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autofs4: fix sparse warning in root.c
[linux-2.6/kmemtrace.git] / drivers / rtc / rtc-m41t80.c
blob1cb33cac12377095fc075e07e4341306dcda4bcc
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 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/i2c.h>
21 #include <linux/rtc.h>
22 #include <linux/bcd.h>
23 #ifdef CONFIG_RTC_DRV_M41T80_WDT
24 #include <linux/miscdevice.h>
25 #include <linux/watchdog.h>
26 #include <linux/reboot.h>
27 #include <linux/fs.h>
28 #include <linux/ioctl.h>
29 #endif
30
31 #define M41T80_REG_SSEC 0
32 #define M41T80_REG_SEC 1
33 #define M41T80_REG_MIN 2
34 #define M41T80_REG_HOUR 3
35 #define M41T80_REG_WDAY 4
36 #define M41T80_REG_DAY 5
37 #define M41T80_REG_MON 6
38 #define M41T80_REG_YEAR 7
39 #define M41T80_REG_ALARM_MON 0xa
40 #define M41T80_REG_ALARM_DAY 0xb
41 #define M41T80_REG_ALARM_HOUR 0xc
42 #define M41T80_REG_ALARM_MIN 0xd
43 #define M41T80_REG_ALARM_SEC 0xe
44 #define M41T80_REG_FLAGS 0xf
45 #define M41T80_REG_SQW 0x13
46
47 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1)
48 #define M41T80_ALARM_REG_SIZE \
49 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
50
51 #define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */
52 #define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */
53 #define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */
54 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
55 #define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
56 #define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
57
58 #define M41T80_FEATURE_HT (1 << 0)
59 #define M41T80_FEATURE_BL (1 << 1)
60
61 #define DRV_VERSION "0.05"
62
63 struct m41t80_chip_info {
64 const char *name;
65 u8 features;
66 };
67
68 static const struct m41t80_chip_info m41t80_chip_info_tbl[] = {
69 {
70 .name = "m41t80",
71 .features = 0,
72 },
73 {
74 .name = "m41t81",
75 .features = M41T80_FEATURE_HT,
76 },
77 {
78 .name = "m41t81s",
79 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
80 },
81 {
82 .name = "m41t82",
83 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
84 },
85 {
86 .name = "m41t83",
87 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
88 },
89 {
90 .name = "m41st84",
91 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
92 },
93 {
94 .name = "m41st85",
95 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
96 },
97 {
98 .name = "m41st87",
99 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
100 },
101 };
102
103 struct m41t80_data {
104 const struct m41t80_chip_info *chip;
105 struct rtc_device *rtc;
106 };
107
108 static int m41t80_get_datetime(struct i2c_client *client,
109 struct rtc_time *tm)
110 {
111 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
112 struct i2c_msg msgs[] = {
113 {
114 .addr = client->addr,
115 .flags = 0,
116 .len = 1,
117 .buf = dt_addr,
118 },
119 {
120 .addr = client->addr,
121 .flags = I2C_M_RD,
122 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
123 .buf = buf + M41T80_REG_SEC,
124 },
125 };
126
127 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
128 dev_err(&client->dev, "read error\n");
129 return -EIO;
130 }
131
132 tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f);
133 tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f);
134 tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f);
135 tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f);
136 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
137 tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1;
138
139 /* assume 20YY not 19YY, and ignore the Century Bit */
140 tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100;
141 return 0;
142 }
143
144 /* Sets the given date and time to the real time clock. */
145 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
146 {
147 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
148 u8 *buf = &wbuf[1];
149 u8 dt_addr[1] = { M41T80_REG_SEC };
150 struct i2c_msg msgs_in[] = {
151 {
152 .addr = client->addr,
153 .flags = 0,
154 .len = 1,
155 .buf = dt_addr,
156 },
157 {
158 .addr = client->addr,
159 .flags = I2C_M_RD,
160 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
161 .buf = buf + M41T80_REG_SEC,
162 },
163 };
164 struct i2c_msg msgs[] = {
165 {
166 .addr = client->addr,
167 .flags = 0,
168 .len = 1 + M41T80_DATETIME_REG_SIZE,
169 .buf = wbuf,
170 },
171 };
172
173 /* Read current reg values into buf[1..7] */
174 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
175 dev_err(&client->dev, "read error\n");
176 return -EIO;
177 }
178
179 wbuf[0] = 0; /* offset into rtc's regs */
180 /* Merge time-data and register flags into buf[0..7] */
181 buf[M41T80_REG_SSEC] = 0;
182 buf[M41T80_REG_SEC] =
183 BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
184 buf[M41T80_REG_MIN] =
185 BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
186 buf[M41T80_REG_HOUR] =
187 BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ;
188 buf[M41T80_REG_WDAY] =
189 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
190 buf[M41T80_REG_DAY] =
191 BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
192 buf[M41T80_REG_MON] =
193 BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
194 /* assume 20YY not 19YY */
195 buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100);
196
197 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
198 dev_err(&client->dev, "write error\n");
199 return -EIO;
200 }
201 return 0;
202 }
203
204 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
205 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
206 {
207 struct i2c_client *client = to_i2c_client(dev);
208 struct m41t80_data *clientdata = i2c_get_clientdata(client);
209 u8 reg;
210
211 if (clientdata->chip->features & M41T80_FEATURE_BL) {
212 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
213 seq_printf(seq, "battery\t\t: %s\n",
214 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
215 }
216 return 0;
217 }
218 #else
219 #define m41t80_rtc_proc NULL
220 #endif
221
222 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
223 {
224 return m41t80_get_datetime(to_i2c_client(dev), tm);
225 }
226
227 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
228 {
229 return m41t80_set_datetime(to_i2c_client(dev), tm);
230 }
231
232 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
233 static int
234 m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
235 {
236 struct i2c_client *client = to_i2c_client(dev);
237 int rc;
238
239 switch (cmd) {
240 case RTC_AIE_OFF:
241 case RTC_AIE_ON:
242 break;
243 default:
244 return -ENOIOCTLCMD;
245 }
246
247 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
248 if (rc < 0)
249 goto err;
250 switch (cmd) {
251 case RTC_AIE_OFF:
252 rc &= ~M41T80_ALMON_AFE;
253 break;
254 case RTC_AIE_ON:
255 rc |= M41T80_ALMON_AFE;
256 break;
257 }
258 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
259 goto err;
260 return 0;
261 err:
262 return -EIO;
263 }
264 #else
265 #define m41t80_rtc_ioctl NULL
266 #endif
267
268 static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
269 {
270 struct i2c_client *client = to_i2c_client(dev);
271 u8 wbuf[1 + M41T80_ALARM_REG_SIZE];
272 u8 *buf = &wbuf[1];
273 u8 *reg = buf - M41T80_REG_ALARM_MON;
274 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
275 struct i2c_msg msgs_in[] = {
276 {
277 .addr = client->addr,
278 .flags = 0,
279 .len = 1,
280 .buf = dt_addr,
281 },
282 {
283 .addr = client->addr,
284 .flags = I2C_M_RD,
285 .len = M41T80_ALARM_REG_SIZE,
286 .buf = buf,
287 },
288 };
289 struct i2c_msg msgs[] = {
290 {
291 .addr = client->addr,
292 .flags = 0,
293 .len = 1 + M41T80_ALARM_REG_SIZE,
294 .buf = wbuf,
295 },
296 };
297
298 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
299 dev_err(&client->dev, "read error\n");
300 return -EIO;
301 }
302 reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE);
303 reg[M41T80_REG_ALARM_DAY] = 0;
304 reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80);
305 reg[M41T80_REG_ALARM_MIN] = 0;
306 reg[M41T80_REG_ALARM_SEC] = 0;
307
308 wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */
309 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
310 BIN2BCD(t->time.tm_sec) : 0x80;
311 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
312 BIN2BCD(t->time.tm_min) : 0x80;
313 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ?
314 BIN2BCD(t->time.tm_hour) : 0x80;
315 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ?
316 BIN2BCD(t->time.tm_mday) : 0x80;
317 if (t->time.tm_mon >= 0)
318 reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1);
319 else
320 reg[M41T80_REG_ALARM_DAY] |= 0x40;
321
322 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
323 dev_err(&client->dev, "write error\n");
324 return -EIO;
325 }
326
327 if (t->enabled) {
328 reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE;
329 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
330 reg[M41T80_REG_ALARM_MON]) < 0) {
331 dev_err(&client->dev, "write error\n");
332 return -EIO;
333 }
334 }
335 return 0;
336 }
337
338 static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
339 {
340 struct i2c_client *client = to_i2c_client(dev);
341 u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */
342 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
343 u8 *reg = buf - M41T80_REG_ALARM_MON;
344 struct i2c_msg msgs[] = {
345 {
346 .addr = client->addr,
347 .flags = 0,
348 .len = 1,
349 .buf = dt_addr,
350 },
351 {
352 .addr = client->addr,
353 .flags = I2C_M_RD,
354 .len = M41T80_ALARM_REG_SIZE + 1,
355 .buf = buf,
356 },
357 };
358
359 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
360 dev_err(&client->dev, "read error\n");
361 return -EIO;
362 }
363 t->time.tm_sec = -1;
364 t->time.tm_min = -1;
365 t->time.tm_hour = -1;
366 t->time.tm_mday = -1;
367 t->time.tm_mon = -1;
368 if (!(reg[M41T80_REG_ALARM_SEC] & 0x80))
369 t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f);
370 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80))
371 t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f);
372 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80))
373 t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f);
374 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80))
375 t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f);
376 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40))
377 t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1;
378 t->time.tm_year = -1;
379 t->time.tm_wday = -1;
380 t->time.tm_yday = -1;
381 t->time.tm_isdst = -1;
382 t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE);
383 t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF);
384 return 0;
385 }
386
387 static struct rtc_class_ops m41t80_rtc_ops = {
388 .read_time = m41t80_rtc_read_time,
389 .set_time = m41t80_rtc_set_time,
390 .read_alarm = m41t80_rtc_read_alarm,
391 .set_alarm = m41t80_rtc_set_alarm,
392 .proc = m41t80_rtc_proc,
393 .ioctl = m41t80_rtc_ioctl,
394 };
395
396 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
397 static ssize_t m41t80_sysfs_show_flags(struct device *dev,
398 struct device_attribute *attr, char *buf)
399 {
400 struct i2c_client *client = to_i2c_client(dev);
401 int val;
402
403 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
404 if (val < 0)
405 return -EIO;
406 return sprintf(buf, "%#x\n", val);
407 }
408 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
409
410 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
411 struct device_attribute *attr, char *buf)
412 {
413 struct i2c_client *client = to_i2c_client(dev);
414 int val;
415
416 val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW);
417 if (val < 0)
418 return -EIO;
419 val = (val >> 4) & 0xf;
420 switch (val) {
421 case 0:
422 break;
423 case 1:
424 val = 32768;
425 break;
426 default:
427 val = 32768 >> val;
428 }
429 return sprintf(buf, "%d\n", val);
430 }
431 static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
432 struct device_attribute *attr,
433 const char *buf, size_t count)
434 {
435 struct i2c_client *client = to_i2c_client(dev);
436 int almon, sqw;
437 int val = simple_strtoul(buf, NULL, 0);
438
439 if (val) {
440 if (!is_power_of_2(val))
441 return -EINVAL;
442 val = ilog2(val);
443 if (val == 15)
444 val = 1;
445 else if (val < 14)
446 val = 15 - val;
447 else
448 return -EINVAL;
449 }
450 /* disable SQW, set SQW frequency & re-enable */
451 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
452 if (almon < 0)
453 return -EIO;
454 sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW);
455 if (sqw < 0)
456 return -EIO;
457 sqw = (sqw & 0x0f) | (val << 4);
458 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
459 almon & ~M41T80_ALMON_SQWE) < 0 ||
460 i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0)
461 return -EIO;
462 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
463 almon | M41T80_ALMON_SQWE) < 0)
464 return -EIO;
465 return count;
466 }
467 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
468 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
469
470 static struct attribute *attrs[] = {
471 &dev_attr_flags.attr,
472 &dev_attr_sqwfreq.attr,
473 NULL,
474 };
475 static struct attribute_group attr_group = {
476 .attrs = attrs,
477 };
478
479 static int m41t80_sysfs_register(struct device *dev)
480 {
481 return sysfs_create_group(&dev->kobj, &attr_group);
482 }
483 #else
484 static int m41t80_sysfs_register(struct device *dev)
485 {
486 return 0;
487 }
488 #endif
489
490 #ifdef CONFIG_RTC_DRV_M41T80_WDT
491 /*
492 *****************************************************************************
493 *
494 * Watchdog Driver
495 *
496 *****************************************************************************
497 */
498 static struct i2c_client *save_client;
499
500 /* Default margin */
501 #define WD_TIMO 60 /* 1..31 seconds */
502
503 static int wdt_margin = WD_TIMO;
504 module_param(wdt_margin, int, 0);
505 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
506
507 static unsigned long wdt_is_open;
508 static int boot_flag;
509
510 /**
511 * wdt_ping:
512 *
513 * Reload counter one with the watchdog timeout. We don't bother reloading
514 * the cascade counter.
515 */
516 static void wdt_ping(void)
517 {
518 unsigned char i2c_data[2];
519 struct i2c_msg msgs1[1] = {
520 {
521 .addr = save_client->addr,
522 .flags = 0,
523 .len = 2,
524 .buf = i2c_data,
525 },
526 };
527 i2c_data[0] = 0x09; /* watchdog register */
528
529 if (wdt_margin > 31)
530 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
531 else
532 /*
533 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
534 */
535 i2c_data[1] = wdt_margin<<2 | 0x82;
536
537 i2c_transfer(save_client->adapter, msgs1, 1);
538 }
539
540 /**
541 * wdt_disable:
542 *
543 * disables watchdog.
544 */
545 static void wdt_disable(void)
546 {
547 unsigned char i2c_data[2], i2c_buf[0x10];
548 struct i2c_msg msgs0[2] = {
549 {
550 .addr = save_client->addr,
551 .flags = 0,
552 .len = 1,
553 .buf = i2c_data,
554 },
555 {
556 .addr = save_client->addr,
557 .flags = I2C_M_RD,
558 .len = 1,
559 .buf = i2c_buf,
560 },
561 };
562 struct i2c_msg msgs1[1] = {
563 {
564 .addr = save_client->addr,
565 .flags = 0,
566 .len = 2,
567 .buf = i2c_data,
568 },
569 };
570
571 i2c_data[0] = 0x09;
572 i2c_transfer(save_client->adapter, msgs0, 2);
573
574 i2c_data[0] = 0x09;
575 i2c_data[1] = 0x00;
576 i2c_transfer(save_client->adapter, msgs1, 1);
577 }
578
579 /**
580 * wdt_write:
581 * @file: file handle to the watchdog
582 * @buf: buffer to write (unused as data does not matter here
583 * @count: count of bytes
584 * @ppos: pointer to the position to write. No seeks allowed
585 *
586 * A write to a watchdog device is defined as a keepalive signal. Any
587 * write of data will do, as we we don't define content meaning.
588 */
589 static ssize_t wdt_write(struct file *file, const char __user *buf,
590 size_t count, loff_t *ppos)
591 {
592 /* Can't seek (pwrite) on this device
593 if (ppos != &file->f_pos)
594 return -ESPIPE;
595 */
596 if (count) {
597 wdt_ping();
598 return 1;
599 }
600 return 0;
601 }
602
603 static ssize_t wdt_read(struct file *file, char __user *buf,
604 size_t count, loff_t *ppos)
605 {
606 return 0;
607 }
608
609 /**
610 * wdt_ioctl:
611 * @inode: inode of the device
612 * @file: file handle to the device
613 * @cmd: watchdog command
614 * @arg: argument pointer
615 *
616 * The watchdog API defines a common set of functions for all watchdogs
617 * according to their available features. We only actually usefully support
618 * querying capabilities and current status.
619 */
620 static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
621 unsigned long arg)
622 {
623 int new_margin, rv;
624 static struct watchdog_info ident = {
625 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
626 WDIOF_SETTIMEOUT,
627 .firmware_version = 1,
628 .identity = "M41T80 WTD"
629 };
630
631 switch (cmd) {
632 case WDIOC_GETSUPPORT:
633 return copy_to_user((struct watchdog_info __user *)arg, &ident,
634 sizeof(ident)) ? -EFAULT : 0;
635
636 case WDIOC_GETSTATUS:
637 case WDIOC_GETBOOTSTATUS:
638 return put_user(boot_flag, (int __user *)arg);
639 case WDIOC_KEEPALIVE:
640 wdt_ping();
641 return 0;
642 case WDIOC_SETTIMEOUT:
643 if (get_user(new_margin, (int __user *)arg))
644 return -EFAULT;
645 /* Arbitrary, can't find the card's limits */
646 if (new_margin < 1 || new_margin > 124)
647 return -EINVAL;
648 wdt_margin = new_margin;
649 wdt_ping();
650 /* Fall */
651 case WDIOC_GETTIMEOUT:
652 return put_user(wdt_margin, (int __user *)arg);
653
654 case WDIOC_SETOPTIONS:
655 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
656 return -EFAULT;
657
658 if (rv & WDIOS_DISABLECARD) {
659 printk(KERN_INFO
660 "rtc-m41t80: disable watchdog\n");
661 wdt_disable();
662 }
663
664 if (rv & WDIOS_ENABLECARD) {
665 printk(KERN_INFO
666 "rtc-m41t80: enable watchdog\n");
667 wdt_ping();
668 }
669
670 return -EINVAL;
671 }
672 return -ENOTTY;
673 }
674
675 /**
676 * wdt_open:
677 * @inode: inode of device
678 * @file: file handle to device
679 *
680 */
681 static int wdt_open(struct inode *inode, struct file *file)
682 {
683 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
684 if (test_and_set_bit(0, &wdt_is_open))
685 return -EBUSY;
686 /*
687 * Activate
688 */
689 wdt_is_open = 1;
690 return 0;
691 }
692 return -ENODEV;
693 }
694
695 /**
696 * wdt_close:
697 * @inode: inode to board
698 * @file: file handle to board
699 *
700 */
701 static int wdt_release(struct inode *inode, struct file *file)
702 {
703 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
704 clear_bit(0, &wdt_is_open);
705 return 0;
706 }
707
708 /**
709 * notify_sys:
710 * @this: our notifier block
711 * @code: the event being reported
712 * @unused: unused
713 *
714 * Our notifier is called on system shutdowns. We want to turn the card
715 * off at reboot otherwise the machine will reboot again during memory
716 * test or worse yet during the following fsck. This would suck, in fact
717 * trust me - if it happens it does suck.
718 */
719 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
720 void *unused)
721 {
722 if (code == SYS_DOWN || code == SYS_HALT)
723 /* Disable Watchdog */
724 wdt_disable();
725 return NOTIFY_DONE;
726 }
727
728 static const struct file_operations wdt_fops = {
729 .owner = THIS_MODULE,
730 .read = wdt_read,
731 .ioctl = wdt_ioctl,
732 .write = wdt_write,
733 .open = wdt_open,
734 .release = wdt_release,
735 };
736
737 static struct miscdevice wdt_dev = {
738 .minor = WATCHDOG_MINOR,
739 .name = "watchdog",
740 .fops = &wdt_fops,
741 };
742
743 /*
744 * The WDT card needs to learn about soft shutdowns in order to
745 * turn the timebomb registers off.
746 */
747 static struct notifier_block wdt_notifier = {
748 .notifier_call = wdt_notify_sys,
749 };
750 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
751
752 /*
753 *****************************************************************************
754 *
755 * Driver Interface
756 *
757 *****************************************************************************
758 */
759 static int m41t80_probe(struct i2c_client *client)
760 {
761 int i, rc = 0;
762 struct rtc_device *rtc = NULL;
763 struct rtc_time tm;
764 const struct m41t80_chip_info *chip;
765 struct m41t80_data *clientdata = NULL;
766
767 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
768 | I2C_FUNC_SMBUS_BYTE_DATA)) {
769 rc = -ENODEV;
770 goto exit;
771 }
772
773 dev_info(&client->dev,
774 "chip found, driver version " DRV_VERSION "\n");
775
776 chip = NULL;
777 for (i = 0; i < ARRAY_SIZE(m41t80_chip_info_tbl); i++) {
778 if (!strcmp(m41t80_chip_info_tbl[i].name, client->name)) {
779 chip = &m41t80_chip_info_tbl[i];
780 break;
781 }
782 }
783 if (!chip) {
784 dev_err(&client->dev, "%s is not supported\n", client->name);
785 rc = -ENODEV;
786 goto exit;
787 }
788
789 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL);
790 if (!clientdata) {
791 rc = -ENOMEM;
792 goto exit;
793 }
794
795 rtc = rtc_device_register(client->name, &client->dev,
796 &m41t80_rtc_ops, THIS_MODULE);
797 if (IS_ERR(rtc)) {
798 rc = PTR_ERR(rtc);
799 rtc = NULL;
800 goto exit;
801 }
802
803 clientdata->rtc = rtc;
804 clientdata->chip = chip;
805 i2c_set_clientdata(client, clientdata);
806
807 /* Make sure HT (Halt Update) bit is cleared */
808 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
809 if (rc < 0)
810 goto ht_err;
811
812 if (rc & M41T80_ALHOUR_HT) {
813 if (chip->features & M41T80_FEATURE_HT) {
814 m41t80_get_datetime(client, &tm);
815 dev_info(&client->dev, "HT bit was set!\n");
816 dev_info(&client->dev,
817 "Power Down at "
818 "%04i-%02i-%02i %02i:%02i:%02i\n",
819 tm.tm_year + 1900,
820 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
821 tm.tm_min, tm.tm_sec);
822 }
823 if (i2c_smbus_write_byte_data(client,
824 M41T80_REG_ALARM_HOUR,
825 rc & ~M41T80_ALHOUR_HT) < 0)
826 goto ht_err;
827 }
828
829 /* Make sure ST (stop) bit is cleared */
830 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
831 if (rc < 0)
832 goto st_err;
833
834 if (rc & M41T80_SEC_ST) {
835 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
836 rc & ~M41T80_SEC_ST) < 0)
837 goto st_err;
838 }
839
840 rc = m41t80_sysfs_register(&client->dev);
841 if (rc)
842 goto exit;
843
844 #ifdef CONFIG_RTC_DRV_M41T80_WDT
845 if (chip->features & M41T80_FEATURE_HT) {
846 rc = misc_register(&wdt_dev);
847 if (rc)
848 goto exit;
849 rc = register_reboot_notifier(&wdt_notifier);
850 if (rc) {
851 misc_deregister(&wdt_dev);
852 goto exit;
853 }
854 save_client = client;
855 }
856 #endif
857 return 0;
858
859 st_err:
860 rc = -EIO;
861 dev_err(&client->dev, "Can't clear ST bit\n");
862 goto exit;
863 ht_err:
864 rc = -EIO;
865 dev_err(&client->dev, "Can't clear HT bit\n");
866 goto exit;
867
868 exit:
869 if (rtc)
870 rtc_device_unregister(rtc);
871 kfree(clientdata);
872 return rc;
873 }
874
875 static int m41t80_remove(struct i2c_client *client)
876 {
877 struct m41t80_data *clientdata = i2c_get_clientdata(client);
878 struct rtc_device *rtc = clientdata->rtc;
879
880 #ifdef CONFIG_RTC_DRV_M41T80_WDT
881 if (clientdata->chip->features & M41T80_FEATURE_HT) {
882 misc_deregister(&wdt_dev);
883 unregister_reboot_notifier(&wdt_notifier);
884 }
885 #endif
886 if (rtc)
887 rtc_device_unregister(rtc);
888 kfree(clientdata);
889
890 return 0;
891 }
892
893 static struct i2c_driver m41t80_driver = {
894 .driver = {
895 .name = "rtc-m41t80",
896 },
897 .probe = m41t80_probe,
898 .remove = m41t80_remove,
899 };
900
901 static int __init m41t80_rtc_init(void)
902 {
903 return i2c_add_driver(&m41t80_driver);
904 }
905
906 static void __exit m41t80_rtc_exit(void)
907 {
908 i2c_del_driver(&m41t80_driver);
909 }
910
911 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
912 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
913 MODULE_LICENSE("GPL");
914 MODULE_VERSION(DRV_VERSION);
915
916 module_init(m41t80_rtc_init);
917 module_exit(m41t80_rtc_exit);
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