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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
4 *
5 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
6 * Copyright (C) 2006 Tower Technologies
7 * Copyright (C) 2008 Paul Mundt
8 */
9
10#include <linux/i2c.h>
11#include <linux/rtc.h>
12#include <linux/bcd.h>
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <linux/of_device.h>
16
17/*
18 * Ricoh has a family of I2C based RTCs, which differ only slightly from
19 * each other. Differences center on pinout (e.g. how many interrupts,
20 * output clock, etc) and how the control registers are used. The '372
21 * is significant only because that's the one this driver first supported.
22 */
23#define RS5C372_REG_SECS 0
24#define RS5C372_REG_MINS 1
25#define RS5C372_REG_HOURS 2
26#define RS5C372_REG_WDAY 3
27#define RS5C372_REG_DAY 4
28#define RS5C372_REG_MONTH 5
29#define RS5C372_REG_YEAR 6
30#define RS5C372_REG_TRIM 7
31# define RS5C372_TRIM_XSL 0x80
32# define RS5C372_TRIM_MASK 0x7F
33
34#define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
35#define RS5C_REG_ALARM_A_HOURS 9
36#define RS5C_REG_ALARM_A_WDAY 10
37
38#define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
39#define RS5C_REG_ALARM_B_HOURS 12
40#define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
41
42#define RS5C_REG_CTRL1 14
43# define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
44# define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
45# define RV5C387_CTRL1_24 (1 << 5)
46# define RS5C372A_CTRL1_SL1 (1 << 5)
47# define RS5C_CTRL1_CT_MASK (7 << 0)
48# define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
49# define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
50#define RS5C_REG_CTRL2 15
51# define RS5C372_CTRL2_24 (1 << 5)
52# define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2x2x */
53# define R2x2x_CTRL2_VDET (1 << 6) /* only if R2x2x */
54# define R2x2x_CTRL2_XSTP (1 << 5) /* only if R2x2x */
55# define R2x2x_CTRL2_PON (1 << 4) /* only if R2x2x */
56# define RS5C_CTRL2_CTFG (1 << 2)
57# define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
58# define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
59
60
61/* to read (style 1) or write registers starting at R */
62#define RS5C_ADDR(R) (((R) << 4) | 0)
63
64
65enum rtc_type {
66 rtc_undef = 0,
67 rtc_r2025sd,
68 rtc_r2221tl,
69 rtc_rs5c372a,
70 rtc_rs5c372b,
71 rtc_rv5c386,
72 rtc_rv5c387a,
73};
74
75static const struct i2c_device_id rs5c372_id[] = {
76 { "r2025sd", rtc_r2025sd },
77 { "r2221tl", rtc_r2221tl },
78 { "rs5c372a", rtc_rs5c372a },
79 { "rs5c372b", rtc_rs5c372b },
80 { "rv5c386", rtc_rv5c386 },
81 { "rv5c387a", rtc_rv5c387a },
82 { }
83};
84MODULE_DEVICE_TABLE(i2c, rs5c372_id);
85
86static const struct of_device_id rs5c372_of_match[] = {
87 {
88 .compatible = "ricoh,r2025sd",
89 .data = (void *)rtc_r2025sd
90 },
91 {
92 .compatible = "ricoh,r2221tl",
93 .data = (void *)rtc_r2221tl
94 },
95 {
96 .compatible = "ricoh,rs5c372a",
97 .data = (void *)rtc_rs5c372a
98 },
99 {
100 .compatible = "ricoh,rs5c372b",
101 .data = (void *)rtc_rs5c372b
102 },
103 {
104 .compatible = "ricoh,rv5c386",
105 .data = (void *)rtc_rv5c386
106 },
107 {
108 .compatible = "ricoh,rv5c387a",
109 .data = (void *)rtc_rv5c387a
110 },
111 { }
112};
113MODULE_DEVICE_TABLE(of, rs5c372_of_match);
114
115/* REVISIT: this assumes that:
116 * - we're in the 21st century, so it's safe to ignore the century
117 * bit for rv5c38[67] (REG_MONTH bit 7);
118 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
119 */
120struct rs5c372 {
121 struct i2c_client *client;
122 struct rtc_device *rtc;
123 enum rtc_type type;
124 unsigned time24:1;
125 unsigned has_irq:1;
126 unsigned smbus:1;
127 char buf[17];
128 char *regs;
129};
130
131static int rs5c_get_regs(struct rs5c372 *rs5c)
132{
133 struct i2c_client *client = rs5c->client;
134 struct i2c_msg msgs[] = {
135 {
136 .addr = client->addr,
137 .flags = I2C_M_RD,
138 .len = sizeof(rs5c->buf),
139 .buf = rs5c->buf
140 },
141 };
142
143 /* This implements the third reading method from the datasheet, using
144 * an internal address that's reset after each transaction (by STOP)
145 * to 0x0f ... so we read extra registers, and skip the first one.
146 *
147 * The first method doesn't work with the iop3xx adapter driver, on at
148 * least 80219 chips; this works around that bug.
149 *
150 * The third method on the other hand doesn't work for the SMBus-only
151 * configurations, so we use the the first method there, stripping off
152 * the extra register in the process.
153 */
154 if (rs5c->smbus) {
155 int addr = RS5C_ADDR(RS5C372_REG_SECS);
156 int size = sizeof(rs5c->buf) - 1;
157
158 if (i2c_smbus_read_i2c_block_data(client, addr, size,
159 rs5c->buf + 1) != size) {
160 dev_warn(&client->dev, "can't read registers\n");
161 return -EIO;
162 }
163 } else {
164 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
165 dev_warn(&client->dev, "can't read registers\n");
166 return -EIO;
167 }
168 }
169
170 dev_dbg(&client->dev,
171 "%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
172 rs5c->regs + 0, rs5c->regs[3],
173 rs5c->regs + 4, rs5c->regs[7],
174 rs5c->regs + 8, rs5c->regs + 11,
175 rs5c->regs[14], rs5c->regs[15]);
176
177 return 0;
178}
179
180static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
181{
182 unsigned hour;
183
184 if (rs5c->time24)
185 return bcd2bin(reg & 0x3f);
186
187 hour = bcd2bin(reg & 0x1f);
188 if (hour == 12)
189 hour = 0;
190 if (reg & 0x20)
191 hour += 12;
192 return hour;
193}
194
195static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
196{
197 if (rs5c->time24)
198 return bin2bcd(hour);
199
200 if (hour > 12)
201 return 0x20 | bin2bcd(hour - 12);
202 if (hour == 12)
203 return 0x20 | bin2bcd(12);
204 if (hour == 0)
205 return bin2bcd(12);
206 return bin2bcd(hour);
207}
208
209static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
210{
211 struct i2c_client *client = to_i2c_client(dev);
212 struct rs5c372 *rs5c = i2c_get_clientdata(client);
213 int status = rs5c_get_regs(rs5c);
214 unsigned char ctrl2 = rs5c->regs[RS5C_REG_CTRL2];
215
216 if (status < 0)
217 return status;
218
219 switch (rs5c->type) {
220 case rtc_r2025sd:
221 case rtc_r2221tl:
222 if ((rs5c->type == rtc_r2025sd && !(ctrl2 & R2x2x_CTRL2_XSTP)) ||
223 (rs5c->type == rtc_r2221tl && (ctrl2 & R2x2x_CTRL2_XSTP))) {
224 dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n");
225 return -EINVAL;
226 }
227 break;
228 default:
229 if (ctrl2 & RS5C_CTRL2_XSTP) {
230 dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n");
231 return -EINVAL;
232 }
233 }
234
235 tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
236 tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
237 tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
238
239 tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
240 tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
241
242 /* tm->tm_mon is zero-based */
243 tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
244
245 /* year is 1900 + tm->tm_year */
246 tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
247
248 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
249 "mday=%d, mon=%d, year=%d, wday=%d\n",
250 __func__,
251 tm->tm_sec, tm->tm_min, tm->tm_hour,
252 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
253
254 return 0;
255}
256
257static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
258{
259 struct i2c_client *client = to_i2c_client(dev);
260 struct rs5c372 *rs5c = i2c_get_clientdata(client);
261 unsigned char buf[7];
262 unsigned char ctrl2;
263 int addr;
264
265 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
266 "mday=%d, mon=%d, year=%d, wday=%d\n",
267 __func__,
268 tm->tm_sec, tm->tm_min, tm->tm_hour,
269 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
270
271 addr = RS5C_ADDR(RS5C372_REG_SECS);
272 buf[0] = bin2bcd(tm->tm_sec);
273 buf[1] = bin2bcd(tm->tm_min);
274 buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
275 buf[3] = bin2bcd(tm->tm_wday);
276 buf[4] = bin2bcd(tm->tm_mday);
277 buf[5] = bin2bcd(tm->tm_mon + 1);
278 buf[6] = bin2bcd(tm->tm_year - 100);
279
280 if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
281 dev_dbg(&client->dev, "%s: write error in line %i\n",
282 __func__, __LINE__);
283 return -EIO;
284 }
285
286 addr = RS5C_ADDR(RS5C_REG_CTRL2);
287 ctrl2 = i2c_smbus_read_byte_data(client, addr);
288
289 /* clear rtc warning bits */
290 switch (rs5c->type) {
291 case rtc_r2025sd:
292 case rtc_r2221tl:
293 ctrl2 &= ~(R2x2x_CTRL2_VDET | R2x2x_CTRL2_PON);
294 if (rs5c->type == rtc_r2025sd)
295 ctrl2 |= R2x2x_CTRL2_XSTP;
296 else
297 ctrl2 &= ~R2x2x_CTRL2_XSTP;
298 break;
299 default:
300 ctrl2 &= ~RS5C_CTRL2_XSTP;
301 break;
302 }
303
304 if (i2c_smbus_write_byte_data(client, addr, ctrl2) < 0) {
305 dev_dbg(&client->dev, "%s: write error in line %i\n",
306 __func__, __LINE__);
307 return -EIO;
308 }
309
310 return 0;
311}
312
313#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
314#define NEED_TRIM
315#endif
316
317#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
318#define NEED_TRIM
319#endif
320
321#ifdef NEED_TRIM
322static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
323{
324 struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
325 u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
326
327 if (osc)
328 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
329
330 if (trim) {
331 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
332 tmp &= RS5C372_TRIM_MASK;
333 if (tmp & 0x3e) {
334 int t = tmp & 0x3f;
335
336 if (tmp & 0x40)
337 t = (~t | (s8)0xc0) + 1;
338 else
339 t = t - 1;
340
341 tmp = t * 2;
342 } else
343 tmp = 0;
344 *trim = tmp;
345 }
346
347 return 0;
348}
349#endif
350
351static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
352{
353 struct i2c_client *client = to_i2c_client(dev);
354 struct rs5c372 *rs5c = i2c_get_clientdata(client);
355 unsigned char buf;
356 int status, addr;
357
358 buf = rs5c->regs[RS5C_REG_CTRL1];
359
360 if (!rs5c->has_irq)
361 return -EINVAL;
362
363 status = rs5c_get_regs(rs5c);
364 if (status < 0)
365 return status;
366
367 addr = RS5C_ADDR(RS5C_REG_CTRL1);
368 if (enabled)
369 buf |= RS5C_CTRL1_AALE;
370 else
371 buf &= ~RS5C_CTRL1_AALE;
372
373 if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
374 dev_warn(dev, "can't update alarm\n");
375 status = -EIO;
376 } else
377 rs5c->regs[RS5C_REG_CTRL1] = buf;
378
379 return status;
380}
381
382
383/* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
384 * which only exposes a polled programming interface; and since
385 * these calls map directly to those EFI requests; we don't demand
386 * we have an IRQ for this chip when we go through this API.
387 *
388 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
389 * though, managed through RTC_AIE_{ON,OFF} requests.
390 */
391
392static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
393{
394 struct i2c_client *client = to_i2c_client(dev);
395 struct rs5c372 *rs5c = i2c_get_clientdata(client);
396 int status;
397
398 status = rs5c_get_regs(rs5c);
399 if (status < 0)
400 return status;
401
402 /* report alarm time */
403 t->time.tm_sec = 0;
404 t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
405 t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
406
407 /* ... and status */
408 t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
409 t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
410
411 return 0;
412}
413
414static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
415{
416 struct i2c_client *client = to_i2c_client(dev);
417 struct rs5c372 *rs5c = i2c_get_clientdata(client);
418 int status, addr, i;
419 unsigned char buf[3];
420
421 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
422 if (t->time.tm_mday != -1
423 || t->time.tm_mon != -1
424 || t->time.tm_year != -1)
425 return -EINVAL;
426
427 /* REVISIT: round up tm_sec */
428
429 /* if needed, disable irq (clears pending status) */
430 status = rs5c_get_regs(rs5c);
431 if (status < 0)
432 return status;
433 if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
434 addr = RS5C_ADDR(RS5C_REG_CTRL1);
435 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
436 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
437 dev_dbg(dev, "can't disable alarm\n");
438 return -EIO;
439 }
440 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
441 }
442
443 /* set alarm */
444 buf[0] = bin2bcd(t->time.tm_min);
445 buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
446 buf[2] = 0x7f; /* any/all days */
447
448 for (i = 0; i < sizeof(buf); i++) {
449 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
450 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
451 dev_dbg(dev, "can't set alarm time\n");
452 return -EIO;
453 }
454 }
455
456 /* ... and maybe enable its irq */
457 if (t->enabled) {
458 addr = RS5C_ADDR(RS5C_REG_CTRL1);
459 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
460 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
461 dev_warn(dev, "can't enable alarm\n");
462 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
463 }
464
465 return 0;
466}
467
468#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
469
470static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
471{
472 int err, osc, trim;
473
474 err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
475 if (err == 0) {
476 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
477 osc / 1000, osc % 1000);
478 seq_printf(seq, "trim\t\t: %d\n", trim);
479 }
480
481 return 0;
482}
483
484#else
485#define rs5c372_rtc_proc NULL
486#endif
487
488static const struct rtc_class_ops rs5c372_rtc_ops = {
489 .proc = rs5c372_rtc_proc,
490 .read_time = rs5c372_rtc_read_time,
491 .set_time = rs5c372_rtc_set_time,
492 .read_alarm = rs5c_read_alarm,
493 .set_alarm = rs5c_set_alarm,
494 .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
495};
496
497#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
498
499static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
500 struct device_attribute *attr, char *buf)
501{
502 int err, trim;
503
504 err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
505 if (err)
506 return err;
507
508 return sprintf(buf, "%d\n", trim);
509}
510static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
511
512static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
513 struct device_attribute *attr, char *buf)
514{
515 int err, osc;
516
517 err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
518 if (err)
519 return err;
520
521 return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
522}
523static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
524
525static int rs5c_sysfs_register(struct device *dev)
526{
527 int err;
528
529 err = device_create_file(dev, &dev_attr_trim);
530 if (err)
531 return err;
532 err = device_create_file(dev, &dev_attr_osc);
533 if (err)
534 device_remove_file(dev, &dev_attr_trim);
535
536 return err;
537}
538
539static void rs5c_sysfs_unregister(struct device *dev)
540{
541 device_remove_file(dev, &dev_attr_trim);
542 device_remove_file(dev, &dev_attr_osc);
543}
544
545#else
546static int rs5c_sysfs_register(struct device *dev)
547{
548 return 0;
549}
550
551static void rs5c_sysfs_unregister(struct device *dev)
552{
553 /* nothing */
554}
555#endif /* SYSFS */
556
557static struct i2c_driver rs5c372_driver;
558
559static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
560{
561 unsigned char buf[2];
562 int addr, i, ret = 0;
563
564 addr = RS5C_ADDR(RS5C_REG_CTRL1);
565 buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
566 buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
567
568 switch (rs5c372->type) {
569 case rtc_r2025sd:
570 if (buf[1] & R2x2x_CTRL2_XSTP)
571 return ret;
572 break;
573 case rtc_r2221tl:
574 if (!(buf[1] & R2x2x_CTRL2_XSTP))
575 return ret;
576 break;
577 default:
578 if (!(buf[1] & RS5C_CTRL2_XSTP))
579 return ret;
580 break;
581 }
582
583 /* use 24hr mode */
584 switch (rs5c372->type) {
585 case rtc_rs5c372a:
586 case rtc_rs5c372b:
587 buf[1] |= RS5C372_CTRL2_24;
588 rs5c372->time24 = 1;
589 break;
590 case rtc_r2025sd:
591 case rtc_r2221tl:
592 case rtc_rv5c386:
593 case rtc_rv5c387a:
594 buf[0] |= RV5C387_CTRL1_24;
595 rs5c372->time24 = 1;
596 break;
597 default:
598 /* impossible */
599 break;
600 }
601
602 for (i = 0; i < sizeof(buf); i++) {
603 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
604 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
605 if (unlikely(ret < 0))
606 return ret;
607 }
608
609 rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
610 rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
611
612 return 0;
613}
614
615static int rs5c372_probe(struct i2c_client *client,
616 const struct i2c_device_id *id)
617{
618 int err = 0;
619 int smbus_mode = 0;
620 struct rs5c372 *rs5c372;
621
622 dev_dbg(&client->dev, "%s\n", __func__);
623
624 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
625 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
626 /*
627 * If we don't have any master mode adapter, try breaking
628 * it down in to the barest of capabilities.
629 */
630 if (i2c_check_functionality(client->adapter,
631 I2C_FUNC_SMBUS_BYTE_DATA |
632 I2C_FUNC_SMBUS_I2C_BLOCK))
633 smbus_mode = 1;
634 else {
635 /* Still no good, give up */
636 err = -ENODEV;
637 goto exit;
638 }
639 }
640
641 rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
642 GFP_KERNEL);
643 if (!rs5c372) {
644 err = -ENOMEM;
645 goto exit;
646 }
647
648 rs5c372->client = client;
649 i2c_set_clientdata(client, rs5c372);
650 if (client->dev.of_node)
651 rs5c372->type = (enum rtc_type)
652 of_device_get_match_data(&client->dev);
653 else
654 rs5c372->type = id->driver_data;
655
656 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
657 rs5c372->regs = &rs5c372->buf[1];
658 rs5c372->smbus = smbus_mode;
659
660 err = rs5c_get_regs(rs5c372);
661 if (err < 0)
662 goto exit;
663
664 /* clock may be set for am/pm or 24 hr time */
665 switch (rs5c372->type) {
666 case rtc_rs5c372a:
667 case rtc_rs5c372b:
668 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
669 * so does periodic irq, except some 327a modes.
670 */
671 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
672 rs5c372->time24 = 1;
673 break;
674 case rtc_r2025sd:
675 case rtc_r2221tl:
676 case rtc_rv5c386:
677 case rtc_rv5c387a:
678 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
679 rs5c372->time24 = 1;
680 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
681 * irq, on both 386 and 387
682 */
683 break;
684 default:
685 dev_err(&client->dev, "unknown RTC type\n");
686 goto exit;
687 }
688
689 /* if the oscillator lost power and no other software (like
690 * the bootloader) set it up, do it here.
691 *
692 * The R2025S/D does this a little differently than the other
693 * parts, so we special case that..
694 */
695 err = rs5c_oscillator_setup(rs5c372);
696 if (unlikely(err < 0)) {
697 dev_err(&client->dev, "setup error\n");
698 goto exit;
699 }
700
701 dev_info(&client->dev, "%s found, %s\n",
702 ({ char *s; switch (rs5c372->type) {
703 case rtc_r2025sd: s = "r2025sd"; break;
704 case rtc_r2221tl: s = "r2221tl"; break;
705 case rtc_rs5c372a: s = "rs5c372a"; break;
706 case rtc_rs5c372b: s = "rs5c372b"; break;
707 case rtc_rv5c386: s = "rv5c386"; break;
708 case rtc_rv5c387a: s = "rv5c387a"; break;
709 default: s = "chip"; break;
710 }; s;}),
711 rs5c372->time24 ? "24hr" : "am/pm"
712 );
713
714 /* REVISIT use client->irq to register alarm irq ... */
715 rs5c372->rtc = devm_rtc_device_register(&client->dev,
716 rs5c372_driver.driver.name,
717 &rs5c372_rtc_ops, THIS_MODULE);
718
719 if (IS_ERR(rs5c372->rtc)) {
720 err = PTR_ERR(rs5c372->rtc);
721 goto exit;
722 }
723
724 err = rs5c_sysfs_register(&client->dev);
725 if (err)
726 goto exit;
727
728 return 0;
729
730exit:
731 return err;
732}
733
734static int rs5c372_remove(struct i2c_client *client)
735{
736 rs5c_sysfs_unregister(&client->dev);
737 return 0;
738}
739
740static struct i2c_driver rs5c372_driver = {
741 .driver = {
742 .name = "rtc-rs5c372",
743 .of_match_table = of_match_ptr(rs5c372_of_match),
744 },
745 .probe = rs5c372_probe,
746 .remove = rs5c372_remove,
747 .id_table = rs5c372_id,
748};
749
750module_i2c_driver(rs5c372_driver);
751
752MODULE_AUTHOR(
753 "Pavel Mironchik <pmironchik@optifacio.net>, "
754 "Alessandro Zummo <a.zummo@towertech.it>, "
755 "Paul Mundt <lethal@linux-sh.org>");
756MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
757MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
4 *
5 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
6 * Copyright (C) 2006 Tower Technologies
7 * Copyright (C) 2008 Paul Mundt
8 */
9
10#include <linux/i2c.h>
11#include <linux/rtc.h>
12#include <linux/bcd.h>
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <linux/of_device.h>
16
17/*
18 * Ricoh has a family of I2C based RTCs, which differ only slightly from
19 * each other. Differences center on pinout (e.g. how many interrupts,
20 * output clock, etc) and how the control registers are used. The '372
21 * is significant only because that's the one this driver first supported.
22 */
23#define RS5C372_REG_SECS 0
24#define RS5C372_REG_MINS 1
25#define RS5C372_REG_HOURS 2
26#define RS5C372_REG_WDAY 3
27#define RS5C372_REG_DAY 4
28#define RS5C372_REG_MONTH 5
29#define RS5C372_REG_YEAR 6
30#define RS5C372_REG_TRIM 7
31# define RS5C372_TRIM_XSL 0x80
32# define RS5C372_TRIM_MASK 0x7F
33
34#define RS5C_REG_ALARM_A_MIN 8 /* or ALARM_W */
35#define RS5C_REG_ALARM_A_HOURS 9
36#define RS5C_REG_ALARM_A_WDAY 10
37
38#define RS5C_REG_ALARM_B_MIN 11 /* or ALARM_D */
39#define RS5C_REG_ALARM_B_HOURS 12
40#define RS5C_REG_ALARM_B_WDAY 13 /* (ALARM_B only) */
41
42#define RS5C_REG_CTRL1 14
43# define RS5C_CTRL1_AALE (1 << 7) /* or WALE */
44# define RS5C_CTRL1_BALE (1 << 6) /* or DALE */
45# define RV5C387_CTRL1_24 (1 << 5)
46# define RS5C372A_CTRL1_SL1 (1 << 5)
47# define RS5C_CTRL1_CT_MASK (7 << 0)
48# define RS5C_CTRL1_CT0 (0 << 0) /* no periodic irq */
49# define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */
50#define RS5C_REG_CTRL2 15
51# define RS5C372_CTRL2_24 (1 << 5)
52# define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2x2x */
53# define R2x2x_CTRL2_VDET (1 << 6) /* only if R2x2x */
54# define R2x2x_CTRL2_XSTP (1 << 5) /* only if R2x2x */
55# define R2x2x_CTRL2_PON (1 << 4) /* only if R2x2x */
56# define RS5C_CTRL2_CTFG (1 << 2)
57# define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */
58# define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */
59
60
61/* to read (style 1) or write registers starting at R */
62#define RS5C_ADDR(R) (((R) << 4) | 0)
63
64
65enum rtc_type {
66 rtc_undef = 0,
67 rtc_r2025sd,
68 rtc_r2221tl,
69 rtc_rs5c372a,
70 rtc_rs5c372b,
71 rtc_rv5c386,
72 rtc_rv5c387a,
73};
74
75static const struct i2c_device_id rs5c372_id[] = {
76 { "r2025sd", rtc_r2025sd },
77 { "r2221tl", rtc_r2221tl },
78 { "rs5c372a", rtc_rs5c372a },
79 { "rs5c372b", rtc_rs5c372b },
80 { "rv5c386", rtc_rv5c386 },
81 { "rv5c387a", rtc_rv5c387a },
82 { }
83};
84MODULE_DEVICE_TABLE(i2c, rs5c372_id);
85
86static const struct of_device_id rs5c372_of_match[] = {
87 {
88 .compatible = "ricoh,r2025sd",
89 .data = (void *)rtc_r2025sd
90 },
91 {
92 .compatible = "ricoh,r2221tl",
93 .data = (void *)rtc_r2221tl
94 },
95 {
96 .compatible = "ricoh,rs5c372a",
97 .data = (void *)rtc_rs5c372a
98 },
99 {
100 .compatible = "ricoh,rs5c372b",
101 .data = (void *)rtc_rs5c372b
102 },
103 {
104 .compatible = "ricoh,rv5c386",
105 .data = (void *)rtc_rv5c386
106 },
107 {
108 .compatible = "ricoh,rv5c387a",
109 .data = (void *)rtc_rv5c387a
110 },
111 { }
112};
113MODULE_DEVICE_TABLE(of, rs5c372_of_match);
114
115/* REVISIT: this assumes that:
116 * - we're in the 21st century, so it's safe to ignore the century
117 * bit for rv5c38[67] (REG_MONTH bit 7);
118 * - we should use ALARM_A not ALARM_B (may be wrong on some boards)
119 */
120struct rs5c372 {
121 struct i2c_client *client;
122 struct rtc_device *rtc;
123 enum rtc_type type;
124 unsigned time24:1;
125 unsigned has_irq:1;
126 unsigned smbus:1;
127 char buf[17];
128 char *regs;
129};
130
131static int rs5c_get_regs(struct rs5c372 *rs5c)
132{
133 struct i2c_client *client = rs5c->client;
134 struct i2c_msg msgs[] = {
135 {
136 .addr = client->addr,
137 .flags = I2C_M_RD,
138 .len = sizeof(rs5c->buf),
139 .buf = rs5c->buf
140 },
141 };
142
143 /* This implements the third reading method from the datasheet, using
144 * an internal address that's reset after each transaction (by STOP)
145 * to 0x0f ... so we read extra registers, and skip the first one.
146 *
147 * The first method doesn't work with the iop3xx adapter driver, on at
148 * least 80219 chips; this works around that bug.
149 *
150 * The third method on the other hand doesn't work for the SMBus-only
151 * configurations, so we use the the first method there, stripping off
152 * the extra register in the process.
153 */
154 if (rs5c->smbus) {
155 int addr = RS5C_ADDR(RS5C372_REG_SECS);
156 int size = sizeof(rs5c->buf) - 1;
157
158 if (i2c_smbus_read_i2c_block_data(client, addr, size,
159 rs5c->buf + 1) != size) {
160 dev_warn(&client->dev, "can't read registers\n");
161 return -EIO;
162 }
163 } else {
164 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
165 dev_warn(&client->dev, "can't read registers\n");
166 return -EIO;
167 }
168 }
169
170 dev_dbg(&client->dev,
171 "%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
172 rs5c->regs + 0, rs5c->regs[3],
173 rs5c->regs + 4, rs5c->regs[7],
174 rs5c->regs + 8, rs5c->regs + 11,
175 rs5c->regs[14], rs5c->regs[15]);
176
177 return 0;
178}
179
180static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
181{
182 unsigned hour;
183
184 if (rs5c->time24)
185 return bcd2bin(reg & 0x3f);
186
187 hour = bcd2bin(reg & 0x1f);
188 if (hour == 12)
189 hour = 0;
190 if (reg & 0x20)
191 hour += 12;
192 return hour;
193}
194
195static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
196{
197 if (rs5c->time24)
198 return bin2bcd(hour);
199
200 if (hour > 12)
201 return 0x20 | bin2bcd(hour - 12);
202 if (hour == 12)
203 return 0x20 | bin2bcd(12);
204 if (hour == 0)
205 return bin2bcd(12);
206 return bin2bcd(hour);
207}
208
209static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
210{
211 struct i2c_client *client = to_i2c_client(dev);
212 struct rs5c372 *rs5c = i2c_get_clientdata(client);
213 int status = rs5c_get_regs(rs5c);
214 unsigned char ctrl2 = rs5c->regs[RS5C_REG_CTRL2];
215
216 if (status < 0)
217 return status;
218
219 switch (rs5c->type) {
220 case rtc_r2025sd:
221 case rtc_r2221tl:
222 if ((rs5c->type == rtc_r2025sd && !(ctrl2 & R2x2x_CTRL2_XSTP)) ||
223 (rs5c->type == rtc_r2221tl && (ctrl2 & R2x2x_CTRL2_XSTP))) {
224 dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n");
225 return -EINVAL;
226 }
227 break;
228 default:
229 if (ctrl2 & RS5C_CTRL2_XSTP) {
230 dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n");
231 return -EINVAL;
232 }
233 }
234
235 tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
236 tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
237 tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
238
239 tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
240 tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
241
242 /* tm->tm_mon is zero-based */
243 tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
244
245 /* year is 1900 + tm->tm_year */
246 tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
247
248 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
249 "mday=%d, mon=%d, year=%d, wday=%d\n",
250 __func__,
251 tm->tm_sec, tm->tm_min, tm->tm_hour,
252 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
253
254 return 0;
255}
256
257static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
258{
259 struct i2c_client *client = to_i2c_client(dev);
260 struct rs5c372 *rs5c = i2c_get_clientdata(client);
261 unsigned char buf[7];
262 unsigned char ctrl2;
263 int addr;
264
265 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
266 "mday=%d, mon=%d, year=%d, wday=%d\n",
267 __func__,
268 tm->tm_sec, tm->tm_min, tm->tm_hour,
269 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
270
271 addr = RS5C_ADDR(RS5C372_REG_SECS);
272 buf[0] = bin2bcd(tm->tm_sec);
273 buf[1] = bin2bcd(tm->tm_min);
274 buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
275 buf[3] = bin2bcd(tm->tm_wday);
276 buf[4] = bin2bcd(tm->tm_mday);
277 buf[5] = bin2bcd(tm->tm_mon + 1);
278 buf[6] = bin2bcd(tm->tm_year - 100);
279
280 if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
281 dev_dbg(&client->dev, "%s: write error in line %i\n",
282 __func__, __LINE__);
283 return -EIO;
284 }
285
286 addr = RS5C_ADDR(RS5C_REG_CTRL2);
287 ctrl2 = i2c_smbus_read_byte_data(client, addr);
288
289 /* clear rtc warning bits */
290 switch (rs5c->type) {
291 case rtc_r2025sd:
292 case rtc_r2221tl:
293 ctrl2 &= ~(R2x2x_CTRL2_VDET | R2x2x_CTRL2_PON);
294 if (rs5c->type == rtc_r2025sd)
295 ctrl2 |= R2x2x_CTRL2_XSTP;
296 else
297 ctrl2 &= ~R2x2x_CTRL2_XSTP;
298 break;
299 default:
300 ctrl2 &= ~RS5C_CTRL2_XSTP;
301 break;
302 }
303
304 if (i2c_smbus_write_byte_data(client, addr, ctrl2) < 0) {
305 dev_dbg(&client->dev, "%s: write error in line %i\n",
306 __func__, __LINE__);
307 return -EIO;
308 }
309
310 return 0;
311}
312
313#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
314#define NEED_TRIM
315#endif
316
317#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
318#define NEED_TRIM
319#endif
320
321#ifdef NEED_TRIM
322static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
323{
324 struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
325 u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
326
327 if (osc)
328 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
329
330 if (trim) {
331 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
332 tmp &= RS5C372_TRIM_MASK;
333 if (tmp & 0x3e) {
334 int t = tmp & 0x3f;
335
336 if (tmp & 0x40)
337 t = (~t | (s8)0xc0) + 1;
338 else
339 t = t - 1;
340
341 tmp = t * 2;
342 } else
343 tmp = 0;
344 *trim = tmp;
345 }
346
347 return 0;
348}
349#endif
350
351static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
352{
353 struct i2c_client *client = to_i2c_client(dev);
354 struct rs5c372 *rs5c = i2c_get_clientdata(client);
355 unsigned char buf;
356 int status, addr;
357
358 buf = rs5c->regs[RS5C_REG_CTRL1];
359
360 if (!rs5c->has_irq)
361 return -EINVAL;
362
363 status = rs5c_get_regs(rs5c);
364 if (status < 0)
365 return status;
366
367 addr = RS5C_ADDR(RS5C_REG_CTRL1);
368 if (enabled)
369 buf |= RS5C_CTRL1_AALE;
370 else
371 buf &= ~RS5C_CTRL1_AALE;
372
373 if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
374 dev_warn(dev, "can't update alarm\n");
375 status = -EIO;
376 } else
377 rs5c->regs[RS5C_REG_CTRL1] = buf;
378
379 return status;
380}
381
382
383/* NOTE: Since RTC_WKALM_{RD,SET} were originally defined for EFI,
384 * which only exposes a polled programming interface; and since
385 * these calls map directly to those EFI requests; we don't demand
386 * we have an IRQ for this chip when we go through this API.
387 *
388 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
389 * though, managed through RTC_AIE_{ON,OFF} requests.
390 */
391
392static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
393{
394 struct i2c_client *client = to_i2c_client(dev);
395 struct rs5c372 *rs5c = i2c_get_clientdata(client);
396 int status;
397
398 status = rs5c_get_regs(rs5c);
399 if (status < 0)
400 return status;
401
402 /* report alarm time */
403 t->time.tm_sec = 0;
404 t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
405 t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
406
407 /* ... and status */
408 t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
409 t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
410
411 return 0;
412}
413
414static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
415{
416 struct i2c_client *client = to_i2c_client(dev);
417 struct rs5c372 *rs5c = i2c_get_clientdata(client);
418 int status, addr, i;
419 unsigned char buf[3];
420
421 /* only handle up to 24 hours in the future, like RTC_ALM_SET */
422 if (t->time.tm_mday != -1
423 || t->time.tm_mon != -1
424 || t->time.tm_year != -1)
425 return -EINVAL;
426
427 /* REVISIT: round up tm_sec */
428
429 /* if needed, disable irq (clears pending status) */
430 status = rs5c_get_regs(rs5c);
431 if (status < 0)
432 return status;
433 if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
434 addr = RS5C_ADDR(RS5C_REG_CTRL1);
435 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
436 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
437 dev_dbg(dev, "can't disable alarm\n");
438 return -EIO;
439 }
440 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
441 }
442
443 /* set alarm */
444 buf[0] = bin2bcd(t->time.tm_min);
445 buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
446 buf[2] = 0x7f; /* any/all days */
447
448 for (i = 0; i < sizeof(buf); i++) {
449 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
450 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
451 dev_dbg(dev, "can't set alarm time\n");
452 return -EIO;
453 }
454 }
455
456 /* ... and maybe enable its irq */
457 if (t->enabled) {
458 addr = RS5C_ADDR(RS5C_REG_CTRL1);
459 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
460 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
461 dev_warn(dev, "can't enable alarm\n");
462 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
463 }
464
465 return 0;
466}
467
468#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
469
470static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
471{
472 int err, osc, trim;
473
474 err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
475 if (err == 0) {
476 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
477 osc / 1000, osc % 1000);
478 seq_printf(seq, "trim\t\t: %d\n", trim);
479 }
480
481 return 0;
482}
483
484#else
485#define rs5c372_rtc_proc NULL
486#endif
487
488static const struct rtc_class_ops rs5c372_rtc_ops = {
489 .proc = rs5c372_rtc_proc,
490 .read_time = rs5c372_rtc_read_time,
491 .set_time = rs5c372_rtc_set_time,
492 .read_alarm = rs5c_read_alarm,
493 .set_alarm = rs5c_set_alarm,
494 .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
495};
496
497#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
498
499static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
500 struct device_attribute *attr, char *buf)
501{
502 int err, trim;
503
504 err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
505 if (err)
506 return err;
507
508 return sprintf(buf, "%d\n", trim);
509}
510static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
511
512static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
513 struct device_attribute *attr, char *buf)
514{
515 int err, osc;
516
517 err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
518 if (err)
519 return err;
520
521 return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
522}
523static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
524
525static int rs5c_sysfs_register(struct device *dev)
526{
527 int err;
528
529 err = device_create_file(dev, &dev_attr_trim);
530 if (err)
531 return err;
532 err = device_create_file(dev, &dev_attr_osc);
533 if (err)
534 device_remove_file(dev, &dev_attr_trim);
535
536 return err;
537}
538
539static void rs5c_sysfs_unregister(struct device *dev)
540{
541 device_remove_file(dev, &dev_attr_trim);
542 device_remove_file(dev, &dev_attr_osc);
543}
544
545#else
546static int rs5c_sysfs_register(struct device *dev)
547{
548 return 0;
549}
550
551static void rs5c_sysfs_unregister(struct device *dev)
552{
553 /* nothing */
554}
555#endif /* SYSFS */
556
557static struct i2c_driver rs5c372_driver;
558
559static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
560{
561 unsigned char buf[2];
562 int addr, i, ret = 0;
563
564 addr = RS5C_ADDR(RS5C_REG_CTRL1);
565 buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
566 buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
567
568 switch (rs5c372->type) {
569 case rtc_r2025sd:
570 if (buf[1] & R2x2x_CTRL2_XSTP)
571 return ret;
572 break;
573 case rtc_r2221tl:
574 if (!(buf[1] & R2x2x_CTRL2_XSTP))
575 return ret;
576 break;
577 default:
578 if (!(buf[1] & RS5C_CTRL2_XSTP))
579 return ret;
580 break;
581 }
582
583 /* use 24hr mode */
584 switch (rs5c372->type) {
585 case rtc_rs5c372a:
586 case rtc_rs5c372b:
587 buf[1] |= RS5C372_CTRL2_24;
588 rs5c372->time24 = 1;
589 break;
590 case rtc_r2025sd:
591 case rtc_r2221tl:
592 case rtc_rv5c386:
593 case rtc_rv5c387a:
594 buf[0] |= RV5C387_CTRL1_24;
595 rs5c372->time24 = 1;
596 break;
597 default:
598 /* impossible */
599 break;
600 }
601
602 for (i = 0; i < sizeof(buf); i++) {
603 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
604 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
605 if (unlikely(ret < 0))
606 return ret;
607 }
608
609 rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
610 rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
611
612 return 0;
613}
614
615static int rs5c372_probe(struct i2c_client *client,
616 const struct i2c_device_id *id)
617{
618 int err = 0;
619 int smbus_mode = 0;
620 struct rs5c372 *rs5c372;
621
622 dev_dbg(&client->dev, "%s\n", __func__);
623
624 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
625 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
626 /*
627 * If we don't have any master mode adapter, try breaking
628 * it down in to the barest of capabilities.
629 */
630 if (i2c_check_functionality(client->adapter,
631 I2C_FUNC_SMBUS_BYTE_DATA |
632 I2C_FUNC_SMBUS_I2C_BLOCK))
633 smbus_mode = 1;
634 else {
635 /* Still no good, give up */
636 err = -ENODEV;
637 goto exit;
638 }
639 }
640
641 rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
642 GFP_KERNEL);
643 if (!rs5c372) {
644 err = -ENOMEM;
645 goto exit;
646 }
647
648 rs5c372->client = client;
649 i2c_set_clientdata(client, rs5c372);
650 if (client->dev.of_node)
651 rs5c372->type = (enum rtc_type)
652 of_device_get_match_data(&client->dev);
653 else
654 rs5c372->type = id->driver_data;
655
656 /* we read registers 0x0f then 0x00-0x0f; skip the first one */
657 rs5c372->regs = &rs5c372->buf[1];
658 rs5c372->smbus = smbus_mode;
659
660 err = rs5c_get_regs(rs5c372);
661 if (err < 0)
662 goto exit;
663
664 /* clock may be set for am/pm or 24 hr time */
665 switch (rs5c372->type) {
666 case rtc_rs5c372a:
667 case rtc_rs5c372b:
668 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
669 * so does periodic irq, except some 327a modes.
670 */
671 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
672 rs5c372->time24 = 1;
673 break;
674 case rtc_r2025sd:
675 case rtc_r2221tl:
676 case rtc_rv5c386:
677 case rtc_rv5c387a:
678 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
679 rs5c372->time24 = 1;
680 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
681 * irq, on both 386 and 387
682 */
683 break;
684 default:
685 dev_err(&client->dev, "unknown RTC type\n");
686 goto exit;
687 }
688
689 /* if the oscillator lost power and no other software (like
690 * the bootloader) set it up, do it here.
691 *
692 * The R2025S/D does this a little differently than the other
693 * parts, so we special case that..
694 */
695 err = rs5c_oscillator_setup(rs5c372);
696 if (unlikely(err < 0)) {
697 dev_err(&client->dev, "setup error\n");
698 goto exit;
699 }
700
701 dev_info(&client->dev, "%s found, %s\n",
702 ({ char *s; switch (rs5c372->type) {
703 case rtc_r2025sd: s = "r2025sd"; break;
704 case rtc_r2221tl: s = "r2221tl"; break;
705 case rtc_rs5c372a: s = "rs5c372a"; break;
706 case rtc_rs5c372b: s = "rs5c372b"; break;
707 case rtc_rv5c386: s = "rv5c386"; break;
708 case rtc_rv5c387a: s = "rv5c387a"; break;
709 default: s = "chip"; break;
710 }; s;}),
711 rs5c372->time24 ? "24hr" : "am/pm"
712 );
713
714 /* REVISIT use client->irq to register alarm irq ... */
715 rs5c372->rtc = devm_rtc_device_register(&client->dev,
716 rs5c372_driver.driver.name,
717 &rs5c372_rtc_ops, THIS_MODULE);
718
719 if (IS_ERR(rs5c372->rtc)) {
720 err = PTR_ERR(rs5c372->rtc);
721 goto exit;
722 }
723
724 err = rs5c_sysfs_register(&client->dev);
725 if (err)
726 goto exit;
727
728 return 0;
729
730exit:
731 return err;
732}
733
734static int rs5c372_remove(struct i2c_client *client)
735{
736 rs5c_sysfs_unregister(&client->dev);
737 return 0;
738}
739
740static struct i2c_driver rs5c372_driver = {
741 .driver = {
742 .name = "rtc-rs5c372",
743 .of_match_table = of_match_ptr(rs5c372_of_match),
744 },
745 .probe = rs5c372_probe,
746 .remove = rs5c372_remove,
747 .id_table = rs5c372_id,
748};
749
750module_i2c_driver(rs5c372_driver);
751
752MODULE_AUTHOR(
753 "Pavel Mironchik <pmironchik@optifacio.net>, "
754 "Alessandro Zummo <a.zummo@towertech.it>, "
755 "Paul Mundt <lethal@linux-sh.org>");
756MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
757MODULE_LICENSE("GPL");