}
160
161	static int arch_timer_available(void)
162	{
163	u32 freq;
164
165	if (arch_timer_rate == 0) {
166	freq = arch_timer_get_cntfrq();
167
168	/* Check the timer frequency. */
169	if (freq == 0) {
170	pr_warn("Architected timer frequency not available\n");
171	return -EINVAL;
172	}
173
174	arch_timer_rate = freq;
175	}
176
177	pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n",
178	(unsigned long)arch_timer_rate / 1000000,
179	(unsigned long)(arch_timer_rate / 10000) % 100,
180	arch_timer_use_virtual ? "virt" : "phys");
181	return 0;
182	}
183
184	u32 arch_timer_get_rate(void)
185	{
186	return arch_timer_rate;
187	}
188
189	/*
190	* Some external users of arch_timer_read_counter (e.g. sched_clock) may try to
191	* call it before it has been initialised. Rather than incur a performance
192	* penalty checking for initialisation, provide a default implementation that
193	* won't lead to time appearing to jump backwards.
194	*/
195	static u64 arch_timer_read_zero(void)
196	{
197	return 0;
198	}
199
200	u64 (*arch_timer_read_counter)(void) = arch_timer_read_zero;
201
202	static cycle_t arch_counter_read(struct clocksource *cs)
203	{
204	return arch_timer_read_counter();
205	}
206
207	static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
208	{
209	return arch_timer_read_counter();
210	}
211
212	static struct clocksource clocksource_counter = {
213	.name = "arch_sys_counter",
214	.rating = 400,
215	.read = arch_counter_read,
216	.mask = CLOCKSOURCE_MASK(56),
217	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
218	};
219
220	static struct cyclecounter cyclecounter = {
221	.read = arch_counter_read_cc,
222	.mask = CLOCKSOURCE_MASK(56),
223	};
224
225	static struct timecounter timecounter;
226
227	struct timecounter *arch_timer_get_timecounter(void)
228	{
229	return &timecounter;
230	}
231
232	static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
233	{
234	pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
235	clk->irq, smp_processor_id());
236
237	if (arch_timer_use_virtual)
238	disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
239	else {
240	disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
241	if (arch_timer_ppi[PHYS_NONSECURE_PPI])
242	disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
243	}
244
245	clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
246	}
247
248	static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
249	unsigned long action, void *hcpu)
250	{
251	struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt);
252
253	switch (action & ~CPU_TASKS_FROZEN) {
254	case CPU_STARTING:
255	arch_timer_setup(evt);
256	break;
257	case CPU_DYING:
258	arch_timer_stop(evt);
259	break;
260	}
261
262	return NOTIFY_OK;
263	}
264
265	static struct notifier_block arch_timer_cpu_nb __cpuinitdata = {
266	.notifier_call = arch_timer_cpu_notify,
267	};
268
269	static int __init arch_timer_register(void)
270	{
271	int err;
272	int ppi;
273
274	err = arch_timer_available();
275	if (err)
276	goto out;
277
278	arch_timer_evt = alloc_percpu(struct clock_event_device);
279	if (!arch_timer_evt) {
280	err = -ENOMEM;
281	goto out;
282	}
283
284	clocksource_register_hz(&clocksource_counter, arch_timer_rate);
285	cyclecounter.mult = clocksource_counter.mult;
286	cyclecounter.shift = clocksource_counter.shift;
287	timecounter_init(&timecounter, &cyclecounter,
288	arch_counter_get_cntpct());
289
290	if (arch_timer_use_virtual) {
291	ppi = arch_timer_ppi[VIRT_PPI];
292	err = request_percpu_irq(ppi, arch_timer_handler_virt,
293	"arch_timer", arch_timer_evt);
294	} else {
295	ppi = arch_timer_ppi[PHYS_SECURE_PPI];
296	err = request_percpu_irq(ppi, arch_timer_handler_phys,
297	"arch_timer", arch_timer_evt);
298	if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
299	ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
300	err = request_percpu_irq(ppi, arch_timer_handler_phys,
301	"arch_timer", arch_timer_evt);
302	if (err)
303	free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
304	arch_timer_evt);
305	}
306	}
307
308	if (err) {
309	pr_err("arch_timer: can't register interrupt %d (%d)\n",
310	ppi, err);
311	goto out_free;
312	}
313
314	err = register_cpu_notifier(&arch_timer_cpu_nb);
315	if (err)
316	goto out_free_irq;
317
318	/* Immediately configure the timer on the boot CPU */
319	arch_timer_setup(this_cpu_ptr(arch_timer_evt));
320
321	return 0;
322
323	out_free_irq:
324	if (arch_timer_use_virtual)
325	free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
326	else {
327	free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
328	arch_timer_evt);
329	if (arch_timer_ppi[PHYS_NONSECURE_PPI])
330	free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
331	arch_timer_evt);
332	}
333
334	out_free:
335	free_percpu(arch_timer_evt);
336	out:
337	return err;
338	}
339
340	static const struct of_device_id arch_timer_of_match[] __initconst = {
341	{ .compatible = "arm,armv7-timer", },
1aee5d7a	342	{ .compatible = "arm,armv8-timer", },
8a4da6e3 MR	343	{},
	344	};
	345
	346	int __init arch_timer_init(void)
	347	{
	348	struct device_node *np;
	349	u32 freq;
	350	int i;
	351
	352	np = of_find_matching_node(NULL, arch_timer_of_match);
	353	if (!np) {
	354	pr_err("arch_timer: can't find DT node\n");
	355	return -ENODEV;
	356	}
	357
	358	/* Try to determine the frequency from the device tree or CNTFRQ */
	359	if (!of_property_read_u32(np, "clock-frequency", &freq))
	360	arch_timer_rate = freq;
	361
	362	for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
	363	arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
	364
	365	of_node_put(np);
	366
	367	/*
8266891e MZ	368	* If HYP mode is available, we know that the physical timer
	369	* has been configured to be accessible from PL1. Use it, so
	370	* that a guest can use the virtual timer instead.
	371	*
8a4da6e3 MR	372	* If no interrupt provided for virtual timer, we'll have to
	373	* stick to the physical timer. It'd better be accessible...
	374	*/
8266891e	375	if (is_hyp_mode_available() \|\| !arch_timer_ppi[VIRT_PPI]) {
8a4da6e3 MR	376	arch_timer_use_virtual = false;
	377
	378	if (!arch_timer_ppi[PHYS_SECURE_PPI] \|\|
	379	!arch_timer_ppi[PHYS_NONSECURE_PPI]) {
	380	pr_warn("arch_timer: No interrupt available, giving up\n");
	381	return -EINVAL;
	382	}
	383	}
	384
	385	if (arch_timer_use_virtual)
	386	arch_timer_read_counter = arch_counter_get_cntvct;
	387	else
	388	arch_timer_read_counter = arch_counter_get_cntpct;
	389
	390	return arch_timer_register();
	391	}