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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6/linux-mips/linux-dm7025.git] / drivers / rtc / rtc-m41t80.c
blob316bfaa80872195badfeda9ec87de81265d77d96
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 static const struct i2c_device_id m41t80_id[] = {
64 { "m41t80", 0 },
65 { "m41t81", M41T80_FEATURE_HT },
66 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
67 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
68 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
69 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
70 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
71 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
72 { }
73 };
74 MODULE_DEVICE_TABLE(i2c, m41t80_id);
75
76 struct m41t80_data {
77 u8 features;
78 struct rtc_device *rtc;
79 };
80
81 static int m41t80_get_datetime(struct i2c_client *client,
82 struct rtc_time *tm)
83 {
84 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
85 struct i2c_msg msgs[] = {
86 {
87 .addr = client->addr,
88 .flags = 0,
89 .len = 1,
90 .buf = dt_addr,
91 },
92 {
93 .addr = client->addr,
94 .flags = I2C_M_RD,
95 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
96 .buf = buf + M41T80_REG_SEC,
97 },
98 };
99
100 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
101 dev_err(&client->dev, "read error\n");
102 return -EIO;
103 }
104
105 tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f);
106 tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f);
107 tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f);
108 tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f);
109 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
110 tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1;
111
112 /* assume 20YY not 19YY, and ignore the Century Bit */
113 tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100;
114 return 0;
115 }
116
117 /* Sets the given date and time to the real time clock. */
118 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
119 {
120 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
121 u8 *buf = &wbuf[1];
122 u8 dt_addr[1] = { M41T80_REG_SEC };
123 struct i2c_msg msgs_in[] = {
124 {
125 .addr = client->addr,
126 .flags = 0,
127 .len = 1,
128 .buf = dt_addr,
129 },
130 {
131 .addr = client->addr,
132 .flags = I2C_M_RD,
133 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
134 .buf = buf + M41T80_REG_SEC,
135 },
136 };
137 struct i2c_msg msgs[] = {
138 {
139 .addr = client->addr,
140 .flags = 0,
141 .len = 1 + M41T80_DATETIME_REG_SIZE,
142 .buf = wbuf,
143 },
144 };
145
146 /* Read current reg values into buf[1..7] */
147 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
148 dev_err(&client->dev, "read error\n");
149 return -EIO;
150 }
151
152 wbuf[0] = 0; /* offset into rtc's regs */
153 /* Merge time-data and register flags into buf[0..7] */
154 buf[M41T80_REG_SSEC] = 0;
155 buf[M41T80_REG_SEC] =
156 BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
157 buf[M41T80_REG_MIN] =
158 BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
159 buf[M41T80_REG_HOUR] =
160 BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ;
161 buf[M41T80_REG_WDAY] =
162 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
163 buf[M41T80_REG_DAY] =
164 BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
165 buf[M41T80_REG_MON] =
166 BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
167 /* assume 20YY not 19YY */
168 buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100);
169
170 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
171 dev_err(&client->dev, "write error\n");
172 return -EIO;
173 }
174 return 0;
175 }
176
177 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
178 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
179 {
180 struct i2c_client *client = to_i2c_client(dev);
181 struct m41t80_data *clientdata = i2c_get_clientdata(client);
182 u8 reg;
183
184 if (clientdata->features & M41T80_FEATURE_BL) {
185 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
186 seq_printf(seq, "battery\t\t: %s\n",
187 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
188 }
189 return 0;
190 }
191 #else
192 #define m41t80_rtc_proc NULL
193 #endif
194
195 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
196 {
197 return m41t80_get_datetime(to_i2c_client(dev), tm);
198 }
199
200 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
201 {
202 return m41t80_set_datetime(to_i2c_client(dev), tm);
203 }
204
205 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
206 static int
207 m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
208 {
209 struct i2c_client *client = to_i2c_client(dev);
210 int rc;
211
212 switch (cmd) {
213 case RTC_AIE_OFF:
214 case RTC_AIE_ON:
215 break;
216 default:
217 return -ENOIOCTLCMD;
218 }
219
220 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
221 if (rc < 0)
222 goto err;
223 switch (cmd) {
224 case RTC_AIE_OFF:
225 rc &= ~M41T80_ALMON_AFE;
226 break;
227 case RTC_AIE_ON:
228 rc |= M41T80_ALMON_AFE;
229 break;
230 }
231 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
232 goto err;
233 return 0;
234 err:
235 return -EIO;
236 }
237 #else
238 #define m41t80_rtc_ioctl NULL
239 #endif
240
241 static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
242 {
243 struct i2c_client *client = to_i2c_client(dev);
244 u8 wbuf[1 + M41T80_ALARM_REG_SIZE];
245 u8 *buf = &wbuf[1];
246 u8 *reg = buf - M41T80_REG_ALARM_MON;
247 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
248 struct i2c_msg msgs_in[] = {
249 {
250 .addr = client->addr,
251 .flags = 0,
252 .len = 1,
253 .buf = dt_addr,
254 },
255 {
256 .addr = client->addr,
257 .flags = I2C_M_RD,
258 .len = M41T80_ALARM_REG_SIZE,
259 .buf = buf,
260 },
261 };
262 struct i2c_msg msgs[] = {
263 {
264 .addr = client->addr,
265 .flags = 0,
266 .len = 1 + M41T80_ALARM_REG_SIZE,
267 .buf = wbuf,
268 },
269 };
270
271 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
272 dev_err(&client->dev, "read error\n");
273 return -EIO;
274 }
275 reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE);
276 reg[M41T80_REG_ALARM_DAY] = 0;
277 reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80);
278 reg[M41T80_REG_ALARM_MIN] = 0;
279 reg[M41T80_REG_ALARM_SEC] = 0;
280
281 wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */
282 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
283 BIN2BCD(t->time.tm_sec) : 0x80;
284 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
285 BIN2BCD(t->time.tm_min) : 0x80;
286 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ?
287 BIN2BCD(t->time.tm_hour) : 0x80;
288 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ?
289 BIN2BCD(t->time.tm_mday) : 0x80;
290 if (t->time.tm_mon >= 0)
291 reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1);
292 else
293 reg[M41T80_REG_ALARM_DAY] |= 0x40;
294
295 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
296 dev_err(&client->dev, "write error\n");
297 return -EIO;
298 }
299
300 if (t->enabled) {
301 reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE;
302 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
303 reg[M41T80_REG_ALARM_MON]) < 0) {
304 dev_err(&client->dev, "write error\n");
305 return -EIO;
306 }
307 }
308 return 0;
309 }
310
311 static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
312 {
313 struct i2c_client *client = to_i2c_client(dev);
314 u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */
315 u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
316 u8 *reg = buf - M41T80_REG_ALARM_MON;
317 struct i2c_msg msgs[] = {
318 {
319 .addr = client->addr,
320 .flags = 0,
321 .len = 1,
322 .buf = dt_addr,
323 },
324 {
325 .addr = client->addr,
326 .flags = I2C_M_RD,
327 .len = M41T80_ALARM_REG_SIZE + 1,
328 .buf = buf,
329 },
330 };
331
332 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
333 dev_err(&client->dev, "read error\n");
334 return -EIO;
335 }
336 t->time.tm_sec = -1;
337 t->time.tm_min = -1;
338 t->time.tm_hour = -1;
339 t->time.tm_mday = -1;
340 t->time.tm_mon = -1;
341 if (!(reg[M41T80_REG_ALARM_SEC] & 0x80))
342 t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f);
343 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80))
344 t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f);
345 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80))
346 t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f);
347 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80))
348 t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f);
349 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40))
350 t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1;
351 t->time.tm_year = -1;
352 t->time.tm_wday = -1;
353 t->time.tm_yday = -1;
354 t->time.tm_isdst = -1;
355 t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE);
356 t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF);
357 return 0;
358 }
359
360 static struct rtc_class_ops m41t80_rtc_ops = {
361 .read_time = m41t80_rtc_read_time,
362 .set_time = m41t80_rtc_set_time,
363 .read_alarm = m41t80_rtc_read_alarm,
364 .set_alarm = m41t80_rtc_set_alarm,
365 .proc = m41t80_rtc_proc,
366 .ioctl = m41t80_rtc_ioctl,
367 };
368
369 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
370 static ssize_t m41t80_sysfs_show_flags(struct device *dev,
371 struct device_attribute *attr, char *buf)
372 {
373 struct i2c_client *client = to_i2c_client(dev);
374 int val;
375
376 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
377 if (val < 0)
378 return -EIO;
379 return sprintf(buf, "%#x\n", val);
380 }
381 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
382
383 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
384 struct device_attribute *attr, char *buf)
385 {
386 struct i2c_client *client = to_i2c_client(dev);
387 int val;
388
389 val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW);
390 if (val < 0)
391 return -EIO;
392 val = (val >> 4) & 0xf;
393 switch (val) {
394 case 0:
395 break;
396 case 1:
397 val = 32768;
398 break;
399 default:
400 val = 32768 >> val;
401 }
402 return sprintf(buf, "%d\n", val);
403 }
404 static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
405 struct device_attribute *attr,
406 const char *buf, size_t count)
407 {
408 struct i2c_client *client = to_i2c_client(dev);
409 int almon, sqw;
410 int val = simple_strtoul(buf, NULL, 0);
411
412 if (val) {
413 if (!is_power_of_2(val))
414 return -EINVAL;
415 val = ilog2(val);
416 if (val == 15)
417 val = 1;
418 else if (val < 14)
419 val = 15 - val;
420 else
421 return -EINVAL;
422 }
423 /* disable SQW, set SQW frequency & re-enable */
424 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
425 if (almon < 0)
426 return -EIO;
427 sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW);
428 if (sqw < 0)
429 return -EIO;
430 sqw = (sqw & 0x0f) | (val << 4);
431 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
432 almon & ~M41T80_ALMON_SQWE) < 0 ||
433 i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0)
434 return -EIO;
435 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
436 almon | M41T80_ALMON_SQWE) < 0)
437 return -EIO;
438 return count;
439 }
440 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
441 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
442
443 static struct attribute *attrs[] = {
444 &dev_attr_flags.attr,
445 &dev_attr_sqwfreq.attr,
446 NULL,
447 };
448 static struct attribute_group attr_group = {
449 .attrs = attrs,
450 };
451
452 static int m41t80_sysfs_register(struct device *dev)
453 {
454 return sysfs_create_group(&dev->kobj, &attr_group);
455 }
456 #else
457 static int m41t80_sysfs_register(struct device *dev)
458 {
459 return 0;
460 }
461 #endif
462
463 #ifdef CONFIG_RTC_DRV_M41T80_WDT
464 /*
465 *****************************************************************************
466 *
467 * Watchdog Driver
468 *
469 *****************************************************************************
470 */
471 static struct i2c_client *save_client;
472
473 /* Default margin */
474 #define WD_TIMO 60 /* 1..31 seconds */
475
476 static int wdt_margin = WD_TIMO;
477 module_param(wdt_margin, int, 0);
478 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
479
480 static unsigned long wdt_is_open;
481 static int boot_flag;
482
483 /**
484 * wdt_ping:
485 *
486 * Reload counter one with the watchdog timeout. We don't bother reloading
487 * the cascade counter.
488 */
489 static void wdt_ping(void)
490 {
491 unsigned char i2c_data[2];
492 struct i2c_msg msgs1[1] = {
493 {
494 .addr = save_client->addr,
495 .flags = 0,
496 .len = 2,
497 .buf = i2c_data,
498 },
499 };
500 i2c_data[0] = 0x09; /* watchdog register */
501
502 if (wdt_margin > 31)
503 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
504 else
505 /*
506 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
507 */
508 i2c_data[1] = wdt_margin<<2 | 0x82;
509
510 i2c_transfer(save_client->adapter, msgs1, 1);
511 }
512
513 /**
514 * wdt_disable:
515 *
516 * disables watchdog.
517 */
518 static void wdt_disable(void)
519 {
520 unsigned char i2c_data[2], i2c_buf[0x10];
521 struct i2c_msg msgs0[2] = {
522 {
523 .addr = save_client->addr,
524 .flags = 0,
525 .len = 1,
526 .buf = i2c_data,
527 },
528 {
529 .addr = save_client->addr,
530 .flags = I2C_M_RD,
531 .len = 1,
532 .buf = i2c_buf,
533 },
534 };
535 struct i2c_msg msgs1[1] = {
536 {
537 .addr = save_client->addr,
538 .flags = 0,
539 .len = 2,
540 .buf = i2c_data,
541 },
542 };
543
544 i2c_data[0] = 0x09;
545 i2c_transfer(save_client->adapter, msgs0, 2);
546
547 i2c_data[0] = 0x09;
548 i2c_data[1] = 0x00;
549 i2c_transfer(save_client->adapter, msgs1, 1);
550 }
551
552 /**
553 * wdt_write:
554 * @file: file handle to the watchdog
555 * @buf: buffer to write (unused as data does not matter here
556 * @count: count of bytes
557 * @ppos: pointer to the position to write. No seeks allowed
558 *
559 * A write to a watchdog device is defined as a keepalive signal. Any
560 * write of data will do, as we we don't define content meaning.
561 */
562 static ssize_t wdt_write(struct file *file, const char __user *buf,
563 size_t count, loff_t *ppos)
564 {
565 /* Can't seek (pwrite) on this device
566 if (ppos != &file->f_pos)
567 return -ESPIPE;
568 */
569 if (count) {
570 wdt_ping();
571 return 1;
572 }
573 return 0;
574 }
575
576 static ssize_t wdt_read(struct file *file, char __user *buf,
577 size_t count, loff_t *ppos)
578 {
579 return 0;
580 }
581
582 /**
583 * wdt_ioctl:
584 * @inode: inode of the device
585 * @file: file handle to the device
586 * @cmd: watchdog command
587 * @arg: argument pointer
588 *
589 * The watchdog API defines a common set of functions for all watchdogs
590 * according to their available features. We only actually usefully support
591 * querying capabilities and current status.
592 */
593 static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
594 unsigned long arg)
595 {
596 int new_margin, rv;
597 static struct watchdog_info ident = {
598 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
599 WDIOF_SETTIMEOUT,
600 .firmware_version = 1,
601 .identity = "M41T80 WTD"
602 };
603
604 switch (cmd) {
605 case WDIOC_GETSUPPORT:
606 return copy_to_user((struct watchdog_info __user *)arg, &ident,
607 sizeof(ident)) ? -EFAULT : 0;
608
609 case WDIOC_GETSTATUS:
610 case WDIOC_GETBOOTSTATUS:
611 return put_user(boot_flag, (int __user *)arg);
612 case WDIOC_KEEPALIVE:
613 wdt_ping();
614 return 0;
615 case WDIOC_SETTIMEOUT:
616 if (get_user(new_margin, (int __user *)arg))
617 return -EFAULT;
618 /* Arbitrary, can't find the card's limits */
619 if (new_margin < 1 || new_margin > 124)
620 return -EINVAL;
621 wdt_margin = new_margin;
622 wdt_ping();
623 /* Fall */
624 case WDIOC_GETTIMEOUT:
625 return put_user(wdt_margin, (int __user *)arg);
626
627 case WDIOC_SETOPTIONS:
628 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
629 return -EFAULT;
630
631 if (rv & WDIOS_DISABLECARD) {
632 printk(KERN_INFO
633 "rtc-m41t80: disable watchdog\n");
634 wdt_disable();
635 }
636
637 if (rv & WDIOS_ENABLECARD) {
638 printk(KERN_INFO
639 "rtc-m41t80: enable watchdog\n");
640 wdt_ping();
641 }
642
643 return -EINVAL;
644 }
645 return -ENOTTY;
646 }
647
648 /**
649 * wdt_open:
650 * @inode: inode of device
651 * @file: file handle to device
652 *
653 */
654 static int wdt_open(struct inode *inode, struct file *file)
655 {
656 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
657 if (test_and_set_bit(0, &wdt_is_open))
658 return -EBUSY;
659 /*
660 * Activate
661 */
662 wdt_is_open = 1;
663 return 0;
664 }
665 return -ENODEV;
666 }
667
668 /**
669 * wdt_close:
670 * @inode: inode to board
671 * @file: file handle to board
672 *
673 */
674 static int wdt_release(struct inode *inode, struct file *file)
675 {
676 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
677 clear_bit(0, &wdt_is_open);
678 return 0;
679 }
680
681 /**
682 * notify_sys:
683 * @this: our notifier block
684 * @code: the event being reported
685 * @unused: unused
686 *
687 * Our notifier is called on system shutdowns. We want to turn the card
688 * off at reboot otherwise the machine will reboot again during memory
689 * test or worse yet during the following fsck. This would suck, in fact
690 * trust me - if it happens it does suck.
691 */
692 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
693 void *unused)
694 {
695 if (code == SYS_DOWN || code == SYS_HALT)
696 /* Disable Watchdog */
697 wdt_disable();
698 return NOTIFY_DONE;
699 }
700
701 static const struct file_operations wdt_fops = {
702 .owner = THIS_MODULE,
703 .read = wdt_read,
704 .ioctl = wdt_ioctl,
705 .write = wdt_write,
706 .open = wdt_open,
707 .release = wdt_release,
708 };
709
710 static struct miscdevice wdt_dev = {
711 .minor = WATCHDOG_MINOR,
712 .name = "watchdog",
713 .fops = &wdt_fops,
714 };
715
716 /*
717 * The WDT card needs to learn about soft shutdowns in order to
718 * turn the timebomb registers off.
719 */
720 static struct notifier_block wdt_notifier = {
721 .notifier_call = wdt_notify_sys,
722 };
723 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
724
725 /*
726 *****************************************************************************
727 *
728 * Driver Interface
729 *
730 *****************************************************************************
731 */
732 static int m41t80_probe(struct i2c_client *client,
733 const struct i2c_device_id *id)
734 {
735 int rc = 0;
736 struct rtc_device *rtc = NULL;
737 struct rtc_time tm;
738 struct m41t80_data *clientdata = NULL;
739
740 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
741 | I2C_FUNC_SMBUS_BYTE_DATA)) {
742 rc = -ENODEV;
743 goto exit;
744 }
745
746 dev_info(&client->dev,
747 "chip found, driver version " DRV_VERSION "\n");
748
749 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL);
750 if (!clientdata) {
751 rc = -ENOMEM;
752 goto exit;
753 }
754
755 rtc = rtc_device_register(client->name, &client->dev,
756 &m41t80_rtc_ops, THIS_MODULE);
757 if (IS_ERR(rtc)) {
758 rc = PTR_ERR(rtc);
759 rtc = NULL;
760 goto exit;
761 }
762
763 clientdata->rtc = rtc;
764 clientdata->features = id->driver_data;
765 i2c_set_clientdata(client, clientdata);
766
767 /* Make sure HT (Halt Update) bit is cleared */
768 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
769 if (rc < 0)
770 goto ht_err;
771
772 if (rc & M41T80_ALHOUR_HT) {
773 if (clientdata->features & M41T80_FEATURE_HT) {
774 m41t80_get_datetime(client, &tm);
775 dev_info(&client->dev, "HT bit was set!\n");
776 dev_info(&client->dev,
777 "Power Down at "
778 "%04i-%02i-%02i %02i:%02i:%02i\n",
779 tm.tm_year + 1900,
780 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
781 tm.tm_min, tm.tm_sec);
782 }
783 if (i2c_smbus_write_byte_data(client,
784 M41T80_REG_ALARM_HOUR,
785 rc & ~M41T80_ALHOUR_HT) < 0)
786 goto ht_err;
787 }
788
789 /* Make sure ST (stop) bit is cleared */
790 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
791 if (rc < 0)
792 goto st_err;
793
794 if (rc & M41T80_SEC_ST) {
795 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
796 rc & ~M41T80_SEC_ST) < 0)
797 goto st_err;
798 }
799
800 rc = m41t80_sysfs_register(&client->dev);
801 if (rc)
802 goto exit;
803
804 #ifdef CONFIG_RTC_DRV_M41T80_WDT
805 if (clientdata->features & M41T80_FEATURE_HT) {
806 rc = misc_register(&wdt_dev);
807 if (rc)
808 goto exit;
809 rc = register_reboot_notifier(&wdt_notifier);
810 if (rc) {
811 misc_deregister(&wdt_dev);
812 goto exit;
813 }
814 save_client = client;
815 }
816 #endif
817 return 0;
818
819 st_err:
820 rc = -EIO;
821 dev_err(&client->dev, "Can't clear ST bit\n");
822 goto exit;
823 ht_err:
824 rc = -EIO;
825 dev_err(&client->dev, "Can't clear HT bit\n");
826 goto exit;
827
828 exit:
829 if (rtc)
830 rtc_device_unregister(rtc);
831 kfree(clientdata);
832 return rc;
833 }
834
835 static int m41t80_remove(struct i2c_client *client)
836 {
837 struct m41t80_data *clientdata = i2c_get_clientdata(client);
838 struct rtc_device *rtc = clientdata->rtc;
839
840 #ifdef CONFIG_RTC_DRV_M41T80_WDT
841 if (clientdata->features & M41T80_FEATURE_HT) {
842 misc_deregister(&wdt_dev);
843 unregister_reboot_notifier(&wdt_notifier);
844 }
845 #endif
846 if (rtc)
847 rtc_device_unregister(rtc);
848 kfree(clientdata);
849
850 return 0;
851 }
852
853 static struct i2c_driver m41t80_driver = {
854 .driver = {
855 .name = "rtc-m41t80",
856 },
857 .probe = m41t80_probe,
858 .remove = m41t80_remove,
859 .id_table = m41t80_id,
860 };
861
862 static int __init m41t80_rtc_init(void)
863 {
864 return i2c_add_driver(&m41t80_driver);
865 }
866
867 static void __exit m41t80_rtc_exit(void)
868 {
869 i2c_del_driver(&m41t80_driver);
870 }
871
872 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
873 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
874 MODULE_LICENSE("GPL");
875 MODULE_VERSION(DRV_VERSION);
876
877 module_init(m41t80_rtc_init);
878 module_exit(m41t80_rtc_exit);
A Kernel for the Dreambox dm7025.