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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Intersil ISL1208 rtc class driver
4 *
5 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
6 */
7
8#include <linux/bcd.h>
9#include <linux/i2c.h>
10#include <linux/module.h>
11#include <linux/of_device.h>
12#include <linux/of_irq.h>
13#include <linux/rtc.h>
14
15/* Register map */
16/* rtc section */
17#define ISL1208_REG_SC 0x00
18#define ISL1208_REG_MN 0x01
19#define ISL1208_REG_HR 0x02
20#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
21#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
22#define ISL1208_REG_DT 0x03
23#define ISL1208_REG_MO 0x04
24#define ISL1208_REG_YR 0x05
25#define ISL1208_REG_DW 0x06
26#define ISL1208_RTC_SECTION_LEN 7
27
28/* control/status section */
29#define ISL1208_REG_SR 0x07
30#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
31#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
32#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
33#define ISL1208_REG_SR_EVT (1<<3) /* event */
34#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
35#define ISL1208_REG_SR_BAT (1<<1) /* battery */
36#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
37#define ISL1208_REG_INT 0x08
38#define ISL1208_REG_INT_ALME (1<<6) /* alarm enable */
39#define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */
40#define ISL1219_REG_EV 0x09
41#define ISL1219_REG_EV_EVEN (1<<4) /* event detection enable */
42#define ISL1219_REG_EV_EVIENB (1<<7) /* event in pull-up disable */
43#define ISL1208_REG_ATR 0x0a
44#define ISL1208_REG_DTR 0x0b
45
46/* alarm section */
47#define ISL1208_REG_SCA 0x0c
48#define ISL1208_REG_MNA 0x0d
49#define ISL1208_REG_HRA 0x0e
50#define ISL1208_REG_DTA 0x0f
51#define ISL1208_REG_MOA 0x10
52#define ISL1208_REG_DWA 0x11
53#define ISL1208_ALARM_SECTION_LEN 6
54
55/* user section */
56#define ISL1208_REG_USR1 0x12
57#define ISL1208_REG_USR2 0x13
58#define ISL1208_USR_SECTION_LEN 2
59
60/* event section */
61#define ISL1219_REG_SCT 0x14
62#define ISL1219_REG_MNT 0x15
63#define ISL1219_REG_HRT 0x16
64#define ISL1219_REG_DTT 0x17
65#define ISL1219_REG_MOT 0x18
66#define ISL1219_REG_YRT 0x19
67#define ISL1219_EVT_SECTION_LEN 6
68
69static struct i2c_driver isl1208_driver;
70
71/* ISL1208 various variants */
72enum isl1208_id {
73 TYPE_ISL1208 = 0,
74 TYPE_ISL1209,
75 TYPE_ISL1218,
76 TYPE_ISL1219,
77 ISL_LAST_ID
78};
79
80/* Chip capabilities table */
81static const struct isl1208_config {
82 const char name[8];
83 unsigned int nvmem_length;
84 unsigned has_tamper:1;
85 unsigned has_timestamp:1;
86} isl1208_configs[] = {
87 [TYPE_ISL1208] = { "isl1208", 2, false, false },
88 [TYPE_ISL1209] = { "isl1209", 2, true, false },
89 [TYPE_ISL1218] = { "isl1218", 8, false, false },
90 [TYPE_ISL1219] = { "isl1219", 2, true, true },
91};
92
93static const struct i2c_device_id isl1208_id[] = {
94 { "isl1208", TYPE_ISL1208 },
95 { "isl1209", TYPE_ISL1209 },
96 { "isl1218", TYPE_ISL1218 },
97 { "isl1219", TYPE_ISL1219 },
98 { }
99};
100MODULE_DEVICE_TABLE(i2c, isl1208_id);
101
102static const __maybe_unused struct of_device_id isl1208_of_match[] = {
103 { .compatible = "isil,isl1208", .data = &isl1208_configs[TYPE_ISL1208] },
104 { .compatible = "isil,isl1209", .data = &isl1208_configs[TYPE_ISL1209] },
105 { .compatible = "isil,isl1218", .data = &isl1208_configs[TYPE_ISL1218] },
106 { .compatible = "isil,isl1219", .data = &isl1208_configs[TYPE_ISL1219] },
107 { }
108};
109MODULE_DEVICE_TABLE(of, isl1208_of_match);
110
111/* Device state */
112struct isl1208_state {
113 struct nvmem_config nvmem_config;
114 struct rtc_device *rtc;
115 const struct isl1208_config *config;
116};
117
118/* block read */
119static int
120isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
121 unsigned len)
122{
123 int ret;
124
125 WARN_ON(reg > ISL1219_REG_YRT);
126 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
127
128 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
129 return (ret < 0) ? ret : 0;
130}
131
132/* block write */
133static int
134isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
135 unsigned len)
136{
137 int ret;
138
139 WARN_ON(reg > ISL1219_REG_YRT);
140 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
141
142 ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf);
143 return (ret < 0) ? ret : 0;
144}
145
146/* simple check to see whether we have a isl1208 */
147static int
148isl1208_i2c_validate_client(struct i2c_client *client)
149{
150 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
151 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
152 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
153 };
154 int i;
155 int ret;
156
157 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
158 if (ret < 0)
159 return ret;
160
161 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
162 if (regs[i] & zero_mask[i]) /* check if bits are cleared */
163 return -ENODEV;
164 }
165
166 return 0;
167}
168
169static int
170isl1208_i2c_get_sr(struct i2c_client *client)
171{
172 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
173}
174
175static int
176isl1208_i2c_get_atr(struct i2c_client *client)
177{
178 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
179 if (atr < 0)
180 return atr;
181
182 /* The 6bit value in the ATR register controls the load
183 * capacitance C_load * in steps of 0.25pF
184 *
185 * bit (1<<5) of the ATR register is inverted
186 *
187 * C_load(ATR=0x20) = 4.50pF
188 * C_load(ATR=0x00) = 12.50pF
189 * C_load(ATR=0x1f) = 20.25pF
190 *
191 */
192
193 atr &= 0x3f; /* mask out lsb */
194 atr ^= 1 << 5; /* invert 6th bit */
195 atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
196
197 return atr;
198}
199
200/* returns adjustment value + 100 */
201static int
202isl1208_i2c_get_dtr(struct i2c_client *client)
203{
204 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
205 if (dtr < 0)
206 return -EIO;
207
208 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
209 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
210
211 return dtr + 100;
212}
213
214static int
215isl1208_i2c_get_usr(struct i2c_client *client)
216{
217 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
218 int ret;
219
220 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
221 ISL1208_USR_SECTION_LEN);
222 if (ret < 0)
223 return ret;
224
225 return (buf[1] << 8) | buf[0];
226}
227
228static int
229isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
230{
231 u8 buf[ISL1208_USR_SECTION_LEN];
232
233 buf[0] = usr & 0xff;
234 buf[1] = (usr >> 8) & 0xff;
235
236 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
237 ISL1208_USR_SECTION_LEN);
238}
239
240static int
241isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
242{
243 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
244
245 if (icr < 0) {
246 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
247 return icr;
248 }
249
250 if (enable)
251 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
252 else
253 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
254
255 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
256 if (icr < 0) {
257 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
258 return icr;
259 }
260
261 return 0;
262}
263
264static int
265isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
266{
267 struct i2c_client *const client = to_i2c_client(dev);
268 int sr, dtr, atr, usr;
269
270 sr = isl1208_i2c_get_sr(client);
271 if (sr < 0) {
272 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
273 return sr;
274 }
275
276 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
277 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
278 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
279 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
280 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
281 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
282 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
283
284 seq_printf(seq, "batt_status\t: %s\n",
285 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
286
287 dtr = isl1208_i2c_get_dtr(client);
288 if (dtr >= 0)
289 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr - 100);
290
291 atr = isl1208_i2c_get_atr(client);
292 if (atr >= 0)
293 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
294 atr >> 2, (atr & 0x3) * 25);
295
296 usr = isl1208_i2c_get_usr(client);
297 if (usr >= 0)
298 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
299
300 return 0;
301}
302
303static int
304isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
305{
306 int sr;
307 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
308
309 sr = isl1208_i2c_get_sr(client);
310 if (sr < 0) {
311 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
312 return -EIO;
313 }
314
315 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
316 if (sr < 0) {
317 dev_err(&client->dev, "%s: reading RTC section failed\n",
318 __func__);
319 return sr;
320 }
321
322 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
323 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
324
325 /* HR field has a more complex interpretation */
326 {
327 const u8 _hr = regs[ISL1208_REG_HR];
328 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
329 tm->tm_hour = bcd2bin(_hr & 0x3f);
330 else {
331 /* 12h format */
332 tm->tm_hour = bcd2bin(_hr & 0x1f);
333 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
334 tm->tm_hour += 12;
335 }
336 }
337
338 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
339 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
340 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
341 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
342
343 return 0;
344}
345
346static int
347isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
348{
349 struct rtc_time *const tm = &alarm->time;
350 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
351 int icr, yr, sr = isl1208_i2c_get_sr(client);
352
353 if (sr < 0) {
354 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
355 return sr;
356 }
357
358 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
359 ISL1208_ALARM_SECTION_LEN);
360 if (sr < 0) {
361 dev_err(&client->dev, "%s: reading alarm section failed\n",
362 __func__);
363 return sr;
364 }
365
366 /* MSB of each alarm register is an enable bit */
367 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
368 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
369 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
370 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
371 tm->tm_mon =
372 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
373 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
374
375 /* The alarm doesn't store the year so get it from the rtc section */
376 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
377 if (yr < 0) {
378 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
379 return yr;
380 }
381 tm->tm_year = bcd2bin(yr) + 100;
382
383 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
384 if (icr < 0) {
385 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
386 return icr;
387 }
388 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
389
390 return 0;
391}
392
393static int
394isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
395{
396 struct rtc_time *alarm_tm = &alarm->time;
397 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
398 const int offs = ISL1208_REG_SCA;
399 struct rtc_time rtc_tm;
400 int err, enable;
401
402 err = isl1208_i2c_read_time(client, &rtc_tm);
403 if (err)
404 return err;
405
406 /* If the alarm time is before the current time disable the alarm */
407 if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
408 enable = 0x00;
409 else
410 enable = 0x80;
411
412 /* Program the alarm and enable it for each setting */
413 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
414 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
415 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
416 ISL1208_REG_HR_MIL | enable;
417
418 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
419 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
420 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
421
422 /* write ALARM registers */
423 err = isl1208_i2c_set_regs(client, offs, regs,
424 ISL1208_ALARM_SECTION_LEN);
425 if (err < 0) {
426 dev_err(&client->dev, "%s: writing ALARM section failed\n",
427 __func__);
428 return err;
429 }
430
431 err = isl1208_rtc_toggle_alarm(client, enable);
432 if (err)
433 return err;
434
435 return 0;
436}
437
438static int
439isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
440{
441 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
442}
443
444static int
445isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
446{
447 int sr;
448 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
449
450 /* The clock has an 8 bit wide bcd-coded register (they never learn)
451 * for the year. tm_year is an offset from 1900 and we are interested
452 * in the 2000-2099 range, so any value less than 100 is invalid.
453 */
454 if (tm->tm_year < 100)
455 return -EINVAL;
456
457 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
458 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
459 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
460
461 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
462 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
463 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
464
465 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
466
467 sr = isl1208_i2c_get_sr(client);
468 if (sr < 0) {
469 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
470 return sr;
471 }
472
473 /* set WRTC */
474 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
475 sr | ISL1208_REG_SR_WRTC);
476 if (sr < 0) {
477 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
478 return sr;
479 }
480
481 /* write RTC registers */
482 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
483 if (sr < 0) {
484 dev_err(&client->dev, "%s: writing RTC section failed\n",
485 __func__);
486 return sr;
487 }
488
489 /* clear WRTC again */
490 sr = isl1208_i2c_get_sr(client);
491 if (sr < 0) {
492 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
493 return sr;
494 }
495 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
496 sr & ~ISL1208_REG_SR_WRTC);
497 if (sr < 0) {
498 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
499 return sr;
500 }
501
502 return 0;
503}
504
505
506static int
507isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
508{
509 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
510}
511
512static int
513isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
514{
515 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
516}
517
518static int
519isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
520{
521 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
522}
523
524static ssize_t timestamp0_store(struct device *dev,
525 struct device_attribute *attr,
526 const char *buf, size_t count)
527{
528 struct i2c_client *client = to_i2c_client(dev->parent);
529 int sr;
530
531 sr = isl1208_i2c_get_sr(client);
532 if (sr < 0) {
533 dev_err(dev, "%s: reading SR failed\n", __func__);
534 return sr;
535 }
536
537 sr &= ~ISL1208_REG_SR_EVT;
538
539 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
540 if (sr < 0)
541 dev_err(dev, "%s: writing SR failed\n",
542 __func__);
543
544 return count;
545};
546
547static ssize_t timestamp0_show(struct device *dev,
548 struct device_attribute *attr, char *buf)
549{
550 struct i2c_client *client = to_i2c_client(dev->parent);
551 u8 regs[ISL1219_EVT_SECTION_LEN] = { 0, };
552 struct rtc_time tm;
553 int sr;
554
555 sr = isl1208_i2c_get_sr(client);
556 if (sr < 0) {
557 dev_err(dev, "%s: reading SR failed\n", __func__);
558 return sr;
559 }
560
561 if (!(sr & ISL1208_REG_SR_EVT))
562 return 0;
563
564 sr = isl1208_i2c_read_regs(client, ISL1219_REG_SCT, regs,
565 ISL1219_EVT_SECTION_LEN);
566 if (sr < 0) {
567 dev_err(dev, "%s: reading event section failed\n",
568 __func__);
569 return 0;
570 }
571
572 /* MSB of each alarm register is an enable bit */
573 tm.tm_sec = bcd2bin(regs[ISL1219_REG_SCT - ISL1219_REG_SCT] & 0x7f);
574 tm.tm_min = bcd2bin(regs[ISL1219_REG_MNT - ISL1219_REG_SCT] & 0x7f);
575 tm.tm_hour = bcd2bin(regs[ISL1219_REG_HRT - ISL1219_REG_SCT] & 0x3f);
576 tm.tm_mday = bcd2bin(regs[ISL1219_REG_DTT - ISL1219_REG_SCT] & 0x3f);
577 tm.tm_mon =
578 bcd2bin(regs[ISL1219_REG_MOT - ISL1219_REG_SCT] & 0x1f) - 1;
579 tm.tm_year = bcd2bin(regs[ISL1219_REG_YRT - ISL1219_REG_SCT]) + 100;
580
581 sr = rtc_valid_tm(&tm);
582 if (sr)
583 return sr;
584
585 return sprintf(buf, "%llu\n",
586 (unsigned long long)rtc_tm_to_time64(&tm));
587};
588
589static DEVICE_ATTR_RW(timestamp0);
590
591static irqreturn_t
592isl1208_rtc_interrupt(int irq, void *data)
593{
594 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
595 struct i2c_client *client = data;
596 struct isl1208_state *isl1208 = i2c_get_clientdata(client);
597 int handled = 0, sr, err;
598
599 /*
600 * I2C reads get NAK'ed if we read straight away after an interrupt?
601 * Using a mdelay/msleep didn't seem to help either, so we work around
602 * this by continually trying to read the register for a short time.
603 */
604 while (1) {
605 sr = isl1208_i2c_get_sr(client);
606 if (sr >= 0)
607 break;
608
609 if (time_after(jiffies, timeout)) {
610 dev_err(&client->dev, "%s: reading SR failed\n",
611 __func__);
612 return sr;
613 }
614 }
615
616 if (sr & ISL1208_REG_SR_ALM) {
617 dev_dbg(&client->dev, "alarm!\n");
618
619 rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF);
620
621 /* Clear the alarm */
622 sr &= ~ISL1208_REG_SR_ALM;
623 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
624 if (sr < 0)
625 dev_err(&client->dev, "%s: writing SR failed\n",
626 __func__);
627 else
628 handled = 1;
629
630 /* Disable the alarm */
631 err = isl1208_rtc_toggle_alarm(client, 0);
632 if (err)
633 return err;
634 }
635
636 if (isl1208->config->has_tamper && (sr & ISL1208_REG_SR_EVT)) {
637 dev_warn(&client->dev, "event detected");
638 handled = 1;
639 if (isl1208->config->has_timestamp)
640 sysfs_notify(&isl1208->rtc->dev.kobj, NULL,
641 dev_attr_timestamp0.attr.name);
642 }
643
644 return handled ? IRQ_HANDLED : IRQ_NONE;
645}
646
647static const struct rtc_class_ops isl1208_rtc_ops = {
648 .proc = isl1208_rtc_proc,
649 .read_time = isl1208_rtc_read_time,
650 .set_time = isl1208_rtc_set_time,
651 .read_alarm = isl1208_rtc_read_alarm,
652 .set_alarm = isl1208_rtc_set_alarm,
653};
654
655/* sysfs interface */
656
657static ssize_t
658isl1208_sysfs_show_atrim(struct device *dev,
659 struct device_attribute *attr, char *buf)
660{
661 int atr = isl1208_i2c_get_atr(to_i2c_client(dev->parent));
662 if (atr < 0)
663 return atr;
664
665 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
666}
667
668static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
669
670static ssize_t
671isl1208_sysfs_show_dtrim(struct device *dev,
672 struct device_attribute *attr, char *buf)
673{
674 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev->parent));
675 if (dtr < 0)
676 return dtr;
677
678 return sprintf(buf, "%d ppm\n", dtr - 100);
679}
680
681static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
682
683static ssize_t
684isl1208_sysfs_show_usr(struct device *dev,
685 struct device_attribute *attr, char *buf)
686{
687 int usr = isl1208_i2c_get_usr(to_i2c_client(dev->parent));
688 if (usr < 0)
689 return usr;
690
691 return sprintf(buf, "0x%.4x\n", usr);
692}
693
694static ssize_t
695isl1208_sysfs_store_usr(struct device *dev,
696 struct device_attribute *attr,
697 const char *buf, size_t count)
698{
699 int usr = -1;
700
701 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
702 if (sscanf(buf, "%x", &usr) != 1)
703 return -EINVAL;
704 } else {
705 if (sscanf(buf, "%d", &usr) != 1)
706 return -EINVAL;
707 }
708
709 if (usr < 0 || usr > 0xffff)
710 return -EINVAL;
711
712 if (isl1208_i2c_set_usr(to_i2c_client(dev->parent), usr))
713 return -EIO;
714
715 return count;
716}
717
718static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
719 isl1208_sysfs_store_usr);
720
721static struct attribute *isl1208_rtc_attrs[] = {
722 &dev_attr_atrim.attr,
723 &dev_attr_dtrim.attr,
724 &dev_attr_usr.attr,
725 NULL
726};
727
728static const struct attribute_group isl1208_rtc_sysfs_files = {
729 .attrs = isl1208_rtc_attrs,
730};
731
732static struct attribute *isl1219_rtc_attrs[] = {
733 &dev_attr_timestamp0.attr,
734 NULL
735};
736
737static const struct attribute_group isl1219_rtc_sysfs_files = {
738 .attrs = isl1219_rtc_attrs,
739};
740
741static int isl1208_nvmem_read(void *priv, unsigned int off, void *buf,
742 size_t count)
743{
744 struct isl1208_state *isl1208 = priv;
745 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
746 int ret;
747
748 /* nvmem sanitizes offset/count for us, but count==0 is possible */
749 if (!count)
750 return count;
751 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1 + off, buf,
752 count);
753 return ret == 0 ? count : ret;
754}
755
756static int isl1208_nvmem_write(void *priv, unsigned int off, void *buf,
757 size_t count)
758{
759 struct isl1208_state *isl1208 = priv;
760 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
761 int ret;
762
763 /* nvmem sanitizes off/count for us, but count==0 is possible */
764 if (!count)
765 return count;
766 ret = isl1208_i2c_set_regs(client, ISL1208_REG_USR1 + off, buf,
767 count);
768
769 return ret == 0 ? count : ret;
770}
771
772static const struct nvmem_config isl1208_nvmem_config = {
773 .name = "isl1208_nvram",
774 .word_size = 1,
775 .stride = 1,
776 /* .size from chip specific config */
777 .reg_read = isl1208_nvmem_read,
778 .reg_write = isl1208_nvmem_write,
779};
780
781static int isl1208_setup_irq(struct i2c_client *client, int irq)
782{
783 int rc = devm_request_threaded_irq(&client->dev, irq, NULL,
784 isl1208_rtc_interrupt,
785 IRQF_SHARED | IRQF_ONESHOT,
786 isl1208_driver.driver.name,
787 client);
788 if (!rc) {
789 device_init_wakeup(&client->dev, 1);
790 enable_irq_wake(irq);
791 } else {
792 dev_err(&client->dev,
793 "Unable to request irq %d, no alarm support\n",
794 irq);
795 }
796 return rc;
797}
798
799static int
800isl1208_probe(struct i2c_client *client)
801{
802 int rc = 0;
803 struct isl1208_state *isl1208;
804 int evdet_irq = -1;
805
806 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
807 return -ENODEV;
808
809 if (isl1208_i2c_validate_client(client) < 0)
810 return -ENODEV;
811
812 /* Allocate driver state, point i2c client data to it */
813 isl1208 = devm_kzalloc(&client->dev, sizeof(*isl1208), GFP_KERNEL);
814 if (!isl1208)
815 return -ENOMEM;
816 i2c_set_clientdata(client, isl1208);
817
818 /* Determine which chip we have */
819 if (client->dev.of_node) {
820 isl1208->config = of_device_get_match_data(&client->dev);
821 if (!isl1208->config)
822 return -ENODEV;
823 } else {
824 const struct i2c_device_id *id = i2c_match_id(isl1208_id, client);
825
826 if (id->driver_data >= ISL_LAST_ID)
827 return -ENODEV;
828 isl1208->config = &isl1208_configs[id->driver_data];
829 }
830
831 isl1208->rtc = devm_rtc_allocate_device(&client->dev);
832 if (IS_ERR(isl1208->rtc))
833 return PTR_ERR(isl1208->rtc);
834
835 isl1208->rtc->ops = &isl1208_rtc_ops;
836
837 /* Setup nvmem configuration in driver state struct */
838 isl1208->nvmem_config = isl1208_nvmem_config;
839 isl1208->nvmem_config.size = isl1208->config->nvmem_length;
840 isl1208->nvmem_config.priv = isl1208;
841
842 rc = isl1208_i2c_get_sr(client);
843 if (rc < 0) {
844 dev_err(&client->dev, "reading status failed\n");
845 return rc;
846 }
847
848 if (rc & ISL1208_REG_SR_RTCF)
849 dev_warn(&client->dev, "rtc power failure detected, "
850 "please set clock.\n");
851
852 if (isl1208->config->has_tamper) {
853 struct device_node *np = client->dev.of_node;
854 u32 evienb;
855
856 rc = i2c_smbus_read_byte_data(client, ISL1219_REG_EV);
857 if (rc < 0) {
858 dev_err(&client->dev, "failed to read EV reg\n");
859 return rc;
860 }
861 rc |= ISL1219_REG_EV_EVEN;
862 if (!of_property_read_u32(np, "isil,ev-evienb", &evienb)) {
863 if (evienb)
864 rc |= ISL1219_REG_EV_EVIENB;
865 else
866 rc &= ~ISL1219_REG_EV_EVIENB;
867 }
868 rc = i2c_smbus_write_byte_data(client, ISL1219_REG_EV, rc);
869 if (rc < 0) {
870 dev_err(&client->dev, "could not enable tamper detection\n");
871 return rc;
872 }
873 evdet_irq = of_irq_get_byname(np, "evdet");
874 }
875 if (isl1208->config->has_timestamp) {
876 rc = rtc_add_group(isl1208->rtc, &isl1219_rtc_sysfs_files);
877 if (rc)
878 return rc;
879 }
880
881 rc = rtc_add_group(isl1208->rtc, &isl1208_rtc_sysfs_files);
882 if (rc)
883 return rc;
884
885 if (client->irq > 0) {
886 rc = isl1208_setup_irq(client, client->irq);
887 if (rc)
888 return rc;
889
890 } else {
891 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, isl1208->rtc->features);
892 }
893
894 if (evdet_irq > 0 && evdet_irq != client->irq)
895 rc = isl1208_setup_irq(client, evdet_irq);
896 if (rc)
897 return rc;
898
899 rc = devm_rtc_nvmem_register(isl1208->rtc, &isl1208->nvmem_config);
900 if (rc)
901 return rc;
902
903 return devm_rtc_register_device(isl1208->rtc);
904}
905
906static struct i2c_driver isl1208_driver = {
907 .driver = {
908 .name = "rtc-isl1208",
909 .of_match_table = of_match_ptr(isl1208_of_match),
910 },
911 .probe_new = isl1208_probe,
912 .id_table = isl1208_id,
913};
914
915module_i2c_driver(isl1208_driver);
916
917MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
918MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
919MODULE_LICENSE("GPL");
1/*
2 * Intersil ISL1208 rtc class driver
3 *
4 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 *
11 */
12
13#include <linux/module.h>
14#include <linux/i2c.h>
15#include <linux/bcd.h>
16#include <linux/rtc.h>
17
18#define DRV_VERSION "0.3"
19
20/* Register map */
21/* rtc section */
22#define ISL1208_REG_SC 0x00
23#define ISL1208_REG_MN 0x01
24#define ISL1208_REG_HR 0x02
25#define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
26#define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
27#define ISL1208_REG_DT 0x03
28#define ISL1208_REG_MO 0x04
29#define ISL1208_REG_YR 0x05
30#define ISL1208_REG_DW 0x06
31#define ISL1208_RTC_SECTION_LEN 7
32
33/* control/status section */
34#define ISL1208_REG_SR 0x07
35#define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
36#define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
37#define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
38#define ISL1208_REG_SR_ALM (1<<2) /* alarm */
39#define ISL1208_REG_SR_BAT (1<<1) /* battery */
40#define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
41#define ISL1208_REG_INT 0x08
42#define ISL1208_REG_INT_ALME (1<<6) /* alarm enable */
43#define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */
44#define ISL1208_REG_09 0x09 /* reserved */
45#define ISL1208_REG_ATR 0x0a
46#define ISL1208_REG_DTR 0x0b
47
48/* alarm section */
49#define ISL1208_REG_SCA 0x0c
50#define ISL1208_REG_MNA 0x0d
51#define ISL1208_REG_HRA 0x0e
52#define ISL1208_REG_DTA 0x0f
53#define ISL1208_REG_MOA 0x10
54#define ISL1208_REG_DWA 0x11
55#define ISL1208_ALARM_SECTION_LEN 6
56
57/* user section */
58#define ISL1208_REG_USR1 0x12
59#define ISL1208_REG_USR2 0x13
60#define ISL1208_USR_SECTION_LEN 2
61
62static struct i2c_driver isl1208_driver;
63
64/* block read */
65static int
66isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
67 unsigned len)
68{
69 u8 reg_addr[1] = { reg };
70 struct i2c_msg msgs[2] = {
71 {
72 .addr = client->addr,
73 .len = sizeof(reg_addr),
74 .buf = reg_addr
75 },
76 {
77 .addr = client->addr,
78 .flags = I2C_M_RD,
79 .len = len,
80 .buf = buf
81 }
82 };
83 int ret;
84
85 BUG_ON(reg > ISL1208_REG_USR2);
86 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
87
88 ret = i2c_transfer(client->adapter, msgs, 2);
89 if (ret > 0)
90 ret = 0;
91 return ret;
92}
93
94/* block write */
95static int
96isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
97 unsigned len)
98{
99 u8 i2c_buf[ISL1208_REG_USR2 + 2];
100 struct i2c_msg msgs[1] = {
101 {
102 .addr = client->addr,
103 .len = len + 1,
104 .buf = i2c_buf
105 }
106 };
107 int ret;
108
109 BUG_ON(reg > ISL1208_REG_USR2);
110 BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
111
112 i2c_buf[0] = reg;
113 memcpy(&i2c_buf[1], &buf[0], len);
114
115 ret = i2c_transfer(client->adapter, msgs, 1);
116 if (ret > 0)
117 ret = 0;
118 return ret;
119}
120
121/* simple check to see whether we have a isl1208 */
122static int
123isl1208_i2c_validate_client(struct i2c_client *client)
124{
125 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
126 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
127 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
128 };
129 int i;
130 int ret;
131
132 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
133 if (ret < 0)
134 return ret;
135
136 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
137 if (regs[i] & zero_mask[i]) /* check if bits are cleared */
138 return -ENODEV;
139 }
140
141 return 0;
142}
143
144static int
145isl1208_i2c_get_sr(struct i2c_client *client)
146{
147 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
148}
149
150static int
151isl1208_i2c_get_atr(struct i2c_client *client)
152{
153 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
154 if (atr < 0)
155 return atr;
156
157 /* The 6bit value in the ATR register controls the load
158 * capacitance C_load * in steps of 0.25pF
159 *
160 * bit (1<<5) of the ATR register is inverted
161 *
162 * C_load(ATR=0x20) = 4.50pF
163 * C_load(ATR=0x00) = 12.50pF
164 * C_load(ATR=0x1f) = 20.25pF
165 *
166 */
167
168 atr &= 0x3f; /* mask out lsb */
169 atr ^= 1 << 5; /* invert 6th bit */
170 atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
171
172 return atr;
173}
174
175static int
176isl1208_i2c_get_dtr(struct i2c_client *client)
177{
178 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
179 if (dtr < 0)
180 return -EIO;
181
182 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
183 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
184
185 return dtr;
186}
187
188static int
189isl1208_i2c_get_usr(struct i2c_client *client)
190{
191 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
192 int ret;
193
194 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
195 ISL1208_USR_SECTION_LEN);
196 if (ret < 0)
197 return ret;
198
199 return (buf[1] << 8) | buf[0];
200}
201
202static int
203isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
204{
205 u8 buf[ISL1208_USR_SECTION_LEN];
206
207 buf[0] = usr & 0xff;
208 buf[1] = (usr >> 8) & 0xff;
209
210 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
211 ISL1208_USR_SECTION_LEN);
212}
213
214static int
215isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
216{
217 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
218
219 if (icr < 0) {
220 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
221 return icr;
222 }
223
224 if (enable)
225 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
226 else
227 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
228
229 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
230 if (icr < 0) {
231 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
232 return icr;
233 }
234
235 return 0;
236}
237
238static int
239isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
240{
241 struct i2c_client *const client = to_i2c_client(dev);
242 int sr, dtr, atr, usr;
243
244 sr = isl1208_i2c_get_sr(client);
245 if (sr < 0) {
246 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
247 return sr;
248 }
249
250 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
251 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
252 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
253 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
254 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
255 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
256 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
257
258 seq_printf(seq, "batt_status\t: %s\n",
259 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
260
261 dtr = isl1208_i2c_get_dtr(client);
262 if (dtr >= 0 - 1)
263 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
264
265 atr = isl1208_i2c_get_atr(client);
266 if (atr >= 0)
267 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
268 atr >> 2, (atr & 0x3) * 25);
269
270 usr = isl1208_i2c_get_usr(client);
271 if (usr >= 0)
272 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
273
274 return 0;
275}
276
277static int
278isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
279{
280 int sr;
281 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
282
283 sr = isl1208_i2c_get_sr(client);
284 if (sr < 0) {
285 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
286 return -EIO;
287 }
288
289 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
290 if (sr < 0) {
291 dev_err(&client->dev, "%s: reading RTC section failed\n",
292 __func__);
293 return sr;
294 }
295
296 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
297 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
298
299 /* HR field has a more complex interpretation */
300 {
301 const u8 _hr = regs[ISL1208_REG_HR];
302 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
303 tm->tm_hour = bcd2bin(_hr & 0x3f);
304 else {
305 /* 12h format */
306 tm->tm_hour = bcd2bin(_hr & 0x1f);
307 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
308 tm->tm_hour += 12;
309 }
310 }
311
312 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
313 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
314 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
315 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
316
317 return 0;
318}
319
320static int
321isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
322{
323 struct rtc_time *const tm = &alarm->time;
324 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
325 int icr, yr, sr = isl1208_i2c_get_sr(client);
326
327 if (sr < 0) {
328 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
329 return sr;
330 }
331
332 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
333 ISL1208_ALARM_SECTION_LEN);
334 if (sr < 0) {
335 dev_err(&client->dev, "%s: reading alarm section failed\n",
336 __func__);
337 return sr;
338 }
339
340 /* MSB of each alarm register is an enable bit */
341 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
342 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
343 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
344 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
345 tm->tm_mon =
346 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
347 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
348
349 /* The alarm doesn't store the year so get it from the rtc section */
350 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
351 if (yr < 0) {
352 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
353 return yr;
354 }
355 tm->tm_year = bcd2bin(yr) + 100;
356
357 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
358 if (icr < 0) {
359 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
360 return icr;
361 }
362 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
363
364 return 0;
365}
366
367static int
368isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
369{
370 struct rtc_time *alarm_tm = &alarm->time;
371 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
372 const int offs = ISL1208_REG_SCA;
373 struct rtc_time rtc_tm;
374 int err, enable;
375
376 err = isl1208_i2c_read_time(client, &rtc_tm);
377 if (err)
378 return err;
379
380 /* If the alarm time is before the current time disable the alarm */
381 if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
382 enable = 0x00;
383 else
384 enable = 0x80;
385
386 /* Program the alarm and enable it for each setting */
387 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
388 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
389 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
390 ISL1208_REG_HR_MIL | enable;
391
392 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
393 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
394 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
395
396 /* write ALARM registers */
397 err = isl1208_i2c_set_regs(client, offs, regs,
398 ISL1208_ALARM_SECTION_LEN);
399 if (err < 0) {
400 dev_err(&client->dev, "%s: writing ALARM section failed\n",
401 __func__);
402 return err;
403 }
404
405 err = isl1208_rtc_toggle_alarm(client, enable);
406 if (err)
407 return err;
408
409 return 0;
410}
411
412static int
413isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
414{
415 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
416}
417
418static int
419isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
420{
421 int sr;
422 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
423
424 /* The clock has an 8 bit wide bcd-coded register (they never learn)
425 * for the year. tm_year is an offset from 1900 and we are interested
426 * in the 2000-2099 range, so any value less than 100 is invalid.
427 */
428 if (tm->tm_year < 100)
429 return -EINVAL;
430
431 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
432 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
433 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
434
435 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
436 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
437 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
438
439 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
440
441 sr = isl1208_i2c_get_sr(client);
442 if (sr < 0) {
443 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
444 return sr;
445 }
446
447 /* set WRTC */
448 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
449 sr | ISL1208_REG_SR_WRTC);
450 if (sr < 0) {
451 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
452 return sr;
453 }
454
455 /* write RTC registers */
456 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
457 if (sr < 0) {
458 dev_err(&client->dev, "%s: writing RTC section failed\n",
459 __func__);
460 return sr;
461 }
462
463 /* clear WRTC again */
464 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
465 sr & ~ISL1208_REG_SR_WRTC);
466 if (sr < 0) {
467 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
468 return sr;
469 }
470
471 return 0;
472}
473
474
475static int
476isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
477{
478 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
479}
480
481static int
482isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
483{
484 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
485}
486
487static int
488isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
489{
490 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
491}
492
493static irqreturn_t
494isl1208_rtc_interrupt(int irq, void *data)
495{
496 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
497 struct i2c_client *client = data;
498 struct rtc_device *rtc = i2c_get_clientdata(client);
499 int handled = 0, sr, err;
500
501 /*
502 * I2C reads get NAK'ed if we read straight away after an interrupt?
503 * Using a mdelay/msleep didn't seem to help either, so we work around
504 * this by continually trying to read the register for a short time.
505 */
506 while (1) {
507 sr = isl1208_i2c_get_sr(client);
508 if (sr >= 0)
509 break;
510
511 if (time_after(jiffies, timeout)) {
512 dev_err(&client->dev, "%s: reading SR failed\n",
513 __func__);
514 return sr;
515 }
516 }
517
518 if (sr & ISL1208_REG_SR_ALM) {
519 dev_dbg(&client->dev, "alarm!\n");
520
521 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
522
523 /* Clear the alarm */
524 sr &= ~ISL1208_REG_SR_ALM;
525 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
526 if (sr < 0)
527 dev_err(&client->dev, "%s: writing SR failed\n",
528 __func__);
529 else
530 handled = 1;
531
532 /* Disable the alarm */
533 err = isl1208_rtc_toggle_alarm(client, 0);
534 if (err)
535 return err;
536 }
537
538 return handled ? IRQ_HANDLED : IRQ_NONE;
539}
540
541static const struct rtc_class_ops isl1208_rtc_ops = {
542 .proc = isl1208_rtc_proc,
543 .read_time = isl1208_rtc_read_time,
544 .set_time = isl1208_rtc_set_time,
545 .read_alarm = isl1208_rtc_read_alarm,
546 .set_alarm = isl1208_rtc_set_alarm,
547};
548
549/* sysfs interface */
550
551static ssize_t
552isl1208_sysfs_show_atrim(struct device *dev,
553 struct device_attribute *attr, char *buf)
554{
555 int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
556 if (atr < 0)
557 return atr;
558
559 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
560}
561
562static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
563
564static ssize_t
565isl1208_sysfs_show_dtrim(struct device *dev,
566 struct device_attribute *attr, char *buf)
567{
568 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
569 if (dtr < 0)
570 return dtr;
571
572 return sprintf(buf, "%d ppm\n", dtr);
573}
574
575static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
576
577static ssize_t
578isl1208_sysfs_show_usr(struct device *dev,
579 struct device_attribute *attr, char *buf)
580{
581 int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
582 if (usr < 0)
583 return usr;
584
585 return sprintf(buf, "0x%.4x\n", usr);
586}
587
588static ssize_t
589isl1208_sysfs_store_usr(struct device *dev,
590 struct device_attribute *attr,
591 const char *buf, size_t count)
592{
593 int usr = -1;
594
595 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
596 if (sscanf(buf, "%x", &usr) != 1)
597 return -EINVAL;
598 } else {
599 if (sscanf(buf, "%d", &usr) != 1)
600 return -EINVAL;
601 }
602
603 if (usr < 0 || usr > 0xffff)
604 return -EINVAL;
605
606 return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
607}
608
609static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
610 isl1208_sysfs_store_usr);
611
612static struct attribute *isl1208_rtc_attrs[] = {
613 &dev_attr_atrim.attr,
614 &dev_attr_dtrim.attr,
615 &dev_attr_usr.attr,
616 NULL
617};
618
619static const struct attribute_group isl1208_rtc_sysfs_files = {
620 .attrs = isl1208_rtc_attrs,
621};
622
623static int
624isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
625{
626 int rc = 0;
627 struct rtc_device *rtc;
628
629 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
630 return -ENODEV;
631
632 if (isl1208_i2c_validate_client(client) < 0)
633 return -ENODEV;
634
635 dev_info(&client->dev,
636 "chip found, driver version " DRV_VERSION "\n");
637
638 if (client->irq > 0) {
639 rc = devm_request_threaded_irq(&client->dev, client->irq, NULL,
640 isl1208_rtc_interrupt,
641 IRQF_SHARED | IRQF_ONESHOT,
642 isl1208_driver.driver.name,
643 client);
644 if (!rc) {
645 device_init_wakeup(&client->dev, 1);
646 enable_irq_wake(client->irq);
647 } else {
648 dev_err(&client->dev,
649 "Unable to request irq %d, no alarm support\n",
650 client->irq);
651 client->irq = 0;
652 }
653 }
654
655 rtc = devm_rtc_device_register(&client->dev, isl1208_driver.driver.name,
656 &isl1208_rtc_ops,
657 THIS_MODULE);
658 if (IS_ERR(rtc))
659 return PTR_ERR(rtc);
660
661 i2c_set_clientdata(client, rtc);
662
663 rc = isl1208_i2c_get_sr(client);
664 if (rc < 0) {
665 dev_err(&client->dev, "reading status failed\n");
666 return rc;
667 }
668
669 if (rc & ISL1208_REG_SR_RTCF)
670 dev_warn(&client->dev, "rtc power failure detected, "
671 "please set clock.\n");
672
673 rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
674 if (rc)
675 return rc;
676
677 return 0;
678}
679
680static int
681isl1208_remove(struct i2c_client *client)
682{
683 sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
684
685 return 0;
686}
687
688static const struct i2c_device_id isl1208_id[] = {
689 { "isl1208", 0 },
690 { "isl1218", 0 },
691 { }
692};
693MODULE_DEVICE_TABLE(i2c, isl1208_id);
694
695static struct i2c_driver isl1208_driver = {
696 .driver = {
697 .name = "rtc-isl1208",
698 },
699 .probe = isl1208_probe,
700 .remove = isl1208_remove,
701 .id_table = isl1208_id,
702};
703
704module_i2c_driver(isl1208_driver);
705
706MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
707MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
708MODULE_LICENSE("GPL");
709MODULE_VERSION(DRV_VERSION);