summaryrefslogtreecommitdiffstats
path: root/arch/sparc/kernel/time_32.c
blob: 2f80d23a0a44964ebff804a2ab4428b9f30cb162 (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
/* linux/arch/sparc/kernel/time.c
 *
 * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
 *
 * Chris Davis (cdavis@cois.on.ca) 03/27/1998
 * Added support for the intersil on the sun4/4200
 *
 * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
 * Support for MicroSPARC-IIep, PCI CPU.
 *
 * This file handles the Sparc specific time handling details.
 *
 * 1997-09-10	Updated NTP code according to technical memorandum Jan '96
 *		"A Kernel Model for Precision Timekeeping" by Dave Mills
 */
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/rtc/m48t59.h>
#include <linux/timex.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/profile.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>

#include <asm/mc146818rtc.h>
#include <asm/oplib.h>
#include <asm/timex.h>
#include <asm/timer.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/idprom.h>
#include <asm/page.h>
#include <asm/pcic.h>
#include <asm/irq_regs.h>
#include <asm/setup.h>

#include "kernel.h"
#include "irq.h"

static __cacheline_aligned_in_smp DEFINE_SEQLOCK(timer_cs_lock);
static __volatile__ u64 timer_cs_internal_counter = 0;
static char timer_cs_enabled = 0;

static struct clock_event_device timer_ce;
static char timer_ce_enabled = 0;

#ifdef CONFIG_SMP
DEFINE_PER_CPU(struct clock_event_device, sparc32_clockevent);
#endif

DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);

static int set_rtc_mmss(unsigned long);

unsigned long profile_pc(struct pt_regs *regs)
{
	extern char __copy_user_begin[], __copy_user_end[];
	extern char __bzero_begin[], __bzero_end[];

	unsigned long pc = regs->pc;

	if (in_lock_functions(pc) ||
	    (pc >= (unsigned long) __copy_user_begin &&
	     pc < (unsigned long) __copy_user_end) ||
	    (pc >= (unsigned long) __bzero_begin &&
	     pc < (unsigned long) __bzero_end))
		pc = regs->u_regs[UREG_RETPC];
	return pc;
}

EXPORT_SYMBOL(profile_pc);

volatile u32 __iomem *master_l10_counter;

int update_persistent_clock(struct timespec now)
{
	return set_rtc_mmss(now.tv_sec);
}

irqreturn_t notrace timer_interrupt(int dummy, void *dev_id)
{
	if (timer_cs_enabled) {
		write_seqlock(&timer_cs_lock);
		timer_cs_internal_counter++;
		sparc_config.clear_clock_irq();
		write_sequnlock(&timer_cs_lock);
	} else {
		sparc_config.clear_clock_irq();
	}

	if (timer_ce_enabled)
		timer_ce.event_handler(&timer_ce);

	return IRQ_HANDLED;
}

static void timer_ce_set_mode(enum clock_event_mode mode,
			      struct clock_event_device *evt)
{
	switch (mode) {
		case CLOCK_EVT_MODE_PERIODIC:
		case CLOCK_EVT_MODE_RESUME:
			timer_ce_enabled = 1;
			break;
		case CLOCK_EVT_MODE_SHUTDOWN:
			timer_ce_enabled = 0;
			break;
		default:
			break;
	}
	smp_mb();
}

static __init void setup_timer_ce(void)
{
	struct clock_event_device *ce = &timer_ce;

	BUG_ON(smp_processor_id() != boot_cpu_id);

	ce->name     = "timer_ce";
	ce->rating   = 100;
	ce->features = CLOCK_EVT_FEAT_PERIODIC;
	ce->set_mode = timer_ce_set_mode;
	ce->cpumask  = cpu_possible_mask;
	ce->shift    = 32;
	ce->mult     = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
	                      ce->shift);
	clockevents_register_device(ce);
}

static unsigned int sbus_cycles_offset(void)
{
	u32 val, offset;

	val = sbus_readl(master_l10_counter);
	offset = (val >> TIMER_VALUE_SHIFT) & TIMER_VALUE_MASK;

	/* Limit hit? */
	if (val & TIMER_LIMIT_BIT)
		offset += sparc_config.cs_period;

	return offset;
}

static cycle_t timer_cs_read(struct clocksource *cs)
{
	unsigned int seq, offset;
	u64 cycles;

	do {
		seq = read_seqbegin(&timer_cs_lock);

		cycles = timer_cs_internal_counter;
		offset = sparc_config.get_cycles_offset();
	} while (read_seqretry(&timer_cs_lock, seq));

	/* Count absolute cycles */
	cycles *= sparc_config.cs_period;
	cycles += offset;

	return cycles;
}

static struct clocksource timer_cs = {
	.name	= "timer_cs",
	.rating	= 100,
	.read	= timer_cs_read,
	.mask	= CLOCKSOURCE_MASK(64),
	.shift	= 2,
	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
};

static __init int setup_timer_cs(void)
{
	timer_cs_enabled = 1;
	timer_cs.mult = clocksource_hz2mult(sparc_config.clock_rate,
	                                    timer_cs.shift);

	return clocksource_register(&timer_cs);
}

#ifdef CONFIG_SMP
static void percpu_ce_setup(enum clock_event_mode mode,
			struct clock_event_device *evt)
{
	int cpu = __first_cpu(evt->cpumask);

	switch (mode) {
		case CLOCK_EVT_MODE_PERIODIC:
			sparc_config.load_profile_irq(cpu,
						      SBUS_CLOCK_RATE / HZ);
			break;
		case CLOCK_EVT_MODE_ONESHOT:
		case CLOCK_EVT_MODE_SHUTDOWN:
		case CLOCK_EVT_MODE_UNUSED:
			sparc_config.load_profile_irq(cpu, 0);
			break;
		default:
			break;
	}
}

static int percpu_ce_set_next_event(unsigned long delta,
				    struct clock_event_device *evt)
{
	int cpu = __first_cpu(evt->cpumask);
	unsigned int next = (unsigned int)delta;

	sparc_config.load_profile_irq(cpu, next);
	return 0;
}

void register_percpu_ce(int cpu)
{
	struct clock_event_device *ce = &per_cpu(sparc32_clockevent, cpu);
	unsigned int features = CLOCK_EVT_FEAT_PERIODIC;

	if (sparc_config.features & FEAT_L14_ONESHOT)
		features |= CLOCK_EVT_FEAT_ONESHOT;

	ce->name           = "percpu_ce";
	ce->rating         = 200;
	ce->features       = features;
	ce->set_mode       = percpu_ce_setup;
	ce->set_next_event = percpu_ce_set_next_event;
	ce->cpumask        = cpumask_of(cpu);
	ce->shift          = 32;
	ce->mult           = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
	                            ce->shift);
	ce->max_delta_ns   = clockevent_delta2ns(sparc_config.clock_rate, ce);
	ce->min_delta_ns   = clockevent_delta2ns(100, ce);

	clockevents_register_device(ce);
}
#endif

static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;

	return readb(pdata->ioaddr + ofs);
}

static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct m48t59_plat_data *pdata = pdev->dev.platform_data;

	writeb(val, pdata->ioaddr + ofs);
}

static struct m48t59_plat_data m48t59_data = {
	.read_byte = mostek_read_byte,
	.write_byte = mostek_write_byte,
};

/* resource is set at runtime */
static struct platform_device m48t59_rtc = {
	.name		= "rtc-m48t59",
	.id		= 0,
	.num_resources	= 1,
	.dev	= {
		.platform_data = &m48t59_data,
	},
};

static int clock_probe(struct platform_device *op)
{
	struct device_node *dp = op->dev.of_node;
	const char *model = of_get_property(dp, "model", NULL);

	if (!model)
		return -ENODEV;

	/* Only the primary RTC has an address property */
	if (!of_find_property(dp, "address", NULL))
		return -ENODEV;

	m48t59_rtc.resource = &op->resource[0];
	if (!strcmp(model, "mk48t02")) {
		/* Map the clock register io area read-only */
		m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
						2048, "rtc-m48t59");
		m48t59_data.type = M48T59RTC_TYPE_M48T02;
	} else if (!strcmp(model, "mk48t08")) {
		m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
						8192, "rtc-m48t59");
		m48t59_data.type = M48T59RTC_TYPE_M48T08;
	} else
		return -ENODEV;

	if (platform_device_register(&m48t59_rtc) < 0)
		printk(KERN_ERR "Registering RTC device failed\n");

	return 0;
}

static struct of_device_id clock_match[] = {
	{
		.name = "eeprom",
	},
	{},
};

static struct platform_driver clock_driver = {
	.probe		= clock_probe,
	.driver = {
		.name = "rtc",
		.of_match_table = clock_match,
	},
};


/* Probe for the mostek real time clock chip. */
static int __init clock_init(void)
{
	return platform_driver_register(&clock_driver);
}
/* Must be after subsys_initcall() so that busses are probed.  Must
 * be before device_initcall() because things like the RTC driver
 * need to see the clock registers.
 */
fs_initcall(clock_init);

static void __init sparc32_late_time_init(void)
{
	if (sparc_config.features & FEAT_L10_CLOCKEVENT)
		setup_timer_ce();
	if (sparc_config.features & FEAT_L10_CLOCKSOURCE)
		setup_timer_cs();
#ifdef CONFIG_SMP
	register_percpu_ce(smp_processor_id());
#endif
}

static void __init sbus_time_init(void)
{
	sparc_config.get_cycles_offset = sbus_cycles_offset;
	sparc_config.init_timers();
}

void __init time_init(void)
{
	sparc_config.features = 0;
	late_time_init = sparc32_late_time_init;

	if (pcic_present())
		pci_time_init();
	else
		sbus_time_init();
}


static int set_rtc_mmss(unsigned long secs)
{
	struct rtc_device *rtc = rtc_class_open("rtc0");
	int err = -1;

	if (rtc) {
		err = rtc_set_mmss(rtc, secs);
		rtc_class_close(rtc);
	}

	return err;
}