diff options
-rw-r--r-- | drivers/rtc/Kconfig | 11 | ||||
-rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
-rw-r--r-- | drivers/rtc/rtc-ds1374.c | 449 |
3 files changed, 461 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index ff9e35cb308d..6420a90a4a92 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig | |||
@@ -139,6 +139,17 @@ config RTC_DRV_DS1307 | |||
139 | This driver can also be built as a module. If so, the module | 139 | This driver can also be built as a module. If so, the module |
140 | will be called rtc-ds1307. | 140 | will be called rtc-ds1307. |
141 | 141 | ||
142 | config RTC_DRV_DS1374 | ||
143 | tristate "Maxim/Dallas Semiconductor DS1374 Real Time Clock" | ||
144 | depends on RTC_CLASS && I2C | ||
145 | help | ||
146 | If you say yes here you get support for Dallas Semiconductor | ||
147 | DS1374 real-time clock chips. If an interrupt is associated | ||
148 | with the device, the alarm functionality is supported. | ||
149 | |||
150 | This driver can also be built as a module. If so, the module | ||
151 | will be called rtc-ds1374. | ||
152 | |||
142 | config RTC_DRV_DS1672 | 153 | config RTC_DRV_DS1672 |
143 | tristate "Dallas/Maxim DS1672" | 154 | tristate "Dallas/Maxim DS1672" |
144 | help | 155 | help |
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index d3a33aa2696f..465db4dd50b2 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile | |||
@@ -23,6 +23,7 @@ obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o | |||
23 | obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o | 23 | obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o |
24 | obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o | 24 | obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o |
25 | obj-$(CONFIG_RTC_DRV_DS1307) += rtc-ds1307.o | 25 | obj-$(CONFIG_RTC_DRV_DS1307) += rtc-ds1307.o |
26 | obj-$(CONFIG_RTC_DRV_DS1374) += rtc-ds1374.o | ||
26 | obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o | 27 | obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o |
27 | obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o | 28 | obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o |
28 | obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o | 29 | obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o |
diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c new file mode 100644 index 000000000000..45bda186befc --- /dev/null +++ b/drivers/rtc/rtc-ds1374.c | |||
@@ -0,0 +1,449 @@ | |||
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 | |||
28 | #define DS1374_REG_TOD0 0x00 /* Time of Day */ | ||
29 | #define DS1374_REG_TOD1 0x01 | ||
30 | #define DS1374_REG_TOD2 0x02 | ||
31 | #define DS1374_REG_TOD3 0x03 | ||
32 | #define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */ | ||
33 | #define DS1374_REG_WDALM1 0x05 | ||
34 | #define DS1374_REG_WDALM2 0x06 | ||
35 | #define DS1374_REG_CR 0x07 /* Control */ | ||
36 | #define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */ | ||
37 | #define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */ | ||
38 | #define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */ | ||
39 | #define DS1374_REG_SR 0x08 /* Status */ | ||
40 | #define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */ | ||
41 | #define DS1374_REG_SR_AF 0x01 /* Alarm Flag */ | ||
42 | #define DS1374_REG_TCR 0x09 /* Trickle Charge */ | ||
43 | |||
44 | struct ds1374 { | ||
45 | struct i2c_client *client; | ||
46 | struct rtc_device *rtc; | ||
47 | struct work_struct work; | ||
48 | |||
49 | /* The mutex protects alarm operations, and prevents a race | ||
50 | * between the enable_irq() in the workqueue and the free_irq() | ||
51 | * in the remove function. | ||
52 | */ | ||
53 | struct mutex mutex; | ||
54 | int exiting; | ||
55 | }; | ||
56 | |||
57 | static struct i2c_driver ds1374_driver; | ||
58 | |||
59 | static int ds1374_read_rtc(struct i2c_client *client, u32 *time, | ||
60 | int reg, int nbytes) | ||
61 | { | ||
62 | u8 buf[4]; | ||
63 | int ret; | ||
64 | int i; | ||
65 | |||
66 | if (nbytes > 4) { | ||
67 | WARN_ON(1); | ||
68 | return -EINVAL; | ||
69 | } | ||
70 | |||
71 | ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf); | ||
72 | |||
73 | if (ret < 0) | ||
74 | return ret; | ||
75 | if (ret < nbytes) | ||
76 | return -EIO; | ||
77 | |||
78 | for (i = nbytes - 1, *time = 0; i >= 0; i--) | ||
79 | *time = (*time << 8) | buf[i]; | ||
80 | |||
81 | return 0; | ||
82 | } | ||
83 | |||
84 | static int ds1374_write_rtc(struct i2c_client *client, u32 time, | ||
85 | int reg, int nbytes) | ||
86 | { | ||
87 | u8 buf[4]; | ||
88 | int i; | ||
89 | |||
90 | if (nbytes > 4) { | ||
91 | WARN_ON(1); | ||
92 | return -EINVAL; | ||
93 | } | ||
94 | |||
95 | for (i = 0; i < nbytes; i++) { | ||
96 | buf[i] = time & 0xff; | ||
97 | time >>= 8; | ||
98 | } | ||
99 | |||
100 | return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf); | ||
101 | } | ||
102 | |||
103 | static int ds1374_check_rtc_status(struct i2c_client *client) | ||
104 | { | ||
105 | int ret = 0; | ||
106 | int control, stat; | ||
107 | |||
108 | stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR); | ||
109 | if (stat < 0) | ||
110 | return stat; | ||
111 | |||
112 | if (stat & DS1374_REG_SR_OSF) | ||
113 | dev_warn(&client->dev, | ||
114 | "oscillator discontinuity flagged, " | ||
115 | "time unreliable\n"); | ||
116 | |||
117 | stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF); | ||
118 | |||
119 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat); | ||
120 | if (ret < 0) | ||
121 | return ret; | ||
122 | |||
123 | /* If the alarm is pending, clear it before requesting | ||
124 | * the interrupt, so an interrupt event isn't reported | ||
125 | * before everything is initialized. | ||
126 | */ | ||
127 | |||
128 | control = i2c_smbus_read_byte_data(client, DS1374_REG_CR); | ||
129 | if (control < 0) | ||
130 | return control; | ||
131 | |||
132 | control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE); | ||
133 | return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control); | ||
134 | } | ||
135 | |||
136 | static int ds1374_read_time(struct device *dev, struct rtc_time *time) | ||
137 | { | ||
138 | struct i2c_client *client = to_i2c_client(dev); | ||
139 | u32 itime; | ||
140 | int ret; | ||
141 | |||
142 | ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4); | ||
143 | if (!ret) | ||
144 | rtc_time_to_tm(itime, time); | ||
145 | |||
146 | return ret; | ||
147 | } | ||
148 | |||
149 | static int ds1374_set_time(struct device *dev, struct rtc_time *time) | ||
150 | { | ||
151 | struct i2c_client *client = to_i2c_client(dev); | ||
152 | unsigned long itime; | ||
153 | |||
154 | rtc_tm_to_time(time, &itime); | ||
155 | return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4); | ||
156 | } | ||
157 | |||
158 | /* The ds1374 has a decrementer for an alarm, rather than a comparator. | ||
159 | * If the time of day is changed, then the alarm will need to be | ||
160 | * reset. | ||
161 | */ | ||
162 | static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) | ||
163 | { | ||
164 | struct i2c_client *client = to_i2c_client(dev); | ||
165 | struct ds1374 *ds1374 = i2c_get_clientdata(client); | ||
166 | u32 now, cur_alarm; | ||
167 | int cr, sr; | ||
168 | int ret = 0; | ||
169 | |||
170 | if (client->irq < 0) | ||
171 | return -EINVAL; | ||
172 | |||
173 | mutex_lock(&ds1374->mutex); | ||
174 | |||
175 | cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR); | ||
176 | if (ret < 0) | ||
177 | goto out; | ||
178 | |||
179 | sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR); | ||
180 | if (ret < 0) | ||
181 | goto out; | ||
182 | |||
183 | ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4); | ||
184 | if (ret) | ||
185 | goto out; | ||
186 | |||
187 | ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3); | ||
188 | if (ret) | ||
189 | goto out; | ||
190 | |||
191 | rtc_time_to_tm(now + cur_alarm, &alarm->time); | ||
192 | alarm->enabled = !!(cr & DS1374_REG_CR_WACE); | ||
193 | alarm->pending = !!(sr & DS1374_REG_SR_AF); | ||
194 | |||
195 | out: | ||
196 | mutex_unlock(&ds1374->mutex); | ||
197 | return ret; | ||
198 | } | ||
199 | |||
200 | static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) | ||
201 | { | ||
202 | struct i2c_client *client = to_i2c_client(dev); | ||
203 | struct ds1374 *ds1374 = i2c_get_clientdata(client); | ||
204 | struct rtc_time now; | ||
205 | unsigned long new_alarm, itime; | ||
206 | int cr; | ||
207 | int ret = 0; | ||
208 | |||
209 | if (client->irq < 0) | ||
210 | return -EINVAL; | ||
211 | |||
212 | ret = ds1374_read_time(dev, &now); | ||
213 | if (ret < 0) | ||
214 | return ret; | ||
215 | |||
216 | rtc_tm_to_time(&alarm->time, &new_alarm); | ||
217 | rtc_tm_to_time(&now, &itime); | ||
218 | |||
219 | new_alarm -= itime; | ||
220 | |||
221 | /* This can happen due to races, in addition to dates that are | ||
222 | * truly in the past. To avoid requiring the caller to check for | ||
223 | * races, dates in the past are assumed to be in the recent past | ||
224 | * (i.e. not something that we'd rather the caller know about via | ||
225 | * an error), and the alarm is set to go off as soon as possible. | ||
226 | */ | ||
227 | if (new_alarm <= 0) | ||
228 | new_alarm = 1; | ||
229 | |||
230 | mutex_lock(&ds1374->mutex); | ||
231 | |||
232 | ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR); | ||
233 | if (ret < 0) | ||
234 | goto out; | ||
235 | |||
236 | /* Disable any existing alarm before setting the new one | ||
237 | * (or lack thereof). */ | ||
238 | cr &= ~DS1374_REG_CR_WACE; | ||
239 | |||
240 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); | ||
241 | if (ret < 0) | ||
242 | goto out; | ||
243 | |||
244 | ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3); | ||
245 | if (ret) | ||
246 | goto out; | ||
247 | |||
248 | if (alarm->enabled) { | ||
249 | cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE; | ||
250 | cr &= ~DS1374_REG_CR_WDALM; | ||
251 | |||
252 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); | ||
253 | } | ||
254 | |||
255 | out: | ||
256 | mutex_unlock(&ds1374->mutex); | ||
257 | return ret; | ||
258 | } | ||
259 | |||
260 | static irqreturn_t ds1374_irq(int irq, void *dev_id) | ||
261 | { | ||
262 | struct i2c_client *client = dev_id; | ||
263 | struct ds1374 *ds1374 = i2c_get_clientdata(client); | ||
264 | |||
265 | disable_irq_nosync(irq); | ||
266 | schedule_work(&ds1374->work); | ||
267 | return IRQ_HANDLED; | ||
268 | } | ||
269 | |||
270 | static void ds1374_work(struct work_struct *work) | ||
271 | { | ||
272 | struct ds1374 *ds1374 = container_of(work, struct ds1374, work); | ||
273 | struct i2c_client *client = ds1374->client; | ||
274 | int stat, control; | ||
275 | |||
276 | mutex_lock(&ds1374->mutex); | ||
277 | |||
278 | stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR); | ||
279 | if (stat < 0) | ||
280 | return; | ||
281 | |||
282 | if (stat & DS1374_REG_SR_AF) { | ||
283 | stat &= ~DS1374_REG_SR_AF; | ||
284 | i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat); | ||
285 | |||
286 | control = i2c_smbus_read_byte_data(client, DS1374_REG_CR); | ||
287 | if (control < 0) | ||
288 | goto out; | ||
289 | |||
290 | control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE); | ||
291 | i2c_smbus_write_byte_data(client, DS1374_REG_CR, control); | ||
292 | |||
293 | /* rtc_update_irq() assumes that it is called | ||
294 | * from IRQ-disabled context. | ||
295 | */ | ||
296 | local_irq_disable(); | ||
297 | rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF); | ||
298 | local_irq_enable(); | ||
299 | } | ||
300 | |||
301 | out: | ||
302 | if (!ds1374->exiting) | ||
303 | enable_irq(client->irq); | ||
304 | |||
305 | mutex_unlock(&ds1374->mutex); | ||
306 | } | ||
307 | |||
308 | static int ds1374_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) | ||
309 | { | ||
310 | struct i2c_client *client = to_i2c_client(dev); | ||
311 | struct ds1374 *ds1374 = i2c_get_clientdata(client); | ||
312 | int ret = -ENOIOCTLCMD; | ||
313 | |||
314 | mutex_lock(&ds1374->mutex); | ||
315 | |||
316 | switch (cmd) { | ||
317 | case RTC_AIE_OFF: | ||
318 | ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR); | ||
319 | if (ret < 0) | ||
320 | goto out; | ||
321 | |||
322 | ret &= ~DS1374_REG_CR_WACE; | ||
323 | |||
324 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret); | ||
325 | if (ret < 0) | ||
326 | goto out; | ||
327 | |||
328 | break; | ||
329 | |||
330 | case RTC_AIE_ON: | ||
331 | ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR); | ||
332 | if (ret < 0) | ||
333 | goto out; | ||
334 | |||
335 | ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE; | ||
336 | ret &= ~DS1374_REG_CR_WDALM; | ||
337 | |||
338 | ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret); | ||
339 | if (ret < 0) | ||
340 | goto out; | ||
341 | |||
342 | break; | ||
343 | } | ||
344 | |||
345 | out: | ||
346 | mutex_unlock(&ds1374->mutex); | ||
347 | return ret; | ||
348 | } | ||
349 | |||
350 | static const struct rtc_class_ops ds1374_rtc_ops = { | ||
351 | .read_time = ds1374_read_time, | ||
352 | .set_time = ds1374_set_time, | ||
353 | .read_alarm = ds1374_read_alarm, | ||
354 | .set_alarm = ds1374_set_alarm, | ||
355 | .ioctl = ds1374_ioctl, | ||
356 | }; | ||
357 | |||
358 | static int ds1374_probe(struct i2c_client *client) | ||
359 | { | ||
360 | struct ds1374 *ds1374; | ||
361 | int ret; | ||
362 | |||
363 | ds1374 = kzalloc(sizeof(struct ds1374), GFP_KERNEL); | ||
364 | if (!ds1374) | ||
365 | return -ENOMEM; | ||
366 | |||
367 | ds1374->client = client; | ||
368 | i2c_set_clientdata(client, ds1374); | ||
369 | |||
370 | INIT_WORK(&ds1374->work, ds1374_work); | ||
371 | mutex_init(&ds1374->mutex); | ||
372 | |||
373 | ret = ds1374_check_rtc_status(client); | ||
374 | if (ret) | ||
375 | goto out_free; | ||
376 | |||
377 | if (client->irq >= 0) { | ||
378 | ret = request_irq(client->irq, ds1374_irq, 0, | ||
379 | "ds1374", client); | ||
380 | if (ret) { | ||
381 | dev_err(&client->dev, "unable to request IRQ\n"); | ||
382 | goto out_free; | ||
383 | } | ||
384 | } | ||
385 | |||
386 | ds1374->rtc = rtc_device_register(client->name, &client->dev, | ||
387 | &ds1374_rtc_ops, THIS_MODULE); | ||
388 | if (IS_ERR(ds1374->rtc)) { | ||
389 | ret = PTR_ERR(ds1374->rtc); | ||
390 | dev_err(&client->dev, "unable to register the class device\n"); | ||
391 | goto out_irq; | ||
392 | } | ||
393 | |||
394 | return 0; | ||
395 | |||
396 | out_irq: | ||
397 | if (client->irq >= 0) | ||
398 | free_irq(client->irq, client); | ||
399 | |||
400 | out_free: | ||
401 | i2c_set_clientdata(client, NULL); | ||
402 | kfree(ds1374); | ||
403 | return ret; | ||
404 | } | ||
405 | |||
406 | static int __devexit ds1374_remove(struct i2c_client *client) | ||
407 | { | ||
408 | struct ds1374 *ds1374 = i2c_get_clientdata(client); | ||
409 | |||
410 | if (client->irq >= 0) { | ||
411 | mutex_lock(&ds1374->mutex); | ||
412 | ds1374->exiting = 1; | ||
413 | mutex_unlock(&ds1374->mutex); | ||
414 | |||
415 | free_irq(client->irq, client); | ||
416 | flush_scheduled_work(); | ||
417 | } | ||
418 | |||
419 | rtc_device_unregister(ds1374->rtc); | ||
420 | i2c_set_clientdata(client, NULL); | ||
421 | kfree(ds1374); | ||
422 | return 0; | ||
423 | } | ||
424 | |||
425 | static struct i2c_driver ds1374_driver = { | ||
426 | .driver = { | ||
427 | .name = "rtc-ds1374", | ||
428 | .owner = THIS_MODULE, | ||
429 | }, | ||
430 | .probe = ds1374_probe, | ||
431 | .remove = __devexit_p(ds1374_remove), | ||
432 | }; | ||
433 | |||
434 | static int __init ds1374_init(void) | ||
435 | { | ||
436 | return i2c_add_driver(&ds1374_driver); | ||
437 | } | ||
438 | |||
439 | static void __exit ds1374_exit(void) | ||
440 | { | ||
441 | i2c_del_driver(&ds1374_driver); | ||
442 | } | ||
443 | |||
444 | module_init(ds1374_init); | ||
445 | module_exit(ds1374_exit); | ||
446 | |||
447 | MODULE_AUTHOR("Scott Wood <scottwood@freescale.com>"); | ||
448 | MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver"); | ||
449 | MODULE_LICENSE("GPL"); | ||