1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C |
4 | * |
5 | * Based on code by Randy Vinson <rvinson@mvista.com>, |
6 | * which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>. |
7 | * |
8 | * Copyright (C) 2014 Rose Technology |
9 | * Copyright (C) 2006-2007 Freescale Semiconductor |
10 | * Copyright (c) 2005 MontaVista Software, Inc. |
11 | */ |
12 | /* |
13 | * It would be more efficient to use i2c msgs/i2c_transfer directly but, as |
14 | * recommended in .../Documentation/i2c/writing-clients.rst section |
15 | * "Sending and receiving", using SMBus level communication is preferred. |
16 | */ |
17 | |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | |
20 | #include <linux/kernel.h> |
21 | #include <linux/module.h> |
22 | #include <linux/interrupt.h> |
23 | #include <linux/i2c.h> |
24 | #include <linux/rtc.h> |
25 | #include <linux/bcd.h> |
26 | #include <linux/workqueue.h> |
27 | #include <linux/slab.h> |
28 | #include <linux/pm.h> |
29 | #ifdef CONFIG_RTC_DRV_DS1374_WDT |
30 | #include <linux/fs.h> |
31 | #include <linux/ioctl.h> |
32 | #include <linux/miscdevice.h> |
33 | #include <linux/reboot.h> |
34 | #include <linux/watchdog.h> |
35 | #endif |
36 | |
37 | #define DS1374_REG_TOD0 0x00 /* Time of Day */ |
38 | #define DS1374_REG_TOD1 0x01 |
39 | #define DS1374_REG_TOD2 0x02 |
40 | #define DS1374_REG_TOD3 0x03 |
41 | #define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */ |
42 | #define DS1374_REG_WDALM1 0x05 |
43 | #define DS1374_REG_WDALM2 0x06 |
44 | #define DS1374_REG_CR 0x07 /* Control */ |
45 | #define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */ |
46 | #define DS1374_REG_CR_WDSTR 0x08 /* 1=INT, 0=RST */ |
47 | #define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */ |
48 | #define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */ |
49 | #define DS1374_REG_SR 0x08 /* Status */ |
50 | #define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */ |
51 | #define DS1374_REG_SR_AF 0x01 /* Alarm Flag */ |
52 | #define DS1374_REG_TCR 0x09 /* Trickle Charge */ |
53 | |
54 | static const struct i2c_device_id ds1374_id[] = { |
55 | { "ds1374" , 0 }, |
56 | { } |
57 | }; |
58 | MODULE_DEVICE_TABLE(i2c, ds1374_id); |
59 | |
60 | #ifdef CONFIG_OF |
61 | static const struct of_device_id ds1374_of_match[] = { |
62 | { .compatible = "dallas,ds1374" }, |
63 | { } |
64 | }; |
65 | MODULE_DEVICE_TABLE(of, ds1374_of_match); |
66 | #endif |
67 | |
68 | struct ds1374 { |
69 | struct i2c_client *client; |
70 | struct rtc_device *rtc; |
71 | struct work_struct work; |
72 | #ifdef CONFIG_RTC_DRV_DS1374_WDT |
73 | struct watchdog_device wdt; |
74 | #endif |
75 | /* The mutex protects alarm operations, and prevents a race |
76 | * between the enable_irq() in the workqueue and the free_irq() |
77 | * in the remove function. |
78 | */ |
79 | struct mutex mutex; |
80 | int exiting; |
81 | }; |
82 | |
83 | static struct i2c_driver ds1374_driver; |
84 | |
85 | static int ds1374_read_rtc(struct i2c_client *client, u32 *time, |
86 | int reg, int nbytes) |
87 | { |
88 | u8 buf[4]; |
89 | int ret; |
90 | int i; |
91 | |
92 | if (WARN_ON(nbytes > 4)) |
93 | return -EINVAL; |
94 | |
95 | ret = i2c_smbus_read_i2c_block_data(client, command: reg, length: nbytes, values: buf); |
96 | |
97 | if (ret < 0) |
98 | return ret; |
99 | if (ret < nbytes) |
100 | return -EIO; |
101 | |
102 | for (i = nbytes - 1, *time = 0; i >= 0; i--) |
103 | *time = (*time << 8) | buf[i]; |
104 | |
105 | return 0; |
106 | } |
107 | |
108 | static int ds1374_write_rtc(struct i2c_client *client, u32 time, |
109 | int reg, int nbytes) |
110 | { |
111 | u8 buf[4]; |
112 | int i; |
113 | |
114 | if (nbytes > 4) { |
115 | WARN_ON(1); |
116 | return -EINVAL; |
117 | } |
118 | |
119 | for (i = 0; i < nbytes; i++) { |
120 | buf[i] = time & 0xff; |
121 | time >>= 8; |
122 | } |
123 | |
124 | return i2c_smbus_write_i2c_block_data(client, command: reg, length: nbytes, values: buf); |
125 | } |
126 | |
127 | static int ds1374_check_rtc_status(struct i2c_client *client) |
128 | { |
129 | int ret = 0; |
130 | int control, stat; |
131 | |
132 | stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR); |
133 | if (stat < 0) |
134 | return stat; |
135 | |
136 | if (stat & DS1374_REG_SR_OSF) |
137 | dev_warn(&client->dev, |
138 | "oscillator discontinuity flagged, time unreliable\n" ); |
139 | |
140 | stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF); |
141 | |
142 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, value: stat); |
143 | if (ret < 0) |
144 | return ret; |
145 | |
146 | /* If the alarm is pending, clear it before requesting |
147 | * the interrupt, so an interrupt event isn't reported |
148 | * before everything is initialized. |
149 | */ |
150 | |
151 | control = i2c_smbus_read_byte_data(client, DS1374_REG_CR); |
152 | if (control < 0) |
153 | return control; |
154 | |
155 | control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE); |
156 | return i2c_smbus_write_byte_data(client, DS1374_REG_CR, value: control); |
157 | } |
158 | |
159 | static int ds1374_read_time(struct device *dev, struct rtc_time *time) |
160 | { |
161 | struct i2c_client *client = to_i2c_client(dev); |
162 | u32 itime; |
163 | int ret; |
164 | |
165 | ret = ds1374_read_rtc(client, time: &itime, DS1374_REG_TOD0, nbytes: 4); |
166 | if (!ret) |
167 | rtc_time64_to_tm(time: itime, tm: time); |
168 | |
169 | return ret; |
170 | } |
171 | |
172 | static int ds1374_set_time(struct device *dev, struct rtc_time *time) |
173 | { |
174 | struct i2c_client *client = to_i2c_client(dev); |
175 | unsigned long itime = rtc_tm_to_time64(tm: time); |
176 | |
177 | return ds1374_write_rtc(client, time: itime, DS1374_REG_TOD0, nbytes: 4); |
178 | } |
179 | |
180 | #ifndef CONFIG_RTC_DRV_DS1374_WDT |
181 | /* The ds1374 has a decrementer for an alarm, rather than a comparator. |
182 | * If the time of day is changed, then the alarm will need to be |
183 | * reset. |
184 | */ |
185 | static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
186 | { |
187 | struct i2c_client *client = to_i2c_client(dev); |
188 | struct ds1374 *ds1374 = i2c_get_clientdata(client); |
189 | u32 now, cur_alarm; |
190 | int cr, sr; |
191 | int ret = 0; |
192 | |
193 | if (client->irq <= 0) |
194 | return -EINVAL; |
195 | |
196 | mutex_lock(&ds1374->mutex); |
197 | |
198 | cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR); |
199 | if (ret < 0) |
200 | goto out; |
201 | |
202 | sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR); |
203 | if (ret < 0) |
204 | goto out; |
205 | |
206 | ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4); |
207 | if (ret) |
208 | goto out; |
209 | |
210 | ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3); |
211 | if (ret) |
212 | goto out; |
213 | |
214 | rtc_time64_to_tm(now + cur_alarm, &alarm->time); |
215 | alarm->enabled = !!(cr & DS1374_REG_CR_WACE); |
216 | alarm->pending = !!(sr & DS1374_REG_SR_AF); |
217 | |
218 | out: |
219 | mutex_unlock(&ds1374->mutex); |
220 | return ret; |
221 | } |
222 | |
223 | static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) |
224 | { |
225 | struct i2c_client *client = to_i2c_client(dev); |
226 | struct ds1374 *ds1374 = i2c_get_clientdata(client); |
227 | struct rtc_time now; |
228 | unsigned long new_alarm, itime; |
229 | int cr; |
230 | int ret = 0; |
231 | |
232 | if (client->irq <= 0) |
233 | return -EINVAL; |
234 | |
235 | ret = ds1374_read_time(dev, &now); |
236 | if (ret < 0) |
237 | return ret; |
238 | |
239 | new_alarm = rtc_tm_to_time64(&alarm->time); |
240 | itime = rtc_tm_to_time64(&now); |
241 | |
242 | /* This can happen due to races, in addition to dates that are |
243 | * truly in the past. To avoid requiring the caller to check for |
244 | * races, dates in the past are assumed to be in the recent past |
245 | * (i.e. not something that we'd rather the caller know about via |
246 | * an error), and the alarm is set to go off as soon as possible. |
247 | */ |
248 | if (time_before_eq(new_alarm, itime)) |
249 | new_alarm = 1; |
250 | else |
251 | new_alarm -= itime; |
252 | |
253 | mutex_lock(&ds1374->mutex); |
254 | |
255 | ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR); |
256 | if (ret < 0) |
257 | goto out; |
258 | |
259 | /* Disable any existing alarm before setting the new one |
260 | * (or lack thereof). */ |
261 | cr &= ~DS1374_REG_CR_WACE; |
262 | |
263 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); |
264 | if (ret < 0) |
265 | goto out; |
266 | |
267 | ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3); |
268 | if (ret) |
269 | goto out; |
270 | |
271 | if (alarm->enabled) { |
272 | cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE; |
273 | cr &= ~DS1374_REG_CR_WDALM; |
274 | |
275 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); |
276 | } |
277 | |
278 | out: |
279 | mutex_unlock(&ds1374->mutex); |
280 | return ret; |
281 | } |
282 | #endif |
283 | |
284 | static irqreturn_t ds1374_irq(int irq, void *dev_id) |
285 | { |
286 | struct i2c_client *client = dev_id; |
287 | struct ds1374 *ds1374 = i2c_get_clientdata(client); |
288 | |
289 | disable_irq_nosync(irq); |
290 | schedule_work(work: &ds1374->work); |
291 | return IRQ_HANDLED; |
292 | } |
293 | |
294 | static void ds1374_work(struct work_struct *work) |
295 | { |
296 | struct ds1374 *ds1374 = container_of(work, struct ds1374, work); |
297 | struct i2c_client *client = ds1374->client; |
298 | int stat, control; |
299 | |
300 | mutex_lock(&ds1374->mutex); |
301 | |
302 | stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR); |
303 | if (stat < 0) |
304 | goto unlock; |
305 | |
306 | if (stat & DS1374_REG_SR_AF) { |
307 | stat &= ~DS1374_REG_SR_AF; |
308 | i2c_smbus_write_byte_data(client, DS1374_REG_SR, value: stat); |
309 | |
310 | control = i2c_smbus_read_byte_data(client, DS1374_REG_CR); |
311 | if (control < 0) |
312 | goto out; |
313 | |
314 | control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE); |
315 | i2c_smbus_write_byte_data(client, DS1374_REG_CR, value: control); |
316 | |
317 | rtc_update_irq(rtc: ds1374->rtc, num: 1, RTC_AF | RTC_IRQF); |
318 | } |
319 | |
320 | out: |
321 | if (!ds1374->exiting) |
322 | enable_irq(irq: client->irq); |
323 | unlock: |
324 | mutex_unlock(lock: &ds1374->mutex); |
325 | } |
326 | |
327 | #ifndef CONFIG_RTC_DRV_DS1374_WDT |
328 | static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled) |
329 | { |
330 | struct i2c_client *client = to_i2c_client(dev); |
331 | struct ds1374 *ds1374 = i2c_get_clientdata(client); |
332 | int ret; |
333 | |
334 | mutex_lock(&ds1374->mutex); |
335 | |
336 | ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR); |
337 | if (ret < 0) |
338 | goto out; |
339 | |
340 | if (enabled) { |
341 | ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE; |
342 | ret &= ~DS1374_REG_CR_WDALM; |
343 | } else { |
344 | ret &= ~DS1374_REG_CR_WACE; |
345 | } |
346 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret); |
347 | |
348 | out: |
349 | mutex_unlock(&ds1374->mutex); |
350 | return ret; |
351 | } |
352 | #endif |
353 | |
354 | static const struct rtc_class_ops ds1374_rtc_ops = { |
355 | .read_time = ds1374_read_time, |
356 | .set_time = ds1374_set_time, |
357 | #ifndef CONFIG_RTC_DRV_DS1374_WDT |
358 | .read_alarm = ds1374_read_alarm, |
359 | .set_alarm = ds1374_set_alarm, |
360 | .alarm_irq_enable = ds1374_alarm_irq_enable, |
361 | #endif |
362 | }; |
363 | |
364 | #ifdef CONFIG_RTC_DRV_DS1374_WDT |
365 | /* |
366 | ***************************************************************************** |
367 | * |
368 | * Watchdog Driver |
369 | * |
370 | ***************************************************************************** |
371 | */ |
372 | /* Default margin */ |
373 | #define TIMER_MARGIN_DEFAULT 32 |
374 | #define TIMER_MARGIN_MIN 1 |
375 | #define TIMER_MARGIN_MAX 4095 /* 24-bit value */ |
376 | |
377 | static int wdt_margin; |
378 | module_param(wdt_margin, int, 0); |
379 | MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)" ); |
380 | |
381 | static bool nowayout = WATCHDOG_NOWAYOUT; |
382 | module_param(nowayout, bool, 0); |
383 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default =" |
384 | __MODULE_STRING(WATCHDOG_NOWAYOUT)")" ); |
385 | |
386 | static const struct watchdog_info ds1374_wdt_info = { |
387 | .identity = "DS1374 Watchdog" , |
388 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | |
389 | WDIOF_MAGICCLOSE, |
390 | }; |
391 | |
392 | static int ds1374_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout) |
393 | { |
394 | struct ds1374 *ds1374 = watchdog_get_drvdata(wdd: wdt); |
395 | struct i2c_client *client = ds1374->client; |
396 | int ret, cr; |
397 | |
398 | wdt->timeout = timeout; |
399 | |
400 | cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR); |
401 | if (cr < 0) |
402 | return cr; |
403 | |
404 | /* Disable any existing watchdog/alarm before setting the new one */ |
405 | cr &= ~DS1374_REG_CR_WACE; |
406 | |
407 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, value: cr); |
408 | if (ret < 0) |
409 | return ret; |
410 | |
411 | /* Set new watchdog time */ |
412 | timeout = timeout * 4096; |
413 | ret = ds1374_write_rtc(client, time: timeout, DS1374_REG_WDALM0, nbytes: 3); |
414 | if (ret) |
415 | return ret; |
416 | |
417 | /* Enable watchdog timer */ |
418 | cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM; |
419 | cr &= ~DS1374_REG_CR_WDSTR;/* for RST PIN */ |
420 | cr &= ~DS1374_REG_CR_AIE; |
421 | |
422 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, value: cr); |
423 | if (ret < 0) |
424 | return ret; |
425 | |
426 | return 0; |
427 | } |
428 | |
429 | /* |
430 | * Reload the watchdog timer. (ie, pat the watchdog) |
431 | */ |
432 | static int ds1374_wdt_start(struct watchdog_device *wdt) |
433 | { |
434 | struct ds1374 *ds1374 = watchdog_get_drvdata(wdd: wdt); |
435 | u32 val; |
436 | |
437 | return ds1374_read_rtc(client: ds1374->client, time: &val, DS1374_REG_WDALM0, nbytes: 3); |
438 | } |
439 | |
440 | static int ds1374_wdt_stop(struct watchdog_device *wdt) |
441 | { |
442 | struct ds1374 *ds1374 = watchdog_get_drvdata(wdd: wdt); |
443 | struct i2c_client *client = ds1374->client; |
444 | int cr; |
445 | |
446 | cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR); |
447 | if (cr < 0) |
448 | return cr; |
449 | |
450 | /* Disable watchdog timer */ |
451 | cr &= ~DS1374_REG_CR_WACE; |
452 | |
453 | return i2c_smbus_write_byte_data(client, DS1374_REG_CR, value: cr); |
454 | } |
455 | |
456 | static const struct watchdog_ops ds1374_wdt_ops = { |
457 | .owner = THIS_MODULE, |
458 | .start = ds1374_wdt_start, |
459 | .stop = ds1374_wdt_stop, |
460 | .set_timeout = ds1374_wdt_settimeout, |
461 | }; |
462 | #endif /*CONFIG_RTC_DRV_DS1374_WDT*/ |
463 | /* |
464 | ***************************************************************************** |
465 | * |
466 | * Driver Interface |
467 | * |
468 | ***************************************************************************** |
469 | */ |
470 | static int ds1374_probe(struct i2c_client *client) |
471 | { |
472 | struct ds1374 *ds1374; |
473 | int ret; |
474 | |
475 | ds1374 = devm_kzalloc(dev: &client->dev, size: sizeof(struct ds1374), GFP_KERNEL); |
476 | if (!ds1374) |
477 | return -ENOMEM; |
478 | |
479 | ds1374->rtc = devm_rtc_allocate_device(dev: &client->dev); |
480 | if (IS_ERR(ptr: ds1374->rtc)) |
481 | return PTR_ERR(ptr: ds1374->rtc); |
482 | |
483 | ds1374->client = client; |
484 | i2c_set_clientdata(client, data: ds1374); |
485 | |
486 | INIT_WORK(&ds1374->work, ds1374_work); |
487 | mutex_init(&ds1374->mutex); |
488 | |
489 | ret = ds1374_check_rtc_status(client); |
490 | if (ret) |
491 | return ret; |
492 | |
493 | if (client->irq > 0) { |
494 | ret = devm_request_irq(dev: &client->dev, irq: client->irq, handler: ds1374_irq, irqflags: 0, |
495 | devname: "ds1374" , dev_id: client); |
496 | if (ret) { |
497 | dev_err(&client->dev, "unable to request IRQ\n" ); |
498 | return ret; |
499 | } |
500 | |
501 | device_set_wakeup_capable(dev: &client->dev, capable: 1); |
502 | } |
503 | |
504 | ds1374->rtc->ops = &ds1374_rtc_ops; |
505 | ds1374->rtc->range_max = U32_MAX; |
506 | |
507 | ret = devm_rtc_register_device(ds1374->rtc); |
508 | if (ret) |
509 | return ret; |
510 | |
511 | #ifdef CONFIG_RTC_DRV_DS1374_WDT |
512 | ds1374->wdt.info = &ds1374_wdt_info; |
513 | ds1374->wdt.ops = &ds1374_wdt_ops; |
514 | ds1374->wdt.timeout = TIMER_MARGIN_DEFAULT; |
515 | ds1374->wdt.min_timeout = TIMER_MARGIN_MIN; |
516 | ds1374->wdt.max_timeout = TIMER_MARGIN_MAX; |
517 | |
518 | watchdog_init_timeout(wdd: &ds1374->wdt, timeout_parm: wdt_margin, dev: &client->dev); |
519 | watchdog_set_nowayout(wdd: &ds1374->wdt, nowayout); |
520 | watchdog_stop_on_reboot(wdd: &ds1374->wdt); |
521 | watchdog_stop_on_unregister(wdd: &ds1374->wdt); |
522 | watchdog_set_drvdata(wdd: &ds1374->wdt, data: ds1374); |
523 | ds1374_wdt_settimeout(wdt: &ds1374->wdt, timeout: ds1374->wdt.timeout); |
524 | |
525 | ret = devm_watchdog_register_device(dev: &client->dev, &ds1374->wdt); |
526 | if (ret) |
527 | return ret; |
528 | #endif |
529 | |
530 | return 0; |
531 | } |
532 | |
533 | static void ds1374_remove(struct i2c_client *client) |
534 | { |
535 | struct ds1374 *ds1374 = i2c_get_clientdata(client); |
536 | |
537 | if (client->irq > 0) { |
538 | mutex_lock(&ds1374->mutex); |
539 | ds1374->exiting = 1; |
540 | mutex_unlock(lock: &ds1374->mutex); |
541 | |
542 | devm_free_irq(dev: &client->dev, irq: client->irq, dev_id: client); |
543 | cancel_work_sync(work: &ds1374->work); |
544 | } |
545 | } |
546 | |
547 | #ifdef CONFIG_PM_SLEEP |
548 | static int ds1374_suspend(struct device *dev) |
549 | { |
550 | struct i2c_client *client = to_i2c_client(dev); |
551 | |
552 | if (client->irq > 0 && device_may_wakeup(dev: &client->dev)) |
553 | enable_irq_wake(irq: client->irq); |
554 | return 0; |
555 | } |
556 | |
557 | static int ds1374_resume(struct device *dev) |
558 | { |
559 | struct i2c_client *client = to_i2c_client(dev); |
560 | |
561 | if (client->irq > 0 && device_may_wakeup(dev: &client->dev)) |
562 | disable_irq_wake(irq: client->irq); |
563 | return 0; |
564 | } |
565 | #endif |
566 | |
567 | static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume); |
568 | |
569 | static struct i2c_driver ds1374_driver = { |
570 | .driver = { |
571 | .name = "rtc-ds1374" , |
572 | .of_match_table = of_match_ptr(ds1374_of_match), |
573 | .pm = &ds1374_pm, |
574 | }, |
575 | .probe = ds1374_probe, |
576 | .remove = ds1374_remove, |
577 | .id_table = ds1374_id, |
578 | }; |
579 | |
580 | module_i2c_driver(ds1374_driver); |
581 | |
582 | MODULE_AUTHOR("Scott Wood <scottwood@freescale.com>" ); |
583 | MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver" ); |
584 | MODULE_LICENSE("GPL" ); |
585 | |