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1/*
2 * RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C
3 *
4 * Based on code by Randy Vinson <rvinson@mvista.com>,
5 * which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>.
6 *
7 * Copyright (C) 2006-2007 Freescale Semiconductor
8 *
9 * 2005 (c) MontaVista Software, Inc. This file is licensed under
10 * the terms of the GNU General Public License version 2. This program
11 * is licensed "as is" without any warranty of any kind, whether express
12 * or implied.
13 */
14/*
15 * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
16 * recommened in .../Documentation/i2c/writing-clients section
17 * "Sending and receiving", using SMBus level communication is preferred.
18 */
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
30#define DS1374_REG_TOD0 0x00 /* Time of Day */
31#define DS1374_REG_TOD1 0x01
32#define DS1374_REG_TOD2 0x02
33#define DS1374_REG_TOD3 0x03
34#define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */
35#define DS1374_REG_WDALM1 0x05
36#define DS1374_REG_WDALM2 0x06
37#define DS1374_REG_CR 0x07 /* Control */
38#define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */
39#define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */
40#define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */
41#define DS1374_REG_SR 0x08 /* Status */
42#define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */
43#define DS1374_REG_SR_AF 0x01 /* Alarm Flag */
44#define DS1374_REG_TCR 0x09 /* Trickle Charge */
45
46static const struct i2c_device_id ds1374_id[] = {
47 { "ds1374", 0 },
48 { }
49};
50MODULE_DEVICE_TABLE(i2c, ds1374_id);
51
52struct ds1374 {
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;
62 int exiting;
63};
64
65static struct i2c_driver ds1374_driver;
66
67static int ds1374_read_rtc(struct i2c_client *client, u32 *time,
68 int reg, int nbytes)
69{
70 u8 buf[4];
71 int ret;
72 int i;
73
74 if (nbytes > 4) {
75 WARN_ON(1);
76 return -EINVAL;
77 }
78
79 ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf);
80
81 if (ret < 0)
82 return ret;
83 if (ret < nbytes)
84 return -EIO;
85
86 for (i = nbytes - 1, *time = 0; i >= 0; i--)
87 *time = (*time << 8) | buf[i];
88
89 return 0;
90}
91
92static int ds1374_write_rtc(struct i2c_client *client, u32 time,
93 int reg, int nbytes)
94{
95 u8 buf[4];
96 int i;
97
98 if (nbytes > 4) {
99 WARN_ON(1);
100 return -EINVAL;
101 }
102
103 for (i = 0; i < nbytes; i++) {
104 buf[i] = time & 0xff;
105 time >>= 8;
106 }
107
108 return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf);
109}
110
111static int ds1374_check_rtc_status(struct i2c_client *client)
112{
113 int ret = 0;
114 int control, stat;
115
116 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
117 if (stat < 0)
118 return stat;
119
120 if (stat & DS1374_REG_SR_OSF)
121 dev_warn(&client->dev,
122 "oscillator discontinuity flagged, "
123 "time unreliable\n");
124
125 stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF);
126
127 ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
128 if (ret < 0)
129 return ret;
130
131 /* If the alarm is pending, clear it before requesting
132 * the interrupt, so an interrupt event isn't reported
133 * before everything is initialized.
134 */
135
136 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
137 if (control < 0)
138 return control;
139
140 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
141 return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
142}
143
144static int ds1374_read_time(struct device *dev, struct rtc_time *time)
145{
146 struct i2c_client *client = to_i2c_client(dev);
147 u32 itime;
148 int ret;
149
150 ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4);
151 if (!ret)
152 rtc_time_to_tm(itime, time);
153
154 return ret;
155}
156
157static int ds1374_set_time(struct device *dev, struct rtc_time *time)
158{
159 struct i2c_client *client = to_i2c_client(dev);
160 unsigned long itime;
161
162 rtc_tm_to_time(time, &itime);
163 return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
164}
165
166/* The ds1374 has a decrementer for an alarm, rather than a comparator.
167 * If the time of day is changed, then the alarm will need to be
168 * reset.
169 */
170static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
171{
172 struct i2c_client *client = to_i2c_client(dev);
173 struct ds1374 *ds1374 = i2c_get_clientdata(client);
174 u32 now, cur_alarm;
175 int cr, sr;
176 int ret = 0;
177
178 if (client->irq <= 0)
179 return -EINVAL;
180
181 mutex_lock(&ds1374->mutex);
182
183 cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
184 if (ret < 0)
185 goto out;
186
187 sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
188 if (ret < 0)
189 goto out;
190
191 ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4);
192 if (ret)
193 goto out;
194
195 ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3);
196 if (ret)
197 goto out;
198
199 rtc_time_to_tm(now + cur_alarm, &alarm->time);
200 alarm->enabled = !!(cr & DS1374_REG_CR_WACE);
201 alarm->pending = !!(sr & DS1374_REG_SR_AF);
202
203out:
204 mutex_unlock(&ds1374->mutex);
205 return ret;
206}
207
208static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
209{
210 struct i2c_client *client = to_i2c_client(dev);
211 struct ds1374 *ds1374 = i2c_get_clientdata(client);
212 struct rtc_time now;
213 unsigned long new_alarm, itime;
214 int cr;
215 int ret = 0;
216
217 if (client->irq <= 0)
218 return -EINVAL;
219
220 ret = ds1374_read_time(dev, &now);
221 if (ret < 0)
222 return ret;
223
224 rtc_tm_to_time(&alarm->time, &new_alarm);
225 rtc_tm_to_time(&now, &itime);
226
227 /* This can happen due to races, in addition to dates that are
228 * truly in the past. To avoid requiring the caller to check for
229 * races, dates in the past are assumed to be in the recent past
230 * (i.e. not something that we'd rather the caller know about via
231 * an error), and the alarm is set to go off as soon as possible.
232 */
233 if (time_before_eq(new_alarm, itime))
234 new_alarm = 1;
235 else
236 new_alarm -= itime;
237
238 mutex_lock(&ds1374->mutex);
239
240 ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
241 if (ret < 0)
242 goto out;
243
244 /* Disable any existing alarm before setting the new one
245 * (or lack thereof). */
246 cr &= ~DS1374_REG_CR_WACE;
247
248 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
249 if (ret < 0)
250 goto out;
251
252 ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3);
253 if (ret)
254 goto out;
255
256 if (alarm->enabled) {
257 cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
258 cr &= ~DS1374_REG_CR_WDALM;
259
260 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
261 }
262
263out:
264 mutex_unlock(&ds1374->mutex);
265 return ret;
266}
267
268static irqreturn_t ds1374_irq(int irq, void *dev_id)
269{
270 struct i2c_client *client = dev_id;
271 struct ds1374 *ds1374 = i2c_get_clientdata(client);
272
273 disable_irq_nosync(irq);
274 schedule_work(&ds1374->work);
275 return IRQ_HANDLED;
276}
277
278static void ds1374_work(struct work_struct *work)
279{
280 struct ds1374 *ds1374 = container_of(work, struct ds1374, work);
281 struct i2c_client *client = ds1374->client;
282 int stat, control;
283
284 mutex_lock(&ds1374->mutex);
285
286 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
287 if (stat < 0)
288 goto unlock;
289
290 if (stat & DS1374_REG_SR_AF) {
291 stat &= ~DS1374_REG_SR_AF;
292 i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
293
294 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
295 if (control < 0)
296 goto out;
297
298 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
299 i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
300
301 rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF);
302 }
303
304out:
305 if (!ds1374->exiting)
306 enable_irq(client->irq);
307unlock:
308 mutex_unlock(&ds1374->mutex);
309}
310
311static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
312{
313 struct i2c_client *client = to_i2c_client(dev);
314 struct ds1374 *ds1374 = i2c_get_clientdata(client);
315 int ret;
316
317 mutex_lock(&ds1374->mutex);
318
319 ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
320 if (ret < 0)
321 goto out;
322
323 if (enabled) {
324 ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
325 ret &= ~DS1374_REG_CR_WDALM;
326 } else {
327 ret &= ~DS1374_REG_CR_WACE;
328 }
329 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret);
330
331out:
332 mutex_unlock(&ds1374->mutex);
333 return ret;
334}
335
336static const struct rtc_class_ops ds1374_rtc_ops = {
337 .read_time = ds1374_read_time,
338 .set_time = ds1374_set_time,
339 .read_alarm = ds1374_read_alarm,
340 .set_alarm = ds1374_set_alarm,
341 .alarm_irq_enable = ds1374_alarm_irq_enable,
342};
343
344static int ds1374_probe(struct i2c_client *client,
345 const struct i2c_device_id *id)
346{
347 struct ds1374 *ds1374;
348 int ret;
349
350 ds1374 = kzalloc(sizeof(struct ds1374), GFP_KERNEL);
351 if (!ds1374)
352 return -ENOMEM;
353
354 ds1374->client = client;
355 i2c_set_clientdata(client, ds1374);
356
357 INIT_WORK(&ds1374->work, ds1374_work);
358 mutex_init(&ds1374->mutex);
359
360 ret = ds1374_check_rtc_status(client);
361 if (ret)
362 goto out_free;
363
364 if (client->irq > 0) {
365 ret = request_irq(client->irq, ds1374_irq, 0,
366 "ds1374", client);
367 if (ret) {
368 dev_err(&client->dev, "unable to request IRQ\n");
369 goto out_free;
370 }
371
372 device_set_wakeup_capable(&client->dev, 1);
373 }
374
375 ds1374->rtc = rtc_device_register(client->name, &client->dev,
376 &ds1374_rtc_ops, THIS_MODULE);
377 if (IS_ERR(ds1374->rtc)) {
378 ret = PTR_ERR(ds1374->rtc);
379 dev_err(&client->dev, "unable to register the class device\n");
380 goto out_irq;
381 }
382
383 return 0;
384
385out_irq:
386 if (client->irq > 0)
387 free_irq(client->irq, client);
388
389out_free:
390 kfree(ds1374);
391 return ret;
392}
393
394static int __devexit ds1374_remove(struct i2c_client *client)
395{
396 struct ds1374 *ds1374 = i2c_get_clientdata(client);
397
398 if (client->irq > 0) {
399 mutex_lock(&ds1374->mutex);
400 ds1374->exiting = 1;
401 mutex_unlock(&ds1374->mutex);
402
403 free_irq(client->irq, client);
404 cancel_work_sync(&ds1374->work);
405 }
406
407 rtc_device_unregister(ds1374->rtc);
408 kfree(ds1374);
409 return 0;
410}
411
412#ifdef CONFIG_PM
413static int ds1374_suspend(struct device *dev)
414{
415 struct i2c_client *client = to_i2c_client(dev);
416
417 if (client->irq >= 0 && device_may_wakeup(&client->dev))
418 enable_irq_wake(client->irq);
419 return 0;
420}
421
422static int ds1374_resume(struct device *dev)
423{
424 struct i2c_client *client = to_i2c_client(dev);
425
426 if (client->irq >= 0 && device_may_wakeup(&client->dev))
427 disable_irq_wake(client->irq);
428 return 0;
429}
430
431static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);
432
433#define DS1374_PM (&ds1374_pm)
434#else
435#define DS1374_PM NULL
436#endif
437
438static struct i2c_driver ds1374_driver = {
439 .driver = {
440 .name = "rtc-ds1374",
441 .owner = THIS_MODULE,
442 .pm = DS1374_PM,
443 },
444 .probe = ds1374_probe,
445 .remove = __devexit_p(ds1374_remove),
446 .id_table = ds1374_id,
447};
448
449static int __init ds1374_init(void)
450{
451 return i2c_add_driver(&ds1374_driver);
452}
453
454static void __exit ds1374_exit(void)
455{
456 i2c_del_driver(&ds1374_driver);
457}
458
459module_init(ds1374_init);
460module_exit(ds1374_exit);
461
462MODULE_AUTHOR("Scott Wood <scottwood@freescale.com>");
463MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver");
464MODULE_LICENSE("GPL");
1/*
2 * RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C
3 *
4 * Based on code by Randy Vinson <rvinson@mvista.com>,
5 * which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>.
6 *
7 * Copyright (C) 2006-2007 Freescale Semiconductor
8 *
9 * 2005 (c) MontaVista Software, Inc. This file is licensed under
10 * the terms of the GNU General Public License version 2. This program
11 * is licensed "as is" without any warranty of any kind, whether express
12 * or implied.
13 */
14/*
15 * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
16 * recommened in .../Documentation/i2c/writing-clients section
17 * "Sending and receiving", using SMBus level communication is preferred.
18 */
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
30#define DS1374_REG_TOD0 0x00 /* Time of Day */
31#define DS1374_REG_TOD1 0x01
32#define DS1374_REG_TOD2 0x02
33#define DS1374_REG_TOD3 0x03
34#define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */
35#define DS1374_REG_WDALM1 0x05
36#define DS1374_REG_WDALM2 0x06
37#define DS1374_REG_CR 0x07 /* Control */
38#define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */
39#define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */
40#define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */
41#define DS1374_REG_SR 0x08 /* Status */
42#define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */
43#define DS1374_REG_SR_AF 0x01 /* Alarm Flag */
44#define DS1374_REG_TCR 0x09 /* Trickle Charge */
45
46static const struct i2c_device_id ds1374_id[] = {
47 { "ds1374", 0 },
48 { }
49};
50MODULE_DEVICE_TABLE(i2c, ds1374_id);
51
52struct ds1374 {
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;
62 int exiting;
63};
64
65static struct i2c_driver ds1374_driver;
66
67static int ds1374_read_rtc(struct i2c_client *client, u32 *time,
68 int reg, int nbytes)
69{
70 u8 buf[4];
71 int ret;
72 int i;
73
74 if (nbytes > 4) {
75 WARN_ON(1);
76 return -EINVAL;
77 }
78
79 ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf);
80
81 if (ret < 0)
82 return ret;
83 if (ret < nbytes)
84 return -EIO;
85
86 for (i = nbytes - 1, *time = 0; i >= 0; i--)
87 *time = (*time << 8) | buf[i];
88
89 return 0;
90}
91
92static int ds1374_write_rtc(struct i2c_client *client, u32 time,
93 int reg, int nbytes)
94{
95 u8 buf[4];
96 int i;
97
98 if (nbytes > 4) {
99 WARN_ON(1);
100 return -EINVAL;
101 }
102
103 for (i = 0; i < nbytes; i++) {
104 buf[i] = time & 0xff;
105 time >>= 8;
106 }
107
108 return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf);
109}
110
111static int ds1374_check_rtc_status(struct i2c_client *client)
112{
113 int ret = 0;
114 int control, stat;
115
116 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
117 if (stat < 0)
118 return stat;
119
120 if (stat & DS1374_REG_SR_OSF)
121 dev_warn(&client->dev,
122 "oscillator discontinuity flagged, time unreliable\n");
123
124 stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF);
125
126 ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
127 if (ret < 0)
128 return ret;
129
130 /* If the alarm is pending, clear it before requesting
131 * the interrupt, so an interrupt event isn't reported
132 * before everything is initialized.
133 */
134
135 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
136 if (control < 0)
137 return control;
138
139 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
140 return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
141}
142
143static int ds1374_read_time(struct device *dev, struct rtc_time *time)
144{
145 struct i2c_client *client = to_i2c_client(dev);
146 u32 itime;
147 int ret;
148
149 ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4);
150 if (!ret)
151 rtc_time_to_tm(itime, time);
152
153 return ret;
154}
155
156static int ds1374_set_time(struct device *dev, struct rtc_time *time)
157{
158 struct i2c_client *client = to_i2c_client(dev);
159 unsigned long itime;
160
161 rtc_tm_to_time(time, &itime);
162 return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
163}
164
165/* The ds1374 has a decrementer for an alarm, rather than a comparator.
166 * If the time of day is changed, then the alarm will need to be
167 * reset.
168 */
169static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
170{
171 struct i2c_client *client = to_i2c_client(dev);
172 struct ds1374 *ds1374 = i2c_get_clientdata(client);
173 u32 now, cur_alarm;
174 int cr, sr;
175 int ret = 0;
176
177 if (client->irq <= 0)
178 return -EINVAL;
179
180 mutex_lock(&ds1374->mutex);
181
182 cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
183 if (ret < 0)
184 goto out;
185
186 sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
187 if (ret < 0)
188 goto out;
189
190 ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4);
191 if (ret)
192 goto out;
193
194 ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3);
195 if (ret)
196 goto out;
197
198 rtc_time_to_tm(now + cur_alarm, &alarm->time);
199 alarm->enabled = !!(cr & DS1374_REG_CR_WACE);
200 alarm->pending = !!(sr & DS1374_REG_SR_AF);
201
202out:
203 mutex_unlock(&ds1374->mutex);
204 return ret;
205}
206
207static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
208{
209 struct i2c_client *client = to_i2c_client(dev);
210 struct ds1374 *ds1374 = i2c_get_clientdata(client);
211 struct rtc_time now;
212 unsigned long new_alarm, itime;
213 int cr;
214 int ret = 0;
215
216 if (client->irq <= 0)
217 return -EINVAL;
218
219 ret = ds1374_read_time(dev, &now);
220 if (ret < 0)
221 return ret;
222
223 rtc_tm_to_time(&alarm->time, &new_alarm);
224 rtc_tm_to_time(&now, &itime);
225
226 /* This can happen due to races, in addition to dates that are
227 * truly in the past. To avoid requiring the caller to check for
228 * races, dates in the past are assumed to be in the recent past
229 * (i.e. not something that we'd rather the caller know about via
230 * an error), and the alarm is set to go off as soon as possible.
231 */
232 if (time_before_eq(new_alarm, itime))
233 new_alarm = 1;
234 else
235 new_alarm -= itime;
236
237 mutex_lock(&ds1374->mutex);
238
239 ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
240 if (ret < 0)
241 goto out;
242
243 /* Disable any existing alarm before setting the new one
244 * (or lack thereof). */
245 cr &= ~DS1374_REG_CR_WACE;
246
247 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
248 if (ret < 0)
249 goto out;
250
251 ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3);
252 if (ret)
253 goto out;
254
255 if (alarm->enabled) {
256 cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
257 cr &= ~DS1374_REG_CR_WDALM;
258
259 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
260 }
261
262out:
263 mutex_unlock(&ds1374->mutex);
264 return ret;
265}
266
267static irqreturn_t ds1374_irq(int irq, void *dev_id)
268{
269 struct i2c_client *client = dev_id;
270 struct ds1374 *ds1374 = i2c_get_clientdata(client);
271
272 disable_irq_nosync(irq);
273 schedule_work(&ds1374->work);
274 return IRQ_HANDLED;
275}
276
277static void ds1374_work(struct work_struct *work)
278{
279 struct ds1374 *ds1374 = container_of(work, struct ds1374, work);
280 struct i2c_client *client = ds1374->client;
281 int stat, control;
282
283 mutex_lock(&ds1374->mutex);
284
285 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
286 if (stat < 0)
287 goto unlock;
288
289 if (stat & DS1374_REG_SR_AF) {
290 stat &= ~DS1374_REG_SR_AF;
291 i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
292
293 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
294 if (control < 0)
295 goto out;
296
297 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
298 i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
299
300 rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF);
301 }
302
303out:
304 if (!ds1374->exiting)
305 enable_irq(client->irq);
306unlock:
307 mutex_unlock(&ds1374->mutex);
308}
309
310static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
311{
312 struct i2c_client *client = to_i2c_client(dev);
313 struct ds1374 *ds1374 = i2c_get_clientdata(client);
314 int ret;
315
316 mutex_lock(&ds1374->mutex);
317
318 ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
319 if (ret < 0)
320 goto out;
321
322 if (enabled) {
323 ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
324 ret &= ~DS1374_REG_CR_WDALM;
325 } else {
326 ret &= ~DS1374_REG_CR_WACE;
327 }
328 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret);
329
330out:
331 mutex_unlock(&ds1374->mutex);
332 return ret;
333}
334
335static const struct rtc_class_ops ds1374_rtc_ops = {
336 .read_time = ds1374_read_time,
337 .set_time = ds1374_set_time,
338 .read_alarm = ds1374_read_alarm,
339 .set_alarm = ds1374_set_alarm,
340 .alarm_irq_enable = ds1374_alarm_irq_enable,
341};
342
343static int ds1374_probe(struct i2c_client *client,
344 const struct i2c_device_id *id)
345{
346 struct ds1374 *ds1374;
347 int ret;
348
349 ds1374 = devm_kzalloc(&client->dev, sizeof(struct ds1374), GFP_KERNEL);
350 if (!ds1374)
351 return -ENOMEM;
352
353 ds1374->client = client;
354 i2c_set_clientdata(client, ds1374);
355
356 INIT_WORK(&ds1374->work, ds1374_work);
357 mutex_init(&ds1374->mutex);
358
359 ret = ds1374_check_rtc_status(client);
360 if (ret)
361 return ret;
362
363 if (client->irq > 0) {
364 ret = devm_request_irq(&client->dev, client->irq, ds1374_irq, 0,
365 "ds1374", client);
366 if (ret) {
367 dev_err(&client->dev, "unable to request IRQ\n");
368 return ret;
369 }
370
371 device_set_wakeup_capable(&client->dev, 1);
372 }
373
374 ds1374->rtc = devm_rtc_device_register(&client->dev, client->name,
375 &ds1374_rtc_ops, THIS_MODULE);
376 if (IS_ERR(ds1374->rtc)) {
377 dev_err(&client->dev, "unable to register the class device\n");
378 return PTR_ERR(ds1374->rtc);
379 }
380
381 return 0;
382}
383
384static int ds1374_remove(struct i2c_client *client)
385{
386 struct ds1374 *ds1374 = i2c_get_clientdata(client);
387
388 if (client->irq > 0) {
389 mutex_lock(&ds1374->mutex);
390 ds1374->exiting = 1;
391 mutex_unlock(&ds1374->mutex);
392
393 devm_free_irq(&client->dev, client->irq, client);
394 cancel_work_sync(&ds1374->work);
395 }
396
397 return 0;
398}
399
400#ifdef CONFIG_PM_SLEEP
401static int ds1374_suspend(struct device *dev)
402{
403 struct i2c_client *client = to_i2c_client(dev);
404
405 if (client->irq >= 0 && device_may_wakeup(&client->dev))
406 enable_irq_wake(client->irq);
407 return 0;
408}
409
410static int ds1374_resume(struct device *dev)
411{
412 struct i2c_client *client = to_i2c_client(dev);
413
414 if (client->irq >= 0 && device_may_wakeup(&client->dev))
415 disable_irq_wake(client->irq);
416 return 0;
417}
418#endif
419
420static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);
421
422static struct i2c_driver ds1374_driver = {
423 .driver = {
424 .name = "rtc-ds1374",
425 .owner = THIS_MODULE,
426 .pm = &ds1374_pm,
427 },
428 .probe = ds1374_probe,
429 .remove = ds1374_remove,
430 .id_table = ds1374_id,
431};
432
433module_i2c_driver(ds1374_driver);
434
435MODULE_AUTHOR("Scott Wood <scottwood@freescale.com>");
436MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver");
437MODULE_LICENSE("GPL");