Commit | Line | Data |
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c03675f0 RZ |
1 | /* |
2 | * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C | |
3 | * | |
a2d6d2fa | 4 | * Copyright (C) 2009-2011 Freescale Semiconductor. |
f46418c5 | 5 | * Author: Jack Lan <jack.lan@freescale.com> |
c03675f0 RZ |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the | |
9 | * Free Software Foundation; either version 2 of the License, or (at your | |
10 | * option) any later version. | |
11 | */ | |
12 | /* | |
13 | * It would be more efficient to use i2c msgs/i2c_transfer directly but, as | |
14 | * recommened in .../Documentation/i2c/writing-clients section | |
15 | * "Sending and receiving", using SMBus level communication is preferred. | |
16 | */ | |
17 | ||
a737e835 JP |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
c03675f0 RZ |
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 | ||
29 | #define DS3232_REG_SECONDS 0x00 | |
30 | #define DS3232_REG_MINUTES 0x01 | |
31 | #define DS3232_REG_HOURS 0x02 | |
32 | #define DS3232_REG_AMPM 0x02 | |
33 | #define DS3232_REG_DAY 0x03 | |
34 | #define DS3232_REG_DATE 0x04 | |
35 | #define DS3232_REG_MONTH 0x05 | |
36 | #define DS3232_REG_CENTURY 0x05 | |
37 | #define DS3232_REG_YEAR 0x06 | |
38 | #define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */ | |
39 | #define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */ | |
40 | #define DS3232_REG_CR 0x0E /* Control register */ | |
41 | # define DS3232_REG_CR_nEOSC 0x80 | |
42 | # define DS3232_REG_CR_INTCN 0x04 | |
43 | # define DS3232_REG_CR_A2IE 0x02 | |
44 | # define DS3232_REG_CR_A1IE 0x01 | |
45 | ||
46 | #define DS3232_REG_SR 0x0F /* control/status register */ | |
47 | # define DS3232_REG_SR_OSF 0x80 | |
48 | # define DS3232_REG_SR_BSY 0x04 | |
49 | # define DS3232_REG_SR_A2F 0x02 | |
50 | # define DS3232_REG_SR_A1F 0x01 | |
51 | ||
52 | struct ds3232 { | |
53 | struct i2c_client *client; | |
54 | struct rtc_device *rtc; | |
55 | struct work_struct work; | |
56 | ||
57 | /* The mutex protects alarm operations, and prevents a race | |
58 | * between the enable_irq() in the workqueue and the free_irq() | |
59 | * in the remove function. | |
60 | */ | |
61 | struct mutex mutex; | |
c93a3ae2 | 62 | bool suspended; |
c03675f0 RZ |
63 | int exiting; |
64 | }; | |
65 | ||
66 | static struct i2c_driver ds3232_driver; | |
67 | ||
68 | static int ds3232_check_rtc_status(struct i2c_client *client) | |
69 | { | |
70 | int ret = 0; | |
71 | int control, stat; | |
72 | ||
73 | stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
74 | if (stat < 0) | |
75 | return stat; | |
76 | ||
77 | if (stat & DS3232_REG_SR_OSF) | |
78 | dev_warn(&client->dev, | |
79 | "oscillator discontinuity flagged, " | |
80 | "time unreliable\n"); | |
81 | ||
82 | stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); | |
83 | ||
84 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); | |
85 | if (ret < 0) | |
86 | return ret; | |
87 | ||
88 | /* If the alarm is pending, clear it before requesting | |
89 | * the interrupt, so an interrupt event isn't reported | |
90 | * before everything is initialized. | |
91 | */ | |
92 | ||
93 | control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
94 | if (control < 0) | |
95 | return control; | |
96 | ||
97 | control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); | |
98 | control |= DS3232_REG_CR_INTCN; | |
99 | ||
100 | return i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
101 | } | |
102 | ||
103 | static int ds3232_read_time(struct device *dev, struct rtc_time *time) | |
104 | { | |
105 | struct i2c_client *client = to_i2c_client(dev); | |
106 | int ret; | |
107 | u8 buf[7]; | |
108 | unsigned int year, month, day, hour, minute, second; | |
109 | unsigned int week, twelve_hr, am_pm; | |
110 | unsigned int century, add_century = 0; | |
111 | ||
112 | ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_SECONDS, 7, buf); | |
113 | ||
114 | if (ret < 0) | |
115 | return ret; | |
116 | if (ret < 7) | |
117 | return -EIO; | |
118 | ||
119 | second = buf[0]; | |
120 | minute = buf[1]; | |
121 | hour = buf[2]; | |
122 | week = buf[3]; | |
123 | day = buf[4]; | |
124 | month = buf[5]; | |
125 | year = buf[6]; | |
126 | ||
127 | /* Extract additional information for AM/PM and century */ | |
128 | ||
129 | twelve_hr = hour & 0x40; | |
130 | am_pm = hour & 0x20; | |
131 | century = month & 0x80; | |
132 | ||
133 | /* Write to rtc_time structure */ | |
134 | ||
135 | time->tm_sec = bcd2bin(second); | |
136 | time->tm_min = bcd2bin(minute); | |
137 | if (twelve_hr) { | |
138 | /* Convert to 24 hr */ | |
139 | if (am_pm) | |
140 | time->tm_hour = bcd2bin(hour & 0x1F) + 12; | |
141 | else | |
142 | time->tm_hour = bcd2bin(hour & 0x1F); | |
143 | } else { | |
144 | time->tm_hour = bcd2bin(hour); | |
145 | } | |
146 | ||
a2d6d2fa LX |
147 | /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ |
148 | time->tm_wday = bcd2bin(week) - 1; | |
c03675f0 | 149 | time->tm_mday = bcd2bin(day); |
a2d6d2fa LX |
150 | /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ |
151 | time->tm_mon = bcd2bin(month & 0x7F) - 1; | |
c03675f0 RZ |
152 | if (century) |
153 | add_century = 100; | |
154 | ||
155 | time->tm_year = bcd2bin(year) + add_century; | |
156 | ||
157 | return rtc_valid_tm(time); | |
158 | } | |
159 | ||
160 | static int ds3232_set_time(struct device *dev, struct rtc_time *time) | |
161 | { | |
162 | struct i2c_client *client = to_i2c_client(dev); | |
163 | u8 buf[7]; | |
164 | ||
165 | /* Extract time from rtc_time and load into ds3232*/ | |
166 | ||
167 | buf[0] = bin2bcd(time->tm_sec); | |
168 | buf[1] = bin2bcd(time->tm_min); | |
169 | buf[2] = bin2bcd(time->tm_hour); | |
a2d6d2fa LX |
170 | /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ |
171 | buf[3] = bin2bcd(time->tm_wday + 1); | |
c03675f0 | 172 | buf[4] = bin2bcd(time->tm_mday); /* Date */ |
a2d6d2fa LX |
173 | /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ |
174 | buf[5] = bin2bcd(time->tm_mon + 1); | |
c03675f0 RZ |
175 | if (time->tm_year >= 100) { |
176 | buf[5] |= 0x80; | |
177 | buf[6] = bin2bcd(time->tm_year - 100); | |
178 | } else { | |
179 | buf[6] = bin2bcd(time->tm_year); | |
180 | } | |
181 | ||
182 | return i2c_smbus_write_i2c_block_data(client, | |
183 | DS3232_REG_SECONDS, 7, buf); | |
184 | } | |
185 | ||
f46418c5 LCB |
186 | /* |
187 | * DS3232 has two alarm, we only use alarm1 | |
188 | * According to linux specification, only support one-shot alarm | |
189 | * no periodic alarm mode | |
190 | */ | |
191 | static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
192 | { | |
193 | struct i2c_client *client = to_i2c_client(dev); | |
194 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
195 | int control, stat; | |
196 | int ret; | |
197 | u8 buf[4]; | |
198 | ||
199 | mutex_lock(&ds3232->mutex); | |
200 | ||
201 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
202 | if (ret < 0) | |
203 | goto out; | |
204 | stat = ret; | |
205 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
206 | if (ret < 0) | |
207 | goto out; | |
208 | control = ret; | |
209 | ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
210 | if (ret < 0) | |
211 | goto out; | |
212 | ||
213 | alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F); | |
214 | alarm->time.tm_min = bcd2bin(buf[1] & 0x7F); | |
215 | alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F); | |
216 | alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F); | |
217 | ||
218 | alarm->time.tm_mon = -1; | |
219 | alarm->time.tm_year = -1; | |
220 | alarm->time.tm_wday = -1; | |
221 | alarm->time.tm_yday = -1; | |
222 | alarm->time.tm_isdst = -1; | |
223 | ||
224 | alarm->enabled = !!(control & DS3232_REG_CR_A1IE); | |
225 | alarm->pending = !!(stat & DS3232_REG_SR_A1F); | |
226 | ||
227 | ret = 0; | |
228 | out: | |
229 | mutex_unlock(&ds3232->mutex); | |
230 | return ret; | |
231 | } | |
232 | ||
233 | /* | |
234 | * linux rtc-module does not support wday alarm | |
235 | * and only 24h time mode supported indeed | |
236 | */ | |
237 | static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
238 | { | |
239 | struct i2c_client *client = to_i2c_client(dev); | |
240 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
241 | int control, stat; | |
242 | int ret; | |
243 | u8 buf[4]; | |
244 | ||
245 | if (client->irq <= 0) | |
246 | return -EINVAL; | |
247 | ||
248 | mutex_lock(&ds3232->mutex); | |
249 | ||
250 | buf[0] = bin2bcd(alarm->time.tm_sec); | |
251 | buf[1] = bin2bcd(alarm->time.tm_min); | |
252 | buf[2] = bin2bcd(alarm->time.tm_hour); | |
253 | buf[3] = bin2bcd(alarm->time.tm_mday); | |
254 | ||
255 | /* clear alarm interrupt enable bit */ | |
256 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
257 | if (ret < 0) | |
258 | goto out; | |
259 | control = ret; | |
260 | control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); | |
261 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
262 | if (ret < 0) | |
263 | goto out; | |
264 | ||
265 | /* clear any pending alarm flag */ | |
266 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
267 | if (ret < 0) | |
268 | goto out; | |
269 | stat = ret; | |
270 | stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); | |
271 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); | |
272 | if (ret < 0) | |
273 | goto out; | |
274 | ||
275 | ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
276 | ||
277 | if (alarm->enabled) { | |
278 | control |= DS3232_REG_CR_A1IE; | |
279 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
280 | } | |
281 | out: | |
282 | mutex_unlock(&ds3232->mutex); | |
283 | return ret; | |
284 | } | |
285 | ||
286 | static void ds3232_update_alarm(struct i2c_client *client) | |
287 | { | |
288 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
289 | int control; | |
290 | int ret; | |
291 | u8 buf[4]; | |
292 | ||
293 | mutex_lock(&ds3232->mutex); | |
294 | ||
295 | ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
296 | if (ret < 0) | |
297 | goto unlock; | |
298 | ||
299 | buf[0] = bcd2bin(buf[0]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
300 | 0x80 : buf[0]; | |
301 | buf[1] = bcd2bin(buf[1]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
302 | 0x80 : buf[1]; | |
303 | buf[2] = bcd2bin(buf[2]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
304 | 0x80 : buf[2]; | |
305 | buf[3] = bcd2bin(buf[3]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
306 | 0x80 : buf[3]; | |
307 | ||
308 | ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
309 | if (ret < 0) | |
310 | goto unlock; | |
311 | ||
312 | control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
313 | if (control < 0) | |
314 | goto unlock; | |
315 | ||
316 | if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF)) | |
317 | /* enable alarm1 interrupt */ | |
318 | control |= DS3232_REG_CR_A1IE; | |
319 | else | |
320 | /* disable alarm1 interrupt */ | |
321 | control &= ~(DS3232_REG_CR_A1IE); | |
322 | i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
323 | ||
324 | unlock: | |
325 | mutex_unlock(&ds3232->mutex); | |
326 | } | |
327 | ||
328 | static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled) | |
329 | { | |
330 | struct i2c_client *client = to_i2c_client(dev); | |
331 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
332 | ||
333 | if (client->irq <= 0) | |
334 | return -EINVAL; | |
335 | ||
336 | if (enabled) | |
337 | ds3232->rtc->irq_data |= RTC_AF; | |
338 | else | |
339 | ds3232->rtc->irq_data &= ~RTC_AF; | |
340 | ||
341 | ds3232_update_alarm(client); | |
342 | return 0; | |
343 | } | |
344 | ||
c03675f0 RZ |
345 | static irqreturn_t ds3232_irq(int irq, void *dev_id) |
346 | { | |
347 | struct i2c_client *client = dev_id; | |
348 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
349 | ||
350 | disable_irq_nosync(irq); | |
c93a3ae2 WD |
351 | |
352 | /* | |
353 | * If rtc as a wakeup source, can't schedule the work | |
354 | * at system resume flow, because at this time the i2c bus | |
355 | * has not been resumed. | |
356 | */ | |
357 | if (!ds3232->suspended) | |
358 | schedule_work(&ds3232->work); | |
359 | ||
c03675f0 RZ |
360 | return IRQ_HANDLED; |
361 | } | |
362 | ||
363 | static void ds3232_work(struct work_struct *work) | |
364 | { | |
365 | struct ds3232 *ds3232 = container_of(work, struct ds3232, work); | |
366 | struct i2c_client *client = ds3232->client; | |
367 | int stat, control; | |
368 | ||
369 | mutex_lock(&ds3232->mutex); | |
370 | ||
371 | stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
372 | if (stat < 0) | |
373 | goto unlock; | |
374 | ||
375 | if (stat & DS3232_REG_SR_A1F) { | |
376 | control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
c93a3ae2 | 377 | if (control < 0) { |
a737e835 JP |
378 | pr_warn("Read Control Register error - Disable IRQ%d\n", |
379 | client->irq); | |
c93a3ae2 WD |
380 | } else { |
381 | /* disable alarm1 interrupt */ | |
382 | control &= ~(DS3232_REG_CR_A1IE); | |
383 | i2c_smbus_write_byte_data(client, DS3232_REG_CR, | |
384 | control); | |
385 | ||
386 | /* clear the alarm pend flag */ | |
387 | stat &= ~DS3232_REG_SR_A1F; | |
388 | i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); | |
389 | ||
390 | rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF); | |
391 | ||
392 | if (!ds3232->exiting) | |
393 | enable_irq(client->irq); | |
394 | } | |
c03675f0 RZ |
395 | } |
396 | ||
c03675f0 RZ |
397 | unlock: |
398 | mutex_unlock(&ds3232->mutex); | |
399 | } | |
400 | ||
401 | static const struct rtc_class_ops ds3232_rtc_ops = { | |
402 | .read_time = ds3232_read_time, | |
403 | .set_time = ds3232_set_time, | |
f46418c5 LCB |
404 | .read_alarm = ds3232_read_alarm, |
405 | .set_alarm = ds3232_set_alarm, | |
406 | .alarm_irq_enable = ds3232_alarm_irq_enable, | |
c03675f0 RZ |
407 | }; |
408 | ||
5a167f45 GKH |
409 | static int ds3232_probe(struct i2c_client *client, |
410 | const struct i2c_device_id *id) | |
c03675f0 RZ |
411 | { |
412 | struct ds3232 *ds3232; | |
413 | int ret; | |
414 | ||
66714612 | 415 | ds3232 = devm_kzalloc(&client->dev, sizeof(struct ds3232), GFP_KERNEL); |
c03675f0 RZ |
416 | if (!ds3232) |
417 | return -ENOMEM; | |
418 | ||
419 | ds3232->client = client; | |
420 | i2c_set_clientdata(client, ds3232); | |
421 | ||
422 | INIT_WORK(&ds3232->work, ds3232_work); | |
423 | mutex_init(&ds3232->mutex); | |
424 | ||
425 | ret = ds3232_check_rtc_status(client); | |
426 | if (ret) | |
66714612 | 427 | return ret; |
c03675f0 | 428 | |
c93a3ae2 | 429 | if (client->irq > 0) { |
a8a15eb1 BB |
430 | ret = devm_request_irq(&client->dev, client->irq, ds3232_irq, |
431 | IRQF_SHARED, "ds3232", client); | |
c03675f0 RZ |
432 | if (ret) { |
433 | dev_err(&client->dev, "unable to request IRQ\n"); | |
c03675f0 | 434 | } |
c93a3ae2 | 435 | device_init_wakeup(&client->dev, 1); |
c03675f0 | 436 | } |
c93a3ae2 WD |
437 | ds3232->rtc = devm_rtc_device_register(&client->dev, client->name, |
438 | &ds3232_rtc_ops, THIS_MODULE); | |
439 | return PTR_ERR_OR_ZERO(ds3232->rtc); | |
c03675f0 RZ |
440 | } |
441 | ||
5a167f45 | 442 | static int ds3232_remove(struct i2c_client *client) |
c03675f0 RZ |
443 | { |
444 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
445 | ||
446 | if (client->irq >= 0) { | |
447 | mutex_lock(&ds3232->mutex); | |
448 | ds3232->exiting = 1; | |
449 | mutex_unlock(&ds3232->mutex); | |
450 | ||
66714612 | 451 | devm_free_irq(&client->dev, client->irq, client); |
9db8995b | 452 | cancel_work_sync(&ds3232->work); |
c03675f0 RZ |
453 | } |
454 | ||
c03675f0 RZ |
455 | return 0; |
456 | } | |
457 | ||
c93a3ae2 WD |
458 | #ifdef CONFIG_PM_SLEEP |
459 | static int ds3232_suspend(struct device *dev) | |
460 | { | |
461 | struct ds3232 *ds3232 = dev_get_drvdata(dev); | |
462 | struct i2c_client *client = to_i2c_client(dev); | |
463 | ||
464 | if (device_can_wakeup(dev)) { | |
465 | ds3232->suspended = true; | |
466 | irq_set_irq_wake(client->irq, 1); | |
467 | } | |
468 | ||
469 | return 0; | |
470 | } | |
471 | ||
472 | static int ds3232_resume(struct device *dev) | |
473 | { | |
474 | struct ds3232 *ds3232 = dev_get_drvdata(dev); | |
475 | struct i2c_client *client = to_i2c_client(dev); | |
476 | ||
477 | if (ds3232->suspended) { | |
478 | ds3232->suspended = false; | |
479 | ||
480 | /* Clear the hardware alarm pend flag */ | |
481 | schedule_work(&ds3232->work); | |
482 | ||
483 | irq_set_irq_wake(client->irq, 0); | |
484 | } | |
485 | ||
486 | return 0; | |
487 | } | |
488 | #endif | |
489 | ||
490 | static const struct dev_pm_ops ds3232_pm_ops = { | |
491 | SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume) | |
492 | }; | |
493 | ||
c03675f0 RZ |
494 | static const struct i2c_device_id ds3232_id[] = { |
495 | { "ds3232", 0 }, | |
496 | { } | |
497 | }; | |
498 | MODULE_DEVICE_TABLE(i2c, ds3232_id); | |
499 | ||
500 | static struct i2c_driver ds3232_driver = { | |
501 | .driver = { | |
502 | .name = "rtc-ds3232", | |
503 | .owner = THIS_MODULE, | |
c93a3ae2 | 504 | .pm = &ds3232_pm_ops, |
c03675f0 RZ |
505 | }, |
506 | .probe = ds3232_probe, | |
5a167f45 | 507 | .remove = ds3232_remove, |
c03675f0 RZ |
508 | .id_table = ds3232_id, |
509 | }; | |
510 | ||
0abc9201 | 511 | module_i2c_driver(ds3232_driver); |
c03675f0 RZ |
512 | |
513 | MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>"); | |
514 | MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver"); | |
515 | MODULE_LICENSE("GPL"); |