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x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
[linux/fpc-iii.git] / drivers / rtc / rtc-m41t80.c
blobc4ca6a385790b5fa36bd9cfddb54fb30e5e82cd9
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 struct m41t80_data *clientdata = i2c_get_clientdata(client);
172 unsigned char buf[8];
173 int err, flags;
174
175 if (tm->tm_year < 100 || tm->tm_year > 199)
176 return -EINVAL;
177
178 buf[M41T80_REG_SSEC] = 0;
179 buf[M41T80_REG_SEC] = bin2bcd(tm->tm_sec);
180 buf[M41T80_REG_MIN] = bin2bcd(tm->tm_min);
181 buf[M41T80_REG_HOUR] = bin2bcd(tm->tm_hour);
182 buf[M41T80_REG_DAY] = bin2bcd(tm->tm_mday);
183 buf[M41T80_REG_MON] = bin2bcd(tm->tm_mon + 1);
184 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100);
185 buf[M41T80_REG_WDAY] = tm->tm_wday;
186
187 /* If the square wave output is controlled in the weekday register */
188 if (clientdata->features & M41T80_FEATURE_SQ_ALT) {
189 int val;
190
191 val = i2c_smbus_read_byte_data(client, M41T80_REG_WDAY);
192 if (val < 0)
193 return val;
194
195 buf[M41T80_REG_WDAY] |= (val & 0xf0);
196 }
197
198 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC,
199 sizeof(buf), buf);
200 if (err < 0) {
201 dev_err(&client->dev, "Unable to write to date registers\n");
202 return err;
203 }
204
205 /* Clear the OF bit of Flags Register */
206 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
207 if (flags < 0)
208 return flags;
209
210 if (i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
211 flags & ~M41T80_FLAGS_OF)) {
212 dev_err(&client->dev, "Unable to write flags register\n");
213 return -EIO;
214 }
215
216 return err;
217 }
218
219 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
220 {
221 struct i2c_client *client = to_i2c_client(dev);
222 struct m41t80_data *clientdata = i2c_get_clientdata(client);
223 u8 reg;
224
225 if (clientdata->features & M41T80_FEATURE_BL) {
226 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
227 seq_printf(seq, "battery\t\t: %s\n",
228 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
229 }
230 return 0;
231 }
232
233 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
234 {
235 return m41t80_get_datetime(to_i2c_client(dev), tm);
236 }
237
238 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
239 {
240 return m41t80_set_datetime(to_i2c_client(dev), tm);
241 }
242
243 static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled)
244 {
245 struct i2c_client *client = to_i2c_client(dev);
246 int flags, retval;
247
248 flags = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
249 if (flags < 0)
250 return flags;
251
252 if (enabled)
253 flags |= M41T80_ALMON_AFE;
254 else
255 flags &= ~M41T80_ALMON_AFE;
256
257 retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags);
258 if (retval < 0) {
259 dev_err(dev, "Unable to enable alarm IRQ %d\n", retval);
260 return retval;
261 }
262 return 0;
263 }
264
265 static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
266 {
267 struct i2c_client *client = to_i2c_client(dev);
268 u8 alarmvals[5];
269 int ret, err;
270
271 alarmvals[0] = bin2bcd(alrm->time.tm_mon + 1);
272 alarmvals[1] = bin2bcd(alrm->time.tm_mday);
273 alarmvals[2] = bin2bcd(alrm->time.tm_hour);
274 alarmvals[3] = bin2bcd(alrm->time.tm_min);
275 alarmvals[4] = bin2bcd(alrm->time.tm_sec);
276
277 /* Clear AF and AFE flags */
278 ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
279 if (ret < 0)
280 return ret;
281 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
282 ret & ~(M41T80_ALMON_AFE));
283 if (err < 0) {
284 dev_err(dev, "Unable to clear AFE bit\n");
285 return err;
286 }
287
288 ret = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
289 if (ret < 0)
290 return ret;
291
292 err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
293 ret & ~(M41T80_FLAGS_AF));
294 if (err < 0) {
295 dev_err(dev, "Unable to clear AF bit\n");
296 return err;
297 }
298
299 /* Write the alarm */
300 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_ALARM_MON,
301 5, alarmvals);
302 if (err)
303 return err;
304
305 /* Enable the alarm interrupt */
306 if (alrm->enabled) {
307 alarmvals[0] |= M41T80_ALMON_AFE;
308 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
309 alarmvals[0]);
310 if (err)
311 return err;
312 }
313
314 return 0;
315 }
316
317 static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
318 {
319 struct i2c_client *client = to_i2c_client(dev);
320 u8 alarmvals[5];
321 int flags, ret;
322
323 ret = i2c_smbus_read_i2c_block_data(client, M41T80_REG_ALARM_MON,
324 5, alarmvals);
325 if (ret != 5)
326 return ret < 0 ? ret : -EIO;
327
328 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
329 if (flags < 0)
330 return flags;
331
332 alrm->time.tm_sec = bcd2bin(alarmvals[4] & 0x7f);
333 alrm->time.tm_min = bcd2bin(alarmvals[3] & 0x7f);
334 alrm->time.tm_hour = bcd2bin(alarmvals[2] & 0x3f);
335 alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f);
336 alrm->time.tm_mon = bcd2bin(alarmvals[0] & 0x3f);
337
338 alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE);
339 alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled;
340
341 return 0;
342 }
343
344 static struct rtc_class_ops m41t80_rtc_ops = {
345 .read_time = m41t80_rtc_read_time,
346 .set_time = m41t80_rtc_set_time,
347 .proc = m41t80_rtc_proc,
348 };
349
350 #ifdef CONFIG_PM_SLEEP
351 static int m41t80_suspend(struct device *dev)
352 {
353 struct i2c_client *client = to_i2c_client(dev);
354
355 if (client->irq >= 0 && device_may_wakeup(dev))
356 enable_irq_wake(client->irq);
357
358 return 0;
359 }
360
361 static int m41t80_resume(struct device *dev)
362 {
363 struct i2c_client *client = to_i2c_client(dev);
364
365 if (client->irq >= 0 && device_may_wakeup(dev))
366 disable_irq_wake(client->irq);
367
368 return 0;
369 }
370 #endif
371
372 static SIMPLE_DEV_PM_OPS(m41t80_pm, m41t80_suspend, m41t80_resume);
373
374 static ssize_t flags_show(struct device *dev,
375 struct device_attribute *attr, char *buf)
376 {
377 struct i2c_client *client = to_i2c_client(dev);
378 int val;
379
380 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
381 if (val < 0)
382 return val;
383 return sprintf(buf, "%#x\n", val);
384 }
385 static DEVICE_ATTR_RO(flags);
386
387 static ssize_t sqwfreq_show(struct device *dev,
388 struct device_attribute *attr, char *buf)
389 {
390 struct i2c_client *client = to_i2c_client(dev);
391 struct m41t80_data *clientdata = i2c_get_clientdata(client);
392 int val, reg_sqw;
393
394 if (!(clientdata->features & M41T80_FEATURE_SQ))
395 return -EINVAL;
396
397 reg_sqw = M41T80_REG_SQW;
398 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
399 reg_sqw = M41T80_REG_WDAY;
400 val = i2c_smbus_read_byte_data(client, reg_sqw);
401 if (val < 0)
402 return val;
403 val = (val >> 4) & 0xf;
404 switch (val) {
405 case 0:
406 break;
407 case 1:
408 val = 32768;
409 break;
410 default:
411 val = 32768 >> val;
412 }
413 return sprintf(buf, "%d\n", val);
414 }
415
416 static ssize_t sqwfreq_store(struct device *dev,
417 struct device_attribute *attr,
418 const char *buf, size_t count)
419 {
420 struct i2c_client *client = to_i2c_client(dev);
421 struct m41t80_data *clientdata = i2c_get_clientdata(client);
422 int almon, sqw, reg_sqw, rc;
423 unsigned long val;
424
425 rc = kstrtoul(buf, 0, &val);
426 if (rc < 0)
427 return rc;
428
429 if (!(clientdata->features & M41T80_FEATURE_SQ))
430 return -EINVAL;
431
432 if (val) {
433 if (!is_power_of_2(val))
434 return -EINVAL;
435 val = ilog2(val);
436 if (val == 15)
437 val = 1;
438 else if (val < 14)
439 val = 15 - val;
440 else
441 return -EINVAL;
442 }
443 /* disable SQW, set SQW frequency & re-enable */
444 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
445 if (almon < 0)
446 return almon;
447 reg_sqw = M41T80_REG_SQW;
448 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
449 reg_sqw = M41T80_REG_WDAY;
450 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
451 if (sqw < 0)
452 return sqw;
453 sqw = (sqw & 0x0f) | (val << 4);
454
455 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
456 almon & ~M41T80_ALMON_SQWE);
457 if (rc < 0)
458 return rc;
459
460 if (val) {
461 rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw);
462 if (rc < 0)
463 return rc;
464
465 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
466 almon | M41T80_ALMON_SQWE);
467 if (rc < 0)
468 return rc;
469 }
470 return count;
471 }
472 static DEVICE_ATTR_RW(sqwfreq);
473
474 static struct attribute *attrs[] = {
475 &dev_attr_flags.attr,
476 &dev_attr_sqwfreq.attr,
477 NULL,
478 };
479
480 static struct attribute_group attr_group = {
481 .attrs = attrs,
482 };
483
484 #ifdef CONFIG_RTC_DRV_M41T80_WDT
485 /*
486 *****************************************************************************
487 *
488 * Watchdog Driver
489 *
490 *****************************************************************************
491 */
492 static struct i2c_client *save_client;
493
494 /* Default margin */
495 #define WD_TIMO 60 /* 1..31 seconds */
496
497 static int wdt_margin = WD_TIMO;
498 module_param(wdt_margin, int, 0);
499 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
500
501 static unsigned long wdt_is_open;
502 static int boot_flag;
503
504 /**
505 * wdt_ping:
506 *
507 * Reload counter one with the watchdog timeout. We don't bother reloading
508 * the cascade counter.
509 */
510 static void wdt_ping(void)
511 {
512 unsigned char i2c_data[2];
513 struct i2c_msg msgs1[1] = {
514 {
515 .addr = save_client->addr,
516 .flags = 0,
517 .len = 2,
518 .buf = i2c_data,
519 },
520 };
521 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
522
523 i2c_data[0] = 0x09; /* watchdog register */
524
525 if (wdt_margin > 31)
526 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
527 else
528 /*
529 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
530 */
531 i2c_data[1] = wdt_margin << 2 | 0x82;
532
533 /*
534 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
535 * that would be an invalid resolution.
536 */
537 if (clientdata->features & M41T80_FEATURE_WD)
538 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
539
540 i2c_transfer(save_client->adapter, msgs1, 1);
541 }
542
543 /**
544 * wdt_disable:
545 *
546 * disables watchdog.
547 */
548 static void wdt_disable(void)
549 {
550 unsigned char i2c_data[2], i2c_buf[0x10];
551 struct i2c_msg msgs0[2] = {
552 {
553 .addr = save_client->addr,
554 .flags = 0,
555 .len = 1,
556 .buf = i2c_data,
557 },
558 {
559 .addr = save_client->addr,
560 .flags = I2C_M_RD,
561 .len = 1,
562 .buf = i2c_buf,
563 },
564 };
565 struct i2c_msg msgs1[1] = {
566 {
567 .addr = save_client->addr,
568 .flags = 0,
569 .len = 2,
570 .buf = i2c_data,
571 },
572 };
573
574 i2c_data[0] = 0x09;
575 i2c_transfer(save_client->adapter, msgs0, 2);
576
577 i2c_data[0] = 0x09;
578 i2c_data[1] = 0x00;
579 i2c_transfer(save_client->adapter, msgs1, 1);
580 }
581
582 /**
583 * wdt_write:
584 * @file: file handle to the watchdog
585 * @buf: buffer to write (unused as data does not matter here
586 * @count: count of bytes
587 * @ppos: pointer to the position to write. No seeks allowed
588 *
589 * A write to a watchdog device is defined as a keepalive signal. Any
590 * write of data will do, as we we don't define content meaning.
591 */
592 static ssize_t wdt_write(struct file *file, const char __user *buf,
593 size_t count, loff_t *ppos)
594 {
595 if (count) {
596 wdt_ping();
597 return 1;
598 }
599 return 0;
600 }
601
602 static ssize_t wdt_read(struct file *file, char __user *buf,
603 size_t count, loff_t *ppos)
604 {
605 return 0;
606 }
607
608 /**
609 * wdt_ioctl:
610 * @inode: inode of the device
611 * @file: file handle to the device
612 * @cmd: watchdog command
613 * @arg: argument pointer
614 *
615 * The watchdog API defines a common set of functions for all watchdogs
616 * according to their available features. We only actually usefully support
617 * querying capabilities and current status.
618 */
619 static int wdt_ioctl(struct file *file, unsigned int cmd,
620 unsigned long arg)
621 {
622 int new_margin, rv;
623 static struct watchdog_info ident = {
624 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
625 WDIOF_SETTIMEOUT,
626 .firmware_version = 1,
627 .identity = "M41T80 WTD"
628 };
629
630 switch (cmd) {
631 case WDIOC_GETSUPPORT:
632 return copy_to_user((struct watchdog_info __user *)arg, &ident,
633 sizeof(ident)) ? -EFAULT : 0;
634
635 case WDIOC_GETSTATUS:
636 case WDIOC_GETBOOTSTATUS:
637 return put_user(boot_flag, (int __user *)arg);
638 case WDIOC_KEEPALIVE:
639 wdt_ping();
640 return 0;
641 case WDIOC_SETTIMEOUT:
642 if (get_user(new_margin, (int __user *)arg))
643 return -EFAULT;
644 /* Arbitrary, can't find the card's limits */
645 if (new_margin < 1 || new_margin > 124)
646 return -EINVAL;
647 wdt_margin = new_margin;
648 wdt_ping();
649 /* Fall */
650 case WDIOC_GETTIMEOUT:
651 return put_user(wdt_margin, (int __user *)arg);
652
653 case WDIOC_SETOPTIONS:
654 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
655 return -EFAULT;
656
657 if (rv & WDIOS_DISABLECARD) {
658 pr_info("disable watchdog\n");
659 wdt_disable();
660 }
661
662 if (rv & WDIOS_ENABLECARD) {
663 pr_info("enable watchdog\n");
664 wdt_ping();
665 }
666
667 return -EINVAL;
668 }
669 return -ENOTTY;
670 }
671
672 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
673 unsigned long arg)
674 {
675 int ret;
676
677 mutex_lock(&m41t80_rtc_mutex);
678 ret = wdt_ioctl(file, cmd, arg);
679 mutex_unlock(&m41t80_rtc_mutex);
680
681 return ret;
682 }
683
684 /**
685 * wdt_open:
686 * @inode: inode of device
687 * @file: file handle to device
688 *
689 */
690 static int wdt_open(struct inode *inode, struct file *file)
691 {
692 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
693 mutex_lock(&m41t80_rtc_mutex);
694 if (test_and_set_bit(0, &wdt_is_open)) {
695 mutex_unlock(&m41t80_rtc_mutex);
696 return -EBUSY;
697 }
698 /*
699 * Activate
700 */
701 wdt_is_open = 1;
702 mutex_unlock(&m41t80_rtc_mutex);
703 return nonseekable_open(inode, file);
704 }
705 return -ENODEV;
706 }
707
708 /**
709 * wdt_close:
710 * @inode: inode to board
711 * @file: file handle to board
712 *
713 */
714 static int wdt_release(struct inode *inode, struct file *file)
715 {
716 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
717 clear_bit(0, &wdt_is_open);
718 return 0;
719 }
720
721 /**
722 * notify_sys:
723 * @this: our notifier block
724 * @code: the event being reported
725 * @unused: unused
726 *
727 * Our notifier is called on system shutdowns. We want to turn the card
728 * off at reboot otherwise the machine will reboot again during memory
729 * test or worse yet during the following fsck. This would suck, in fact
730 * trust me - if it happens it does suck.
731 */
732 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
733 void *unused)
734 {
735 if (code == SYS_DOWN || code == SYS_HALT)
736 /* Disable Watchdog */
737 wdt_disable();
738 return NOTIFY_DONE;
739 }
740
741 static const struct file_operations wdt_fops = {
742 .owner = THIS_MODULE,
743 .read = wdt_read,
744 .unlocked_ioctl = wdt_unlocked_ioctl,
745 .write = wdt_write,
746 .open = wdt_open,
747 .release = wdt_release,
748 .llseek = no_llseek,
749 };
750
751 static struct miscdevice wdt_dev = {
752 .minor = WATCHDOG_MINOR,
753 .name = "watchdog",
754 .fops = &wdt_fops,
755 };
756
757 /*
758 * The WDT card needs to learn about soft shutdowns in order to
759 * turn the timebomb registers off.
760 */
761 static struct notifier_block wdt_notifier = {
762 .notifier_call = wdt_notify_sys,
763 };
764 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
765
766 /*
767 *****************************************************************************
768 *
769 * Driver Interface
770 *
771 *****************************************************************************
772 */
773
774 static void m41t80_remove_sysfs_group(void *_dev)
775 {
776 struct device *dev = _dev;
777
778 sysfs_remove_group(&dev->kobj, &attr_group);
779 }
780
781 static int m41t80_probe(struct i2c_client *client,
782 const struct i2c_device_id *id)
783 {
784 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
785 int rc = 0;
786 struct rtc_device *rtc = NULL;
787 struct rtc_time tm;
788 struct m41t80_data *m41t80_data = NULL;
789
790 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
791 I2C_FUNC_SMBUS_BYTE_DATA)) {
792 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
793 return -ENODEV;
794 }
795
796 m41t80_data = devm_kzalloc(&client->dev, sizeof(*m41t80_data),
797 GFP_KERNEL);
798 if (!m41t80_data)
799 return -ENOMEM;
800
801 m41t80_data->features = id->driver_data;
802 i2c_set_clientdata(client, m41t80_data);
803
804 if (client->irq > 0) {
805 rc = devm_request_threaded_irq(&client->dev, client->irq,
806 NULL, m41t80_handle_irq,
807 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
808 "m41t80", client);
809 if (rc) {
810 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
811 client->irq = 0;
812 } else {
813 m41t80_rtc_ops.read_alarm = m41t80_read_alarm;
814 m41t80_rtc_ops.set_alarm = m41t80_set_alarm;
815 m41t80_rtc_ops.alarm_irq_enable = m41t80_alarm_irq_enable;
816 /* Enable the wakealarm */
817 device_init_wakeup(&client->dev, true);
818 }
819 }
820
821 rtc = devm_rtc_device_register(&client->dev, client->name,
822 &m41t80_rtc_ops, THIS_MODULE);
823 if (IS_ERR(rtc))
824 return PTR_ERR(rtc);
825
826 m41t80_data->rtc = rtc;
827
828 /* Make sure HT (Halt Update) bit is cleared */
829 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
830
831 if (rc >= 0 && rc & M41T80_ALHOUR_HT) {
832 if (m41t80_data->features & M41T80_FEATURE_HT) {
833 m41t80_get_datetime(client, &tm);
834 dev_info(&client->dev, "HT bit was set!\n");
835 dev_info(&client->dev,
836 "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n",
837 tm.tm_year + 1900,
838 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
839 tm.tm_min, tm.tm_sec);
840 }
841 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR,
842 rc & ~M41T80_ALHOUR_HT);
843 }
844
845 if (rc < 0) {
846 dev_err(&client->dev, "Can't clear HT bit\n");
847 return rc;
848 }
849
850 /* Make sure ST (stop) bit is cleared */
851 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
852
853 if (rc >= 0 && rc & M41T80_SEC_ST)
854 rc = i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
855 rc & ~M41T80_SEC_ST);
856 if (rc < 0) {
857 dev_err(&client->dev, "Can't clear ST bit\n");
858 return rc;
859 }
860
861 /* Export sysfs entries */
862 rc = sysfs_create_group(&(&client->dev)->kobj, &attr_group);
863 if (rc) {
864 dev_err(&client->dev, "Failed to create sysfs group: %d\n", rc);
865 return rc;
866 }
867
868 rc = devm_add_action_or_reset(&client->dev, m41t80_remove_sysfs_group,
869 &client->dev);
870 if (rc) {
871 dev_err(&client->dev,
872 "Failed to add sysfs cleanup action: %d\n", rc);
873 return rc;
874 }
875
876 #ifdef CONFIG_RTC_DRV_M41T80_WDT
877 if (m41t80_data->features & M41T80_FEATURE_HT) {
878 save_client = client;
879 rc = misc_register(&wdt_dev);
880 if (rc)
881 return rc;
882 rc = register_reboot_notifier(&wdt_notifier);
883 if (rc) {
884 misc_deregister(&wdt_dev);
885 return rc;
886 }
887 }
888 #endif
889 return 0;
890 }
891
892 static int m41t80_remove(struct i2c_client *client)
893 {
894 #ifdef CONFIG_RTC_DRV_M41T80_WDT
895 struct m41t80_data *clientdata = i2c_get_clientdata(client);
896
897 if (clientdata->features & M41T80_FEATURE_HT) {
898 misc_deregister(&wdt_dev);
899 unregister_reboot_notifier(&wdt_notifier);
900 }
901 #endif
902
903 return 0;
904 }
905
906 static struct i2c_driver m41t80_driver = {
907 .driver = {
908 .name = "rtc-m41t80",
909 .pm = &m41t80_pm,
910 },
911 .probe = m41t80_probe,
912 .remove = m41t80_remove,
913 .id_table = m41t80_id,
914 };
915
916 module_i2c_driver(m41t80_driver);
917
918 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
919 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
920 MODULE_LICENSE("GPL");
Linux with added FPC-III support