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x86/mm/pat: Don't report PAT on CPUs that don't support it
[linux/fpc-iii.git] / drivers / rtc / rtc-m41t80.c
blob58698d21c2c3d37878deedf442a34331659a5c7a
1 /*
2 * I2C client/driver for the ST M41T80 family of i2c rtc chips.
3 *
4 * Author: Alexander Bigga <ab@mycable.de>
5 *
6 * Based on m41t00.c by Mark A. Greer <mgreer@mvista.com>
7 *
8 * 2006 (c) mycable GmbH
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 */
15
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18 #include <linux/bcd.h>
19 #include <linux/i2c.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/rtc.h>
24 #include <linux/slab.h>
25 #include <linux/mutex.h>
26 #include <linux/string.h>
27 #ifdef CONFIG_RTC_DRV_M41T80_WDT
28 #include <linux/fs.h>
29 #include <linux/ioctl.h>
30 #include <linux/miscdevice.h>
31 #include <linux/reboot.h>
32 #include <linux/watchdog.h>
33 #endif
34
35 #define M41T80_REG_SSEC 0x00
36 #define M41T80_REG_SEC 0x01
37 #define M41T80_REG_MIN 0x02
38 #define M41T80_REG_HOUR 0x03
39 #define M41T80_REG_WDAY 0x04
40 #define M41T80_REG_DAY 0x05
41 #define M41T80_REG_MON 0x06
42 #define M41T80_REG_YEAR 0x07
43 #define M41T80_REG_ALARM_MON 0x0a
44 #define M41T80_REG_ALARM_DAY 0x0b
45 #define M41T80_REG_ALARM_HOUR 0x0c
46 #define M41T80_REG_ALARM_MIN 0x0d
47 #define M41T80_REG_ALARM_SEC 0x0e
48 #define M41T80_REG_FLAGS 0x0f
49 #define M41T80_REG_SQW 0x13
50
51 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1)
52 #define M41T80_ALARM_REG_SIZE \
53 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
54
55 #define M41T80_SEC_ST BIT(7) /* ST: Stop Bit */
56 #define M41T80_ALMON_AFE BIT(7) /* AFE: AF Enable Bit */
57 #define M41T80_ALMON_SQWE BIT(6) /* SQWE: SQW Enable Bit */
58 #define M41T80_ALHOUR_HT BIT(6) /* HT: Halt Update Bit */
59 #define M41T80_FLAGS_OF BIT(2) /* OF: Oscillator Failure Bit */
60 #define M41T80_FLAGS_AF BIT(6) /* AF: Alarm Flag Bit */
61 #define M41T80_FLAGS_BATT_LOW BIT(4) /* BL: Battery Low Bit */
62 #define M41T80_WATCHDOG_RB2 BIT(7) /* RB: Watchdog resolution */
63 #define M41T80_WATCHDOG_RB1 BIT(1) /* RB: Watchdog resolution */
64 #define M41T80_WATCHDOG_RB0 BIT(0) /* RB: Watchdog resolution */
65
66 #define M41T80_FEATURE_HT BIT(0) /* Halt feature */
67 #define M41T80_FEATURE_BL BIT(1) /* Battery low indicator */
68 #define M41T80_FEATURE_SQ BIT(2) /* Squarewave feature */
69 #define M41T80_FEATURE_WD BIT(3) /* Extra watchdog resolution */
70 #define M41T80_FEATURE_SQ_ALT BIT(4) /* RSx bits are in reg 4 */
71
72 static DEFINE_MUTEX(m41t80_rtc_mutex);
73 static const struct i2c_device_id m41t80_id[] = {
74 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
75 { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
76 { "m41t80", M41T80_FEATURE_SQ },
77 { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
78 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
79 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
80 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
81 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
82 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
83 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
84 { "rv4162", M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT },
85 { }
86 };
87 MODULE_DEVICE_TABLE(i2c, m41t80_id);
88
89 struct m41t80_data {
90 u8 features;
91 struct rtc_device *rtc;
92 };
93
94 static irqreturn_t m41t80_handle_irq(int irq, void *dev_id)
95 {
96 struct i2c_client *client = dev_id;
97 struct m41t80_data *m41t80 = i2c_get_clientdata(client);
98 struct mutex *lock = &m41t80->rtc->ops_lock;
99 unsigned long events = 0;
100 int flags, flags_afe;
101
102 mutex_lock(lock);
103
104 flags_afe = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
105 if (flags_afe < 0) {
106 mutex_unlock(lock);
107 return IRQ_NONE;
108 }
109
110 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
111 if (flags <= 0) {
112 mutex_unlock(lock);
113 return IRQ_NONE;
114 }
115
116 if (flags & M41T80_FLAGS_AF) {
117 flags &= ~M41T80_FLAGS_AF;
118 flags_afe &= ~M41T80_ALMON_AFE;
119 events |= RTC_AF;
120 }
121
122 if (events) {
123 rtc_update_irq(m41t80->rtc, 1, events);
124 i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, flags);
125 i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
126 flags_afe);
127 }
128
129 mutex_unlock(lock);
130
131 return IRQ_HANDLED;
132 }
133
134 static int m41t80_get_datetime(struct i2c_client *client,
135 struct rtc_time *tm)
136 {
137 unsigned char buf[8];
138 int err, flags;
139
140 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
141 if (flags < 0)
142 return flags;
143
144 if (flags & M41T80_FLAGS_OF) {
145 dev_err(&client->dev, "Oscillator failure, data is invalid.\n");
146 return -EINVAL;
147 }
148
149 err = i2c_smbus_read_i2c_block_data(client, M41T80_REG_SSEC,
150 sizeof(buf), buf);
151 if (err < 0) {
152 dev_err(&client->dev, "Unable to read date\n");
153 return -EIO;
154 }
155
156 tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
157 tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f);
158 tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f);
159 tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f);
160 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
161 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1;
162
163 /* assume 20YY not 19YY, and ignore the Century Bit */
164 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100;
165 return rtc_valid_tm(tm);
166 }
167
168 /* Sets the given date and time to the real time clock. */
169 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
170 {
171 unsigned char buf[8];
172 int err, flags;
173
174 if (tm->tm_year < 100 || tm->tm_year > 199)
175 return -EINVAL;
176
177 buf[M41T80_REG_SSEC] = 0;
178 buf[M41T80_REG_SEC] = bin2bcd(tm->tm_sec);
179 buf[M41T80_REG_MIN] = bin2bcd(tm->tm_min);
180 buf[M41T80_REG_HOUR] = bin2bcd(tm->tm_hour);
181 buf[M41T80_REG_DAY] = bin2bcd(tm->tm_mday);
182 buf[M41T80_REG_MON] = bin2bcd(tm->tm_mon + 1);
183 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100);
184 buf[M41T80_REG_WDAY] = tm->tm_wday;
185
186 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC,
187 sizeof(buf), buf);
188 if (err < 0) {
189 dev_err(&client->dev, "Unable to write to date registers\n");
190 return err;
191 }
192
193 /* Clear the OF bit of Flags Register */
194 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
195 if (flags < 0)
196 return flags;
197
198 if (i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
199 flags & ~M41T80_FLAGS_OF)) {
200 dev_err(&client->dev, "Unable to write flags register\n");
201 return -EIO;
202 }
203
204 return err;
205 }
206
207 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
208 {
209 struct i2c_client *client = to_i2c_client(dev);
210 struct m41t80_data *clientdata = i2c_get_clientdata(client);
211 u8 reg;
212
213 if (clientdata->features & M41T80_FEATURE_BL) {
214 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
215 seq_printf(seq, "battery\t\t: %s\n",
216 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
217 }
218 return 0;
219 }
220
221 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
222 {
223 return m41t80_get_datetime(to_i2c_client(dev), tm);
224 }
225
226 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
227 {
228 return m41t80_set_datetime(to_i2c_client(dev), tm);
229 }
230
231 static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled)
232 {
233 struct i2c_client *client = to_i2c_client(dev);
234 int flags, retval;
235
236 flags = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
237 if (flags < 0)
238 return flags;
239
240 if (enabled)
241 flags |= M41T80_ALMON_AFE;
242 else
243 flags &= ~M41T80_ALMON_AFE;
244
245 retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags);
246 if (retval < 0) {
247 dev_err(dev, "Unable to enable alarm IRQ %d\n", retval);
248 return retval;
249 }
250 return 0;
251 }
252
253 static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
254 {
255 struct i2c_client *client = to_i2c_client(dev);
256 u8 alarmvals[5];
257 int ret, err;
258
259 alarmvals[0] = bin2bcd(alrm->time.tm_mon + 1);
260 alarmvals[1] = bin2bcd(alrm->time.tm_mday);
261 alarmvals[2] = bin2bcd(alrm->time.tm_hour);
262 alarmvals[3] = bin2bcd(alrm->time.tm_min);
263 alarmvals[4] = bin2bcd(alrm->time.tm_sec);
264
265 /* Clear AF and AFE flags */
266 ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
267 if (ret < 0)
268 return ret;
269 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
270 ret & ~(M41T80_ALMON_AFE));
271 if (err < 0) {
272 dev_err(dev, "Unable to clear AFE bit\n");
273 return err;
274 }
275
276 ret = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
277 if (ret < 0)
278 return ret;
279
280 err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
281 ret & ~(M41T80_FLAGS_AF));
282 if (err < 0) {
283 dev_err(dev, "Unable to clear AF bit\n");
284 return err;
285 }
286
287 /* Write the alarm */
288 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_ALARM_MON,
289 5, alarmvals);
290 if (err)
291 return err;
292
293 /* Enable the alarm interrupt */
294 if (alrm->enabled) {
295 alarmvals[0] |= M41T80_ALMON_AFE;
296 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
297 alarmvals[0]);
298 if (err)
299 return err;
300 }
301
302 return 0;
303 }
304
305 static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
306 {
307 struct i2c_client *client = to_i2c_client(dev);
308 u8 alarmvals[5];
309 int flags, ret;
310
311 ret = i2c_smbus_read_i2c_block_data(client, M41T80_REG_ALARM_MON,
312 5, alarmvals);
313 if (ret != 5)
314 return ret < 0 ? ret : -EIO;
315
316 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
317 if (flags < 0)
318 return flags;
319
320 alrm->time.tm_sec = bcd2bin(alarmvals[4] & 0x7f);
321 alrm->time.tm_min = bcd2bin(alarmvals[3] & 0x7f);
322 alrm->time.tm_hour = bcd2bin(alarmvals[2] & 0x3f);
323 alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f);
324 alrm->time.tm_mon = bcd2bin(alarmvals[0] & 0x3f);
325
326 alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE);
327 alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled;
328
329 return 0;
330 }
331
332 static struct rtc_class_ops m41t80_rtc_ops = {
333 .read_time = m41t80_rtc_read_time,
334 .set_time = m41t80_rtc_set_time,
335 .proc = m41t80_rtc_proc,
336 };
337
338 #ifdef CONFIG_PM_SLEEP
339 static int m41t80_suspend(struct device *dev)
340 {
341 struct i2c_client *client = to_i2c_client(dev);
342
343 if (client->irq >= 0 && device_may_wakeup(dev))
344 enable_irq_wake(client->irq);
345
346 return 0;
347 }
348
349 static int m41t80_resume(struct device *dev)
350 {
351 struct i2c_client *client = to_i2c_client(dev);
352
353 if (client->irq >= 0 && device_may_wakeup(dev))
354 disable_irq_wake(client->irq);
355
356 return 0;
357 }
358 #endif
359
360 static SIMPLE_DEV_PM_OPS(m41t80_pm, m41t80_suspend, m41t80_resume);
361
362 static ssize_t flags_show(struct device *dev,
363 struct device_attribute *attr, char *buf)
364 {
365 struct i2c_client *client = to_i2c_client(dev);
366 int val;
367
368 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
369 if (val < 0)
370 return val;
371 return sprintf(buf, "%#x\n", val);
372 }
373 static DEVICE_ATTR_RO(flags);
374
375 static ssize_t sqwfreq_show(struct device *dev,
376 struct device_attribute *attr, char *buf)
377 {
378 struct i2c_client *client = to_i2c_client(dev);
379 struct m41t80_data *clientdata = i2c_get_clientdata(client);
380 int val, reg_sqw;
381
382 if (!(clientdata->features & M41T80_FEATURE_SQ))
383 return -EINVAL;
384
385 reg_sqw = M41T80_REG_SQW;
386 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
387 reg_sqw = M41T80_REG_WDAY;
388 val = i2c_smbus_read_byte_data(client, reg_sqw);
389 if (val < 0)
390 return val;
391 val = (val >> 4) & 0xf;
392 switch (val) {
393 case 0:
394 break;
395 case 1:
396 val = 32768;
397 break;
398 default:
399 val = 32768 >> val;
400 }
401 return sprintf(buf, "%d\n", val);
402 }
403
404 static ssize_t sqwfreq_store(struct device *dev,
405 struct device_attribute *attr,
406 const char *buf, size_t count)
407 {
408 struct i2c_client *client = to_i2c_client(dev);
409 struct m41t80_data *clientdata = i2c_get_clientdata(client);
410 int almon, sqw, reg_sqw, rc;
411 unsigned long val;
412
413 rc = kstrtoul(buf, 0, &val);
414 if (rc < 0)
415 return rc;
416
417 if (!(clientdata->features & M41T80_FEATURE_SQ))
418 return -EINVAL;
419
420 if (val) {
421 if (!is_power_of_2(val))
422 return -EINVAL;
423 val = ilog2(val);
424 if (val == 15)
425 val = 1;
426 else if (val < 14)
427 val = 15 - val;
428 else
429 return -EINVAL;
430 }
431 /* disable SQW, set SQW frequency & re-enable */
432 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
433 if (almon < 0)
434 return almon;
435 reg_sqw = M41T80_REG_SQW;
436 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
437 reg_sqw = M41T80_REG_WDAY;
438 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
439 if (sqw < 0)
440 return sqw;
441 sqw = (sqw & 0x0f) | (val << 4);
442
443 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
444 almon & ~M41T80_ALMON_SQWE);
445 if (rc < 0)
446 return rc;
447
448 if (val) {
449 rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw);
450 if (rc < 0)
451 return rc;
452
453 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
454 almon | M41T80_ALMON_SQWE);
455 if (rc < 0)
456 return rc;
457 }
458 return count;
459 }
460 static DEVICE_ATTR_RW(sqwfreq);
461
462 static struct attribute *attrs[] = {
463 &dev_attr_flags.attr,
464 &dev_attr_sqwfreq.attr,
465 NULL,
466 };
467
468 static struct attribute_group attr_group = {
469 .attrs = attrs,
470 };
471
472 #ifdef CONFIG_RTC_DRV_M41T80_WDT
473 /*
474 *****************************************************************************
475 *
476 * Watchdog Driver
477 *
478 *****************************************************************************
479 */
480 static struct i2c_client *save_client;
481
482 /* Default margin */
483 #define WD_TIMO 60 /* 1..31 seconds */
484
485 static int wdt_margin = WD_TIMO;
486 module_param(wdt_margin, int, 0);
487 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
488
489 static unsigned long wdt_is_open;
490 static int boot_flag;
491
492 /**
493 * wdt_ping:
494 *
495 * Reload counter one with the watchdog timeout. We don't bother reloading
496 * the cascade counter.
497 */
498 static void wdt_ping(void)
499 {
500 unsigned char i2c_data[2];
501 struct i2c_msg msgs1[1] = {
502 {
503 .addr = save_client->addr,
504 .flags = 0,
505 .len = 2,
506 .buf = i2c_data,
507 },
508 };
509 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
510
511 i2c_data[0] = 0x09; /* watchdog register */
512
513 if (wdt_margin > 31)
514 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
515 else
516 /*
517 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
518 */
519 i2c_data[1] = wdt_margin << 2 | 0x82;
520
521 /*
522 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
523 * that would be an invalid resolution.
524 */
525 if (clientdata->features & M41T80_FEATURE_WD)
526 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
527
528 i2c_transfer(save_client->adapter, msgs1, 1);
529 }
530
531 /**
532 * wdt_disable:
533 *
534 * disables watchdog.
535 */
536 static void wdt_disable(void)
537 {
538 unsigned char i2c_data[2], i2c_buf[0x10];
539 struct i2c_msg msgs0[2] = {
540 {
541 .addr = save_client->addr,
542 .flags = 0,
543 .len = 1,
544 .buf = i2c_data,
545 },
546 {
547 .addr = save_client->addr,
548 .flags = I2C_M_RD,
549 .len = 1,
550 .buf = i2c_buf,
551 },
552 };
553 struct i2c_msg msgs1[1] = {
554 {
555 .addr = save_client->addr,
556 .flags = 0,
557 .len = 2,
558 .buf = i2c_data,
559 },
560 };
561
562 i2c_data[0] = 0x09;
563 i2c_transfer(save_client->adapter, msgs0, 2);
564
565 i2c_data[0] = 0x09;
566 i2c_data[1] = 0x00;
567 i2c_transfer(save_client->adapter, msgs1, 1);
568 }
569
570 /**
571 * wdt_write:
572 * @file: file handle to the watchdog
573 * @buf: buffer to write (unused as data does not matter here
574 * @count: count of bytes
575 * @ppos: pointer to the position to write. No seeks allowed
576 *
577 * A write to a watchdog device is defined as a keepalive signal. Any
578 * write of data will do, as we we don't define content meaning.
579 */
580 static ssize_t wdt_write(struct file *file, const char __user *buf,
581 size_t count, loff_t *ppos)
582 {
583 if (count) {
584 wdt_ping();
585 return 1;
586 }
587 return 0;
588 }
589
590 static ssize_t wdt_read(struct file *file, char __user *buf,
591 size_t count, loff_t *ppos)
592 {
593 return 0;
594 }
595
596 /**
597 * wdt_ioctl:
598 * @inode: inode of the device
599 * @file: file handle to the device
600 * @cmd: watchdog command
601 * @arg: argument pointer
602 *
603 * The watchdog API defines a common set of functions for all watchdogs
604 * according to their available features. We only actually usefully support
605 * querying capabilities and current status.
606 */
607 static int wdt_ioctl(struct file *file, unsigned int cmd,
608 unsigned long arg)
609 {
610 int new_margin, rv;
611 static struct watchdog_info ident = {
612 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
613 WDIOF_SETTIMEOUT,
614 .firmware_version = 1,
615 .identity = "M41T80 WTD"
616 };
617
618 switch (cmd) {
619 case WDIOC_GETSUPPORT:
620 return copy_to_user((struct watchdog_info __user *)arg, &ident,
621 sizeof(ident)) ? -EFAULT : 0;
622
623 case WDIOC_GETSTATUS:
624 case WDIOC_GETBOOTSTATUS:
625 return put_user(boot_flag, (int __user *)arg);
626 case WDIOC_KEEPALIVE:
627 wdt_ping();
628 return 0;
629 case WDIOC_SETTIMEOUT:
630 if (get_user(new_margin, (int __user *)arg))
631 return -EFAULT;
632 /* Arbitrary, can't find the card's limits */
633 if (new_margin < 1 || new_margin > 124)
634 return -EINVAL;
635 wdt_margin = new_margin;
636 wdt_ping();
637 /* Fall */
638 case WDIOC_GETTIMEOUT:
639 return put_user(wdt_margin, (int __user *)arg);
640
641 case WDIOC_SETOPTIONS:
642 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
643 return -EFAULT;
644
645 if (rv & WDIOS_DISABLECARD) {
646 pr_info("disable watchdog\n");
647 wdt_disable();
648 }
649
650 if (rv & WDIOS_ENABLECARD) {
651 pr_info("enable watchdog\n");
652 wdt_ping();
653 }
654
655 return -EINVAL;
656 }
657 return -ENOTTY;
658 }
659
660 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
661 unsigned long arg)
662 {
663 int ret;
664
665 mutex_lock(&m41t80_rtc_mutex);
666 ret = wdt_ioctl(file, cmd, arg);
667 mutex_unlock(&m41t80_rtc_mutex);
668
669 return ret;
670 }
671
672 /**
673 * wdt_open:
674 * @inode: inode of device
675 * @file: file handle to device
676 *
677 */
678 static int wdt_open(struct inode *inode, struct file *file)
679 {
680 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
681 mutex_lock(&m41t80_rtc_mutex);
682 if (test_and_set_bit(0, &wdt_is_open)) {
683 mutex_unlock(&m41t80_rtc_mutex);
684 return -EBUSY;
685 }
686 /*
687 * Activate
688 */
689 wdt_is_open = 1;
690 mutex_unlock(&m41t80_rtc_mutex);
691 return nonseekable_open(inode, file);
692 }
693 return -ENODEV;
694 }
695
696 /**
697 * wdt_close:
698 * @inode: inode to board
699 * @file: file handle to board
700 *
701 */
702 static int wdt_release(struct inode *inode, struct file *file)
703 {
704 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
705 clear_bit(0, &wdt_is_open);
706 return 0;
707 }
708
709 /**
710 * notify_sys:
711 * @this: our notifier block
712 * @code: the event being reported
713 * @unused: unused
714 *
715 * Our notifier is called on system shutdowns. We want to turn the card
716 * off at reboot otherwise the machine will reboot again during memory
717 * test or worse yet during the following fsck. This would suck, in fact
718 * trust me - if it happens it does suck.
719 */
720 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
721 void *unused)
722 {
723 if (code == SYS_DOWN || code == SYS_HALT)
724 /* Disable Watchdog */
725 wdt_disable();
726 return NOTIFY_DONE;
727 }
728
729 static const struct file_operations wdt_fops = {
730 .owner = THIS_MODULE,
731 .read = wdt_read,
732 .unlocked_ioctl = wdt_unlocked_ioctl,
733 .write = wdt_write,
734 .open = wdt_open,
735 .release = wdt_release,
736 .llseek = no_llseek,
737 };
738
739 static struct miscdevice wdt_dev = {
740 .minor = WATCHDOG_MINOR,
741 .name = "watchdog",
742 .fops = &wdt_fops,
743 };
744
745 /*
746 * The WDT card needs to learn about soft shutdowns in order to
747 * turn the timebomb registers off.
748 */
749 static struct notifier_block wdt_notifier = {
750 .notifier_call = wdt_notify_sys,
751 };
752 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
753
754 /*
755 *****************************************************************************
756 *
757 * Driver Interface
758 *
759 *****************************************************************************
760 */
761
762 static void m41t80_remove_sysfs_group(void *_dev)
763 {
764 struct device *dev = _dev;
765
766 sysfs_remove_group(&dev->kobj, &attr_group);
767 }
768
769 static int m41t80_probe(struct i2c_client *client,
770 const struct i2c_device_id *id)
771 {
772 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
773 int rc = 0;
774 struct rtc_device *rtc = NULL;
775 struct rtc_time tm;
776 struct m41t80_data *m41t80_data = NULL;
777
778 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
779 I2C_FUNC_SMBUS_BYTE_DATA)) {
780 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
781 return -ENODEV;
782 }
783
784 m41t80_data = devm_kzalloc(&client->dev, sizeof(*m41t80_data),
785 GFP_KERNEL);
786 if (!m41t80_data)
787 return -ENOMEM;
788
789 m41t80_data->features = id->driver_data;
790 i2c_set_clientdata(client, m41t80_data);
791
792 if (client->irq > 0) {
793 rc = devm_request_threaded_irq(&client->dev, client->irq,
794 NULL, m41t80_handle_irq,
795 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
796 "m41t80", client);
797 if (rc) {
798 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
799 client->irq = 0;
800 } else {
801 m41t80_rtc_ops.read_alarm = m41t80_read_alarm;
802 m41t80_rtc_ops.set_alarm = m41t80_set_alarm;
803 m41t80_rtc_ops.alarm_irq_enable = m41t80_alarm_irq_enable;
804 /* Enable the wakealarm */
805 device_init_wakeup(&client->dev, true);
806 }
807 }
808
809 rtc = devm_rtc_device_register(&client->dev, client->name,
810 &m41t80_rtc_ops, THIS_MODULE);
811 if (IS_ERR(rtc))
812 return PTR_ERR(rtc);
813
814 m41t80_data->rtc = rtc;
815
816 /* Make sure HT (Halt Update) bit is cleared */
817 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
818
819 if (rc >= 0 && rc & M41T80_ALHOUR_HT) {
820 if (m41t80_data->features & M41T80_FEATURE_HT) {
821 m41t80_get_datetime(client, &tm);
822 dev_info(&client->dev, "HT bit was set!\n");
823 dev_info(&client->dev,
824 "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n",
825 tm.tm_year + 1900,
826 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
827 tm.tm_min, tm.tm_sec);
828 }
829 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR,
830 rc & ~M41T80_ALHOUR_HT);
831 }
832
833 if (rc < 0) {
834 dev_err(&client->dev, "Can't clear HT bit\n");
835 return rc;
836 }
837
838 /* Make sure ST (stop) bit is cleared */
839 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
840
841 if (rc >= 0 && rc & M41T80_SEC_ST)
842 rc = i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
843 rc & ~M41T80_SEC_ST);
844 if (rc < 0) {
845 dev_err(&client->dev, "Can't clear ST bit\n");
846 return rc;
847 }
848
849 /* Export sysfs entries */
850 rc = sysfs_create_group(&(&client->dev)->kobj, &attr_group);
851 if (rc) {
852 dev_err(&client->dev, "Failed to create sysfs group: %d\n", rc);
853 return rc;
854 }
855
856 rc = devm_add_action_or_reset(&client->dev, m41t80_remove_sysfs_group,
857 &client->dev);
858 if (rc) {
859 dev_err(&client->dev,
860 "Failed to add sysfs cleanup action: %d\n", rc);
861 return rc;
862 }
863
864 #ifdef CONFIG_RTC_DRV_M41T80_WDT
865 if (m41t80_data->features & M41T80_FEATURE_HT) {
866 save_client = client;
867 rc = misc_register(&wdt_dev);
868 if (rc)
869 return rc;
870 rc = register_reboot_notifier(&wdt_notifier);
871 if (rc) {
872 misc_deregister(&wdt_dev);
873 return rc;
874 }
875 }
876 #endif
877 return 0;
878 }
879
880 static int m41t80_remove(struct i2c_client *client)
881 {
882 #ifdef CONFIG_RTC_DRV_M41T80_WDT
883 struct m41t80_data *clientdata = i2c_get_clientdata(client);
884
885 if (clientdata->features & M41T80_FEATURE_HT) {
886 misc_deregister(&wdt_dev);
887 unregister_reboot_notifier(&wdt_notifier);
888 }
889 #endif
890
891 return 0;
892 }
893
894 static struct i2c_driver m41t80_driver = {
895 .driver = {
896 .name = "rtc-m41t80",
897 .pm = &m41t80_pm,
898 },
899 .probe = m41t80_probe,
900 .remove = m41t80_remove,
901 .id_table = m41t80_id,
902 };
903
904 module_i2c_driver(m41t80_driver);
905
906 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
907 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
908 MODULE_LICENSE("GPL");
Linux with added FPC-III support