summaryrefslogtreecommitdiff
path: root/arch/arm/mach-msm/timer.c
blob: 2969027f02fa57045ec7bb3d65d7a98927cfde3c (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
330
331
332
333
334
335
336
/*
 *
 * Copyright (C) 2007 Google, Inc.
 * Copyright (c) 2009-2012, The Linux Foundation. All rights reserved.
 *
 * 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/clocksource.h>
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

#include <asm/mach/time.h>
#include <asm/localtimer.h>
#include <asm/sched_clock.h>

#include "common.h"

#define TIMER_MATCH_VAL         0x0000
#define TIMER_COUNT_VAL         0x0004
#define TIMER_ENABLE            0x0008
#define TIMER_ENABLE_CLR_ON_MATCH_EN    BIT(1)
#define TIMER_ENABLE_EN                 BIT(0)
#define TIMER_CLEAR             0x000C
#define DGT_CLK_CTL_DIV_4	0x3

#define GPT_HZ 32768

#define MSM_DGT_SHIFT 5

static void __iomem *event_base;

static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
	/* Stop the timer tick */
	if (evt->mode == CLOCK_EVT_MODE_ONESHOT) {
		u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
		ctrl &= ~TIMER_ENABLE_EN;
		writel_relaxed(ctrl, event_base + TIMER_ENABLE);
	}
	evt->event_handler(evt);
	return IRQ_HANDLED;
}

static int msm_timer_set_next_event(unsigned long cycles,
				    struct clock_event_device *evt)
{
	u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);

	writel_relaxed(0, event_base + TIMER_CLEAR);
	writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
	writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE);
	return 0;
}

static void msm_timer_set_mode(enum clock_event_mode mode,
			      struct clock_event_device *evt)
{
	u32 ctrl;

	ctrl = readl_relaxed(event_base + TIMER_ENABLE);
	ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);

	switch (mode) {
	case CLOCK_EVT_MODE_RESUME:
	case CLOCK_EVT_MODE_PERIODIC:
		break;
	case CLOCK_EVT_MODE_ONESHOT:
		/* Timer is enabled in set_next_event */
		break;
	case CLOCK_EVT_MODE_UNUSED:
	case CLOCK_EVT_MODE_SHUTDOWN:
		break;
	}
	writel_relaxed(ctrl, event_base + TIMER_ENABLE);
}

static struct clock_event_device msm_clockevent = {
	.name		= "gp_timer",
	.features	= CLOCK_EVT_FEAT_ONESHOT,
	.rating		= 200,
	.set_next_event	= msm_timer_set_next_event,
	.set_mode	= msm_timer_set_mode,
};

static union {
	struct clock_event_device *evt;
	struct clock_event_device * __percpu *percpu_evt;
} msm_evt;

static void __iomem *source_base;

static notrace cycle_t msm_read_timer_count(struct clocksource *cs)
{
	return readl_relaxed(source_base + TIMER_COUNT_VAL);
}

static notrace cycle_t msm_read_timer_count_shift(struct clocksource *cs)
{
	/*
	 * Shift timer count down by a constant due to unreliable lower bits
	 * on some targets.
	 */
	return msm_read_timer_count(cs) >> MSM_DGT_SHIFT;
}

static struct clocksource msm_clocksource = {
	.name	= "dg_timer",
	.rating	= 300,
	.read	= msm_read_timer_count,
	.mask	= CLOCKSOURCE_MASK(32),
	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
};

#ifdef CONFIG_LOCAL_TIMERS
static int __cpuinit msm_local_timer_setup(struct clock_event_device *evt)
{
	/* Use existing clock_event for cpu 0 */
	if (!smp_processor_id())
		return 0;

	writel_relaxed(0, event_base + TIMER_ENABLE);
	writel_relaxed(0, event_base + TIMER_CLEAR);
	writel_relaxed(~0, event_base + TIMER_MATCH_VAL);
	evt->irq = msm_clockevent.irq;
	evt->name = "local_timer";
	evt->features = msm_clockevent.features;
	evt->rating = msm_clockevent.rating;
	evt->set_mode = msm_timer_set_mode;
	evt->set_next_event = msm_timer_set_next_event;

	*__this_cpu_ptr(msm_evt.percpu_evt) = evt;
	clockevents_config_and_register(evt, GPT_HZ, 4, 0xf0000000);
	enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
	return 0;
}

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

static struct local_timer_ops msm_local_timer_ops __cpuinitdata = {
	.setup	= msm_local_timer_setup,
	.stop	= msm_local_timer_stop,
};
#endif /* CONFIG_LOCAL_TIMERS */

static notrace u32 msm_sched_clock_read(void)
{
	return msm_clocksource.read(&msm_clocksource);
}

static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
				  bool percpu)
{
	struct clock_event_device *ce = &msm_clockevent;
	struct clocksource *cs = &msm_clocksource;
	int res;

	writel_relaxed(0, event_base + TIMER_ENABLE);
	writel_relaxed(0, event_base + TIMER_CLEAR);
	writel_relaxed(~0, event_base + TIMER_MATCH_VAL);
	ce->cpumask = cpumask_of(0);
	ce->irq = irq;

	clockevents_config_and_register(ce, GPT_HZ, 4, 0xffffffff);
	if (percpu) {
		msm_evt.percpu_evt = alloc_percpu(struct clock_event_device *);
		if (!msm_evt.percpu_evt) {
			pr_err("memory allocation failed for %s\n", ce->name);
			goto err;
		}
		*__this_cpu_ptr(msm_evt.percpu_evt) = ce;
		res = request_percpu_irq(ce->irq, msm_timer_interrupt,
					 ce->name, msm_evt.percpu_evt);
		if (!res) {
			enable_percpu_irq(ce->irq, IRQ_TYPE_EDGE_RISING);
#ifdef CONFIG_LOCAL_TIMERS
			local_timer_register(&msm_local_timer_ops);
#endif
		}
	} else {
		msm_evt.evt = ce;
		res = request_irq(ce->irq, msm_timer_interrupt,
				  IRQF_TIMER | IRQF_NOBALANCING |
				  IRQF_TRIGGER_RISING, ce->name, &msm_evt.evt);
	}

	if (res)
		pr_err("request_irq failed for %s\n", ce->name);
err:
	writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
	res = clocksource_register_hz(cs, dgt_hz);
	if (res)
		pr_err("clocksource_register failed\n");
	setup_sched_clock(msm_sched_clock_read, sched_bits, dgt_hz);
}

#ifdef CONFIG_OF
static const struct of_device_id msm_dgt_match[] __initconst = {
	{ .compatible = "qcom,msm-dgt" },
	{ },
};

static const struct of_device_id msm_gpt_match[] __initconst = {
	{ .compatible = "qcom,msm-gpt" },
	{ },
};

void __init msm_dt_timer_init(void)
{
	struct device_node *np;
	u32 freq;
	int irq;
	struct resource res;
	u32 percpu_offset;
	void __iomem *dgt_clk_ctl;

	np = of_find_matching_node(NULL, msm_gpt_match);
	if (!np) {
		pr_err("Can't find GPT DT node\n");
		return;
	}

	event_base = of_iomap(np, 0);
	if (!event_base) {
		pr_err("Failed to map event base\n");
		return;
	}

	irq = irq_of_parse_and_map(np, 0);
	if (irq <= 0) {
		pr_err("Can't get irq\n");
		return;
	}
	of_node_put(np);

	np = of_find_matching_node(NULL, msm_dgt_match);
	if (!np) {
		pr_err("Can't find DGT DT node\n");
		return;
	}

	if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
		percpu_offset = 0;

	if (of_address_to_resource(np, 0, &res)) {
		pr_err("Failed to parse DGT resource\n");
		return;
	}

	source_base = ioremap(res.start + percpu_offset, resource_size(&res));
	if (!source_base) {
		pr_err("Failed to map source base\n");
		return;
	}

	if (!of_address_to_resource(np, 1, &res)) {
		dgt_clk_ctl = ioremap(res.start + percpu_offset,
				      resource_size(&res));
		if (!dgt_clk_ctl) {
			pr_err("Failed to map DGT control base\n");
			return;
		}
		writel_relaxed(DGT_CLK_CTL_DIV_4, dgt_clk_ctl);
		iounmap(dgt_clk_ctl);
	}

	if (of_property_read_u32(np, "clock-frequency", &freq)) {
		pr_err("Unknown frequency\n");
		return;
	}
	of_node_put(np);

	msm_timer_init(freq, 32, irq, !!percpu_offset);
}
#endif

static int __init msm_timer_map(phys_addr_t event, phys_addr_t source)
{
	event_base = ioremap(event, SZ_64);
	if (!event_base) {
		pr_err("Failed to map event base\n");
		return 1;
	}
	source_base = ioremap(source, SZ_64);
	if (!source_base) {
		pr_err("Failed to map source base\n");
		return 1;
	}
	return 0;
}

void __init msm7x01_timer_init(void)
{
	struct clocksource *cs = &msm_clocksource;

	if (msm_timer_map(0xc0100000, 0xc0100010))
		return;
	cs->read = msm_read_timer_count_shift;
	cs->mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT));
	/* 600 KHz */
	msm_timer_init(19200000 >> MSM_DGT_SHIFT, 32 - MSM_DGT_SHIFT, 7,
			false);
}

void __init msm7x30_timer_init(void)
{
	if (msm_timer_map(0xc0100004, 0xc0100024))
		return;
	msm_timer_init(24576000 / 4, 32, 1, false);
}

void __init qsd8x50_timer_init(void)
{
	if (msm_timer_map(0xAC100000, 0xAC100010))
		return;
	msm_timer_init(19200000 / 4, 32, 7, false);
}