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drivers/rtc/rtc-m41t80.c: remove DRV_VERSION macro
[deliverable/linux.git] / drivers / rtc / rtc-m41t80.c
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/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/mutex.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) /* ST: Stop Bit */
54 #define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */
55 #define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */
56 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
57 #define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
58 #define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
59 #define M41T80_WATCHDOG_RB2 (1 << 7) /* RB: Watchdog resolution */
60 #define M41T80_WATCHDOG_RB1 (1 << 1) /* RB: Watchdog resolution */
61 #define M41T80_WATCHDOG_RB0 (1 << 0) /* RB: Watchdog resolution */
62
63 #define M41T80_FEATURE_HT (1 << 0) /* Halt feature */
64 #define M41T80_FEATURE_BL (1 << 1) /* Battery low indicator */
65 #define M41T80_FEATURE_SQ (1 << 2) /* Squarewave feature */
66 #define M41T80_FEATURE_WD (1 << 3) /* Extra watchdog resolution */
67 #define M41T80_FEATURE_SQ_ALT (1 << 4) /* RSx bits are in reg 4 */
68
69 static DEFINE_MUTEX(m41t80_rtc_mutex);
70 static const struct i2c_device_id m41t80_id[] = {
71 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
72 { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
73 { "m41t80", M41T80_FEATURE_SQ },
74 { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
75 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
76 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
77 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
78 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
79 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
80 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
81 { }
82 };
83 MODULE_DEVICE_TABLE(i2c, m41t80_id);
84
85 struct m41t80_data {
86 u8 features;
87 struct rtc_device *rtc;
88 };
89
90 static int m41t80_get_datetime(struct i2c_client *client,
91 struct rtc_time *tm)
92 {
93 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
94 struct i2c_msg msgs[] = {
95 {
96 .addr = client->addr,
97 .flags = 0,
98 .len = 1,
99 .buf = dt_addr,
100 },
101 {
102 .addr = client->addr,
103 .flags = I2C_M_RD,
104 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
105 .buf = buf + M41T80_REG_SEC,
106 },
107 };
108
109 if (i2c_transfer(client->adapter, msgs, 2) < 0) {
110 dev_err(&client->dev, "read error\n");
111 return -EIO;
112 }
113
114 tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
115 tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f);
116 tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f);
117 tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f);
118 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
119 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1;
120
121 /* assume 20YY not 19YY, and ignore the Century Bit */
122 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100;
123 return rtc_valid_tm(tm);
124 }
125
126 /* Sets the given date and time to the real time clock. */
127 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
128 {
129 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
130 u8 *buf = &wbuf[1];
131 u8 dt_addr[1] = { M41T80_REG_SEC };
132 struct i2c_msg msgs_in[] = {
133 {
134 .addr = client->addr,
135 .flags = 0,
136 .len = 1,
137 .buf = dt_addr,
138 },
139 {
140 .addr = client->addr,
141 .flags = I2C_M_RD,
142 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
143 .buf = buf + M41T80_REG_SEC,
144 },
145 };
146 struct i2c_msg msgs[] = {
147 {
148 .addr = client->addr,
149 .flags = 0,
150 .len = 1 + M41T80_DATETIME_REG_SIZE,
151 .buf = wbuf,
152 },
153 };
154
155 /* Read current reg values into buf[1..7] */
156 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
157 dev_err(&client->dev, "read error\n");
158 return -EIO;
159 }
160
161 wbuf[0] = 0; /* offset into rtc's regs */
162 /* Merge time-data and register flags into buf[0..7] */
163 buf[M41T80_REG_SSEC] = 0;
164 buf[M41T80_REG_SEC] =
165 bin2bcd(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
166 buf[M41T80_REG_MIN] =
167 bin2bcd(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
168 buf[M41T80_REG_HOUR] =
169 bin2bcd(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f);
170 buf[M41T80_REG_WDAY] =
171 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
172 buf[M41T80_REG_DAY] =
173 bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
174 buf[M41T80_REG_MON] =
175 bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
176 /* assume 20YY not 19YY */
177 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
178
179 if (i2c_transfer(client->adapter, msgs, 1) != 1) {
180 dev_err(&client->dev, "write error\n");
181 return -EIO;
182 }
183 return 0;
184 }
185
186 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
187 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
188 {
189 struct i2c_client *client = to_i2c_client(dev);
190 struct m41t80_data *clientdata = i2c_get_clientdata(client);
191 u8 reg;
192
193 if (clientdata->features & M41T80_FEATURE_BL) {
194 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
195 seq_printf(seq, "battery\t\t: %s\n",
196 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
197 }
198 return 0;
199 }
200 #else
201 #define m41t80_rtc_proc NULL
202 #endif
203
204 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
205 {
206 return m41t80_get_datetime(to_i2c_client(dev), tm);
207 }
208
209 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
210 {
211 return m41t80_set_datetime(to_i2c_client(dev), tm);
212 }
213
214 /*
215 * XXX - m41t80 alarm functionality is reported broken.
216 * until it is fixed, don't register alarm functions.
217 */
218 static struct rtc_class_ops m41t80_rtc_ops = {
219 .read_time = m41t80_rtc_read_time,
220 .set_time = m41t80_rtc_set_time,
221 .proc = m41t80_rtc_proc,
222 };
223
224 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
225 static ssize_t m41t80_sysfs_show_flags(struct device *dev,
226 struct device_attribute *attr, char *buf)
227 {
228 struct i2c_client *client = to_i2c_client(dev);
229 int val;
230
231 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
232 if (val < 0)
233 return -EIO;
234 return sprintf(buf, "%#x\n", val);
235 }
236 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
237
238 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
239 struct device_attribute *attr, char *buf)
240 {
241 struct i2c_client *client = to_i2c_client(dev);
242 struct m41t80_data *clientdata = i2c_get_clientdata(client);
243 int val, reg_sqw;
244
245 if (!(clientdata->features & M41T80_FEATURE_SQ))
246 return -EINVAL;
247
248 reg_sqw = M41T80_REG_SQW;
249 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
250 reg_sqw = M41T80_REG_WDAY;
251 val = i2c_smbus_read_byte_data(client, reg_sqw);
252 if (val < 0)
253 return -EIO;
254 val = (val >> 4) & 0xf;
255 switch (val) {
256 case 0:
257 break;
258 case 1:
259 val = 32768;
260 break;
261 default:
262 val = 32768 >> val;
263 }
264 return sprintf(buf, "%d\n", val);
265 }
266 static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
267 struct device_attribute *attr,
268 const char *buf, size_t count)
269 {
270 struct i2c_client *client = to_i2c_client(dev);
271 struct m41t80_data *clientdata = i2c_get_clientdata(client);
272 int almon, sqw, reg_sqw;
273 int val = simple_strtoul(buf, NULL, 0);
274
275 if (!(clientdata->features & M41T80_FEATURE_SQ))
276 return -EINVAL;
277
278 if (val) {
279 if (!is_power_of_2(val))
280 return -EINVAL;
281 val = ilog2(val);
282 if (val == 15)
283 val = 1;
284 else if (val < 14)
285 val = 15 - val;
286 else
287 return -EINVAL;
288 }
289 /* disable SQW, set SQW frequency & re-enable */
290 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
291 if (almon < 0)
292 return -EIO;
293 reg_sqw = M41T80_REG_SQW;
294 if (clientdata->features & M41T80_FEATURE_SQ_ALT)
295 reg_sqw = M41T80_REG_WDAY;
296 sqw = i2c_smbus_read_byte_data(client, reg_sqw);
297 if (sqw < 0)
298 return -EIO;
299 sqw = (sqw & 0x0f) | (val << 4);
300 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
301 almon & ~M41T80_ALMON_SQWE) < 0 ||
302 i2c_smbus_write_byte_data(client, reg_sqw, sqw) < 0)
303 return -EIO;
304 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
305 almon | M41T80_ALMON_SQWE) < 0)
306 return -EIO;
307 return count;
308 }
309 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
310 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
311
312 static struct attribute *attrs[] = {
313 &dev_attr_flags.attr,
314 &dev_attr_sqwfreq.attr,
315 NULL,
316 };
317 static struct attribute_group attr_group = {
318 .attrs = attrs,
319 };
320
321 static int m41t80_sysfs_register(struct device *dev)
322 {
323 return sysfs_create_group(&dev->kobj, &attr_group);
324 }
325 #else
326 static int m41t80_sysfs_register(struct device *dev)
327 {
328 return 0;
329 }
330 #endif
331
332 #ifdef CONFIG_RTC_DRV_M41T80_WDT
333 /*
334 *****************************************************************************
335 *
336 * Watchdog Driver
337 *
338 *****************************************************************************
339 */
340 static struct i2c_client *save_client;
341
342 /* Default margin */
343 #define WD_TIMO 60 /* 1..31 seconds */
344
345 static int wdt_margin = WD_TIMO;
346 module_param(wdt_margin, int, 0);
347 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
348
349 static unsigned long wdt_is_open;
350 static int boot_flag;
351
352 /**
353 * wdt_ping:
354 *
355 * Reload counter one with the watchdog timeout. We don't bother reloading
356 * the cascade counter.
357 */
358 static void wdt_ping(void)
359 {
360 unsigned char i2c_data[2];
361 struct i2c_msg msgs1[1] = {
362 {
363 .addr = save_client->addr,
364 .flags = 0,
365 .len = 2,
366 .buf = i2c_data,
367 },
368 };
369 struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
370
371 i2c_data[0] = 0x09; /* watchdog register */
372
373 if (wdt_margin > 31)
374 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
375 else
376 /*
377 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
378 */
379 i2c_data[1] = wdt_margin<<2 | 0x82;
380
381 /*
382 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
383 * that would be an invalid resolution.
384 */
385 if (clientdata->features & M41T80_FEATURE_WD)
386 i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
387
388 i2c_transfer(save_client->adapter, msgs1, 1);
389 }
390
391 /**
392 * wdt_disable:
393 *
394 * disables watchdog.
395 */
396 static void wdt_disable(void)
397 {
398 unsigned char i2c_data[2], i2c_buf[0x10];
399 struct i2c_msg msgs0[2] = {
400 {
401 .addr = save_client->addr,
402 .flags = 0,
403 .len = 1,
404 .buf = i2c_data,
405 },
406 {
407 .addr = save_client->addr,
408 .flags = I2C_M_RD,
409 .len = 1,
410 .buf = i2c_buf,
411 },
412 };
413 struct i2c_msg msgs1[1] = {
414 {
415 .addr = save_client->addr,
416 .flags = 0,
417 .len = 2,
418 .buf = i2c_data,
419 },
420 };
421
422 i2c_data[0] = 0x09;
423 i2c_transfer(save_client->adapter, msgs0, 2);
424
425 i2c_data[0] = 0x09;
426 i2c_data[1] = 0x00;
427 i2c_transfer(save_client->adapter, msgs1, 1);
428 }
429
430 /**
431 * wdt_write:
432 * @file: file handle to the watchdog
433 * @buf: buffer to write (unused as data does not matter here
434 * @count: count of bytes
435 * @ppos: pointer to the position to write. No seeks allowed
436 *
437 * A write to a watchdog device is defined as a keepalive signal. Any
438 * write of data will do, as we we don't define content meaning.
439 */
440 static ssize_t wdt_write(struct file *file, const char __user *buf,
441 size_t count, loff_t *ppos)
442 {
443 if (count) {
444 wdt_ping();
445 return 1;
446 }
447 return 0;
448 }
449
450 static ssize_t wdt_read(struct file *file, char __user *buf,
451 size_t count, loff_t *ppos)
452 {
453 return 0;
454 }
455
456 /**
457 * wdt_ioctl:
458 * @inode: inode of the device
459 * @file: file handle to the device
460 * @cmd: watchdog command
461 * @arg: argument pointer
462 *
463 * The watchdog API defines a common set of functions for all watchdogs
464 * according to their available features. We only actually usefully support
465 * querying capabilities and current status.
466 */
467 static int wdt_ioctl(struct file *file, unsigned int cmd,
468 unsigned long arg)
469 {
470 int new_margin, rv;
471 static struct watchdog_info ident = {
472 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
473 WDIOF_SETTIMEOUT,
474 .firmware_version = 1,
475 .identity = "M41T80 WTD"
476 };
477
478 switch (cmd) {
479 case WDIOC_GETSUPPORT:
480 return copy_to_user((struct watchdog_info __user *)arg, &ident,
481 sizeof(ident)) ? -EFAULT : 0;
482
483 case WDIOC_GETSTATUS:
484 case WDIOC_GETBOOTSTATUS:
485 return put_user(boot_flag, (int __user *)arg);
486 case WDIOC_KEEPALIVE:
487 wdt_ping();
488 return 0;
489 case WDIOC_SETTIMEOUT:
490 if (get_user(new_margin, (int __user *)arg))
491 return -EFAULT;
492 /* Arbitrary, can't find the card's limits */
493 if (new_margin < 1 || new_margin > 124)
494 return -EINVAL;
495 wdt_margin = new_margin;
496 wdt_ping();
497 /* Fall */
498 case WDIOC_GETTIMEOUT:
499 return put_user(wdt_margin, (int __user *)arg);
500
501 case WDIOC_SETOPTIONS:
502 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
503 return -EFAULT;
504
505 if (rv & WDIOS_DISABLECARD) {
506 pr_info("rtc-m41t80: disable watchdog\n");
507 wdt_disable();
508 }
509
510 if (rv & WDIOS_ENABLECARD) {
511 pr_info("rtc-m41t80: enable watchdog\n");
512 wdt_ping();
513 }
514
515 return -EINVAL;
516 }
517 return -ENOTTY;
518 }
519
520 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
521 unsigned long arg)
522 {
523 int ret;
524
525 mutex_lock(&m41t80_rtc_mutex);
526 ret = wdt_ioctl(file, cmd, arg);
527 mutex_unlock(&m41t80_rtc_mutex);
528
529 return ret;
530 }
531
532 /**
533 * wdt_open:
534 * @inode: inode of device
535 * @file: file handle to device
536 *
537 */
538 static int wdt_open(struct inode *inode, struct file *file)
539 {
540 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
541 mutex_lock(&m41t80_rtc_mutex);
542 if (test_and_set_bit(0, &wdt_is_open)) {
543 mutex_unlock(&m41t80_rtc_mutex);
544 return -EBUSY;
545 }
546 /*
547 * Activate
548 */
549 wdt_is_open = 1;
550 mutex_unlock(&m41t80_rtc_mutex);
551 return nonseekable_open(inode, file);
552 }
553 return -ENODEV;
554 }
555
556 /**
557 * wdt_close:
558 * @inode: inode to board
559 * @file: file handle to board
560 *
561 */
562 static int wdt_release(struct inode *inode, struct file *file)
563 {
564 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
565 clear_bit(0, &wdt_is_open);
566 return 0;
567 }
568
569 /**
570 * notify_sys:
571 * @this: our notifier block
572 * @code: the event being reported
573 * @unused: unused
574 *
575 * Our notifier is called on system shutdowns. We want to turn the card
576 * off at reboot otherwise the machine will reboot again during memory
577 * test or worse yet during the following fsck. This would suck, in fact
578 * trust me - if it happens it does suck.
579 */
580 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
581 void *unused)
582 {
583 if (code == SYS_DOWN || code == SYS_HALT)
584 /* Disable Watchdog */
585 wdt_disable();
586 return NOTIFY_DONE;
587 }
588
589 static const struct file_operations wdt_fops = {
590 .owner = THIS_MODULE,
591 .read = wdt_read,
592 .unlocked_ioctl = wdt_unlocked_ioctl,
593 .write = wdt_write,
594 .open = wdt_open,
595 .release = wdt_release,
596 .llseek = no_llseek,
597 };
598
599 static struct miscdevice wdt_dev = {
600 .minor = WATCHDOG_MINOR,
601 .name = "watchdog",
602 .fops = &wdt_fops,
603 };
604
605 /*
606 * The WDT card needs to learn about soft shutdowns in order to
607 * turn the timebomb registers off.
608 */
609 static struct notifier_block wdt_notifier = {
610 .notifier_call = wdt_notify_sys,
611 };
612 #endif /* CONFIG_RTC_DRV_M41T80_WDT */
613
614 /*
615 *****************************************************************************
616 *
617 * Driver Interface
618 *
619 *****************************************************************************
620 */
621 static int m41t80_probe(struct i2c_client *client,
622 const struct i2c_device_id *id)
623 {
624 int rc = 0;
625 struct rtc_device *rtc = NULL;
626 struct rtc_time tm;
627 struct m41t80_data *clientdata = NULL;
628
629 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
630 | I2C_FUNC_SMBUS_BYTE_DATA)) {
631 rc = -ENODEV;
632 goto exit;
633 }
634
635 clientdata = devm_kzalloc(&client->dev, sizeof(*clientdata),
636 GFP_KERNEL);
637 if (!clientdata) {
638 rc = -ENOMEM;
639 goto exit;
640 }
641
642 clientdata->features = id->driver_data;
643 i2c_set_clientdata(client, clientdata);
644
645 rtc = devm_rtc_device_register(&client->dev, client->name,
646 &m41t80_rtc_ops, THIS_MODULE);
647 if (IS_ERR(rtc)) {
648 rc = PTR_ERR(rtc);
649 rtc = NULL;
650 goto exit;
651 }
652
653 clientdata->rtc = rtc;
654
655 /* Make sure HT (Halt Update) bit is cleared */
656 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
657 if (rc < 0)
658 goto ht_err;
659
660 if (rc & M41T80_ALHOUR_HT) {
661 if (clientdata->features & M41T80_FEATURE_HT) {
662 m41t80_get_datetime(client, &tm);
663 dev_info(&client->dev, "HT bit was set!\n");
664 dev_info(&client->dev,
665 "Power Down at "
666 "%04i-%02i-%02i %02i:%02i:%02i\n",
667 tm.tm_year + 1900,
668 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
669 tm.tm_min, tm.tm_sec);
670 }
671 if (i2c_smbus_write_byte_data(client,
672 M41T80_REG_ALARM_HOUR,
673 rc & ~M41T80_ALHOUR_HT) < 0)
674 goto ht_err;
675 }
676
677 /* Make sure ST (stop) bit is cleared */
678 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
679 if (rc < 0)
680 goto st_err;
681
682 if (rc & M41T80_SEC_ST) {
683 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
684 rc & ~M41T80_SEC_ST) < 0)
685 goto st_err;
686 }
687
688 rc = m41t80_sysfs_register(&client->dev);
689 if (rc)
690 goto exit;
691
692 #ifdef CONFIG_RTC_DRV_M41T80_WDT
693 if (clientdata->features & M41T80_FEATURE_HT) {
694 save_client = client;
695 rc = misc_register(&wdt_dev);
696 if (rc)
697 goto exit;
698 rc = register_reboot_notifier(&wdt_notifier);
699 if (rc) {
700 misc_deregister(&wdt_dev);
701 goto exit;
702 }
703 }
704 #endif
705 return 0;
706
707 st_err:
708 rc = -EIO;
709 dev_err(&client->dev, "Can't clear ST bit\n");
710 goto exit;
711 ht_err:
712 rc = -EIO;
713 dev_err(&client->dev, "Can't clear HT bit\n");
714 goto exit;
715
716 exit:
717 return rc;
718 }
719
720 static int m41t80_remove(struct i2c_client *client)
721 {
722 #ifdef CONFIG_RTC_DRV_M41T80_WDT
723 struct m41t80_data *clientdata = i2c_get_clientdata(client);
724
725 if (clientdata->features & M41T80_FEATURE_HT) {
726 misc_deregister(&wdt_dev);
727 unregister_reboot_notifier(&wdt_notifier);
728 }
729 #endif
730
731 return 0;
732 }
733
734 static struct i2c_driver m41t80_driver = {
735 .driver = {
736 .name = "rtc-m41t80",
737 },
738 .probe = m41t80_probe,
739 .remove = m41t80_remove,
740 .id_table = m41t80_id,
741 };
742
743 module_i2c_driver(m41t80_driver);
744
745 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
746 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
747 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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