summaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-samsung/samsung-time.c
blob: aa8aa8014cc128e58278c1a97a281e982733c567 (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
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
/*
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com/
 *
 * SAMSUNG - Common hr-timer support
 *
 * 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/interrupt.h>
#include <linux/irq.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/platform_device.h>

#include <asm/smp_twd.h>
#include <asm/mach/time.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/sched_clock.h>

#include <mach/map.h>
#include <plat/devs.h>
#include <plat/regs-timer.h>
#include <plat/samsung-time.h>

static struct clk *tin_event;
static struct clk *tin_source;
static struct clk *tdiv_event;
static struct clk *tdiv_source;
static struct clk *timerclk;
static struct samsung_timer_source timer_source;
static unsigned long clock_count_per_tick;
static void samsung_timer_resume(void);

static void samsung_time_stop(enum samsung_timer_mode mode)
{
	unsigned long tcon;

	tcon = __raw_readl(S3C2410_TCON);

	switch (mode) {
	case SAMSUNG_PWM0:
		tcon &= ~S3C2410_TCON_T0START;
		break;

	case SAMSUNG_PWM1:
		tcon &= ~S3C2410_TCON_T1START;
		break;

	case SAMSUNG_PWM2:
		tcon &= ~S3C2410_TCON_T2START;
		break;

	case SAMSUNG_PWM3:
		tcon &= ~S3C2410_TCON_T3START;
		break;

	case SAMSUNG_PWM4:
		tcon &= ~S3C2410_TCON_T4START;
		break;

	default:
		printk(KERN_ERR "Invalid Timer %d\n", mode);
		break;
	}
	__raw_writel(tcon, S3C2410_TCON);
}

static void samsung_time_setup(enum samsung_timer_mode mode, unsigned long tcnt)
{
	unsigned long tcon;

	tcon = __raw_readl(S3C2410_TCON);

	tcnt--;

	switch (mode) {
	case SAMSUNG_PWM0:
		tcon &= ~(0x0f << 0);
		tcon |= S3C2410_TCON_T0MANUALUPD;
		break;

	case SAMSUNG_PWM1:
		tcon &= ~(0x0f << 8);
		tcon |= S3C2410_TCON_T1MANUALUPD;
		break;

	case SAMSUNG_PWM2:
		tcon &= ~(0x0f << 12);
		tcon |= S3C2410_TCON_T2MANUALUPD;
		break;

	case SAMSUNG_PWM3:
		tcon &= ~(0x0f << 16);
		tcon |= S3C2410_TCON_T3MANUALUPD;
		break;

	case SAMSUNG_PWM4:
		tcon &= ~(0x07 << 20);
		tcon |= S3C2410_TCON_T4MANUALUPD;
		break;

	default:
		printk(KERN_ERR "Invalid Timer %d\n", mode);
		break;
	}

	__raw_writel(tcnt, S3C2410_TCNTB(mode));
	__raw_writel(tcnt, S3C2410_TCMPB(mode));
	__raw_writel(tcon, S3C2410_TCON);
}

static void samsung_time_start(enum samsung_timer_mode mode, bool periodic)
{
	unsigned long tcon;

	tcon  = __raw_readl(S3C2410_TCON);

	switch (mode) {
	case SAMSUNG_PWM0:
		tcon |= S3C2410_TCON_T0START;
		tcon &= ~S3C2410_TCON_T0MANUALUPD;

		if (periodic)
			tcon |= S3C2410_TCON_T0RELOAD;
		else
			tcon &= ~S3C2410_TCON_T0RELOAD;
		break;

	case SAMSUNG_PWM1:
		tcon |= S3C2410_TCON_T1START;
		tcon &= ~S3C2410_TCON_T1MANUALUPD;

		if (periodic)
			tcon |= S3C2410_TCON_T1RELOAD;
		else
			tcon &= ~S3C2410_TCON_T1RELOAD;
		break;

	case SAMSUNG_PWM2:
		tcon |= S3C2410_TCON_T2START;
		tcon &= ~S3C2410_TCON_T2MANUALUPD;

		if (periodic)
			tcon |= S3C2410_TCON_T2RELOAD;
		else
			tcon &= ~S3C2410_TCON_T2RELOAD;
		break;

	case SAMSUNG_PWM3:
		tcon |= S3C2410_TCON_T3START;
		tcon &= ~S3C2410_TCON_T3MANUALUPD;

		if (periodic)
			tcon |= S3C2410_TCON_T3RELOAD;
		else
			tcon &= ~S3C2410_TCON_T3RELOAD;
		break;

	case SAMSUNG_PWM4:
		tcon |= S3C2410_TCON_T4START;
		tcon &= ~S3C2410_TCON_T4MANUALUPD;

		if (periodic)
			tcon |= S3C2410_TCON_T4RELOAD;
		else
			tcon &= ~S3C2410_TCON_T4RELOAD;
		break;

	default:
		printk(KERN_ERR "Invalid Timer %d\n", mode);
		break;
	}
	__raw_writel(tcon, S3C2410_TCON);
}

static int samsung_set_next_event(unsigned long cycles,
				struct clock_event_device *evt)
{
	samsung_time_setup(timer_source.event_id, cycles);
	samsung_time_start(timer_source.event_id, NON_PERIODIC);

	return 0;
}

static void samsung_set_mode(enum clock_event_mode mode,
				struct clock_event_device *evt)
{
	samsung_time_stop(timer_source.event_id);

	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
		samsung_time_setup(timer_source.event_id, clock_count_per_tick);
		samsung_time_start(timer_source.event_id, PERIODIC);
		break;

	case CLOCK_EVT_MODE_ONESHOT:
		break;

	case CLOCK_EVT_MODE_UNUSED:
	case CLOCK_EVT_MODE_SHUTDOWN:
		break;

	case CLOCK_EVT_MODE_RESUME:
		samsung_timer_resume();
		break;
	}
}

static void samsung_timer_resume(void)
{
	/* event timer restart */
	samsung_time_setup(timer_source.event_id, clock_count_per_tick);
	samsung_time_start(timer_source.event_id, PERIODIC);

	/* source timer restart */
	samsung_time_setup(timer_source.source_id, TCNT_MAX);
	samsung_time_start(timer_source.source_id, PERIODIC);
}

void __init samsung_set_timer_source(enum samsung_timer_mode event,
				 enum samsung_timer_mode source)
{
	s3c_device_timer[event].dev.bus = &platform_bus_type;
	s3c_device_timer[source].dev.bus = &platform_bus_type;

	timer_source.event_id = event;
	timer_source.source_id = source;
}

static struct clock_event_device time_event_device = {
	.name		= "samsung_event_timer",
	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
	.rating		= 200,
	.set_next_event	= samsung_set_next_event,
	.set_mode	= samsung_set_mode,
};

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

	evt->event_handler(evt);

	return IRQ_HANDLED;
}

static struct irqaction samsung_clock_event_irq = {
	.name		= "samsung_time_irq",
	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
	.handler	= samsung_clock_event_isr,
	.dev_id		= &time_event_device,
};

static void __init samsung_clockevent_init(void)
{
	unsigned long pclk;
	unsigned long clock_rate;
	unsigned int irq_number;
	struct clk *tscaler;

	pclk = clk_get_rate(timerclk);

	tscaler = clk_get_parent(tdiv_event);

	clk_set_rate(tscaler, pclk / 2);
	clk_set_rate(tdiv_event, pclk / 2);
	clk_set_parent(tin_event, tdiv_event);

	clock_rate = clk_get_rate(tin_event);
	clock_count_per_tick = clock_rate / HZ;

	time_event_device.cpumask = cpumask_of(0);
	clockevents_config_and_register(&time_event_device, clock_rate, 1, -1);

	irq_number = timer_source.event_id + IRQ_TIMER0;
	setup_irq(irq_number, &samsung_clock_event_irq);
}

static void __iomem *samsung_timer_reg(void)
{
	unsigned long offset = 0;

	switch (timer_source.source_id) {
	case SAMSUNG_PWM0:
	case SAMSUNG_PWM1:
	case SAMSUNG_PWM2:
	case SAMSUNG_PWM3:
		offset = (timer_source.source_id * 0x0c) + 0x14;
		break;

	case SAMSUNG_PWM4:
		offset = 0x40;
		break;

	default:
		printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
		return NULL;
	}

	return S3C_TIMERREG(offset);
}

/*
 * Override the global weak sched_clock symbol with this
 * local implementation which uses the clocksource to get some
 * better resolution when scheduling the kernel. We accept that
 * this wraps around for now, since it is just a relative time
 * stamp. (Inspired by U300 implementation.)
 */
static u32 notrace samsung_read_sched_clock(void)
{
	void __iomem *reg = samsung_timer_reg();

	if (!reg)
		return 0;

	return ~__raw_readl(reg);
}

static void __init samsung_clocksource_init(void)
{
	unsigned long pclk;
	unsigned long clock_rate;

	pclk = clk_get_rate(timerclk);

	clk_set_rate(tdiv_source, pclk / 2);
	clk_set_parent(tin_source, tdiv_source);

	clock_rate = clk_get_rate(tin_source);

	samsung_time_setup(timer_source.source_id, TCNT_MAX);
	samsung_time_start(timer_source.source_id, PERIODIC);

	setup_sched_clock(samsung_read_sched_clock, 32, clock_rate);

	if (clocksource_mmio_init(samsung_timer_reg(), "samsung_clocksource_timer",
			clock_rate, 250, 32, clocksource_mmio_readl_down))
		panic("samsung_clocksource_timer: can't register clocksource\n");
}

static void __init samsung_timer_resources(void)
{

	unsigned long event_id = timer_source.event_id;
	unsigned long source_id = timer_source.source_id;
	char devname[15];

	timerclk = clk_get(NULL, "timers");
	if (IS_ERR(timerclk))
		panic("failed to get timers clock for timer");

	clk_enable(timerclk);

	sprintf(devname, "s3c24xx-pwm.%lu", event_id);
	s3c_device_timer[event_id].id = event_id;
	s3c_device_timer[event_id].dev.init_name = devname;

	tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin");
	if (IS_ERR(tin_event))
		panic("failed to get pwm-tin clock for event timer");

	tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv");
	if (IS_ERR(tdiv_event))
		panic("failed to get pwm-tdiv clock for event timer");

	clk_enable(tin_event);

	sprintf(devname, "s3c24xx-pwm.%lu", source_id);
	s3c_device_timer[source_id].id = source_id;
	s3c_device_timer[source_id].dev.init_name = devname;

	tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin");
	if (IS_ERR(tin_source))
		panic("failed to get pwm-tin clock for source timer");

	tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv");
	if (IS_ERR(tdiv_source))
		panic("failed to get pwm-tdiv clock for source timer");

	clk_enable(tin_source);
}

void __init samsung_timer_init(void)
{
	samsung_timer_resources();
	samsung_clockevent_init();
	samsung_clocksource_init();
}
OpenPOWER on IntegriCloud