Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Seiko Instruments S-35390A RTC Driver
4 *
5 * Copyright (c) 2007 Byron Bradley
6 */
7
8#include <linux/module.h>
9#include <linux/rtc.h>
10#include <linux/i2c.h>
11#include <linux/bitrev.h>
12#include <linux/bcd.h>
13#include <linux/slab.h>
14#include <linux/delay.h>
15
16#define S35390A_CMD_STATUS1 0
17#define S35390A_CMD_STATUS2 1
18#define S35390A_CMD_TIME1 2
19#define S35390A_CMD_TIME2 3
20#define S35390A_CMD_INT2_REG1 5
21
22#define S35390A_BYTE_YEAR 0
23#define S35390A_BYTE_MONTH 1
24#define S35390A_BYTE_DAY 2
25#define S35390A_BYTE_WDAY 3
26#define S35390A_BYTE_HOURS 4
27#define S35390A_BYTE_MINS 5
28#define S35390A_BYTE_SECS 6
29
30#define S35390A_ALRM_BYTE_WDAY 0
31#define S35390A_ALRM_BYTE_HOURS 1
32#define S35390A_ALRM_BYTE_MINS 2
33
34/* flags for STATUS1 */
35#define S35390A_FLAG_POC BIT(0)
36#define S35390A_FLAG_BLD BIT(1)
37#define S35390A_FLAG_INT2 BIT(2)
38#define S35390A_FLAG_24H BIT(6)
39#define S35390A_FLAG_RESET BIT(7)
40
41/* flag for STATUS2 */
42#define S35390A_FLAG_TEST BIT(0)
43
44/* INT2 pin output mode */
45#define S35390A_INT2_MODE_MASK 0x0E
46#define S35390A_INT2_MODE_NOINTR 0x00
47#define S35390A_INT2_MODE_ALARM BIT(1) /* INT2AE */
48#define S35390A_INT2_MODE_PMIN_EDG BIT(2) /* INT2ME */
49#define S35390A_INT2_MODE_FREQ BIT(3) /* INT2FE */
50#define S35390A_INT2_MODE_PMIN (BIT(3) | BIT(2)) /* INT2FE | INT2ME */
51
52static const struct i2c_device_id s35390a_id[] = {
53 { "s35390a" },
54 { }
55};
56MODULE_DEVICE_TABLE(i2c, s35390a_id);
57
58static const __maybe_unused struct of_device_id s35390a_of_match[] = {
59 { .compatible = "sii,s35390a" },
60 { }
61};
62MODULE_DEVICE_TABLE(of, s35390a_of_match);
63
64struct s35390a {
65 struct i2c_client *client[8];
66 struct rtc_device *rtc;
67 int twentyfourhour;
68};
69
70static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
71{
72 struct i2c_client *client = s35390a->client[reg];
73 struct i2c_msg msg[] = {
74 {
75 .addr = client->addr,
76 .len = len,
77 .buf = buf
78 },
79 };
80
81 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
82 return -EIO;
83
84 return 0;
85}
86
87static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
88{
89 struct i2c_client *client = s35390a->client[reg];
90 struct i2c_msg msg[] = {
91 {
92 .addr = client->addr,
93 .flags = I2C_M_RD,
94 .len = len,
95 .buf = buf
96 },
97 };
98
99 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
100 return -EIO;
101
102 return 0;
103}
104
105static int s35390a_init(struct s35390a *s35390a)
106{
107 u8 buf;
108 int ret;
109 unsigned initcount = 0;
110
111 /*
112 * At least one of POC and BLD are set, so reinitialise chip. Keeping
113 * this information in the hardware to know later that the time isn't
114 * valid is unfortunately not possible because POC and BLD are cleared
115 * on read. So the reset is best done now.
116 *
117 * The 24H bit is kept over reset, so set it already here.
118 */
119initialize:
120 buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
121 ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
122
123 if (ret < 0)
124 return ret;
125
126 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
127 if (ret < 0)
128 return ret;
129
130 if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
131 /* Try up to five times to reset the chip */
132 if (initcount < 5) {
133 ++initcount;
134 goto initialize;
135 } else
136 return -EIO;
137 }
138
139 return 1;
140}
141
142/*
143 * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
144 * To keep the information if an irq is pending, pass the value read from
145 * STATUS1 to the caller.
146 */
147static int s35390a_read_status(struct s35390a *s35390a, char *status1)
148{
149 int ret;
150
151 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
152 if (ret < 0)
153 return ret;
154
155 if (*status1 & S35390A_FLAG_POC) {
156 /*
157 * Do not communicate for 0.5 seconds since the power-on
158 * detection circuit is in operation.
159 */
160 msleep(500);
161 return 1;
162 } else if (*status1 & S35390A_FLAG_BLD)
163 return 1;
164 /*
165 * If both POC and BLD are unset everything is fine.
166 */
167 return 0;
168}
169
170static int s35390a_disable_test_mode(struct s35390a *s35390a)
171{
172 char buf[1];
173
174 if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
175 return -EIO;
176
177 if (!(buf[0] & S35390A_FLAG_TEST))
178 return 0;
179
180 buf[0] &= ~S35390A_FLAG_TEST;
181 return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
182}
183
184static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
185{
186 if (s35390a->twentyfourhour)
187 return bin2bcd(hour);
188
189 if (hour < 12)
190 return bin2bcd(hour);
191
192 return 0x40 | bin2bcd(hour - 12);
193}
194
195static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
196{
197 unsigned hour;
198
199 if (s35390a->twentyfourhour)
200 return bcd2bin(reg & 0x3f);
201
202 hour = bcd2bin(reg & 0x3f);
203 if (reg & 0x40)
204 hour += 12;
205
206 return hour;
207}
208
209static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
210{
211 struct i2c_client *client = to_i2c_client(dev);
212 struct s35390a *s35390a = i2c_get_clientdata(client);
213 int i;
214 char buf[7], status;
215
216 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
217 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
218 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
219 tm->tm_wday);
220
221 if (s35390a_read_status(s35390a, &status) == 1)
222 s35390a_init(s35390a);
223
224 buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
225 buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
226 buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
227 buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
228 buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
229 buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
230 buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
231
232 /* This chip expects the bits of each byte to be in reverse order */
233 for (i = 0; i < 7; ++i)
234 buf[i] = bitrev8(buf[i]);
235
236 return s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
237}
238
239static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
240{
241 struct i2c_client *client = to_i2c_client(dev);
242 struct s35390a *s35390a = i2c_get_clientdata(client);
243 char buf[7], status;
244 int i, err;
245
246 if (s35390a_read_status(s35390a, &status) == 1)
247 return -EINVAL;
248
249 err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
250 if (err < 0)
251 return err;
252
253 /* This chip returns the bits of each byte in reverse order */
254 for (i = 0; i < 7; ++i)
255 buf[i] = bitrev8(buf[i]);
256
257 tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
258 tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
259 tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
260 tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
261 tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
262 tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
263 tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
264
265 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
266 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
267 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
268 tm->tm_wday);
269
270 return 0;
271}
272
273static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
274{
275 struct i2c_client *client = to_i2c_client(dev);
276 struct s35390a *s35390a = i2c_get_clientdata(client);
277 char buf[3], sts = 0;
278 int err, i;
279
280 dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
281 "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
282 alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
283 alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
284
285 /* disable interrupt (which deasserts the irq line) */
286 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
287 if (err < 0)
288 return err;
289
290 /* clear pending interrupt (in STATUS1 only), if any */
291 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
292 if (err < 0)
293 return err;
294
295 if (alm->enabled)
296 sts = S35390A_INT2_MODE_ALARM;
297 else
298 sts = S35390A_INT2_MODE_NOINTR;
299
300 /* set interupt mode*/
301 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
302 if (err < 0)
303 return err;
304
305 if (alm->time.tm_wday != -1)
306 buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
307 else
308 buf[S35390A_ALRM_BYTE_WDAY] = 0;
309
310 buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
311 alm->time.tm_hour) | 0x80;
312 buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;
313
314 if (alm->time.tm_hour >= 12)
315 buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;
316
317 for (i = 0; i < 3; ++i)
318 buf[i] = bitrev8(buf[i]);
319
320 err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
321 sizeof(buf));
322
323 return err;
324}
325
326static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
327{
328 struct i2c_client *client = to_i2c_client(dev);
329 struct s35390a *s35390a = i2c_get_clientdata(client);
330 char buf[3], sts;
331 int i, err;
332
333 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
334 if (err < 0)
335 return err;
336
337 if ((sts & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
338 /*
339 * When the alarm isn't enabled, the register to configure
340 * the alarm time isn't accessible.
341 */
342 alm->enabled = 0;
343 return 0;
344 } else {
345 alm->enabled = 1;
346 }
347
348 err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
349 if (err < 0)
350 return err;
351
352 /* This chip returns the bits of each byte in reverse order */
353 for (i = 0; i < 3; ++i)
354 buf[i] = bitrev8(buf[i]);
355
356 /*
357 * B0 of the three matching registers is an enable flag. Iff it is set
358 * the configured value is used for matching.
359 */
360 if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
361 alm->time.tm_wday =
362 bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
363
364 if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
365 alm->time.tm_hour =
366 s35390a_reg2hr(s35390a,
367 buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
368
369 if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
370 alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
371
372 /* alarm triggers always at s=0 */
373 alm->time.tm_sec = 0;
374
375 dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
376 __func__, alm->time.tm_min, alm->time.tm_hour,
377 alm->time.tm_wday);
378
379 return 0;
380}
381
382static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd,
383 unsigned long arg)
384{
385 struct i2c_client *client = to_i2c_client(dev);
386 struct s35390a *s35390a = i2c_get_clientdata(client);
387 char sts;
388 int err;
389
390 switch (cmd) {
391 case RTC_VL_READ:
392 /* s35390a_reset set lowvoltage flag and init RTC if needed */
393 err = s35390a_read_status(s35390a, &sts);
394 if (err < 0)
395 return err;
396 if (copy_to_user((void __user *)arg, &err, sizeof(int)))
397 return -EFAULT;
398 break;
399 case RTC_VL_CLR:
400 /* update flag and clear register */
401 err = s35390a_init(s35390a);
402 if (err < 0)
403 return err;
404 break;
405 default:
406 return -ENOIOCTLCMD;
407 }
408
409 return 0;
410}
411
412static const struct rtc_class_ops s35390a_rtc_ops = {
413 .read_time = s35390a_rtc_read_time,
414 .set_time = s35390a_rtc_set_time,
415 .set_alarm = s35390a_rtc_set_alarm,
416 .read_alarm = s35390a_rtc_read_alarm,
417 .ioctl = s35390a_rtc_ioctl,
418};
419
420static int s35390a_probe(struct i2c_client *client)
421{
422 int err, err_read;
423 unsigned int i;
424 struct s35390a *s35390a;
425 char buf, status1;
426 struct device *dev = &client->dev;
427
428 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
429 return -ENODEV;
430
431 s35390a = devm_kzalloc(dev, sizeof(struct s35390a), GFP_KERNEL);
432 if (!s35390a)
433 return -ENOMEM;
434
435 s35390a->client[0] = client;
436 i2c_set_clientdata(client, s35390a);
437
438 /* This chip uses multiple addresses, use dummy devices for them */
439 for (i = 1; i < 8; ++i) {
440 s35390a->client[i] = devm_i2c_new_dummy_device(dev,
441 client->adapter,
442 client->addr + i);
443 if (IS_ERR(s35390a->client[i])) {
444 dev_err(dev, "Address %02x unavailable\n",
445 client->addr + i);
446 return PTR_ERR(s35390a->client[i]);
447 }
448 }
449
450 s35390a->rtc = devm_rtc_allocate_device(dev);
451 if (IS_ERR(s35390a->rtc))
452 return PTR_ERR(s35390a->rtc);
453
454 err_read = s35390a_read_status(s35390a, &status1);
455 if (err_read < 0) {
456 dev_err(dev, "error resetting chip\n");
457 return err_read;
458 }
459
460 if (status1 & S35390A_FLAG_24H)
461 s35390a->twentyfourhour = 1;
462 else
463 s35390a->twentyfourhour = 0;
464
465 if (status1 & S35390A_FLAG_INT2) {
466 /* disable alarm (and maybe test mode) */
467 buf = 0;
468 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
469 if (err < 0) {
470 dev_err(dev, "error disabling alarm");
471 return err;
472 }
473 } else {
474 err = s35390a_disable_test_mode(s35390a);
475 if (err < 0) {
476 dev_err(dev, "error disabling test mode\n");
477 return err;
478 }
479 }
480
481 device_set_wakeup_capable(dev, 1);
482
483 s35390a->rtc->ops = &s35390a_rtc_ops;
484 s35390a->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
485 s35390a->rtc->range_max = RTC_TIMESTAMP_END_2099;
486
487 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, s35390a->rtc->features);
488 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, s35390a->rtc->features );
489
490 if (status1 & S35390A_FLAG_INT2)
491 rtc_update_irq(s35390a->rtc, 1, RTC_AF);
492
493 return devm_rtc_register_device(s35390a->rtc);
494}
495
496static struct i2c_driver s35390a_driver = {
497 .driver = {
498 .name = "rtc-s35390a",
499 .of_match_table = of_match_ptr(s35390a_of_match),
500 },
501 .probe = s35390a_probe,
502 .id_table = s35390a_id,
503};
504
505module_i2c_driver(s35390a_driver);
506
507MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
508MODULE_DESCRIPTION("S35390A RTC driver");
509MODULE_LICENSE("GPL");
1/*
2 * Seiko Instruments S-35390A RTC Driver
3 *
4 * Copyright (c) 2007 Byron Bradley
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/rtc.h>
14#include <linux/i2c.h>
15#include <linux/bitrev.h>
16#include <linux/bcd.h>
17#include <linux/slab.h>
18#include <linux/delay.h>
19
20#define S35390A_CMD_STATUS1 0
21#define S35390A_CMD_STATUS2 1
22#define S35390A_CMD_TIME1 2
23#define S35390A_CMD_TIME2 3
24#define S35390A_CMD_INT2_REG1 5
25
26#define S35390A_BYTE_YEAR 0
27#define S35390A_BYTE_MONTH 1
28#define S35390A_BYTE_DAY 2
29#define S35390A_BYTE_WDAY 3
30#define S35390A_BYTE_HOURS 4
31#define S35390A_BYTE_MINS 5
32#define S35390A_BYTE_SECS 6
33
34#define S35390A_ALRM_BYTE_WDAY 0
35#define S35390A_ALRM_BYTE_HOURS 1
36#define S35390A_ALRM_BYTE_MINS 2
37
38/* flags for STATUS1 */
39#define S35390A_FLAG_POC 0x01
40#define S35390A_FLAG_BLD 0x02
41#define S35390A_FLAG_INT2 0x04
42#define S35390A_FLAG_24H 0x40
43#define S35390A_FLAG_RESET 0x80
44
45/* flag for STATUS2 */
46#define S35390A_FLAG_TEST 0x01
47
48#define S35390A_INT2_MODE_MASK 0xF0
49
50#define S35390A_INT2_MODE_NOINTR 0x00
51#define S35390A_INT2_MODE_FREQ 0x10
52#define S35390A_INT2_MODE_ALARM 0x40
53#define S35390A_INT2_MODE_PMIN_EDG 0x20
54
55static const struct i2c_device_id s35390a_id[] = {
56 { "s35390a", 0 },
57 { }
58};
59MODULE_DEVICE_TABLE(i2c, s35390a_id);
60
61static const struct of_device_id s35390a_of_match[] = {
62 { .compatible = "s35390a" },
63 { .compatible = "sii,s35390a" },
64 { }
65};
66MODULE_DEVICE_TABLE(of, s35390a_of_match);
67
68struct s35390a {
69 struct i2c_client *client[8];
70 struct rtc_device *rtc;
71 int twentyfourhour;
72};
73
74static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
75{
76 struct i2c_client *client = s35390a->client[reg];
77 struct i2c_msg msg[] = {
78 {
79 .addr = client->addr,
80 .len = len,
81 .buf = buf
82 },
83 };
84
85 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
86 return -EIO;
87
88 return 0;
89}
90
91static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
92{
93 struct i2c_client *client = s35390a->client[reg];
94 struct i2c_msg msg[] = {
95 {
96 .addr = client->addr,
97 .flags = I2C_M_RD,
98 .len = len,
99 .buf = buf
100 },
101 };
102
103 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
104 return -EIO;
105
106 return 0;
107}
108
109static int s35390a_init(struct s35390a *s35390a)
110{
111 char buf;
112 int ret;
113 unsigned initcount = 0;
114
115 /*
116 * At least one of POC and BLD are set, so reinitialise chip. Keeping
117 * this information in the hardware to know later that the time isn't
118 * valid is unfortunately not possible because POC and BLD are cleared
119 * on read. So the reset is best done now.
120 *
121 * The 24H bit is kept over reset, so set it already here.
122 */
123initialize:
124 buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
125 ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
126
127 if (ret < 0)
128 return ret;
129
130 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
131 if (ret < 0)
132 return ret;
133
134 if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
135 /* Try up to five times to reset the chip */
136 if (initcount < 5) {
137 ++initcount;
138 goto initialize;
139 } else
140 return -EIO;
141 }
142
143 return 1;
144}
145
146/*
147 * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
148 * To keep the information if an irq is pending, pass the value read from
149 * STATUS1 to the caller.
150 */
151static int s35390a_read_status(struct s35390a *s35390a, char *status1)
152{
153 int ret;
154
155 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
156 if (ret < 0)
157 return ret;
158
159 if (*status1 & S35390A_FLAG_POC) {
160 /*
161 * Do not communicate for 0.5 seconds since the power-on
162 * detection circuit is in operation.
163 */
164 msleep(500);
165 return 1;
166 } else if (*status1 & S35390A_FLAG_BLD)
167 return 1;
168 /*
169 * If both POC and BLD are unset everything is fine.
170 */
171 return 0;
172}
173
174static int s35390a_disable_test_mode(struct s35390a *s35390a)
175{
176 char buf[1];
177
178 if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
179 return -EIO;
180
181 if (!(buf[0] & S35390A_FLAG_TEST))
182 return 0;
183
184 buf[0] &= ~S35390A_FLAG_TEST;
185 return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
186}
187
188static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
189{
190 if (s35390a->twentyfourhour)
191 return bin2bcd(hour);
192
193 if (hour < 12)
194 return bin2bcd(hour);
195
196 return 0x40 | bin2bcd(hour - 12);
197}
198
199static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
200{
201 unsigned hour;
202
203 if (s35390a->twentyfourhour)
204 return bcd2bin(reg & 0x3f);
205
206 hour = bcd2bin(reg & 0x3f);
207 if (reg & 0x40)
208 hour += 12;
209
210 return hour;
211}
212
213static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
214{
215 struct i2c_client *client = to_i2c_client(dev);
216 struct s35390a *s35390a = i2c_get_clientdata(client);
217 int i, err;
218 char buf[7], status;
219
220 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
221 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
222 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
223 tm->tm_wday);
224
225 if (s35390a_read_status(s35390a, &status) == 1)
226 s35390a_init(s35390a);
227
228 buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
229 buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
230 buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
231 buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
232 buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
233 buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
234 buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
235
236 /* This chip expects the bits of each byte to be in reverse order */
237 for (i = 0; i < 7; ++i)
238 buf[i] = bitrev8(buf[i]);
239
240 err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
241
242 return err;
243}
244
245static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
246{
247 struct i2c_client *client = to_i2c_client(dev);
248 struct s35390a *s35390a = i2c_get_clientdata(client);
249 char buf[7], status;
250 int i, err;
251
252 if (s35390a_read_status(s35390a, &status) == 1)
253 return -EINVAL;
254
255 err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
256 if (err < 0)
257 return err;
258
259 /* This chip returns the bits of each byte in reverse order */
260 for (i = 0; i < 7; ++i)
261 buf[i] = bitrev8(buf[i]);
262
263 tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
264 tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
265 tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
266 tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
267 tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
268 tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
269 tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
270
271 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
272 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
273 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
274 tm->tm_wday);
275
276 return 0;
277}
278
279static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
280{
281 struct i2c_client *client = to_i2c_client(dev);
282 struct s35390a *s35390a = i2c_get_clientdata(client);
283 char buf[3], sts = 0;
284 int err, i;
285
286 dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
287 "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
288 alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
289 alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
290
291 /* disable interrupt (which deasserts the irq line) */
292 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
293 if (err < 0)
294 return err;
295
296 /* clear pending interrupt (in STATUS1 only), if any */
297 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
298 if (err < 0)
299 return err;
300
301 if (alm->enabled)
302 sts = S35390A_INT2_MODE_ALARM;
303 else
304 sts = S35390A_INT2_MODE_NOINTR;
305
306 /* This chip expects the bits of each byte to be in reverse order */
307 sts = bitrev8(sts);
308
309 /* set interupt mode*/
310 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
311 if (err < 0)
312 return err;
313
314 if (alm->time.tm_wday != -1)
315 buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
316 else
317 buf[S35390A_ALRM_BYTE_WDAY] = 0;
318
319 buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
320 alm->time.tm_hour) | 0x80;
321 buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;
322
323 if (alm->time.tm_hour >= 12)
324 buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;
325
326 for (i = 0; i < 3; ++i)
327 buf[i] = bitrev8(buf[i]);
328
329 err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
330 sizeof(buf));
331
332 return err;
333}
334
335static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
336{
337 struct i2c_client *client = to_i2c_client(dev);
338 struct s35390a *s35390a = i2c_get_clientdata(client);
339 char buf[3], sts;
340 int i, err;
341
342 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
343 if (err < 0)
344 return err;
345
346 if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
347 /*
348 * When the alarm isn't enabled, the register to configure
349 * the alarm time isn't accessible.
350 */
351 alm->enabled = 0;
352 return 0;
353 } else {
354 alm->enabled = 1;
355 }
356
357 err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
358 if (err < 0)
359 return err;
360
361 /* This chip returns the bits of each byte in reverse order */
362 for (i = 0; i < 3; ++i)
363 buf[i] = bitrev8(buf[i]);
364
365 /*
366 * B0 of the three matching registers is an enable flag. Iff it is set
367 * the configured value is used for matching.
368 */
369 if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
370 alm->time.tm_wday =
371 bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
372
373 if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
374 alm->time.tm_hour =
375 s35390a_reg2hr(s35390a,
376 buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
377
378 if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
379 alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
380
381 /* alarm triggers always at s=0 */
382 alm->time.tm_sec = 0;
383
384 dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
385 __func__, alm->time.tm_min, alm->time.tm_hour,
386 alm->time.tm_wday);
387
388 return 0;
389}
390
391static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd,
392 unsigned long arg)
393{
394 struct i2c_client *client = to_i2c_client(dev);
395 struct s35390a *s35390a = i2c_get_clientdata(client);
396 char sts;
397 int err;
398
399 switch (cmd) {
400 case RTC_VL_READ:
401 /* s35390a_reset set lowvoltage flag and init RTC if needed */
402 err = s35390a_read_status(s35390a, &sts);
403 if (err < 0)
404 return err;
405 if (copy_to_user((void __user *)arg, &err, sizeof(int)))
406 return -EFAULT;
407 break;
408 case RTC_VL_CLR:
409 /* update flag and clear register */
410 err = s35390a_init(s35390a);
411 if (err < 0)
412 return err;
413 break;
414 default:
415 return -ENOIOCTLCMD;
416 }
417
418 return 0;
419}
420
421static const struct rtc_class_ops s35390a_rtc_ops = {
422 .read_time = s35390a_rtc_read_time,
423 .set_time = s35390a_rtc_set_time,
424 .set_alarm = s35390a_rtc_set_alarm,
425 .read_alarm = s35390a_rtc_read_alarm,
426 .ioctl = s35390a_rtc_ioctl,
427};
428
429static struct i2c_driver s35390a_driver;
430
431static int s35390a_probe(struct i2c_client *client,
432 const struct i2c_device_id *id)
433{
434 int err, err_read;
435 unsigned int i;
436 struct s35390a *s35390a;
437 char buf, status1;
438
439 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
440 err = -ENODEV;
441 goto exit;
442 }
443
444 s35390a = devm_kzalloc(&client->dev, sizeof(struct s35390a),
445 GFP_KERNEL);
446 if (!s35390a) {
447 err = -ENOMEM;
448 goto exit;
449 }
450
451 s35390a->client[0] = client;
452 i2c_set_clientdata(client, s35390a);
453
454 /* This chip uses multiple addresses, use dummy devices for them */
455 for (i = 1; i < 8; ++i) {
456 s35390a->client[i] = i2c_new_dummy(client->adapter,
457 client->addr + i);
458 if (!s35390a->client[i]) {
459 dev_err(&client->dev, "Address %02x unavailable\n",
460 client->addr + i);
461 err = -EBUSY;
462 goto exit_dummy;
463 }
464 }
465
466 err_read = s35390a_read_status(s35390a, &status1);
467 if (err_read < 0) {
468 err = err_read;
469 dev_err(&client->dev, "error resetting chip\n");
470 goto exit_dummy;
471 }
472
473 if (status1 & S35390A_FLAG_24H)
474 s35390a->twentyfourhour = 1;
475 else
476 s35390a->twentyfourhour = 0;
477
478 if (status1 & S35390A_FLAG_INT2) {
479 /* disable alarm (and maybe test mode) */
480 buf = 0;
481 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
482 if (err < 0) {
483 dev_err(&client->dev, "error disabling alarm");
484 goto exit_dummy;
485 }
486 } else {
487 err = s35390a_disable_test_mode(s35390a);
488 if (err < 0) {
489 dev_err(&client->dev, "error disabling test mode\n");
490 goto exit_dummy;
491 }
492 }
493
494 device_set_wakeup_capable(&client->dev, 1);
495
496 s35390a->rtc = devm_rtc_device_register(&client->dev,
497 s35390a_driver.driver.name,
498 &s35390a_rtc_ops, THIS_MODULE);
499
500 if (IS_ERR(s35390a->rtc)) {
501 err = PTR_ERR(s35390a->rtc);
502 goto exit_dummy;
503 }
504
505 if (status1 & S35390A_FLAG_INT2)
506 rtc_update_irq(s35390a->rtc, 1, RTC_AF);
507
508 return 0;
509
510exit_dummy:
511 for (i = 1; i < 8; ++i)
512 if (s35390a->client[i])
513 i2c_unregister_device(s35390a->client[i]);
514
515exit:
516 return err;
517}
518
519static int s35390a_remove(struct i2c_client *client)
520{
521 unsigned int i;
522 struct s35390a *s35390a = i2c_get_clientdata(client);
523
524 for (i = 1; i < 8; ++i)
525 if (s35390a->client[i])
526 i2c_unregister_device(s35390a->client[i]);
527
528 return 0;
529}
530
531static struct i2c_driver s35390a_driver = {
532 .driver = {
533 .name = "rtc-s35390a",
534 .of_match_table = of_match_ptr(s35390a_of_match),
535 },
536 .probe = s35390a_probe,
537 .remove = s35390a_remove,
538 .id_table = s35390a_id,
539};
540
541module_i2c_driver(s35390a_driver);
542
543MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
544MODULE_DESCRIPTION("S35390A RTC driver");
545MODULE_LICENSE("GPL");