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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 | ||
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/i2c.h> | |
22 | #include <linux/rtc.h> | |
23 | #include <linux/bcd.h> | |
24 | #include <linux/workqueue.h> | |
25 | #include <linux/slab.h> | |
26 | ||
27 | #define DS3232_REG_SECONDS 0x00 | |
28 | #define DS3232_REG_MINUTES 0x01 | |
29 | #define DS3232_REG_HOURS 0x02 | |
30 | #define DS3232_REG_AMPM 0x02 | |
31 | #define DS3232_REG_DAY 0x03 | |
32 | #define DS3232_REG_DATE 0x04 | |
33 | #define DS3232_REG_MONTH 0x05 | |
34 | #define DS3232_REG_CENTURY 0x05 | |
35 | #define DS3232_REG_YEAR 0x06 | |
36 | #define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */ | |
37 | #define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */ | |
38 | #define DS3232_REG_CR 0x0E /* Control register */ | |
39 | # define DS3232_REG_CR_nEOSC 0x80 | |
40 | # define DS3232_REG_CR_INTCN 0x04 | |
41 | # define DS3232_REG_CR_A2IE 0x02 | |
42 | # define DS3232_REG_CR_A1IE 0x01 | |
43 | ||
44 | #define DS3232_REG_SR 0x0F /* control/status register */ | |
45 | # define DS3232_REG_SR_OSF 0x80 | |
46 | # define DS3232_REG_SR_BSY 0x04 | |
47 | # define DS3232_REG_SR_A2F 0x02 | |
48 | # define DS3232_REG_SR_A1F 0x01 | |
49 | ||
50 | struct ds3232 { | |
51 | struct i2c_client *client; | |
52 | struct rtc_device *rtc; | |
53 | struct work_struct work; | |
54 | ||
55 | /* The mutex protects alarm operations, and prevents a race | |
56 | * between the enable_irq() in the workqueue and the free_irq() | |
57 | * in the remove function. | |
58 | */ | |
59 | struct mutex mutex; | |
60 | int exiting; | |
61 | }; | |
62 | ||
63 | static struct i2c_driver ds3232_driver; | |
64 | ||
65 | static int ds3232_check_rtc_status(struct i2c_client *client) | |
66 | { | |
67 | int ret = 0; | |
68 | int control, stat; | |
69 | ||
70 | stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
71 | if (stat < 0) | |
72 | return stat; | |
73 | ||
74 | if (stat & DS3232_REG_SR_OSF) | |
75 | dev_warn(&client->dev, | |
76 | "oscillator discontinuity flagged, " | |
77 | "time unreliable\n"); | |
78 | ||
79 | stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); | |
80 | ||
81 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); | |
82 | if (ret < 0) | |
83 | return ret; | |
84 | ||
85 | /* If the alarm is pending, clear it before requesting | |
86 | * the interrupt, so an interrupt event isn't reported | |
87 | * before everything is initialized. | |
88 | */ | |
89 | ||
90 | control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
91 | if (control < 0) | |
92 | return control; | |
93 | ||
94 | control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); | |
95 | control |= DS3232_REG_CR_INTCN; | |
96 | ||
97 | return i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
98 | } | |
99 | ||
100 | static int ds3232_read_time(struct device *dev, struct rtc_time *time) | |
101 | { | |
102 | struct i2c_client *client = to_i2c_client(dev); | |
103 | int ret; | |
104 | u8 buf[7]; | |
105 | unsigned int year, month, day, hour, minute, second; | |
106 | unsigned int week, twelve_hr, am_pm; | |
107 | unsigned int century, add_century = 0; | |
108 | ||
109 | ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_SECONDS, 7, buf); | |
110 | ||
111 | if (ret < 0) | |
112 | return ret; | |
113 | if (ret < 7) | |
114 | return -EIO; | |
115 | ||
116 | second = buf[0]; | |
117 | minute = buf[1]; | |
118 | hour = buf[2]; | |
119 | week = buf[3]; | |
120 | day = buf[4]; | |
121 | month = buf[5]; | |
122 | year = buf[6]; | |
123 | ||
124 | /* Extract additional information for AM/PM and century */ | |
125 | ||
126 | twelve_hr = hour & 0x40; | |
127 | am_pm = hour & 0x20; | |
128 | century = month & 0x80; | |
129 | ||
130 | /* Write to rtc_time structure */ | |
131 | ||
132 | time->tm_sec = bcd2bin(second); | |
133 | time->tm_min = bcd2bin(minute); | |
134 | if (twelve_hr) { | |
135 | /* Convert to 24 hr */ | |
136 | if (am_pm) | |
137 | time->tm_hour = bcd2bin(hour & 0x1F) + 12; | |
138 | else | |
139 | time->tm_hour = bcd2bin(hour & 0x1F); | |
140 | } else { | |
141 | time->tm_hour = bcd2bin(hour); | |
142 | } | |
143 | ||
a2d6d2fa LX |
144 | /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ |
145 | time->tm_wday = bcd2bin(week) - 1; | |
c03675f0 | 146 | time->tm_mday = bcd2bin(day); |
a2d6d2fa LX |
147 | /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ |
148 | time->tm_mon = bcd2bin(month & 0x7F) - 1; | |
c03675f0 RZ |
149 | if (century) |
150 | add_century = 100; | |
151 | ||
152 | time->tm_year = bcd2bin(year) + add_century; | |
153 | ||
154 | return rtc_valid_tm(time); | |
155 | } | |
156 | ||
157 | static int ds3232_set_time(struct device *dev, struct rtc_time *time) | |
158 | { | |
159 | struct i2c_client *client = to_i2c_client(dev); | |
160 | u8 buf[7]; | |
161 | ||
162 | /* Extract time from rtc_time and load into ds3232*/ | |
163 | ||
164 | buf[0] = bin2bcd(time->tm_sec); | |
165 | buf[1] = bin2bcd(time->tm_min); | |
166 | buf[2] = bin2bcd(time->tm_hour); | |
a2d6d2fa LX |
167 | /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ |
168 | buf[3] = bin2bcd(time->tm_wday + 1); | |
c03675f0 | 169 | buf[4] = bin2bcd(time->tm_mday); /* Date */ |
a2d6d2fa LX |
170 | /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ |
171 | buf[5] = bin2bcd(time->tm_mon + 1); | |
c03675f0 RZ |
172 | if (time->tm_year >= 100) { |
173 | buf[5] |= 0x80; | |
174 | buf[6] = bin2bcd(time->tm_year - 100); | |
175 | } else { | |
176 | buf[6] = bin2bcd(time->tm_year); | |
177 | } | |
178 | ||
179 | return i2c_smbus_write_i2c_block_data(client, | |
180 | DS3232_REG_SECONDS, 7, buf); | |
181 | } | |
182 | ||
f46418c5 LCB |
183 | /* |
184 | * DS3232 has two alarm, we only use alarm1 | |
185 | * According to linux specification, only support one-shot alarm | |
186 | * no periodic alarm mode | |
187 | */ | |
188 | static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
189 | { | |
190 | struct i2c_client *client = to_i2c_client(dev); | |
191 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
192 | int control, stat; | |
193 | int ret; | |
194 | u8 buf[4]; | |
195 | ||
196 | mutex_lock(&ds3232->mutex); | |
197 | ||
198 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
199 | if (ret < 0) | |
200 | goto out; | |
201 | stat = ret; | |
202 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
203 | if (ret < 0) | |
204 | goto out; | |
205 | control = ret; | |
206 | ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
207 | if (ret < 0) | |
208 | goto out; | |
209 | ||
210 | alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F); | |
211 | alarm->time.tm_min = bcd2bin(buf[1] & 0x7F); | |
212 | alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F); | |
213 | alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F); | |
214 | ||
215 | alarm->time.tm_mon = -1; | |
216 | alarm->time.tm_year = -1; | |
217 | alarm->time.tm_wday = -1; | |
218 | alarm->time.tm_yday = -1; | |
219 | alarm->time.tm_isdst = -1; | |
220 | ||
221 | alarm->enabled = !!(control & DS3232_REG_CR_A1IE); | |
222 | alarm->pending = !!(stat & DS3232_REG_SR_A1F); | |
223 | ||
224 | ret = 0; | |
225 | out: | |
226 | mutex_unlock(&ds3232->mutex); | |
227 | return ret; | |
228 | } | |
229 | ||
230 | /* | |
231 | * linux rtc-module does not support wday alarm | |
232 | * and only 24h time mode supported indeed | |
233 | */ | |
234 | static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) | |
235 | { | |
236 | struct i2c_client *client = to_i2c_client(dev); | |
237 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
238 | int control, stat; | |
239 | int ret; | |
240 | u8 buf[4]; | |
241 | ||
242 | if (client->irq <= 0) | |
243 | return -EINVAL; | |
244 | ||
245 | mutex_lock(&ds3232->mutex); | |
246 | ||
247 | buf[0] = bin2bcd(alarm->time.tm_sec); | |
248 | buf[1] = bin2bcd(alarm->time.tm_min); | |
249 | buf[2] = bin2bcd(alarm->time.tm_hour); | |
250 | buf[3] = bin2bcd(alarm->time.tm_mday); | |
251 | ||
252 | /* clear alarm interrupt enable bit */ | |
253 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
254 | if (ret < 0) | |
255 | goto out; | |
256 | control = ret; | |
257 | control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); | |
258 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
259 | if (ret < 0) | |
260 | goto out; | |
261 | ||
262 | /* clear any pending alarm flag */ | |
263 | ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
264 | if (ret < 0) | |
265 | goto out; | |
266 | stat = ret; | |
267 | stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); | |
268 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); | |
269 | if (ret < 0) | |
270 | goto out; | |
271 | ||
272 | ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
273 | ||
274 | if (alarm->enabled) { | |
275 | control |= DS3232_REG_CR_A1IE; | |
276 | ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
277 | } | |
278 | out: | |
279 | mutex_unlock(&ds3232->mutex); | |
280 | return ret; | |
281 | } | |
282 | ||
283 | static void ds3232_update_alarm(struct i2c_client *client) | |
284 | { | |
285 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
286 | int control; | |
287 | int ret; | |
288 | u8 buf[4]; | |
289 | ||
290 | mutex_lock(&ds3232->mutex); | |
291 | ||
292 | ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
293 | if (ret < 0) | |
294 | goto unlock; | |
295 | ||
296 | buf[0] = bcd2bin(buf[0]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
297 | 0x80 : buf[0]; | |
298 | buf[1] = bcd2bin(buf[1]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
299 | 0x80 : buf[1]; | |
300 | buf[2] = bcd2bin(buf[2]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
301 | 0x80 : buf[2]; | |
302 | buf[3] = bcd2bin(buf[3]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? | |
303 | 0x80 : buf[3]; | |
304 | ||
305 | ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); | |
306 | if (ret < 0) | |
307 | goto unlock; | |
308 | ||
309 | control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
310 | if (control < 0) | |
311 | goto unlock; | |
312 | ||
313 | if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF)) | |
314 | /* enable alarm1 interrupt */ | |
315 | control |= DS3232_REG_CR_A1IE; | |
316 | else | |
317 | /* disable alarm1 interrupt */ | |
318 | control &= ~(DS3232_REG_CR_A1IE); | |
319 | i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
320 | ||
321 | unlock: | |
322 | mutex_unlock(&ds3232->mutex); | |
323 | } | |
324 | ||
325 | static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled) | |
326 | { | |
327 | struct i2c_client *client = to_i2c_client(dev); | |
328 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
329 | ||
330 | if (client->irq <= 0) | |
331 | return -EINVAL; | |
332 | ||
333 | if (enabled) | |
334 | ds3232->rtc->irq_data |= RTC_AF; | |
335 | else | |
336 | ds3232->rtc->irq_data &= ~RTC_AF; | |
337 | ||
338 | ds3232_update_alarm(client); | |
339 | return 0; | |
340 | } | |
341 | ||
c03675f0 RZ |
342 | static irqreturn_t ds3232_irq(int irq, void *dev_id) |
343 | { | |
344 | struct i2c_client *client = dev_id; | |
345 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
346 | ||
347 | disable_irq_nosync(irq); | |
348 | schedule_work(&ds3232->work); | |
349 | return IRQ_HANDLED; | |
350 | } | |
351 | ||
352 | static void ds3232_work(struct work_struct *work) | |
353 | { | |
354 | struct ds3232 *ds3232 = container_of(work, struct ds3232, work); | |
355 | struct i2c_client *client = ds3232->client; | |
356 | int stat, control; | |
357 | ||
358 | mutex_lock(&ds3232->mutex); | |
359 | ||
360 | stat = i2c_smbus_read_byte_data(client, DS3232_REG_SR); | |
361 | if (stat < 0) | |
362 | goto unlock; | |
363 | ||
364 | if (stat & DS3232_REG_SR_A1F) { | |
365 | control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); | |
366 | if (control < 0) | |
367 | goto out; | |
368 | /* disable alarm1 interrupt */ | |
369 | control &= ~(DS3232_REG_CR_A1IE); | |
370 | i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); | |
371 | ||
372 | /* clear the alarm pend flag */ | |
373 | stat &= ~DS3232_REG_SR_A1F; | |
374 | i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); | |
375 | ||
376 | rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF); | |
377 | } | |
378 | ||
379 | out: | |
380 | if (!ds3232->exiting) | |
381 | enable_irq(client->irq); | |
382 | unlock: | |
383 | mutex_unlock(&ds3232->mutex); | |
384 | } | |
385 | ||
386 | static const struct rtc_class_ops ds3232_rtc_ops = { | |
387 | .read_time = ds3232_read_time, | |
388 | .set_time = ds3232_set_time, | |
f46418c5 LCB |
389 | .read_alarm = ds3232_read_alarm, |
390 | .set_alarm = ds3232_set_alarm, | |
391 | .alarm_irq_enable = ds3232_alarm_irq_enable, | |
c03675f0 RZ |
392 | }; |
393 | ||
5a167f45 GKH |
394 | static int ds3232_probe(struct i2c_client *client, |
395 | const struct i2c_device_id *id) | |
c03675f0 RZ |
396 | { |
397 | struct ds3232 *ds3232; | |
398 | int ret; | |
399 | ||
66714612 | 400 | ds3232 = devm_kzalloc(&client->dev, sizeof(struct ds3232), GFP_KERNEL); |
c03675f0 RZ |
401 | if (!ds3232) |
402 | return -ENOMEM; | |
403 | ||
404 | ds3232->client = client; | |
405 | i2c_set_clientdata(client, ds3232); | |
406 | ||
407 | INIT_WORK(&ds3232->work, ds3232_work); | |
408 | mutex_init(&ds3232->mutex); | |
409 | ||
410 | ret = ds3232_check_rtc_status(client); | |
411 | if (ret) | |
66714612 | 412 | return ret; |
c03675f0 | 413 | |
66714612 | 414 | ds3232->rtc = devm_rtc_device_register(&client->dev, client->name, |
c03675f0 RZ |
415 | &ds3232_rtc_ops, THIS_MODULE); |
416 | if (IS_ERR(ds3232->rtc)) { | |
c03675f0 | 417 | dev_err(&client->dev, "unable to register the class device\n"); |
66714612 | 418 | return PTR_ERR(ds3232->rtc); |
c03675f0 RZ |
419 | } |
420 | ||
421 | if (client->irq >= 0) { | |
66714612 | 422 | ret = devm_request_irq(&client->dev, client->irq, ds3232_irq, 0, |
c03675f0 RZ |
423 | "ds3232", client); |
424 | if (ret) { | |
425 | dev_err(&client->dev, "unable to request IRQ\n"); | |
66714612 | 426 | return ret; |
c03675f0 RZ |
427 | } |
428 | } | |
429 | ||
430 | return 0; | |
c03675f0 RZ |
431 | } |
432 | ||
5a167f45 | 433 | static int ds3232_remove(struct i2c_client *client) |
c03675f0 RZ |
434 | { |
435 | struct ds3232 *ds3232 = i2c_get_clientdata(client); | |
436 | ||
437 | if (client->irq >= 0) { | |
438 | mutex_lock(&ds3232->mutex); | |
439 | ds3232->exiting = 1; | |
440 | mutex_unlock(&ds3232->mutex); | |
441 | ||
66714612 | 442 | devm_free_irq(&client->dev, client->irq, client); |
9db8995b | 443 | cancel_work_sync(&ds3232->work); |
c03675f0 RZ |
444 | } |
445 | ||
c03675f0 RZ |
446 | return 0; |
447 | } | |
448 | ||
449 | static const struct i2c_device_id ds3232_id[] = { | |
450 | { "ds3232", 0 }, | |
451 | { } | |
452 | }; | |
453 | MODULE_DEVICE_TABLE(i2c, ds3232_id); | |
454 | ||
455 | static struct i2c_driver ds3232_driver = { | |
456 | .driver = { | |
457 | .name = "rtc-ds3232", | |
458 | .owner = THIS_MODULE, | |
459 | }, | |
460 | .probe = ds3232_probe, | |
5a167f45 | 461 | .remove = ds3232_remove, |
c03675f0 RZ |
462 | .id_table = ds3232_id, |
463 | }; | |
464 | ||
0abc9201 | 465 | module_i2c_driver(ds3232_driver); |
c03675f0 RZ |
466 | |
467 | MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>"); | |
468 | MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver"); | |
469 | MODULE_LICENSE("GPL"); |