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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
19#define S35390A_CMD_STATUS1 0
20#define S35390A_CMD_STATUS2 1
21#define S35390A_CMD_TIME1 2
22#define S35390A_CMD_TIME2 3
23#define S35390A_CMD_INT2_REG1 5
24
25#define S35390A_BYTE_YEAR 0
26#define S35390A_BYTE_MONTH 1
27#define S35390A_BYTE_DAY 2
28#define S35390A_BYTE_WDAY 3
29#define S35390A_BYTE_HOURS 4
30#define S35390A_BYTE_MINS 5
31#define S35390A_BYTE_SECS 6
32
33#define S35390A_ALRM_BYTE_WDAY 0
34#define S35390A_ALRM_BYTE_HOURS 1
35#define S35390A_ALRM_BYTE_MINS 2
36
37#define S35390A_FLAG_POC 0x01
38#define S35390A_FLAG_BLD 0x02
39#define S35390A_FLAG_24H 0x40
40#define S35390A_FLAG_RESET 0x80
41#define S35390A_FLAG_TEST 0x01
42
43#define S35390A_INT2_MODE_MASK 0xF0
44
45#define S35390A_INT2_MODE_NOINTR 0x00
46#define S35390A_INT2_MODE_FREQ 0x10
47#define S35390A_INT2_MODE_ALARM 0x40
48#define S35390A_INT2_MODE_PMIN_EDG 0x20
49
50static const struct i2c_device_id s35390a_id[] = {
51 { "s35390a", 0 },
52 { }
53};
54MODULE_DEVICE_TABLE(i2c, s35390a_id);
55
56struct s35390a {
57 struct i2c_client *client[8];
58 struct rtc_device *rtc;
59 int twentyfourhour;
60};
61
62static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
63{
64 struct i2c_client *client = s35390a->client[reg];
65 struct i2c_msg msg[] = {
66 {
67 .addr = client->addr,
68 .len = len,
69 .buf = buf
70 },
71 };
72
73 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
74 return -EIO;
75
76 return 0;
77}
78
79static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
80{
81 struct i2c_client *client = s35390a->client[reg];
82 struct i2c_msg msg[] = {
83 {
84 .addr = client->addr,
85 .flags = I2C_M_RD,
86 .len = len,
87 .buf = buf
88 },
89 };
90
91 if ((i2c_transfer(client->adapter, msg, 1)) != 1)
92 return -EIO;
93
94 return 0;
95}
96
97static int s35390a_reset(struct s35390a *s35390a)
98{
99 char buf[1];
100
101 if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0)
102 return -EIO;
103
104 if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD)))
105 return 0;
106
107 buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H);
108 buf[0] &= 0xf0;
109 return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
110}
111
112static int s35390a_disable_test_mode(struct s35390a *s35390a)
113{
114 char buf[1];
115
116 if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
117 return -EIO;
118
119 if (!(buf[0] & S35390A_FLAG_TEST))
120 return 0;
121
122 buf[0] &= ~S35390A_FLAG_TEST;
123 return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
124}
125
126static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
127{
128 if (s35390a->twentyfourhour)
129 return bin2bcd(hour);
130
131 if (hour < 12)
132 return bin2bcd(hour);
133
134 return 0x40 | bin2bcd(hour - 12);
135}
136
137static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
138{
139 unsigned hour;
140
141 if (s35390a->twentyfourhour)
142 return bcd2bin(reg & 0x3f);
143
144 hour = bcd2bin(reg & 0x3f);
145 if (reg & 0x40)
146 hour += 12;
147
148 return hour;
149}
150
151static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm)
152{
153 struct s35390a *s35390a = i2c_get_clientdata(client);
154 int i, err;
155 char buf[7];
156
157 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
158 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
159 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
160 tm->tm_wday);
161
162 buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
163 buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
164 buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
165 buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
166 buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
167 buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
168 buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
169
170 /* This chip expects the bits of each byte to be in reverse order */
171 for (i = 0; i < 7; ++i)
172 buf[i] = bitrev8(buf[i]);
173
174 err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
175
176 return err;
177}
178
179static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm)
180{
181 struct s35390a *s35390a = i2c_get_clientdata(client);
182 char buf[7];
183 int i, err;
184
185 err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
186 if (err < 0)
187 return err;
188
189 /* This chip returns the bits of each byte in reverse order */
190 for (i = 0; i < 7; ++i)
191 buf[i] = bitrev8(buf[i]);
192
193 tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
194 tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
195 tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
196 tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
197 tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
198 tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
199 tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
200
201 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
202 "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
203 tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
204 tm->tm_wday);
205
206 return rtc_valid_tm(tm);
207}
208
209static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
210{
211 struct s35390a *s35390a = i2c_get_clientdata(client);
212 char buf[3], sts = 0;
213 int err, i;
214
215 dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
216 "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
217 alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
218 alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
219
220 /* disable interrupt */
221 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
222 if (err < 0)
223 return err;
224
225 /* clear pending interrupt, if any */
226 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
227 if (err < 0)
228 return err;
229
230 if (alm->enabled)
231 sts = S35390A_INT2_MODE_ALARM;
232 else
233 sts = S35390A_INT2_MODE_NOINTR;
234
235 /* This chip expects the bits of each byte to be in reverse order */
236 sts = bitrev8(sts);
237
238 /* set interupt mode*/
239 err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
240 if (err < 0)
241 return err;
242
243 if (alm->time.tm_wday != -1)
244 buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
245
246 buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
247 alm->time.tm_hour) | 0x80;
248 buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;
249
250 if (alm->time.tm_hour >= 12)
251 buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;
252
253 for (i = 0; i < 3; ++i)
254 buf[i] = bitrev8(buf[i]);
255
256 err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
257 sizeof(buf));
258
259 return err;
260}
261
262static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
263{
264 struct s35390a *s35390a = i2c_get_clientdata(client);
265 char buf[3], sts;
266 int i, err;
267
268 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
269 if (err < 0)
270 return err;
271
272 if (bitrev8(sts) != S35390A_INT2_MODE_ALARM)
273 return -EINVAL;
274
275 err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
276 if (err < 0)
277 return err;
278
279 /* This chip returns the bits of each byte in reverse order */
280 for (i = 0; i < 3; ++i) {
281 buf[i] = bitrev8(buf[i]);
282 buf[i] &= ~0x80;
283 }
284
285 alm->time.tm_wday = bcd2bin(buf[S35390A_ALRM_BYTE_WDAY]);
286 alm->time.tm_hour = s35390a_reg2hr(s35390a,
287 buf[S35390A_ALRM_BYTE_HOURS]);
288 alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS]);
289
290 dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
291 __func__, alm->time.tm_min, alm->time.tm_hour,
292 alm->time.tm_wday);
293
294 return 0;
295}
296
297static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
298{
299 return s35390a_read_alarm(to_i2c_client(dev), alm);
300}
301
302static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
303{
304 return s35390a_set_alarm(to_i2c_client(dev), alm);
305}
306
307static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
308{
309 return s35390a_get_datetime(to_i2c_client(dev), tm);
310}
311
312static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
313{
314 return s35390a_set_datetime(to_i2c_client(dev), tm);
315}
316
317static const struct rtc_class_ops s35390a_rtc_ops = {
318 .read_time = s35390a_rtc_read_time,
319 .set_time = s35390a_rtc_set_time,
320 .set_alarm = s35390a_rtc_set_alarm,
321 .read_alarm = s35390a_rtc_read_alarm,
322
323};
324
325static struct i2c_driver s35390a_driver;
326
327static int s35390a_probe(struct i2c_client *client,
328 const struct i2c_device_id *id)
329{
330 int err;
331 unsigned int i;
332 struct s35390a *s35390a;
333 struct rtc_time tm;
334 char buf[1];
335
336 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
337 err = -ENODEV;
338 goto exit;
339 }
340
341 s35390a = devm_kzalloc(&client->dev, sizeof(struct s35390a),
342 GFP_KERNEL);
343 if (!s35390a) {
344 err = -ENOMEM;
345 goto exit;
346 }
347
348 s35390a->client[0] = client;
349 i2c_set_clientdata(client, s35390a);
350
351 /* This chip uses multiple addresses, use dummy devices for them */
352 for (i = 1; i < 8; ++i) {
353 s35390a->client[i] = i2c_new_dummy(client->adapter,
354 client->addr + i);
355 if (!s35390a->client[i]) {
356 dev_err(&client->dev, "Address %02x unavailable\n",
357 client->addr + i);
358 err = -EBUSY;
359 goto exit_dummy;
360 }
361 }
362
363 err = s35390a_reset(s35390a);
364 if (err < 0) {
365 dev_err(&client->dev, "error resetting chip\n");
366 goto exit_dummy;
367 }
368
369 err = s35390a_disable_test_mode(s35390a);
370 if (err < 0) {
371 dev_err(&client->dev, "error disabling test mode\n");
372 goto exit_dummy;
373 }
374
375 err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
376 if (err < 0) {
377 dev_err(&client->dev, "error checking 12/24 hour mode\n");
378 goto exit_dummy;
379 }
380 if (buf[0] & S35390A_FLAG_24H)
381 s35390a->twentyfourhour = 1;
382 else
383 s35390a->twentyfourhour = 0;
384
385 if (s35390a_get_datetime(client, &tm) < 0)
386 dev_warn(&client->dev, "clock needs to be set\n");
387
388 device_set_wakeup_capable(&client->dev, 1);
389
390 s35390a->rtc = devm_rtc_device_register(&client->dev,
391 s35390a_driver.driver.name,
392 &s35390a_rtc_ops, THIS_MODULE);
393
394 if (IS_ERR(s35390a->rtc)) {
395 err = PTR_ERR(s35390a->rtc);
396 goto exit_dummy;
397 }
398 return 0;
399
400exit_dummy:
401 for (i = 1; i < 8; ++i)
402 if (s35390a->client[i])
403 i2c_unregister_device(s35390a->client[i]);
404
405exit:
406 return err;
407}
408
409static int s35390a_remove(struct i2c_client *client)
410{
411 unsigned int i;
412 struct s35390a *s35390a = i2c_get_clientdata(client);
413
414 for (i = 1; i < 8; ++i)
415 if (s35390a->client[i])
416 i2c_unregister_device(s35390a->client[i]);
417
418 return 0;
419}
420
421static struct i2c_driver s35390a_driver = {
422 .driver = {
423 .name = "rtc-s35390a",
424 },
425 .probe = s35390a_probe,
426 .remove = s35390a_remove,
427 .id_table = s35390a_id,
428};
429
430module_i2c_driver(s35390a_driver);
431
432MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
433MODULE_DESCRIPTION("S35390A RTC driver");
434MODULE_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");