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Merge branch 'r6040-next'
[linux/fpc-iii.git] / drivers / rtc / rtc-m41t80.c
blobd1bf93a8720027e529b6e51b8dbab304c4155c58
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_info(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_wday = -1;
324 alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f);
325 alrm->time.tm_mon = bcd2bin(alarmvals[0] & 0x3f);
326 alrm->time.tm_year = -1;
327
328 alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE);
329 alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled;
330
331 return 0;
332 }
333
334 static struct rtc_class_ops m41t80_rtc_ops = {
335 .read_time = m41t80_rtc_read_time,
336 .set_time = m41t80_rtc_set_time,
337 .proc = m41t80_rtc_proc,
338 };
339
340 static ssize_t flags_show(struct device *dev,
341 struct device_attribute *attr, char *buf)
342 {
343 struct i2c_client *client = to_i2c_client(dev);
344 int val;
345
346 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
347 if (val < 0)
348 return val;
349 return sprintf(buf, "%#x\n", val);
350 }
351 static DEVICE_ATTR_RO(flags);
352
353 static ssize_t sqwfreq_show(struct device *dev,
354 struct device_attribute *attr, char *buf)
355 {
356 struct i2c_client *client = to_i2c_client(dev);
357 struct m41t80_data *clientdata = i2c_get_clientdata(client);
358 int val, reg_sqw;
359
360 if (!(clientdata->features & M41T80_FEATURE_SQ))
361 return -EINVAL;
362
363 reg_sqw = M41T80_REG_SQW;
364 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
365 reg_sqw = M41T80_REG_WDAY;
366 val = i2c_smbus_read_byte_data(client, reg_sqw);
367 if (val < 0)
368 return val;
369 val = (val >> 4) & 0xf;
370 switch (val) {
371 case 0:
372 break;
373 case 1:
374 val = 32768;
375 break;
376 default:
377 val = 32768 >> val;
378 }
379 return sprintf(buf, "%d\n", val);
380 }
381
382 static ssize_t sqwfreq_store(struct device *dev,
383 struct device_attribute *attr,
384 const char *buf, size_t count)
385 {
386 struct i2c_client *client = to_i2c_client(dev);
387 struct m41t80_data *clientdata = i2c_get_clientdata(client);
388 int almon, sqw, reg_sqw, rc;
389 unsigned long val;
390
391 rc = kstrtoul(buf, 0, &val);
392 if (rc < 0)
393 return rc;
394
395 if (!(clientdata->features & M41T80_FEATURE_SQ))
396 return -EINVAL;
397
398 if (val) {
399 if (!is_power_of_2(val))
400 return -EINVAL;
401 val = ilog2(val);
402 if (val == 15)
403 val = 1;
404 else if (val < 14)
405 val = 15 - val;
406 else
407 return -EINVAL;
408 }
409 /* disable SQW, set SQW frequency & re-enable */
410 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
411 if (almon < 0)
412 return almon;
413 reg_sqw = M41T80_REG_SQW;
414 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
415 reg_sqw = M41T80_REG_WDAY;
416 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
417 if (sqw < 0)
418 return sqw;
419 sqw = (sqw & 0x0f) | (val << 4);
420
421 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
422 almon & ~M41T80_ALMON_SQWE);
423 if (rc < 0)
424 return rc;
425
426 if (val) {
427 rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw);
428 if (rc < 0)
429 return rc;
430
431 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
432 almon | M41T80_ALMON_SQWE);
433 if (rc < 0)
434 return rc;
435 }
436 return count;
437 }
438 static DEVICE_ATTR_RW(sqwfreq);
439
440 static struct attribute *attrs[] = {
441 &dev_attr_flags.attr,
442 &dev_attr_sqwfreq.attr,
443 NULL,
444 };
445
446 static struct attribute_group attr_group = {
447 .attrs = attrs,
448 };
449
450 #ifdef CONFIG_RTC_DRV_M41T80_WDT
451 /*
452 *****************************************************************************
453 *
454 * Watchdog Driver
455 *
456 *****************************************************************************
457 */
458 static struct i2c_client *save_client;
459
460 /* Default margin */
461 #define WD_TIMO 60 /* 1..31 seconds */
462
463 static int wdt_margin = WD_TIMO;
464 module_param(wdt_margin, int, 0);
465 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
466
467 static unsigned long wdt_is_open;
468 static int boot_flag;
469
470 /**
471 * wdt_ping:
472 *
473 * Reload counter one with the watchdog timeout. We don't bother reloading
474 * the cascade counter.
475 */
476 static void wdt_ping(void)
477 {
478 unsigned char i2c_data[2];
479 struct i2c_msg msgs1[1] = {
480 {
481 .addr = save_client->addr,
482 .flags = 0,
483 .len = 2,
484 .buf = i2c_data,
485 },
486 };
487 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
488
489 i2c_data[0] = 0x09; /* watchdog register */
490
491 if (wdt_margin > 31)
492 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
493 else
494 /*
495 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
496 */
497 i2c_data[1] = wdt_margin << 2 | 0x82;
498
499 /*
500 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
501 * that would be an invalid resolution.
502 */
503 if (clientdata->features & M41T80_FEATURE_WD)
504 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
505
506 i2c_transfer(save_client->adapter, msgs1, 1);
507 }
508
509 /**
510 * wdt_disable:
511 *
512 * disables watchdog.
513 */
514 static void wdt_disable(void)
515 {
516 unsigned char i2c_data[2], i2c_buf[0x10];
517 struct i2c_msg msgs0[2] = {
518 {
519 .addr = save_client->addr,
520 .flags = 0,
521 .len = 1,
522 .buf = i2c_data,
523 },
524 {
525 .addr = save_client->addr,
526 .flags = I2C_M_RD,
527 .len = 1,
528 .buf = i2c_buf,
529 },
530 };
531 struct i2c_msg msgs1[1] = {
532 {
533 .addr = save_client->addr,
534 .flags = 0,
535 .len = 2,
536 .buf = i2c_data,
537 },
538 };
539
540 i2c_data[0] = 0x09;
541 i2c_transfer(save_client->adapter, msgs0, 2);
542
543 i2c_data[0] = 0x09;
544 i2c_data[1] = 0x00;
545 i2c_transfer(save_client->adapter, msgs1, 1);
546 }
547
548 /**
549 * wdt_write:
550 * @file: file handle to the watchdog
551 * @buf: buffer to write (unused as data does not matter here
552 * @count: count of bytes
553 * @ppos: pointer to the position to write. No seeks allowed
554 *
555 * A write to a watchdog device is defined as a keepalive signal. Any
556 * write of data will do, as we we don't define content meaning.
557 */
558 static ssize_t wdt_write(struct file *file, const char __user *buf,
559 size_t count, loff_t *ppos)
560 {
561 if (count) {
562 wdt_ping();
563 return 1;
564 }
565 return 0;
566 }
567
568 static ssize_t wdt_read(struct file *file, char __user *buf,
569 size_t count, loff_t *ppos)
570 {
571 return 0;
572 }
573
574 /**
575 * wdt_ioctl:
576 * @inode: inode of the device
577 * @file: file handle to the device
578 * @cmd: watchdog command
579 * @arg: argument pointer
580 *
581 * The watchdog API defines a common set of functions for all watchdogs
582 * according to their available features. We only actually usefully support
583 * querying capabilities and current status.
584 */
585 static int wdt_ioctl(struct file *file, unsigned int cmd,
586 unsigned long arg)
587 {
588 int new_margin, rv;
589 static struct watchdog_info ident = {
590 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
591 WDIOF_SETTIMEOUT,
592 .firmware_version = 1,
593 .identity = "M41T80 WTD"
594 };
595
596 switch (cmd) {
597 case WDIOC_GETSUPPORT:
598 return copy_to_user((struct watchdog_info __user *)arg, &ident,
599 sizeof(ident)) ? -EFAULT : 0;
600
601 case WDIOC_GETSTATUS:
602 case WDIOC_GETBOOTSTATUS:
603 return put_user(boot_flag, (int __user *)arg);
604 case WDIOC_KEEPALIVE:
605 wdt_ping();
606 return 0;
607 case WDIOC_SETTIMEOUT:
608 if (get_user(new_margin, (int __user *)arg))
609 return -EFAULT;
610 /* Arbitrary, can't find the card's limits */
611 if (new_margin < 1 || new_margin > 124)
612 return -EINVAL;
613 wdt_margin = new_margin;
614 wdt_ping();
615 /* Fall */
616 case WDIOC_GETTIMEOUT:
617 return put_user(wdt_margin, (int __user *)arg);
618
619 case WDIOC_SETOPTIONS:
620 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
621 return -EFAULT;
622
623 if (rv & WDIOS_DISABLECARD) {
624 pr_info("disable watchdog\n");
625 wdt_disable();
626 }
627
628 if (rv & WDIOS_ENABLECARD) {
629 pr_info("enable watchdog\n");
630 wdt_ping();
631 }
632
633 return -EINVAL;
634 }
635 return -ENOTTY;
636 }
637
638 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
639 unsigned long arg)
640 {
641 int ret;
642
643 mutex_lock(&m41t80_rtc_mutex);
644 ret = wdt_ioctl(file, cmd, arg);
645 mutex_unlock(&m41t80_rtc_mutex);
646
647 return ret;
648 }
649
650 /**
651 * wdt_open:
652 * @inode: inode of device
653 * @file: file handle to device
654 *
655 */
656 static int wdt_open(struct inode *inode, struct file *file)
657 {
658 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
659 mutex_lock(&m41t80_rtc_mutex);
660 if (test_and_set_bit(0, &wdt_is_open)) {
661 mutex_unlock(&m41t80_rtc_mutex);
662 return -EBUSY;
663 }
664 /*
665 * Activate
666 */
667 wdt_is_open = 1;
668 mutex_unlock(&m41t80_rtc_mutex);
669 return nonseekable_open(inode, file);
670 }
671 return -ENODEV;
672 }
673
674 /**
675 * wdt_close:
676 * @inode: inode to board
677 * @file: file handle to board
678 *
679 */
680 static int wdt_release(struct inode *inode, struct file *file)
681 {
682 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
683 clear_bit(0, &wdt_is_open);
684 return 0;
685 }
686
687 /**
688 * notify_sys:
689 * @this: our notifier block
690 * @code: the event being reported
691 * @unused: unused
692 *
693 * Our notifier is called on system shutdowns. We want to turn the card
694 * off at reboot otherwise the machine will reboot again during memory
695 * test or worse yet during the following fsck. This would suck, in fact
696 * trust me - if it happens it does suck.
697 */
698 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
699 void *unused)
700 {
701 if (code == SYS_DOWN || code == SYS_HALT)
702 /* Disable Watchdog */
703 wdt_disable();
704 return NOTIFY_DONE;
705 }
706
707 static const struct file_operations wdt_fops = {
708 .owner = THIS_MODULE,
709 .read = wdt_read,
710 .unlocked_ioctl = wdt_unlocked_ioctl,
711 .write = wdt_write,
712 .open = wdt_open,
713 .release = wdt_release,
714 .llseek = no_llseek,
715 };
716
717 static struct miscdevice wdt_dev = {
718 .minor = WATCHDOG_MINOR,
719 .name = "watchdog",
720 .fops = &wdt_fops,
721 };
722
723 /*
724 * The WDT card needs to learn about soft shutdowns in order to
725 * turn the timebomb registers off.
726 */
727 static struct notifier_block wdt_notifier = {
728 .notifier_call = wdt_notify_sys,
729 };
730 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
731
732 /*
733 *****************************************************************************
734 *
735 * Driver Interface
736 *
737 *****************************************************************************
738 */
739
740 static void m41t80_remove_sysfs_group(void *_dev)
741 {
742 struct device *dev = _dev;
743
744 sysfs_remove_group(&dev->kobj, &attr_group);
745 }
746
747 static int m41t80_probe(struct i2c_client *client,
748 const struct i2c_device_id *id)
749 {
750 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
751 int rc = 0;
752 struct rtc_device *rtc = NULL;
753 struct rtc_time tm;
754 struct m41t80_data *m41t80_data = NULL;
755
756 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
757 I2C_FUNC_SMBUS_BYTE_DATA)) {
758 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
759 return -ENODEV;
760 }
761
762 m41t80_data = devm_kzalloc(&client->dev, sizeof(*m41t80_data),
763 GFP_KERNEL);
764 if (!m41t80_data)
765 return -ENOMEM;
766
767 m41t80_data->features = id->driver_data;
768 i2c_set_clientdata(client, m41t80_data);
769
770 if (client->irq > 0) {
771 rc = devm_request_threaded_irq(&client->dev, client->irq,
772 NULL, m41t80_handle_irq,
773 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
774 "m41t80", client);
775 if (rc) {
776 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
777 client->irq = 0;
778 } else {
779 m41t80_rtc_ops.read_alarm = m41t80_read_alarm;
780 m41t80_rtc_ops.set_alarm = m41t80_set_alarm;
781 m41t80_rtc_ops.alarm_irq_enable = m41t80_alarm_irq_enable;
782 /* Enable the wakealarm */
783 device_init_wakeup(&client->dev, true);
784 }
785 }
786
787 rtc = devm_rtc_device_register(&client->dev, client->name,
788 &m41t80_rtc_ops, THIS_MODULE);
789 if (IS_ERR(rtc))
790 return PTR_ERR(rtc);
791
792 m41t80_data->rtc = rtc;
793
794 /* Make sure HT (Halt Update) bit is cleared */
795 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
796
797 if (rc >= 0 && rc & M41T80_ALHOUR_HT) {
798 if (m41t80_data->features & M41T80_FEATURE_HT) {
799 m41t80_get_datetime(client, &tm);
800 dev_info(&client->dev, "HT bit was set!\n");
801 dev_info(&client->dev,
802 "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n",
803 tm.tm_year + 1900,
804 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
805 tm.tm_min, tm.tm_sec);
806 }
807 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR,
808 rc & ~M41T80_ALHOUR_HT);
809 }
810
811 if (rc < 0) {
812 dev_err(&client->dev, "Can't clear HT bit\n");
813 return rc;
814 }
815
816 /* Make sure ST (stop) bit is cleared */
817 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
818
819 if (rc >= 0 && rc & M41T80_SEC_ST)
820 rc = i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
821 rc & ~M41T80_SEC_ST);
822 if (rc < 0) {
823 dev_err(&client->dev, "Can't clear ST bit\n");
824 return rc;
825 }
826
827 /* Export sysfs entries */
828 rc = sysfs_create_group(&(&client->dev)->kobj, &attr_group);
829 if (rc) {
830 dev_err(&client->dev, "Failed to create sysfs group: %d\n", rc);
831 return rc;
832 }
833
834 rc = devm_add_action(&client->dev, m41t80_remove_sysfs_group,
835 &client->dev);
836 if (rc) {
837 m41t80_remove_sysfs_group(&client->dev);
838 dev_err(&client->dev,
839 "Failed to add sysfs cleanup action: %d\n", rc);
840 return rc;
841 }
842
843 #ifdef CONFIG_RTC_DRV_M41T80_WDT
844 if (m41t80_data->features & M41T80_FEATURE_HT) {
845 save_client = client;
846 rc = misc_register(&wdt_dev);
847 if (rc)
848 return rc;
849 rc = register_reboot_notifier(&wdt_notifier);
850 if (rc) {
851 misc_deregister(&wdt_dev);
852 return rc;
853 }
854 }
855 #endif
856 return 0;
857 }
858
859 static int m41t80_remove(struct i2c_client *client)
860 {
861 #ifdef CONFIG_RTC_DRV_M41T80_WDT
862 struct m41t80_data *clientdata = i2c_get_clientdata(client);
863
864 if (clientdata->features & M41T80_FEATURE_HT) {
865 misc_deregister(&wdt_dev);
866 unregister_reboot_notifier(&wdt_notifier);
867 }
868 #endif
869
870 return 0;
871 }
872
873 static struct i2c_driver m41t80_driver = {
874 .driver = {
875 .name = "rtc-m41t80",
876 },
877 .probe = m41t80_probe,
878 .remove = m41t80_remove,
879 .id_table = m41t80_id,
880 };
881
882 module_i2c_driver(m41t80_driver);
883
884 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
885 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
886 MODULE_LICENSE("GPL");
Linux with added FPC-III support