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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", 0 },
54 { }
55};
56MODULE_DEVICE_TABLE(i2c, s35390a_id);
57
58static const __maybe_unused struct of_device_id s35390a_of_match[] = {
59 { .compatible = "s35390a" },
60 { .compatible = "sii,s35390a" },
61 { }
62};
63MODULE_DEVICE_TABLE(of, s35390a_of_match);
64
65struct s35390a {
66 struct i2c_client *client[8];
67 struct rtc_device *rtc;
68 int twentyfourhour;
69};
70
71static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
72{
73 struct i2c_client *client = s35390a->client[reg];
74 struct i2c_msg msg[] = {
75 {
76 .addr = client->addr,
77 .len = len,
78 .buf = buf
79 },
80 };
81
82 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
83 return -EIO;
84
85 return 0;
86}
87
88static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
89{
90 struct i2c_client *client = s35390a->client[reg];
91 struct i2c_msg msg[] = {
92 {
93 .addr = client->addr,
94 .flags = I2C_M_RD,
95 .len = len,
96 .buf = buf
97 },
98 };
99
100 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
101 return -EIO;
102
103 return 0;
104}
105
106static int s35390a_init(struct s35390a *s35390a)
107{
108 u8 buf;
109 int ret;
110 unsigned initcount = 0;
111
112 /*
113 * At least one of POC and BLD are set, so reinitialise chip. Keeping
114 * this information in the hardware to know later that the time isn't
115 * valid is unfortunately not possible because POC and BLD are cleared
116 * on read. So the reset is best done now.
117 *
118 * The 24H bit is kept over reset, so set it already here.
119 */
120initialize:
121 buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
122 ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
123
124 if (ret < 0)
125 return ret;
126
127 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
128 if (ret < 0)
129 return ret;
130
131 if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
132 /* Try up to five times to reset the chip */
133 if (initcount < 5) {
134 ++initcount;
135 goto initialize;
136 } else
137 return -EIO;
138 }
139
140 return 1;
141}
142
143/*
144 * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
145 * To keep the information if an irq is pending, pass the value read from
146 * STATUS1 to the caller.
147 */
148static int s35390a_read_status(struct s35390a *s35390a, char *status1)
149{
150 int ret;
151
152 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
153 if (ret < 0)
154 return ret;
155
156 if (*status1 & S35390A_FLAG_POC) {
157 /*
158 * Do not communicate for 0.5 seconds since the power-on
159 * detection circuit is in operation.
160 */
161 msleep(500);
162 return 1;
163 } else if (*status1 & S35390A_FLAG_BLD)
164 return 1;
165 /*
166 * If both POC and BLD are unset everything is fine.
167 */
168 return 0;
169}
170
171static int s35390a_disable_test_mode(struct s35390a *s35390a)
172{
173 char buf[1];
174
175 if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
176 return -EIO;
177
178 if (!(buf[0] & S35390A_FLAG_TEST))
179 return 0;
180
181 buf[0] &= ~S35390A_FLAG_TEST;
182 return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
183}
184
185static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
186{
187 if (s35390a->twentyfourhour)
188 return bin2bcd(hour);
189
190 if (hour < 12)
191 return bin2bcd(hour);
192
193 return 0x40 | bin2bcd(hour - 12);
194}
195
196static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
197{
198 unsigned hour;
199
200 if (s35390a->twentyfourhour)
201 return bcd2bin(reg & 0x3f);
202
203 hour = bcd2bin(reg & 0x3f);
204 if (reg & 0x40)
205 hour += 12;
206
207 return hour;
208}
209
210static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
211{
212 struct i2c_client *client = to_i2c_client(dev);
213 struct s35390a *s35390a = i2c_get_clientdata(client);
214 int i;
215 char buf[7], status;
216
217 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
218 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
219 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
220 tm->tm_wday);
221
222 if (s35390a_read_status(s35390a, &status) == 1)
223 s35390a_init(s35390a);
224
225 buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
226 buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
227 buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
228 buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
229 buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
230 buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
231 buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
232
233 /* This chip expects the bits of each byte to be in reverse order */
234 for (i = 0; i < 7; ++i)
235 buf[i] = bitrev8(buf[i]);
236
237 return s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
238}
239
240static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
241{
242 struct i2c_client *client = to_i2c_client(dev);
243 struct s35390a *s35390a = i2c_get_clientdata(client);
244 char buf[7], status;
245 int i, err;
246
247 if (s35390a_read_status(s35390a, &status) == 1)
248 return -EINVAL;
249
250 err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
251 if (err < 0)
252 return err;
253
254 /* This chip returns the bits of each byte in reverse order */
255 for (i = 0; i < 7; ++i)
256 buf[i] = bitrev8(buf[i]);
257
258 tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
259 tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
260 tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
261 tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
262 tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
263 tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
264 tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
265
266 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
267 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
268 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
269 tm->tm_wday);
270
271 return 0;
272}
273
274static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
275{
276 struct i2c_client *client = to_i2c_client(dev);
277 struct s35390a *s35390a = i2c_get_clientdata(client);
278 char buf[3], sts = 0;
279 int err, i;
280
281 dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
282 "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
283 alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
284 alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
285
286 /* disable interrupt (which deasserts the irq line) */
287 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
288 if (err < 0)
289 return err;
290
291 /* clear pending interrupt (in STATUS1 only), if any */
292 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
293 if (err < 0)
294 return err;
295
296 if (alm->enabled)
297 sts = S35390A_INT2_MODE_ALARM;
298 else
299 sts = S35390A_INT2_MODE_NOINTR;
300
301 /* set interupt mode*/
302 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
303 if (err < 0)
304 return err;
305
306 if (alm->time.tm_wday != -1)
307 buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
308 else
309 buf[S35390A_ALRM_BYTE_WDAY] = 0;
310
311 buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
312 alm->time.tm_hour) | 0x80;
313 buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;
314
315 if (alm->time.tm_hour >= 12)
316 buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;
317
318 for (i = 0; i < 3; ++i)
319 buf[i] = bitrev8(buf[i]);
320
321 err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
322 sizeof(buf));
323
324 return err;
325}
326
327static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
328{
329 struct i2c_client *client = to_i2c_client(dev);
330 struct s35390a *s35390a = i2c_get_clientdata(client);
331 char buf[3], sts;
332 int i, err;
333
334 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
335 if (err < 0)
336 return err;
337
338 if ((sts & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
339 /*
340 * When the alarm isn't enabled, the register to configure
341 * the alarm time isn't accessible.
342 */
343 alm->enabled = 0;
344 return 0;
345 } else {
346 alm->enabled = 1;
347 }
348
349 err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
350 if (err < 0)
351 return err;
352
353 /* This chip returns the bits of each byte in reverse order */
354 for (i = 0; i < 3; ++i)
355 buf[i] = bitrev8(buf[i]);
356
357 /*
358 * B0 of the three matching registers is an enable flag. Iff it is set
359 * the configured value is used for matching.
360 */
361 if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
362 alm->time.tm_wday =
363 bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
364
365 if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
366 alm->time.tm_hour =
367 s35390a_reg2hr(s35390a,
368 buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
369
370 if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
371 alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
372
373 /* alarm triggers always at s=0 */
374 alm->time.tm_sec = 0;
375
376 dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
377 __func__, alm->time.tm_min, alm->time.tm_hour,
378 alm->time.tm_wday);
379
380 return 0;
381}
382
383static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd,
384 unsigned long arg)
385{
386 struct i2c_client *client = to_i2c_client(dev);
387 struct s35390a *s35390a = i2c_get_clientdata(client);
388 char sts;
389 int err;
390
391 switch (cmd) {
392 case RTC_VL_READ:
393 /* s35390a_reset set lowvoltage flag and init RTC if needed */
394 err = s35390a_read_status(s35390a, &sts);
395 if (err < 0)
396 return err;
397 if (copy_to_user((void __user *)arg, &err, sizeof(int)))
398 return -EFAULT;
399 break;
400 case RTC_VL_CLR:
401 /* update flag and clear register */
402 err = s35390a_init(s35390a);
403 if (err < 0)
404 return err;
405 break;
406 default:
407 return -ENOIOCTLCMD;
408 }
409
410 return 0;
411}
412
413static const struct rtc_class_ops s35390a_rtc_ops = {
414 .read_time = s35390a_rtc_read_time,
415 .set_time = s35390a_rtc_set_time,
416 .set_alarm = s35390a_rtc_set_alarm,
417 .read_alarm = s35390a_rtc_read_alarm,
418 .ioctl = s35390a_rtc_ioctl,
419};
420
421static int s35390a_probe(struct i2c_client *client)
422{
423 int err, err_read;
424 unsigned int i;
425 struct s35390a *s35390a;
426 char buf, status1;
427 struct device *dev = &client->dev;
428
429 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
430 return -ENODEV;
431
432 s35390a = devm_kzalloc(dev, sizeof(struct s35390a), GFP_KERNEL);
433 if (!s35390a)
434 return -ENOMEM;
435
436 s35390a->client[0] = client;
437 i2c_set_clientdata(client, s35390a);
438
439 /* This chip uses multiple addresses, use dummy devices for them */
440 for (i = 1; i < 8; ++i) {
441 s35390a->client[i] = devm_i2c_new_dummy_device(dev,
442 client->adapter,
443 client->addr + i);
444 if (IS_ERR(s35390a->client[i])) {
445 dev_err(dev, "Address %02x unavailable\n",
446 client->addr + i);
447 return PTR_ERR(s35390a->client[i]);
448 }
449 }
450
451 s35390a->rtc = devm_rtc_allocate_device(dev);
452 if (IS_ERR(s35390a->rtc))
453 return PTR_ERR(s35390a->rtc);
454
455 err_read = s35390a_read_status(s35390a, &status1);
456 if (err_read < 0) {
457 dev_err(dev, "error resetting chip\n");
458 return err_read;
459 }
460
461 if (status1 & S35390A_FLAG_24H)
462 s35390a->twentyfourhour = 1;
463 else
464 s35390a->twentyfourhour = 0;
465
466 if (status1 & S35390A_FLAG_INT2) {
467 /* disable alarm (and maybe test mode) */
468 buf = 0;
469 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
470 if (err < 0) {
471 dev_err(dev, "error disabling alarm");
472 return err;
473 }
474 } else {
475 err = s35390a_disable_test_mode(s35390a);
476 if (err < 0) {
477 dev_err(dev, "error disabling test mode\n");
478 return err;
479 }
480 }
481
482 device_set_wakeup_capable(dev, 1);
483
484 s35390a->rtc->ops = &s35390a_rtc_ops;
485 s35390a->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
486 s35390a->rtc->range_max = RTC_TIMESTAMP_END_2099;
487
488 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, s35390a->rtc->features);
489 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, s35390a->rtc->features );
490
491 if (status1 & S35390A_FLAG_INT2)
492 rtc_update_irq(s35390a->rtc, 1, RTC_AF);
493
494 return devm_rtc_register_device(s35390a->rtc);
495}
496
497static struct i2c_driver s35390a_driver = {
498 .driver = {
499 .name = "rtc-s35390a",
500 .of_match_table = of_match_ptr(s35390a_of_match),
501 },
502 .probe = s35390a_probe,
503 .id_table = s35390a_id,
504};
505
506module_i2c_driver(s35390a_driver);
507
508MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
509MODULE_DESCRIPTION("S35390A RTC driver");
510MODULE_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
61struct s35390a {
62 struct i2c_client *client[8];
63 struct rtc_device *rtc;
64 int twentyfourhour;
65};
66
67static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
68{
69 struct i2c_client *client = s35390a->client[reg];
70 struct i2c_msg msg[] = {
71 {
72 .addr = client->addr,
73 .len = len,
74 .buf = buf
75 },
76 };
77
78 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
79 return -EIO;
80
81 return 0;
82}
83
84static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
85{
86 struct i2c_client *client = s35390a->client[reg];
87 struct i2c_msg msg[] = {
88 {
89 .addr = client->addr,
90 .flags = I2C_M_RD,
91 .len = len,
92 .buf = buf
93 },
94 };
95
96 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
97 return -EIO;
98
99 return 0;
100}
101
102/*
103 * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
104 * To keep the information if an irq is pending, pass the value read from
105 * STATUS1 to the caller.
106 */
107static int s35390a_reset(struct s35390a *s35390a, char *status1)
108{
109 char buf;
110 int ret;
111 unsigned initcount = 0;
112
113 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
114 if (ret < 0)
115 return ret;
116
117 if (*status1 & S35390A_FLAG_POC)
118 /*
119 * Do not communicate for 0.5 seconds since the power-on
120 * detection circuit is in operation.
121 */
122 msleep(500);
123 else if (!(*status1 & S35390A_FLAG_BLD))
124 /*
125 * If both POC and BLD are unset everything is fine.
126 */
127 return 0;
128
129 /*
130 * At least one of POC and BLD are set, so reinitialise chip. Keeping
131 * this information in the hardware to know later that the time isn't
132 * valid is unfortunately not possible because POC and BLD are cleared
133 * on read. So the reset is best done now.
134 *
135 * The 24H bit is kept over reset, so set it already here.
136 */
137initialize:
138 *status1 = S35390A_FLAG_24H;
139 buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
140 ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
141
142 if (ret < 0)
143 return ret;
144
145 ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
146 if (ret < 0)
147 return ret;
148
149 if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
150 /* Try up to five times to reset the chip */
151 if (initcount < 5) {
152 ++initcount;
153 goto initialize;
154 } else
155 return -EIO;
156 }
157
158 return 1;
159}
160
161static int s35390a_disable_test_mode(struct s35390a *s35390a)
162{
163 char buf[1];
164
165 if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
166 return -EIO;
167
168 if (!(buf[0] & S35390A_FLAG_TEST))
169 return 0;
170
171 buf[0] &= ~S35390A_FLAG_TEST;
172 return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
173}
174
175static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
176{
177 if (s35390a->twentyfourhour)
178 return bin2bcd(hour);
179
180 if (hour < 12)
181 return bin2bcd(hour);
182
183 return 0x40 | bin2bcd(hour - 12);
184}
185
186static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
187{
188 unsigned hour;
189
190 if (s35390a->twentyfourhour)
191 return bcd2bin(reg & 0x3f);
192
193 hour = bcd2bin(reg & 0x3f);
194 if (reg & 0x40)
195 hour += 12;
196
197 return hour;
198}
199
200static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm)
201{
202 struct s35390a *s35390a = i2c_get_clientdata(client);
203 int i, err;
204 char buf[7];
205
206 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
207 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
208 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
209 tm->tm_wday);
210
211 buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
212 buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
213 buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
214 buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
215 buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
216 buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
217 buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
218
219 /* This chip expects the bits of each byte to be in reverse order */
220 for (i = 0; i < 7; ++i)
221 buf[i] = bitrev8(buf[i]);
222
223 err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
224
225 return err;
226}
227
228static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm)
229{
230 struct s35390a *s35390a = i2c_get_clientdata(client);
231 char buf[7];
232 int i, err;
233
234 err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
235 if (err < 0)
236 return err;
237
238 /* This chip returns the bits of each byte in reverse order */
239 for (i = 0; i < 7; ++i)
240 buf[i] = bitrev8(buf[i]);
241
242 tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
243 tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
244 tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
245 tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
246 tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
247 tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
248 tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
249
250 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
251 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
252 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
253 tm->tm_wday);
254
255 return rtc_valid_tm(tm);
256}
257
258static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
259{
260 struct s35390a *s35390a = i2c_get_clientdata(client);
261 char buf[3], sts = 0;
262 int err, i;
263
264 dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
265 "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
266 alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
267 alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
268
269 /* disable interrupt (which deasserts the irq line) */
270 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
271 if (err < 0)
272 return err;
273
274 /* clear pending interrupt (in STATUS1 only), if any */
275 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
276 if (err < 0)
277 return err;
278
279 if (alm->enabled)
280 sts = S35390A_INT2_MODE_ALARM;
281 else
282 sts = S35390A_INT2_MODE_NOINTR;
283
284 /* This chip expects the bits of each byte to be in reverse order */
285 sts = bitrev8(sts);
286
287 /* set interupt mode*/
288 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
289 if (err < 0)
290 return err;
291
292 if (alm->time.tm_wday != -1)
293 buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
294 else
295 buf[S35390A_ALRM_BYTE_WDAY] = 0;
296
297 buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
298 alm->time.tm_hour) | 0x80;
299 buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;
300
301 if (alm->time.tm_hour >= 12)
302 buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;
303
304 for (i = 0; i < 3; ++i)
305 buf[i] = bitrev8(buf[i]);
306
307 err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
308 sizeof(buf));
309
310 return err;
311}
312
313static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
314{
315 struct s35390a *s35390a = i2c_get_clientdata(client);
316 char buf[3], sts;
317 int i, err;
318
319 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
320 if (err < 0)
321 return err;
322
323 if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
324 /*
325 * When the alarm isn't enabled, the register to configure
326 * the alarm time isn't accessible.
327 */
328 alm->enabled = 0;
329 return 0;
330 } else {
331 alm->enabled = 1;
332 }
333
334 err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
335 if (err < 0)
336 return err;
337
338 /* This chip returns the bits of each byte in reverse order */
339 for (i = 0; i < 3; ++i)
340 buf[i] = bitrev8(buf[i]);
341
342 /*
343 * B0 of the three matching registers is an enable flag. Iff it is set
344 * the configured value is used for matching.
345 */
346 if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
347 alm->time.tm_wday =
348 bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
349
350 if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
351 alm->time.tm_hour =
352 s35390a_reg2hr(s35390a,
353 buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
354
355 if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
356 alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
357
358 /* alarm triggers always at s=0 */
359 alm->time.tm_sec = 0;
360
361 dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
362 __func__, alm->time.tm_min, alm->time.tm_hour,
363 alm->time.tm_wday);
364
365 return 0;
366}
367
368static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
369{
370 return s35390a_read_alarm(to_i2c_client(dev), alm);
371}
372
373static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
374{
375 return s35390a_set_alarm(to_i2c_client(dev), alm);
376}
377
378static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
379{
380 return s35390a_get_datetime(to_i2c_client(dev), tm);
381}
382
383static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
384{
385 return s35390a_set_datetime(to_i2c_client(dev), tm);
386}
387
388static const struct rtc_class_ops s35390a_rtc_ops = {
389 .read_time = s35390a_rtc_read_time,
390 .set_time = s35390a_rtc_set_time,
391 .set_alarm = s35390a_rtc_set_alarm,
392 .read_alarm = s35390a_rtc_read_alarm,
393
394};
395
396static struct i2c_driver s35390a_driver;
397
398static int s35390a_probe(struct i2c_client *client,
399 const struct i2c_device_id *id)
400{
401 int err, err_reset;
402 unsigned int i;
403 struct s35390a *s35390a;
404 struct rtc_time tm;
405 char buf, status1;
406
407 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
408 err = -ENODEV;
409 goto exit;
410 }
411
412 s35390a = devm_kzalloc(&client->dev, sizeof(struct s35390a),
413 GFP_KERNEL);
414 if (!s35390a) {
415 err = -ENOMEM;
416 goto exit;
417 }
418
419 s35390a->client[0] = client;
420 i2c_set_clientdata(client, s35390a);
421
422 /* This chip uses multiple addresses, use dummy devices for them */
423 for (i = 1; i < 8; ++i) {
424 s35390a->client[i] = i2c_new_dummy(client->adapter,
425 client->addr + i);
426 if (!s35390a->client[i]) {
427 dev_err(&client->dev, "Address %02x unavailable\n",
428 client->addr + i);
429 err = -EBUSY;
430 goto exit_dummy;
431 }
432 }
433
434 err_reset = s35390a_reset(s35390a, &status1);
435 if (err_reset < 0) {
436 err = err_reset;
437 dev_err(&client->dev, "error resetting chip\n");
438 goto exit_dummy;
439 }
440
441 if (status1 & S35390A_FLAG_24H)
442 s35390a->twentyfourhour = 1;
443 else
444 s35390a->twentyfourhour = 0;
445
446 if (status1 & S35390A_FLAG_INT2) {
447 /* disable alarm (and maybe test mode) */
448 buf = 0;
449 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
450 if (err < 0) {
451 dev_err(&client->dev, "error disabling alarm");
452 goto exit_dummy;
453 }
454 } else {
455 err = s35390a_disable_test_mode(s35390a);
456 if (err < 0) {
457 dev_err(&client->dev, "error disabling test mode\n");
458 goto exit_dummy;
459 }
460 }
461
462 if (err_reset > 0 || s35390a_get_datetime(client, &tm) < 0)
463 dev_warn(&client->dev, "clock needs to be set\n");
464
465 device_set_wakeup_capable(&client->dev, 1);
466
467 s35390a->rtc = devm_rtc_device_register(&client->dev,
468 s35390a_driver.driver.name,
469 &s35390a_rtc_ops, THIS_MODULE);
470
471 if (IS_ERR(s35390a->rtc)) {
472 err = PTR_ERR(s35390a->rtc);
473 goto exit_dummy;
474 }
475
476 if (status1 & S35390A_FLAG_INT2)
477 rtc_update_irq(s35390a->rtc, 1, RTC_AF);
478
479 return 0;
480
481exit_dummy:
482 for (i = 1; i < 8; ++i)
483 if (s35390a->client[i])
484 i2c_unregister_device(s35390a->client[i]);
485
486exit:
487 return err;
488}
489
490static int s35390a_remove(struct i2c_client *client)
491{
492 unsigned int i;
493 struct s35390a *s35390a = i2c_get_clientdata(client);
494
495 for (i = 1; i < 8; ++i)
496 if (s35390a->client[i])
497 i2c_unregister_device(s35390a->client[i]);
498
499 return 0;
500}
501
502static struct i2c_driver s35390a_driver = {
503 .driver = {
504 .name = "rtc-s35390a",
505 },
506 .probe = s35390a_probe,
507 .remove = s35390a_remove,
508 .id_table = s35390a_id,
509};
510
511module_i2c_driver(s35390a_driver);
512
513MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
514MODULE_DESCRIPTION("S35390A RTC driver");
515MODULE_LICENSE("GPL");