1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16#include <linux/bcd.h>
17#include <linux/i2c.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/rtc.h>
22#include <linux/slab.h>
23#include <linux/smp_lock.h>
24#include <linux/string.h>
25#ifdef CONFIG_RTC_DRV_M41T80_WDT
26#include <linux/fs.h>
27#include <linux/ioctl.h>
28#include <linux/miscdevice.h>
29#include <linux/reboot.h>
30#include <linux/watchdog.h>
31#endif
32
33#define M41T80_REG_SSEC 0
34#define M41T80_REG_SEC 1
35#define M41T80_REG_MIN 2
36#define M41T80_REG_HOUR 3
37#define M41T80_REG_WDAY 4
38#define M41T80_REG_DAY 5
39#define M41T80_REG_MON 6
40#define M41T80_REG_YEAR 7
41#define M41T80_REG_ALARM_MON 0xa
42#define M41T80_REG_ALARM_DAY 0xb
43#define M41T80_REG_ALARM_HOUR 0xc
44#define M41T80_REG_ALARM_MIN 0xd
45#define M41T80_REG_ALARM_SEC 0xe
46#define M41T80_REG_FLAGS 0xf
47#define M41T80_REG_SQW 0x13
48
49#define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1)
50#define M41T80_ALARM_REG_SIZE \
51 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
52
53#define M41T80_SEC_ST (1 << 7)
54#define M41T80_ALMON_AFE (1 << 7)
55#define M41T80_ALMON_SQWE (1 << 6)
56#define M41T80_ALHOUR_HT (1 << 6)
57#define M41T80_FLAGS_AF (1 << 6)
58#define M41T80_FLAGS_BATT_LOW (1 << 4)
59#define M41T80_WATCHDOG_RB2 (1 << 7)
60#define M41T80_WATCHDOG_RB1 (1 << 1)
61#define M41T80_WATCHDOG_RB0 (1 << 0)
62
63#define M41T80_FEATURE_HT (1 << 0)
64#define M41T80_FEATURE_BL (1 << 1)
65#define M41T80_FEATURE_SQ (1 << 2)
66#define M41T80_FEATURE_WD (1 << 3)
67#define M41T80_FEATURE_SQ_ALT (1 << 4)
68
69#define DRV_VERSION "0.05"
70
71static const struct i2c_device_id m41t80_id[] = {
72 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
73 { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
74 { "m41t80", M41T80_FEATURE_SQ },
75 { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
76 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
77 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
78 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
79 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
80 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
81 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
82 { }
83};
84MODULE_DEVICE_TABLE(i2c, m41t80_id);
85
86struct m41t80_data {
87 u8 features;
88 struct rtc_device *rtc;
89};
90
91static int m41t80_get_datetime(struct i2c_client *client,
92 struct rtc_time *tm)
93{
94 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
95 struct i2c_msg msgs[] = {
96 {
97 .addr = client->addr,
98 .flags = 0,
99 .len = 1,
100 .buf = dt_addr,
101 },
102 {
103 .addr = client->addr,
104 .flags = I2C_M_RD,
105 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
106 .buf = buf + M41T80_REG_SEC,
107 },
108 };
109
110 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
111 dev_err(&client->dev, "read error\n");
112 return -EIO;
113 }
114
115 tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
116 tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f);
117 tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f);
118 tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f);
119 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
120 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1;
121
122
123 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100;
124 return 0;
125}
126
127
128static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
129{
130 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
131 u8 *buf = &wbuf[1];
132 u8 dt_addr[1] = { M41T80_REG_SEC };
133 struct i2c_msg msgs_in[] = {
134 {
135 .addr = client->addr,
136 .flags = 0,
137 .len = 1,
138 .buf = dt_addr,
139 },
140 {
141 .addr = client->addr,
142 .flags = I2C_M_RD,
143 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
144 .buf = buf + M41T80_REG_SEC,
145 },
146 };
147 struct i2c_msg msgs[] = {
148 {
149 .addr = client->addr,
150 .flags = 0,
151 .len = 1 + M41T80_DATETIME_REG_SIZE,
152 .buf = wbuf,
153 },
154 };
155
156
157 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
158 dev_err(&client->dev, "read error\n");
159 return -EIO;
160 }
161
162 wbuf[0] = 0;
163
164 buf[M41T80_REG_SSEC] = 0;
165 buf[M41T80_REG_SEC] =
166 bin2bcd(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
167 buf[M41T80_REG_MIN] =
168 bin2bcd(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
169 buf[M41T80_REG_HOUR] =
170 bin2bcd(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ;
171 buf[M41T80_REG_WDAY] =
172 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
173 buf[M41T80_REG_DAY] =
174 bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
175 buf[M41T80_REG_MON] =
176 bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
177
178 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
179
180 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
181 dev_err(&client->dev, "write error\n");
182 return -EIO;
183 }
184 return 0;
185}
186
187#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
188static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
189{
190 struct i2c_client *client = to_i2c_client(dev);
191 struct m41t80_data *clientdata = i2c_get_clientdata(client);
192 u8 reg;
193
194 if (clientdata->features & M41T80_FEATURE_BL) {
195 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
196 seq_printf(seq, "battery\t\t: %s\n",
197 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
198 }
199 return 0;
200}
201#else
202#define m41t80_rtc_proc NULL
203#endif
204
205static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
206{
207 return m41t80_get_datetime(to_i2c_client(dev), tm);
208}
209
210static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
211{
212 return m41t80_set_datetime(to_i2c_client(dev), tm);
213}
214
215#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
216static int
217m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
218{
219 struct i2c_client *client = to_i2c_client(dev);
220 int rc;
221
222 switch (cmd) {
223 case RTC_AIE_OFF:
224 case RTC_AIE_ON:
225 break;
226 default:
227 return -ENOIOCTLCMD;
228 }
229
230 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
231 if (rc < 0)
232 goto err;
233 switch (cmd) {
234 case RTC_AIE_OFF:
235 rc &= ~M41T80_ALMON_AFE;
236 break;
237 case RTC_AIE_ON:
238 rc |= M41T80_ALMON_AFE;
239 break;
240 }
241 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
242 goto err;
243 return 0;
244err:
245 return -EIO;
246}
247#else
248#define m41t80_rtc_ioctl NULL
249#endif
250
251static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
252{
253 struct i2c_client *client = to_i2c_client(dev);
254 u8 wbuf[1 + M41T80_ALARM_REG_SIZE];
255 u8 *buf = &wbuf[1];
256 u8 *reg = buf - M41T80_REG_ALARM_MON;
257 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
258 struct i2c_msg msgs_in[] = {
259 {
260 .addr = client->addr,
261 .flags = 0,
262 .len = 1,
263 .buf = dt_addr,
264 },
265 {
266 .addr = client->addr,
267 .flags = I2C_M_RD,
268 .len = M41T80_ALARM_REG_SIZE,
269 .buf = buf,
270 },
271 };
272 struct i2c_msg msgs[] = {
273 {
274 .addr = client->addr,
275 .flags = 0,
276 .len = 1 + M41T80_ALARM_REG_SIZE,
277 .buf = wbuf,
278 },
279 };
280
281 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
282 dev_err(&client->dev, "read error\n");
283 return -EIO;
284 }
285 reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE);
286 reg[M41T80_REG_ALARM_DAY] = 0;
287 reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80);
288 reg[M41T80_REG_ALARM_MIN] = 0;
289 reg[M41T80_REG_ALARM_SEC] = 0;
290
291 wbuf[0] = M41T80_REG_ALARM_MON;
292 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
293 bin2bcd(t->time.tm_sec) : 0x80;
294 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
295 bin2bcd(t->time.tm_min) : 0x80;
296 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ?
297 bin2bcd(t->time.tm_hour) : 0x80;
298 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ?
299 bin2bcd(t->time.tm_mday) : 0x80;
300 if (t->time.tm_mon >= 0)
301 reg[M41T80_REG_ALARM_MON] |= bin2bcd(t->time.tm_mon + 1);
302 else
303 reg[M41T80_REG_ALARM_DAY] |= 0x40;
304
305 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
306 dev_err(&client->dev, "write error\n");
307 return -EIO;
308 }
309
310 if (t->enabled) {
311 reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE;
312 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
313 reg[M41T80_REG_ALARM_MON]) < 0) {
314 dev_err(&client->dev, "write error\n");
315 return -EIO;
316 }
317 }
318 return 0;
319}
320
321static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
322{
323 struct i2c_client *client = to_i2c_client(dev);
324 u8 buf[M41T80_ALARM_REG_SIZE + 1];
325 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
326 u8 *reg = buf - M41T80_REG_ALARM_MON;
327 struct i2c_msg msgs[] = {
328 {
329 .addr = client->addr,
330 .flags = 0,
331 .len = 1,
332 .buf = dt_addr,
333 },
334 {
335 .addr = client->addr,
336 .flags = I2C_M_RD,
337 .len = M41T80_ALARM_REG_SIZE + 1,
338 .buf = buf,
339 },
340 };
341
342 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
343 dev_err(&client->dev, "read error\n");
344 return -EIO;
345 }
346 t->time.tm_sec = -1;
347 t->time.tm_min = -1;
348 t->time.tm_hour = -1;
349 t->time.tm_mday = -1;
350 t->time.tm_mon = -1;
351 if (!(reg[M41T80_REG_ALARM_SEC] & 0x80))
352 t->time.tm_sec = bcd2bin(reg[M41T80_REG_ALARM_SEC] & 0x7f);
353 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80))
354 t->time.tm_min = bcd2bin(reg[M41T80_REG_ALARM_MIN] & 0x7f);
355 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80))
356 t->time.tm_hour = bcd2bin(reg[M41T80_REG_ALARM_HOUR] & 0x3f);
357 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80))
358 t->time.tm_mday = bcd2bin(reg[M41T80_REG_ALARM_DAY] & 0x3f);
359 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40))
360 t->time.tm_mon = bcd2bin(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1;
361 t->time.tm_year = -1;
362 t->time.tm_wday = -1;
363 t->time.tm_yday = -1;
364 t->time.tm_isdst = -1;
365 t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE);
366 t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF);
367 return 0;
368}
369
370static struct rtc_class_ops m41t80_rtc_ops = {
371 .read_time = m41t80_rtc_read_time,
372 .set_time = m41t80_rtc_set_time,
373 .read_alarm = m41t80_rtc_read_alarm,
374 .set_alarm = m41t80_rtc_set_alarm,
375 .proc = m41t80_rtc_proc,
376 .ioctl = m41t80_rtc_ioctl,
377};
378
379#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
380static ssize_t m41t80_sysfs_show_flags(struct device *dev,
381 struct device_attribute *attr, char *buf)
382{
383 struct i2c_client *client = to_i2c_client(dev);
384 int val;
385
386 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
387 if (val < 0)
388 return -EIO;
389 return sprintf(buf, "%#x\n", val);
390}
391static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
392
393static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
394 struct device_attribute *attr, char *buf)
395{
396 struct i2c_client *client = to_i2c_client(dev);
397 struct m41t80_data *clientdata = i2c_get_clientdata(client);
398 int val, reg_sqw;
399
400 if (!(clientdata->features & M41T80_FEATURE_SQ))
401 return -EINVAL;
402
403 reg_sqw = M41T80_REG_SQW;
404 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
405 reg_sqw = M41T80_REG_WDAY;
406 val = i2c_smbus_read_byte_data(client, reg_sqw);
407 if (val < 0)
408 return -EIO;
409 val = (val >> 4) & 0xf;
410 switch (val) {
411 case 0:
412 break;
413 case 1:
414 val = 32768;
415 break;
416 default:
417 val = 32768 >> val;
418 }
419 return sprintf(buf, "%d\n", val);
420}
421static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
422 struct device_attribute *attr,
423 const char *buf, size_t count)
424{
425 struct i2c_client *client = to_i2c_client(dev);
426 struct m41t80_data *clientdata = i2c_get_clientdata(client);
427 int almon, sqw, reg_sqw;
428 int val = simple_strtoul(buf, NULL, 0);
429
430 if (!(clientdata->features & M41T80_FEATURE_SQ))
431 return -EINVAL;
432
433 if (val) {
434 if (!is_power_of_2(val))
435 return -EINVAL;
436 val = ilog2(val);
437 if (val == 15)
438 val = 1;
439 else if (val < 14)
440 val = 15 - val;
441 else
442 return -EINVAL;
443 }
444
445 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
446 if (almon < 0)
447 return -EIO;
448 reg_sqw = M41T80_REG_SQW;
449 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
450 reg_sqw = M41T80_REG_WDAY;
451 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
452 if (sqw < 0)
453 return -EIO;
454 sqw = (sqw & 0x0f) | (val << 4);
455 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
456 almon & ~M41T80_ALMON_SQWE) < 0 ||
457 i2c_smbus_write_byte_data(client, reg_sqw, sqw) < 0)
458 return -EIO;
459 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
460 almon | M41T80_ALMON_SQWE) < 0)
461 return -EIO;
462 return count;
463}
464static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
465 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
466
467static struct attribute *attrs[] = {
468 &dev_attr_flags.attr,
469 &dev_attr_sqwfreq.attr,
470 NULL,
471};
472static struct attribute_group attr_group = {
473 .attrs = attrs,
474};
475
476static int m41t80_sysfs_register(struct device *dev)
477{
478 return sysfs_create_group(&dev->kobj, &attr_group);
479}
480#else
481static int m41t80_sysfs_register(struct device *dev)
482{
483 return 0;
484}
485#endif
486
487#ifdef CONFIG_RTC_DRV_M41T80_WDT
488
489
490
491
492
493
494
495static struct i2c_client *save_client;
496
497
498#define WD_TIMO 60
499
500static int wdt_margin = WD_TIMO;
501module_param(wdt_margin, int, 0);
502MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
503
504static unsigned long wdt_is_open;
505static int boot_flag;
506
507
508
509
510
511
512
513static void wdt_ping(void)
514{
515 unsigned char i2c_data[2];
516 struct i2c_msg msgs1[1] = {
517 {
518 .addr = save_client->addr,
519 .flags = 0,
520 .len = 2,
521 .buf = i2c_data,
522 },
523 };
524 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
525
526 i2c_data[0] = 0x09;
527
528 if (wdt_margin > 31)
529 i2c_data[1] = (wdt_margin & 0xFC) | 0x83;
530 else
531
532
533
534 i2c_data[1] = wdt_margin<<2 | 0x82;
535
536
537
538
539
540 if (clientdata->features & M41T80_FEATURE_WD)
541 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
542
543 i2c_transfer(save_client->adapter, msgs1, 1);
544}
545
546
547
548
549
550
551static void wdt_disable(void)
552{
553 unsigned char i2c_data[2], i2c_buf[0x10];
554 struct i2c_msg msgs0[2] = {
555 {
556 .addr = save_client->addr,
557 .flags = 0,
558 .len = 1,
559 .buf = i2c_data,
560 },
561 {
562 .addr = save_client->addr,
563 .flags = I2C_M_RD,
564 .len = 1,
565 .buf = i2c_buf,
566 },
567 };
568 struct i2c_msg msgs1[1] = {
569 {
570 .addr = save_client->addr,
571 .flags = 0,
572 .len = 2,
573 .buf = i2c_data,
574 },
575 };
576
577 i2c_data[0] = 0x09;
578 i2c_transfer(save_client->adapter, msgs0, 2);
579
580 i2c_data[0] = 0x09;
581 i2c_data[1] = 0x00;
582 i2c_transfer(save_client->adapter, msgs1, 1);
583}
584
585
586
587
588
589
590
591
592
593
594
595static ssize_t wdt_write(struct file *file, const char __user *buf,
596 size_t count, loff_t *ppos)
597{
598
599
600
601
602 if (count) {
603 wdt_ping();
604 return 1;
605 }
606 return 0;
607}
608
609static ssize_t wdt_read(struct file *file, char __user *buf,
610 size_t count, loff_t *ppos)
611{
612 return 0;
613}
614
615
616
617
618
619
620
621
622
623
624
625
626static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
627 unsigned long arg)
628{
629 int new_margin, rv;
630 static struct watchdog_info ident = {
631 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
632 WDIOF_SETTIMEOUT,
633 .firmware_version = 1,
634 .identity = "M41T80 WTD"
635 };
636
637 switch (cmd) {
638 case WDIOC_GETSUPPORT:
639 return copy_to_user((struct watchdog_info __user *)arg, &ident,
640 sizeof(ident)) ? -EFAULT : 0;
641
642 case WDIOC_GETSTATUS:
643 case WDIOC_GETBOOTSTATUS:
644 return put_user(boot_flag, (int __user *)arg);
645 case WDIOC_KEEPALIVE:
646 wdt_ping();
647 return 0;
648 case WDIOC_SETTIMEOUT:
649 if (get_user(new_margin, (int __user *)arg))
650 return -EFAULT;
651
652 if (new_margin < 1 || new_margin > 124)
653 return -EINVAL;
654 wdt_margin = new_margin;
655 wdt_ping();
656
657 case WDIOC_GETTIMEOUT:
658 return put_user(wdt_margin, (int __user *)arg);
659
660 case WDIOC_SETOPTIONS:
661 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
662 return -EFAULT;
663
664 if (rv & WDIOS_DISABLECARD) {
665 pr_info("rtc-m41t80: disable watchdog\n");
666 wdt_disable();
667 }
668
669 if (rv & WDIOS_ENABLECARD) {
670 pr_info("rtc-m41t80: enable watchdog\n");
671 wdt_ping();
672 }
673
674 return -EINVAL;
675 }
676 return -ENOTTY;
677}
678
679
680
681
682
683
684
685static int wdt_open(struct inode *inode, struct file *file)
686{
687 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
688 lock_kernel();
689 if (test_and_set_bit(0, &wdt_is_open)) {
690 unlock_kernel();
691 return -EBUSY;
692 }
693
694
695
696 wdt_is_open = 1;
697 unlock_kernel();
698 return 0;
699 }
700 return -ENODEV;
701}
702
703
704
705
706
707
708
709static int wdt_release(struct inode *inode, struct file *file)
710{
711 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
712 clear_bit(0, &wdt_is_open);
713 return 0;
714}
715
716
717
718
719
720
721
722
723
724
725
726
727static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
728 void *unused)
729{
730 if (code == SYS_DOWN || code == SYS_HALT)
731
732 wdt_disable();
733 return NOTIFY_DONE;
734}
735
736static const struct file_operations wdt_fops = {
737 .owner = THIS_MODULE,
738 .read = wdt_read,
739 .ioctl = wdt_ioctl,
740 .write = wdt_write,
741 .open = wdt_open,
742 .release = wdt_release,
743};
744
745static struct miscdevice wdt_dev = {
746 .minor = WATCHDOG_MINOR,
747 .name = "watchdog",
748 .fops = &wdt_fops,
749};
750
751
752
753
754
755static struct notifier_block wdt_notifier = {
756 .notifier_call = wdt_notify_sys,
757};
758#endif
759
760
761
762
763
764
765
766
767static int m41t80_probe(struct i2c_client *client,
768 const struct i2c_device_id *id)
769{
770 int rc = 0;
771 struct rtc_device *rtc = NULL;
772 struct rtc_time tm;
773 struct m41t80_data *clientdata = NULL;
774
775 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
776 | I2C_FUNC_SMBUS_BYTE_DATA)) {
777 rc = -ENODEV;
778 goto exit;
779 }
780
781 dev_info(&client->dev,
782 "chip found, driver version " DRV_VERSION "\n");
783
784 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL);
785 if (!clientdata) {
786 rc = -ENOMEM;
787 goto exit;
788 }
789
790 rtc = rtc_device_register(client->name, &client->dev,
791 &m41t80_rtc_ops, THIS_MODULE);
792 if (IS_ERR(rtc)) {
793 rc = PTR_ERR(rtc);
794 rtc = NULL;
795 goto exit;
796 }
797
798 clientdata->rtc = rtc;
799 clientdata->features = id->driver_data;
800 i2c_set_clientdata(client, clientdata);
801
802
803 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
804 if (rc < 0)
805 goto ht_err;
806
807 if (rc & M41T80_ALHOUR_HT) {
808 if (clientdata->features & M41T80_FEATURE_HT) {
809 m41t80_get_datetime(client, &tm);
810 dev_info(&client->dev, "HT bit was set!\n");
811 dev_info(&client->dev,
812 "Power Down at "
813 "%04i-%02i-%02i %02i:%02i:%02i\n",
814 tm.tm_year + 1900,
815 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
816 tm.tm_min, tm.tm_sec);
817 }
818 if (i2c_smbus_write_byte_data(client,
819 M41T80_REG_ALARM_HOUR,
820 rc & ~M41T80_ALHOUR_HT) < 0)
821 goto ht_err;
822 }
823
824
825 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
826 if (rc < 0)
827 goto st_err;
828
829 if (rc & M41T80_SEC_ST) {
830 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
831 rc & ~M41T80_SEC_ST) < 0)
832 goto st_err;
833 }
834
835 rc = m41t80_sysfs_register(&client->dev);
836 if (rc)
837 goto exit;
838
839#ifdef CONFIG_RTC_DRV_M41T80_WDT
840 if (clientdata->features & M41T80_FEATURE_HT) {
841 save_client = client;
842 rc = misc_register(&wdt_dev);
843 if (rc)
844 goto exit;
845 rc = register_reboot_notifier(&wdt_notifier);
846 if (rc) {
847 misc_deregister(&wdt_dev);
848 goto exit;
849 }
850 }
851#endif
852 return 0;
853
854st_err:
855 rc = -EIO;
856 dev_err(&client->dev, "Can't clear ST bit\n");
857 goto exit;
858ht_err:
859 rc = -EIO;
860 dev_err(&client->dev, "Can't clear HT bit\n");
861 goto exit;
862
863exit:
864 if (rtc)
865 rtc_device_unregister(rtc);
866 kfree(clientdata);
867 return rc;
868}
869
870static int m41t80_remove(struct i2c_client *client)
871{
872 struct m41t80_data *clientdata = i2c_get_clientdata(client);
873 struct rtc_device *rtc = clientdata->rtc;
874
875#ifdef CONFIG_RTC_DRV_M41T80_WDT
876 if (clientdata->features & M41T80_FEATURE_HT) {
877 misc_deregister(&wdt_dev);
878 unregister_reboot_notifier(&wdt_notifier);
879 }
880#endif
881 if (rtc)
882 rtc_device_unregister(rtc);
883 kfree(clientdata);
884
885 return 0;
886}
887
888static struct i2c_driver m41t80_driver = {
889 .driver = {
890 .name = "rtc-m41t80",
891 },
892 .probe = m41t80_probe,
893 .remove = m41t80_remove,
894 .id_table = m41t80_id,
895};
896
897static int __init m41t80_rtc_init(void)
898{
899 return i2c_add_driver(&m41t80_driver);
900}
901
902static void __exit m41t80_rtc_exit(void)
903{
904 i2c_del_driver(&m41t80_driver);
905}
906
907MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
908MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
909MODULE_LICENSE("GPL");
910MODULE_VERSION(DRV_VERSION);
911
912module_init(m41t80_rtc_init);
913module_exit(m41t80_rtc_exit);
914
