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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) 2014 Rose Technology
8 * Copyright (C) 2006-2007 Freescale Semiconductor
9 *
10 * 2005 (c) MontaVista Software, Inc. This file is licensed under
11 * the terms of the GNU General Public License version 2. This program
12 * is licensed "as is" without any warranty of any kind, whether express
13 * or implied.
14 */
15/*
16 * It would be more efficient to use i2c msgs/i2c_transfer directly but, as
17 * recommened in .../Documentation/i2c/writing-clients section
18 * "Sending and receiving", using SMBus level communication is preferred.
19 */
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/interrupt.h>
26#include <linux/i2c.h>
27#include <linux/rtc.h>
28#include <linux/bcd.h>
29#include <linux/workqueue.h>
30#include <linux/slab.h>
31#include <linux/pm.h>
32#ifdef CONFIG_RTC_DRV_DS1374_WDT
33#include <linux/fs.h>
34#include <linux/ioctl.h>
35#include <linux/miscdevice.h>
36#include <linux/reboot.h>
37#include <linux/watchdog.h>
38#endif
39
40#define DS1374_REG_TOD0 0x00 /* Time of Day */
41#define DS1374_REG_TOD1 0x01
42#define DS1374_REG_TOD2 0x02
43#define DS1374_REG_TOD3 0x03
44#define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */
45#define DS1374_REG_WDALM1 0x05
46#define DS1374_REG_WDALM2 0x06
47#define DS1374_REG_CR 0x07 /* Control */
48#define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */
49#define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */
50#define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */
51#define DS1374_REG_SR 0x08 /* Status */
52#define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */
53#define DS1374_REG_SR_AF 0x01 /* Alarm Flag */
54#define DS1374_REG_TCR 0x09 /* Trickle Charge */
55
56static const struct i2c_device_id ds1374_id[] = {
57 { "ds1374", 0 },
58 { }
59};
60MODULE_DEVICE_TABLE(i2c, ds1374_id);
61
62#ifdef CONFIG_OF
63static const struct of_device_id ds1374_of_match[] = {
64 { .compatible = "dallas,ds1374" },
65 { }
66};
67MODULE_DEVICE_TABLE(of, ds1374_of_match);
68#endif
69
70struct ds1374 {
71 struct i2c_client *client;
72 struct rtc_device *rtc;
73 struct work_struct work;
74
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
83static struct i2c_driver ds1374_driver;
84
85static 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 (nbytes > 4) {
93 WARN_ON(1);
94 return -EINVAL;
95 }
96
97 ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf);
98
99 if (ret < 0)
100 return ret;
101 if (ret < nbytes)
102 return -EIO;
103
104 for (i = nbytes - 1, *time = 0; i >= 0; i--)
105 *time = (*time << 8) | buf[i];
106
107 return 0;
108}
109
110static int ds1374_write_rtc(struct i2c_client *client, u32 time,
111 int reg, int nbytes)
112{
113 u8 buf[4];
114 int i;
115
116 if (nbytes > 4) {
117 WARN_ON(1);
118 return -EINVAL;
119 }
120
121 for (i = 0; i < nbytes; i++) {
122 buf[i] = time & 0xff;
123 time >>= 8;
124 }
125
126 return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf);
127}
128
129static int ds1374_check_rtc_status(struct i2c_client *client)
130{
131 int ret = 0;
132 int control, stat;
133
134 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
135 if (stat < 0)
136 return stat;
137
138 if (stat & DS1374_REG_SR_OSF)
139 dev_warn(&client->dev,
140 "oscillator discontinuity flagged, time unreliable\n");
141
142 stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF);
143
144 ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
145 if (ret < 0)
146 return ret;
147
148 /* If the alarm is pending, clear it before requesting
149 * the interrupt, so an interrupt event isn't reported
150 * before everything is initialized.
151 */
152
153 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
154 if (control < 0)
155 return control;
156
157 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
158 return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
159}
160
161static int ds1374_read_time(struct device *dev, struct rtc_time *time)
162{
163 struct i2c_client *client = to_i2c_client(dev);
164 u32 itime;
165 int ret;
166
167 ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4);
168 if (!ret)
169 rtc_time_to_tm(itime, time);
170
171 return ret;
172}
173
174static int ds1374_set_time(struct device *dev, struct rtc_time *time)
175{
176 struct i2c_client *client = to_i2c_client(dev);
177 unsigned long itime;
178
179 rtc_tm_to_time(time, &itime);
180 return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
181}
182
183#ifndef CONFIG_RTC_DRV_DS1374_WDT
184/* The ds1374 has a decrementer for an alarm, rather than a comparator.
185 * If the time of day is changed, then the alarm will need to be
186 * reset.
187 */
188static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
189{
190 struct i2c_client *client = to_i2c_client(dev);
191 struct ds1374 *ds1374 = i2c_get_clientdata(client);
192 u32 now, cur_alarm;
193 int cr, sr;
194 int ret = 0;
195
196 if (client->irq <= 0)
197 return -EINVAL;
198
199 mutex_lock(&ds1374->mutex);
200
201 cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
202 if (ret < 0)
203 goto out;
204
205 sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
206 if (ret < 0)
207 goto out;
208
209 ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4);
210 if (ret)
211 goto out;
212
213 ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3);
214 if (ret)
215 goto out;
216
217 rtc_time_to_tm(now + cur_alarm, &alarm->time);
218 alarm->enabled = !!(cr & DS1374_REG_CR_WACE);
219 alarm->pending = !!(sr & DS1374_REG_SR_AF);
220
221out:
222 mutex_unlock(&ds1374->mutex);
223 return ret;
224}
225
226static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
227{
228 struct i2c_client *client = to_i2c_client(dev);
229 struct ds1374 *ds1374 = i2c_get_clientdata(client);
230 struct rtc_time now;
231 unsigned long new_alarm, itime;
232 int cr;
233 int ret = 0;
234
235 if (client->irq <= 0)
236 return -EINVAL;
237
238 ret = ds1374_read_time(dev, &now);
239 if (ret < 0)
240 return ret;
241
242 rtc_tm_to_time(&alarm->time, &new_alarm);
243 rtc_tm_to_time(&now, &itime);
244
245 /* This can happen due to races, in addition to dates that are
246 * truly in the past. To avoid requiring the caller to check for
247 * races, dates in the past are assumed to be in the recent past
248 * (i.e. not something that we'd rather the caller know about via
249 * an error), and the alarm is set to go off as soon as possible.
250 */
251 if (time_before_eq(new_alarm, itime))
252 new_alarm = 1;
253 else
254 new_alarm -= itime;
255
256 mutex_lock(&ds1374->mutex);
257
258 ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
259 if (ret < 0)
260 goto out;
261
262 /* Disable any existing alarm before setting the new one
263 * (or lack thereof). */
264 cr &= ~DS1374_REG_CR_WACE;
265
266 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
267 if (ret < 0)
268 goto out;
269
270 ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3);
271 if (ret)
272 goto out;
273
274 if (alarm->enabled) {
275 cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
276 cr &= ~DS1374_REG_CR_WDALM;
277
278 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
279 }
280
281out:
282 mutex_unlock(&ds1374->mutex);
283 return ret;
284}
285#endif
286
287static irqreturn_t ds1374_irq(int irq, void *dev_id)
288{
289 struct i2c_client *client = dev_id;
290 struct ds1374 *ds1374 = i2c_get_clientdata(client);
291
292 disable_irq_nosync(irq);
293 schedule_work(&ds1374->work);
294 return IRQ_HANDLED;
295}
296
297static void ds1374_work(struct work_struct *work)
298{
299 struct ds1374 *ds1374 = container_of(work, struct ds1374, work);
300 struct i2c_client *client = ds1374->client;
301 int stat, control;
302
303 mutex_lock(&ds1374->mutex);
304
305 stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
306 if (stat < 0)
307 goto unlock;
308
309 if (stat & DS1374_REG_SR_AF) {
310 stat &= ~DS1374_REG_SR_AF;
311 i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
312
313 control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
314 if (control < 0)
315 goto out;
316
317 control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
318 i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
319
320 rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF);
321 }
322
323out:
324 if (!ds1374->exiting)
325 enable_irq(client->irq);
326unlock:
327 mutex_unlock(&ds1374->mutex);
328}
329
330#ifndef CONFIG_RTC_DRV_DS1374_WDT
331static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
332{
333 struct i2c_client *client = to_i2c_client(dev);
334 struct ds1374 *ds1374 = i2c_get_clientdata(client);
335 int ret;
336
337 mutex_lock(&ds1374->mutex);
338
339 ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
340 if (ret < 0)
341 goto out;
342
343 if (enabled) {
344 ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
345 ret &= ~DS1374_REG_CR_WDALM;
346 } else {
347 ret &= ~DS1374_REG_CR_WACE;
348 }
349 ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret);
350
351out:
352 mutex_unlock(&ds1374->mutex);
353 return ret;
354}
355#endif
356
357static const struct rtc_class_ops ds1374_rtc_ops = {
358 .read_time = ds1374_read_time,
359 .set_time = ds1374_set_time,
360#ifndef CONFIG_RTC_DRV_DS1374_WDT
361 .read_alarm = ds1374_read_alarm,
362 .set_alarm = ds1374_set_alarm,
363 .alarm_irq_enable = ds1374_alarm_irq_enable,
364#endif
365};
366
367#ifdef CONFIG_RTC_DRV_DS1374_WDT
368/*
369 *****************************************************************************
370 *
371 * Watchdog Driver
372 *
373 *****************************************************************************
374 */
375static struct i2c_client *save_client;
376/* Default margin */
377#define WD_TIMO 131762
378
379#define DRV_NAME "DS1374 Watchdog"
380
381static int wdt_margin = WD_TIMO;
382static unsigned long wdt_is_open;
383module_param(wdt_margin, int, 0);
384MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");
385
386static const struct watchdog_info ds1374_wdt_info = {
387 .identity = "DS1374 WTD",
388 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
389 WDIOF_MAGICCLOSE,
390};
391
392static int ds1374_wdt_settimeout(unsigned int timeout)
393{
394 int ret = -ENOIOCTLCMD;
395 int cr;
396
397 ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
398 if (ret < 0)
399 goto out;
400
401 /* Disable any existing watchdog/alarm before setting the new one */
402 cr &= ~DS1374_REG_CR_WACE;
403
404 ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
405 if (ret < 0)
406 goto out;
407
408 /* Set new watchdog time */
409 ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
410 if (ret) {
411 pr_info("couldn't set new watchdog time\n");
412 goto out;
413 }
414
415 /* Enable watchdog timer */
416 cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM;
417 cr &= ~DS1374_REG_CR_AIE;
418
419 ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
420 if (ret < 0)
421 goto out;
422
423 return 0;
424out:
425 return ret;
426}
427
428
429/*
430 * Reload the watchdog timer. (ie, pat the watchdog)
431 */
432static void ds1374_wdt_ping(void)
433{
434 u32 val;
435 int ret = 0;
436
437 ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3);
438 if (ret)
439 pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret);
440}
441
442static void ds1374_wdt_disable(void)
443{
444 int ret = -ENOIOCTLCMD;
445 int cr;
446
447 cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
448 /* Disable watchdog timer */
449 cr &= ~DS1374_REG_CR_WACE;
450
451 ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
452}
453
454/*
455 * Watchdog device is opened, and watchdog starts running.
456 */
457static int ds1374_wdt_open(struct inode *inode, struct file *file)
458{
459 struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
460
461 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
462 mutex_lock(&ds1374->mutex);
463 if (test_and_set_bit(0, &wdt_is_open)) {
464 mutex_unlock(&ds1374->mutex);
465 return -EBUSY;
466 }
467 /*
468 * Activate
469 */
470 wdt_is_open = 1;
471 mutex_unlock(&ds1374->mutex);
472 return nonseekable_open(inode, file);
473 }
474 return -ENODEV;
475}
476
477/*
478 * Close the watchdog device.
479 */
480static int ds1374_wdt_release(struct inode *inode, struct file *file)
481{
482 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
483 clear_bit(0, &wdt_is_open);
484
485 return 0;
486}
487
488/*
489 * Pat the watchdog whenever device is written to.
490 */
491static ssize_t ds1374_wdt_write(struct file *file, const char __user *data,
492 size_t len, loff_t *ppos)
493{
494 if (len) {
495 ds1374_wdt_ping();
496 return 1;
497 }
498 return 0;
499}
500
501static ssize_t ds1374_wdt_read(struct file *file, char __user *data,
502 size_t len, loff_t *ppos)
503{
504 return 0;
505}
506
507/*
508 * Handle commands from user-space.
509 */
510static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
511 unsigned long arg)
512{
513 int new_margin, options;
514
515 switch (cmd) {
516 case WDIOC_GETSUPPORT:
517 return copy_to_user((struct watchdog_info __user *)arg,
518 &ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0;
519
520 case WDIOC_GETSTATUS:
521 case WDIOC_GETBOOTSTATUS:
522 return put_user(0, (int __user *)arg);
523 case WDIOC_KEEPALIVE:
524 ds1374_wdt_ping();
525 return 0;
526 case WDIOC_SETTIMEOUT:
527 if (get_user(new_margin, (int __user *)arg))
528 return -EFAULT;
529
530 if (new_margin < 1 || new_margin > 16777216)
531 return -EINVAL;
532
533 wdt_margin = new_margin;
534 ds1374_wdt_settimeout(new_margin);
535 ds1374_wdt_ping();
536 /* fallthrough */
537 case WDIOC_GETTIMEOUT:
538 return put_user(wdt_margin, (int __user *)arg);
539 case WDIOC_SETOPTIONS:
540 if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
541 return -EFAULT;
542
543 if (options & WDIOS_DISABLECARD) {
544 pr_info("disable watchdog\n");
545 ds1374_wdt_disable();
546 }
547
548 if (options & WDIOS_ENABLECARD) {
549 pr_info("enable watchdog\n");
550 ds1374_wdt_settimeout(wdt_margin);
551 ds1374_wdt_ping();
552 }
553
554 return -EINVAL;
555 }
556 return -ENOTTY;
557}
558
559static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
560 unsigned long arg)
561{
562 int ret;
563 struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
564
565 mutex_lock(&ds1374->mutex);
566 ret = ds1374_wdt_ioctl(file, cmd, arg);
567 mutex_unlock(&ds1374->mutex);
568
569 return ret;
570}
571
572static int ds1374_wdt_notify_sys(struct notifier_block *this,
573 unsigned long code, void *unused)
574{
575 if (code == SYS_DOWN || code == SYS_HALT)
576 /* Disable Watchdog */
577 ds1374_wdt_disable();
578 return NOTIFY_DONE;
579}
580
581static const struct file_operations ds1374_wdt_fops = {
582 .owner = THIS_MODULE,
583 .read = ds1374_wdt_read,
584 .unlocked_ioctl = ds1374_wdt_unlocked_ioctl,
585 .write = ds1374_wdt_write,
586 .open = ds1374_wdt_open,
587 .release = ds1374_wdt_release,
588 .llseek = no_llseek,
589};
590
591static struct miscdevice ds1374_miscdev = {
592 .minor = WATCHDOG_MINOR,
593 .name = "watchdog",
594 .fops = &ds1374_wdt_fops,
595};
596
597static struct notifier_block ds1374_wdt_notifier = {
598 .notifier_call = ds1374_wdt_notify_sys,
599};
600
601#endif /*CONFIG_RTC_DRV_DS1374_WDT*/
602/*
603 *****************************************************************************
604 *
605 * Driver Interface
606 *
607 *****************************************************************************
608 */
609static int ds1374_probe(struct i2c_client *client,
610 const struct i2c_device_id *id)
611{
612 struct ds1374 *ds1374;
613 int ret;
614
615 ds1374 = devm_kzalloc(&client->dev, sizeof(struct ds1374), GFP_KERNEL);
616 if (!ds1374)
617 return -ENOMEM;
618
619 ds1374->client = client;
620 i2c_set_clientdata(client, ds1374);
621
622 INIT_WORK(&ds1374->work, ds1374_work);
623 mutex_init(&ds1374->mutex);
624
625 ret = ds1374_check_rtc_status(client);
626 if (ret)
627 return ret;
628
629 if (client->irq > 0) {
630 ret = devm_request_irq(&client->dev, client->irq, ds1374_irq, 0,
631 "ds1374", client);
632 if (ret) {
633 dev_err(&client->dev, "unable to request IRQ\n");
634 return ret;
635 }
636
637 device_set_wakeup_capable(&client->dev, 1);
638 }
639
640 ds1374->rtc = devm_rtc_device_register(&client->dev, client->name,
641 &ds1374_rtc_ops, THIS_MODULE);
642 if (IS_ERR(ds1374->rtc)) {
643 dev_err(&client->dev, "unable to register the class device\n");
644 return PTR_ERR(ds1374->rtc);
645 }
646
647#ifdef CONFIG_RTC_DRV_DS1374_WDT
648 save_client = client;
649 ret = misc_register(&ds1374_miscdev);
650 if (ret)
651 return ret;
652 ret = register_reboot_notifier(&ds1374_wdt_notifier);
653 if (ret) {
654 misc_deregister(&ds1374_miscdev);
655 return ret;
656 }
657 ds1374_wdt_settimeout(131072);
658#endif
659
660 return 0;
661}
662
663static int ds1374_remove(struct i2c_client *client)
664{
665 struct ds1374 *ds1374 = i2c_get_clientdata(client);
666#ifdef CONFIG_RTC_DRV_DS1374_WDT
667 misc_deregister(&ds1374_miscdev);
668 ds1374_miscdev.parent = NULL;
669 unregister_reboot_notifier(&ds1374_wdt_notifier);
670#endif
671
672 if (client->irq > 0) {
673 mutex_lock(&ds1374->mutex);
674 ds1374->exiting = 1;
675 mutex_unlock(&ds1374->mutex);
676
677 devm_free_irq(&client->dev, client->irq, client);
678 cancel_work_sync(&ds1374->work);
679 }
680
681 return 0;
682}
683
684#ifdef CONFIG_PM_SLEEP
685static int ds1374_suspend(struct device *dev)
686{
687 struct i2c_client *client = to_i2c_client(dev);
688
689 if (client->irq > 0 && device_may_wakeup(&client->dev))
690 enable_irq_wake(client->irq);
691 return 0;
692}
693
694static int ds1374_resume(struct device *dev)
695{
696 struct i2c_client *client = to_i2c_client(dev);
697
698 if (client->irq > 0 && device_may_wakeup(&client->dev))
699 disable_irq_wake(client->irq);
700 return 0;
701}
702#endif
703
704static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);
705
706static struct i2c_driver ds1374_driver = {
707 .driver = {
708 .name = "rtc-ds1374",
709 .pm = &ds1374_pm,
710 },
711 .probe = ds1374_probe,
712 .remove = ds1374_remove,
713 .id_table = ds1374_id,
714};
715
716module_i2c_driver(ds1374_driver);
717
718MODULE_AUTHOR("Scott Wood <scottwood@freescale.com>");
719MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver");
720MODULE_LICENSE("GPL");