summaryrefslogtreecommitdiff
path: root/arch/arm/mach-msm/timer.c
blob: afeeca52fc664d1c6c9a36928eb48ecc7d5afc2c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
/* linux/arch/arm/mach-msm/timer.c
 *
 * Copyright (C) 2007 Google, Inc.
 *
 * 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/time.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/delay.h>
#include <linux/io.h>

#include <asm/mach/time.h>
#include <asm/hardware/gic.h>

#include <mach/msm_iomap.h>
#include <mach/cpu.h>

#define TIMER_MATCH_VAL         0x0000
#define TIMER_COUNT_VAL         0x0004
#define TIMER_ENABLE            0x0008
#define TIMER_ENABLE_CLR_ON_MATCH_EN    2
#define TIMER_ENABLE_EN                 1
#define TIMER_CLEAR             0x000C
#define DGT_CLK_CTL             0x0034
enum {
	DGT_CLK_CTL_DIV_1 = 0,
	DGT_CLK_CTL_DIV_2 = 1,
	DGT_CLK_CTL_DIV_3 = 2,
	DGT_CLK_CTL_DIV_4 = 3,
};
#define CSR_PROTECTION          0x0020
#define CSR_PROTECTION_EN               1

#define GPT_HZ 32768

enum timer_location {
	LOCAL_TIMER = 0,
	GLOBAL_TIMER = 1,
};

#define MSM_GLOBAL_TIMER MSM_CLOCK_DGT

/* TODO: Remove these ifdefs */
#if defined(CONFIG_ARCH_QSD8X50)
#define DGT_HZ (19200000 / 4) /* 19.2 MHz / 4 by default */
#define MSM_DGT_SHIFT (0)
#elif defined(CONFIG_ARCH_MSM7X30)
#define DGT_HZ (24576000 / 4) /* 24.576 MHz (LPXO) / 4 by default */
#define MSM_DGT_SHIFT (0)
#elif defined(CONFIG_ARCH_MSM8X60) || defined(CONFIG_ARCH_MSM8960)
#define DGT_HZ (27000000 / 4) /* 27 MHz (PXO) / 4 by default */
#define MSM_DGT_SHIFT (0)
#else
#define DGT_HZ 19200000 /* 19.2 MHz or 600 KHz after shift */
#define MSM_DGT_SHIFT (5)
#endif

struct msm_clock {
	struct clock_event_device   clockevent;
	struct clocksource          clocksource;
	unsigned int		    irq;
	void __iomem                *regbase;
	uint32_t                    freq;
	uint32_t                    shift;
	void __iomem                *global_counter;
	void __iomem                *local_counter;
	union {
		struct clock_event_device		*evt;
		struct clock_event_device __percpu	**percpu_evt;
	};		
};

enum {
	MSM_CLOCK_GPT,
	MSM_CLOCK_DGT,
	NR_TIMERS,
};


static struct msm_clock msm_clocks[];

static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
	if (evt->event_handler == NULL)
		return IRQ_HANDLED;
	evt->event_handler(evt);
	return IRQ_HANDLED;
}

static cycle_t msm_read_timer_count(struct clocksource *cs)
{
	struct msm_clock *clk = container_of(cs, struct msm_clock, clocksource);

	/*
	 * Shift timer count down by a constant due to unreliable lower bits
	 * on some targets.
	 */
	return readl(clk->global_counter) >> clk->shift;
}

static struct msm_clock *clockevent_to_clock(struct clock_event_device *evt)
{
#ifdef CONFIG_SMP
	int i;
	for (i = 0; i < NR_TIMERS; i++)
		if (evt == &(msm_clocks[i].clockevent))
			return &msm_clocks[i];
	return &msm_clocks[MSM_GLOBAL_TIMER];
#else
	return container_of(evt, struct msm_clock, clockevent);
#endif
}

static int msm_timer_set_next_event(unsigned long cycles,
				    struct clock_event_device *evt)
{
	struct msm_clock *clock = clockevent_to_clock(evt);
	uint32_t now = readl(clock->local_counter);
	uint32_t alarm = now + (cycles << clock->shift);

	writel(alarm, clock->regbase + TIMER_MATCH_VAL);
	return 0;
}

static void msm_timer_set_mode(enum clock_event_mode mode,
			      struct clock_event_device *evt)
{
	struct msm_clock *clock = clockevent_to_clock(evt);

	switch (mode) {
	case CLOCK_EVT_MODE_RESUME:
	case CLOCK_EVT_MODE_PERIODIC:
		break;
	case CLOCK_EVT_MODE_ONESHOT:
		writel(TIMER_ENABLE_EN, clock->regbase + TIMER_ENABLE);
		break;
	case CLOCK_EVT_MODE_UNUSED:
	case CLOCK_EVT_MODE_SHUTDOWN:
		writel(0, clock->regbase + TIMER_ENABLE);
		break;
	}
}

static struct msm_clock msm_clocks[] = {
	[MSM_CLOCK_GPT] = {
		.clockevent = {
			.name           = "gp_timer",
			.features       = CLOCK_EVT_FEAT_ONESHOT,
			.shift          = 32,
			.rating         = 200,
			.set_next_event = msm_timer_set_next_event,
			.set_mode       = msm_timer_set_mode,
		},
		.clocksource = {
			.name           = "gp_timer",
			.rating         = 200,
			.read           = msm_read_timer_count,
			.mask           = CLOCKSOURCE_MASK(32),
			.flags          = CLOCK_SOURCE_IS_CONTINUOUS,
		},
		.irq = INT_GP_TIMER_EXP,
		.freq = GPT_HZ,
	},
	[MSM_CLOCK_DGT] = {
		.clockevent = {
			.name           = "dg_timer",
			.features       = CLOCK_EVT_FEAT_ONESHOT,
			.shift          = 32 + MSM_DGT_SHIFT,
			.rating         = 300,
			.set_next_event = msm_timer_set_next_event,
			.set_mode       = msm_timer_set_mode,
		},
		.clocksource = {
			.name           = "dg_timer",
			.rating         = 300,
			.read           = msm_read_timer_count,
			.mask           = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
			.flags          = CLOCK_SOURCE_IS_CONTINUOUS,
		},
		.irq = INT_DEBUG_TIMER_EXP,
		.freq = DGT_HZ >> MSM_DGT_SHIFT,
		.shift = MSM_DGT_SHIFT,
	}
};

static void __init msm_timer_init(void)
{
	int i;
	int res;
	int global_offset = 0;

	if (cpu_is_msm7x01()) {
		msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
		msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
	} else if (cpu_is_msm7x30()) {
		msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE + 0x04;
		msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x24;
	} else if (cpu_is_qsd8x50()) {
		msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
		msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
	} else if (cpu_is_msm8x60() || cpu_is_msm8960()) {
		msm_clocks[MSM_CLOCK_GPT].regbase = MSM_TMR_BASE + 0x04;
		msm_clocks[MSM_CLOCK_DGT].regbase = MSM_TMR_BASE + 0x24;

		/* Use CPU0's timer as the global timer. */
		global_offset = MSM_TMR0_BASE - MSM_TMR_BASE;
	} else
		BUG();

#ifdef CONFIG_ARCH_MSM_SCORPIONMP
	writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
#endif

	for (i = 0; i < ARRAY_SIZE(msm_clocks); i++) {
		struct msm_clock *clock = &msm_clocks[i];
		struct clock_event_device *ce = &clock->clockevent;
		struct clocksource *cs = &clock->clocksource;

		clock->local_counter = clock->regbase + TIMER_COUNT_VAL;
		clock->global_counter = clock->local_counter + global_offset;

		writel(0, clock->regbase + TIMER_ENABLE);
		writel(0, clock->regbase + TIMER_CLEAR);
		writel(~0, clock->regbase + TIMER_MATCH_VAL);

		ce->mult = div_sc(clock->freq, NSEC_PER_SEC, ce->shift);
		/* allow at least 10 seconds to notice that the timer wrapped */
		ce->max_delta_ns =
			clockevent_delta2ns(0xf0000000 >> clock->shift, ce);
		/* 4 gets rounded down to 3 */
		ce->min_delta_ns = clockevent_delta2ns(4, ce);
		ce->cpumask = cpumask_of(0);

		res = clocksource_register_hz(cs, clock->freq);
		if (res)
			printk(KERN_ERR "msm_timer_init: clocksource_register "
			       "failed for %s\n", cs->name);

		ce->irq = clock->irq;
		if (cpu_is_msm8x60() || cpu_is_msm8960()) {
			clock->percpu_evt = alloc_percpu(struct clock_event_device *);
			if (!clock->percpu_evt) {
				pr_err("msm_timer_init: memory allocation "
				       "failed for %s\n", ce->name);
				continue;
			}

			*__this_cpu_ptr(clock->percpu_evt) = ce;
			res = request_percpu_irq(ce->irq, msm_timer_interrupt,
						 ce->name, clock->percpu_evt);
			if (!res)
				enable_percpu_irq(ce->irq, 0);
		} else {
			clock->evt = ce;
			res = request_irq(ce->irq, msm_timer_interrupt,
					  IRQF_TIMER | IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
					  ce->name, &clock->evt);
		}

		if (res)
			pr_err("msm_timer_init: request_irq failed for %s\n",
			       ce->name);

		clockevents_register_device(ce);
	}
}

#ifdef CONFIG_SMP
int __cpuinit local_timer_setup(struct clock_event_device *evt)
{
	static bool local_timer_inited;
	struct msm_clock *clock = &msm_clocks[MSM_GLOBAL_TIMER];

	/* Use existing clock_event for cpu 0 */
	if (!smp_processor_id())
		return 0;

	writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);

	if (!local_timer_inited) {
		writel(0, clock->regbase  + TIMER_ENABLE);
		writel(0, clock->regbase + TIMER_CLEAR);
		writel(~0, clock->regbase + TIMER_MATCH_VAL);
		local_timer_inited = true;
	}
	evt->irq = clock->irq;
	evt->name = "local_timer";
	evt->features = CLOCK_EVT_FEAT_ONESHOT;
	evt->rating = clock->clockevent.rating;
	evt->set_mode = msm_timer_set_mode;
	evt->set_next_event = msm_timer_set_next_event;
	evt->shift = clock->clockevent.shift;
	evt->mult = div_sc(clock->freq, NSEC_PER_SEC, evt->shift);
	evt->max_delta_ns =
		clockevent_delta2ns(0xf0000000 >> clock->shift, evt);
	evt->min_delta_ns = clockevent_delta2ns(4, evt);

	*__this_cpu_ptr(clock->percpu_evt) = evt;
	enable_percpu_irq(evt->irq, 0);

	clockevents_register_device(evt);
	return 0;
}

void local_timer_stop(struct clock_event_device *evt)
{
	evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
	disable_percpu_irq(evt->irq);
}

#endif

struct sys_timer msm_timer = {
	.init = msm_timer_init
};