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