summaryrefslogtreecommitdiffstats
path: root/arch/sparc/kernel/time_32.c
blob: 614ac7b4a9dd4c6c2d2d662670c4a956439221e2 (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
/* 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/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/oplib.h>
#include <asm/timer.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/idprom.h>
#include <asm/machines.h>
#include <asm/page.h>
#include <asm/pcic.h>
#include <asm/irq_regs.h>

#include "irq.h"

DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);

static int set_rtc_mmss(unsigned long);
static int sbus_do_settimeofday(struct timespec *tv);

unsigned long profile_pc(struct pt_regs *regs)
{
	extern char __copy_user_begin[], __copy_user_end[];
	extern char __atomic_begin[], __atomic_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) __atomic_begin &&
	     pc < (unsigned long) __atomic_end) ||
	    (pc >= (unsigned long) __bzero_begin &&
	     pc < (unsigned long) __bzero_end))
		pc = regs->u_regs[UREG_RETPC];
	return pc;
}

EXPORT_SYMBOL(profile_pc);

__volatile__ unsigned int *master_l10_counter;

/*
 * timer_interrupt() needs to keep up the real-time clock,
 * as well as call the "do_timer()" routine every clocktick
 */

#define TICK_SIZE (tick_nsec / 1000)

static irqreturn_t timer_interrupt(int dummy, void *dev_id)
{
	/* last time the cmos clock got updated */
	static long last_rtc_update;

#ifndef CONFIG_SMP
	profile_tick(CPU_PROFILING);
#endif

	/* Protect counter clear so that do_gettimeoffset works */
	write_seqlock(&xtime_lock);

	clear_clock_irq();

	do_timer(1);

	/* Determine when to update the Mostek clock. */
	if (ntp_synced() &&
	    xtime.tv_sec > last_rtc_update + 660 &&
	    (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
	    (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
	  if (set_rtc_mmss(xtime.tv_sec) == 0)
	    last_rtc_update = xtime.tv_sec;
	  else
	    last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
	}
	write_sequnlock(&xtime_lock);

#ifndef CONFIG_SMP
	update_process_times(user_mode(get_irq_regs()));
#endif
	return IRQ_HANDLED;
}

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 __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
{
	struct device_node *dp = op->node;
	const char *model = of_get_property(dp, "model", NULL);

	if (!model)
		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 __initdata clock_match[] = {
	{
		.name = "eeprom",
	},
	{},
};

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


/* Probe for the mostek real time clock chip. */
static int __init clock_init(void)
{
	return of_register_driver(&clock_driver, &of_platform_bus_type);
}

/* 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 sbus_time_init(void)
{

	BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
	btfixup();

	sparc_init_timers(timer_interrupt);
	
	/* Now that OBP ticker has been silenced, it is safe to enable IRQ. */
	local_irq_enable();
}

void __init time_init(void)
{
#ifdef CONFIG_PCI
	extern void pci_time_init(void);
	if (pcic_present()) {
		pci_time_init();
		return;
	}
#endif
	sbus_time_init();
}

static inline unsigned long do_gettimeoffset(void)
{
	unsigned long val = *master_l10_counter;
	unsigned long usec = (val >> 10) & 0x1fffff;

	/* Limit hit?  */
	if (val & 0x80000000)
		usec += 1000000 / HZ;

	return usec;
}

/* Ok, my cute asm atomicity trick doesn't work anymore.
 * There are just too many variables that need to be protected
 * now (both members of xtime, et al.)
 */
void do_gettimeofday(struct timeval *tv)
{
	unsigned long flags;
	unsigned long seq;
	unsigned long usec, sec;
	unsigned long max_ntp_tick = tick_usec - tickadj;

	do {
		seq = read_seqbegin_irqsave(&xtime_lock, flags);
		usec = do_gettimeoffset();

		/*
		 * If time_adjust is negative then NTP is slowing the clock
		 * so make sure not to go into next possible interval.
		 * Better to lose some accuracy than have time go backwards..
		 */
		if (unlikely(time_adjust < 0))
			usec = min(usec, max_ntp_tick);

		sec = xtime.tv_sec;
		usec += (xtime.tv_nsec / 1000);
	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));

	while (usec >= 1000000) {
		usec -= 1000000;
		sec++;
	}

	tv->tv_sec = sec;
	tv->tv_usec = usec;
}

EXPORT_SYMBOL(do_gettimeofday);

int do_settimeofday(struct timespec *tv)
{
	int ret;

	write_seqlock_irq(&xtime_lock);
	ret = bus_do_settimeofday(tv);
	write_sequnlock_irq(&xtime_lock);
	clock_was_set();
	return ret;
}

EXPORT_SYMBOL(do_settimeofday);

static int sbus_do_settimeofday(struct timespec *tv)
{
	time_t wtm_sec, sec = tv->tv_sec;
	long wtm_nsec, nsec = tv->tv_nsec;

	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
		return -EINVAL;

	/*
	 * This is revolting. We need to set "xtime" correctly. However, the
	 * value in this location is the value at the most recent update of
	 * wall time.  Discover what correction gettimeofday() would have
	 * made, and then undo it!
	 */
	nsec -= 1000 * do_gettimeoffset();

	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

	set_normalized_timespec(&xtime, sec, nsec);
	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);

	ntp_clear();
	return 0;
}

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;
}
OpenPOWER on IntegriCloud