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/clk.h>
10 #include <linux/i2c.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_irq.h>
14 #include <linux/rtc.h>
15
16 /* Register map */
17 /* rtc section */
18 #define ISL1208_REG_SC 0x00
19 #define ISL1208_REG_MN 0x01
20 #define ISL1208_REG_HR 0x02
21 #define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */
22 #define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
23 #define ISL1208_REG_DT 0x03
24 #define ISL1208_REG_MO 0x04
25 #define ISL1208_REG_YR 0x05
26 #define ISL1208_REG_DW 0x06
27 #define ISL1208_RTC_SECTION_LEN 7
28
29 /* control/status section */
30 #define ISL1208_REG_SR 0x07
31 #define ISL1208_REG_SR_ARST (1<<7) /* auto reset */
32 #define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */
33 #define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */
34 #define ISL1208_REG_SR_EVT (1<<3) /* event */
35 #define ISL1208_REG_SR_ALM (1<<2) /* alarm */
36 #define ISL1208_REG_SR_BAT (1<<1) /* battery */
37 #define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */
38 #define ISL1208_REG_INT 0x08
39 #define ISL1208_REG_INT_ALME (1<<6) /* alarm enable */
40 #define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */
41 #define ISL1219_REG_EV 0x09
42 #define ISL1219_REG_EV_EVEN (1<<4) /* event detection enable */
43 #define ISL1219_REG_EV_EVIENB (1<<7) /* event in pull-up disable */
44 #define ISL1208_REG_ATR 0x0a
45 #define ISL1208_REG_DTR 0x0b
46
47 /* alarm section */
48 #define ISL1208_REG_SCA 0x0c
49 #define ISL1208_REG_MNA 0x0d
50 #define ISL1208_REG_HRA 0x0e
51 #define ISL1208_REG_DTA 0x0f
52 #define ISL1208_REG_MOA 0x10
53 #define ISL1208_REG_DWA 0x11
54 #define ISL1208_ALARM_SECTION_LEN 6
55
56 /* user section */
57 #define ISL1208_REG_USR1 0x12
58 #define ISL1208_REG_USR2 0x13
59 #define ISL1208_USR_SECTION_LEN 2
60
61 /* event section */
62 #define ISL1219_REG_SCT 0x14
63 #define ISL1219_REG_MNT 0x15
64 #define ISL1219_REG_HRT 0x16
65 #define ISL1219_REG_DTT 0x17
66 #define ISL1219_REG_MOT 0x18
67 #define ISL1219_REG_YRT 0x19
68 #define ISL1219_EVT_SECTION_LEN 6
69
70 static struct i2c_driver isl1208_driver;
71
72 /* Chip capabilities table */
73 struct isl1208_config {
74 unsigned int nvmem_length;
75 unsigned has_tamper:1;
76 unsigned has_timestamp:1;
77 unsigned has_inverted_osc_bit:1;
78 };
79
80 static const struct isl1208_config config_isl1208 = {
81 .nvmem_length = 2,
82 .has_tamper = false,
83 .has_timestamp = false
84 };
85
86 static const struct isl1208_config config_isl1209 = {
87 .nvmem_length = 2,
88 .has_tamper = true,
89 .has_timestamp = false
90 };
91
92 static const struct isl1208_config config_isl1218 = {
93 .nvmem_length = 8,
94 .has_tamper = false,
95 .has_timestamp = false
96 };
97
98 static const struct isl1208_config config_isl1219 = {
99 .nvmem_length = 2,
100 .has_tamper = true,
101 .has_timestamp = true
102 };
103
104 static const struct isl1208_config config_raa215300_a0 = {
105 .nvmem_length = 2,
106 .has_tamper = false,
107 .has_timestamp = false,
108 .has_inverted_osc_bit = true
109 };
110
111 static const struct i2c_device_id isl1208_id[] = {
112 { "isl1208", .driver_data = (kernel_ulong_t)&config_isl1208 },
113 { "isl1209", .driver_data = (kernel_ulong_t)&config_isl1209 },
114 { "isl1218", .driver_data = (kernel_ulong_t)&config_isl1218 },
115 { "isl1219", .driver_data = (kernel_ulong_t)&config_isl1219 },
116 { "raa215300_a0", .driver_data = (kernel_ulong_t)&config_raa215300_a0 },
117 { }
118 };
119 MODULE_DEVICE_TABLE(i2c, isl1208_id);
120
121 static const __maybe_unused struct of_device_id isl1208_of_match[] = {
122 { .compatible = "isil,isl1208", .data = &config_isl1208 },
123 { .compatible = "isil,isl1209", .data = &config_isl1209 },
124 { .compatible = "isil,isl1218", .data = &config_isl1218 },
125 { .compatible = "isil,isl1219", .data = &config_isl1219 },
126 { }
127 };
128 MODULE_DEVICE_TABLE(of, isl1208_of_match);
129
130 /* Device state */
131 struct isl1208_state {
132 struct nvmem_config nvmem_config;
133 struct rtc_device *rtc;
134 const struct isl1208_config *config;
135 };
136
137 /* block read */
138 static int
isl1208_i2c_read_regs(struct i2c_client * client,u8 reg,u8 buf[],unsigned len)139 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
140 unsigned len)
141 {
142 int ret;
143
144 WARN_ON(reg > ISL1219_REG_YRT);
145 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
146
147 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
148 return (ret < 0) ? ret : 0;
149 }
150
151 /* block write */
152 static int
isl1208_i2c_set_regs(struct i2c_client * client,u8 reg,u8 const buf[],unsigned len)153 isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
154 unsigned len)
155 {
156 int ret;
157
158 WARN_ON(reg > ISL1219_REG_YRT);
159 WARN_ON(reg + len > ISL1219_REG_YRT + 1);
160
161 ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf);
162 return (ret < 0) ? ret : 0;
163 }
164
165 /* simple check to see whether we have a isl1208 */
166 static int
isl1208_i2c_validate_client(struct i2c_client * client)167 isl1208_i2c_validate_client(struct i2c_client *client)
168 {
169 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
170 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
171 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
172 };
173 int i;
174 int ret;
175
176 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
177 if (ret < 0)
178 return ret;
179
180 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
181 if (regs[i] & zero_mask[i]) /* check if bits are cleared */
182 return -ENODEV;
183 }
184
185 return 0;
186 }
187
isl1208_set_xtoscb(struct i2c_client * client,int sr,int xtosb_val)188 static int isl1208_set_xtoscb(struct i2c_client *client, int sr, int xtosb_val)
189 {
190 /* Do nothing if bit is already set to desired value */
191 if (!!(sr & ISL1208_REG_SR_XTOSCB) == xtosb_val)
192 return 0;
193
194 if (xtosb_val)
195 sr |= ISL1208_REG_SR_XTOSCB;
196 else
197 sr &= ~ISL1208_REG_SR_XTOSCB;
198
199 return i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
200 }
201
202 static int
isl1208_i2c_get_sr(struct i2c_client * client)203 isl1208_i2c_get_sr(struct i2c_client *client)
204 {
205 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
206 }
207
208 static int
isl1208_i2c_get_atr(struct i2c_client * client)209 isl1208_i2c_get_atr(struct i2c_client *client)
210 {
211 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
212 if (atr < 0)
213 return atr;
214
215 /* The 6bit value in the ATR register controls the load
216 * capacitance C_load * in steps of 0.25pF
217 *
218 * bit (1<<5) of the ATR register is inverted
219 *
220 * C_load(ATR=0x20) = 4.50pF
221 * C_load(ATR=0x00) = 12.50pF
222 * C_load(ATR=0x1f) = 20.25pF
223 *
224 */
225
226 atr &= 0x3f; /* mask out lsb */
227 atr ^= 1 << 5; /* invert 6th bit */
228 atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */
229
230 return atr;
231 }
232
233 /* returns adjustment value + 100 */
234 static int
isl1208_i2c_get_dtr(struct i2c_client * client)235 isl1208_i2c_get_dtr(struct i2c_client *client)
236 {
237 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
238 if (dtr < 0)
239 return -EIO;
240
241 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
242 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
243
244 return dtr + 100;
245 }
246
247 static int
isl1208_i2c_get_usr(struct i2c_client * client)248 isl1208_i2c_get_usr(struct i2c_client *client)
249 {
250 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
251 int ret;
252
253 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
254 ISL1208_USR_SECTION_LEN);
255 if (ret < 0)
256 return ret;
257
258 return (buf[1] << 8) | buf[0];
259 }
260
261 static int
isl1208_i2c_set_usr(struct i2c_client * client,u16 usr)262 isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
263 {
264 u8 buf[ISL1208_USR_SECTION_LEN];
265
266 buf[0] = usr & 0xff;
267 buf[1] = (usr >> 8) & 0xff;
268
269 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
270 ISL1208_USR_SECTION_LEN);
271 }
272
273 static int
isl1208_rtc_toggle_alarm(struct i2c_client * client,int enable)274 isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
275 {
276 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
277
278 if (icr < 0) {
279 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
280 return icr;
281 }
282
283 if (enable)
284 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
285 else
286 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
287
288 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
289 if (icr < 0) {
290 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
291 return icr;
292 }
293
294 return 0;
295 }
296
297 static int
isl1208_rtc_proc(struct device * dev,struct seq_file * seq)298 isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
299 {
300 struct i2c_client *const client = to_i2c_client(dev);
301 int sr, dtr, atr, usr;
302
303 sr = isl1208_i2c_get_sr(client);
304 if (sr < 0) {
305 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
306 return sr;
307 }
308
309 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
310 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
311 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
312 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
313 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
314 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
315 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
316
317 seq_printf(seq, "batt_status\t: %s\n",
318 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
319
320 dtr = isl1208_i2c_get_dtr(client);
321 if (dtr >= 0)
322 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr - 100);
323
324 atr = isl1208_i2c_get_atr(client);
325 if (atr >= 0)
326 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
327 atr >> 2, (atr & 0x3) * 25);
328
329 usr = isl1208_i2c_get_usr(client);
330 if (usr >= 0)
331 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
332
333 return 0;
334 }
335
336 static int
isl1208_i2c_read_time(struct i2c_client * client,struct rtc_time * tm)337 isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
338 {
339 int sr;
340 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
341
342 sr = isl1208_i2c_get_sr(client);
343 if (sr < 0) {
344 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
345 return -EIO;
346 }
347
348 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
349 if (sr < 0) {
350 dev_err(&client->dev, "%s: reading RTC section failed\n",
351 __func__);
352 return sr;
353 }
354
355 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
356 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
357
358 /* HR field has a more complex interpretation */
359 {
360 const u8 _hr = regs[ISL1208_REG_HR];
361 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
362 tm->tm_hour = bcd2bin(_hr & 0x3f);
363 else {
364 /* 12h format */
365 tm->tm_hour = bcd2bin(_hr & 0x1f);
366 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
367 tm->tm_hour += 12;
368 }
369 }
370
371 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
372 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
373 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
374 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
375
376 return 0;
377 }
378
379 static int
isl1208_i2c_read_alarm(struct i2c_client * client,struct rtc_wkalrm * alarm)380 isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
381 {
382 struct rtc_time *const tm = &alarm->time;
383 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
384 int icr, yr, sr = isl1208_i2c_get_sr(client);
385
386 if (sr < 0) {
387 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
388 return sr;
389 }
390
391 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
392 ISL1208_ALARM_SECTION_LEN);
393 if (sr < 0) {
394 dev_err(&client->dev, "%s: reading alarm section failed\n",
395 __func__);
396 return sr;
397 }
398
399 /* MSB of each alarm register is an enable bit */
400 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
401 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
402 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
403 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
404 tm->tm_mon =
405 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
406 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
407
408 /* The alarm doesn't store the year so get it from the rtc section */
409 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
410 if (yr < 0) {
411 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
412 return yr;
413 }
414 tm->tm_year = bcd2bin(yr) + 100;
415
416 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
417 if (icr < 0) {
418 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
419 return icr;
420 }
421 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
422
423 return 0;
424 }
425
426 static int
isl1208_i2c_set_alarm(struct i2c_client * client,struct rtc_wkalrm * alarm)427 isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
428 {
429 struct rtc_time *alarm_tm = &alarm->time;
430 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
431 const int offs = ISL1208_REG_SCA;
432 struct rtc_time rtc_tm;
433 int err, enable;
434
435 err = isl1208_i2c_read_time(client, &rtc_tm);
436 if (err)
437 return err;
438
439 /* If the alarm time is before the current time disable the alarm */
440 if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0)
441 enable = 0x00;
442 else
443 enable = 0x80;
444
445 /* Program the alarm and enable it for each setting */
446 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
447 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
448 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
449 ISL1208_REG_HR_MIL | enable;
450
451 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
452 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
453 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
454
455 /* write ALARM registers */
456 err = isl1208_i2c_set_regs(client, offs, regs,
457 ISL1208_ALARM_SECTION_LEN);
458 if (err < 0) {
459 dev_err(&client->dev, "%s: writing ALARM section failed\n",
460 __func__);
461 return err;
462 }
463
464 err = isl1208_rtc_toggle_alarm(client, enable);
465 if (err)
466 return err;
467
468 return 0;
469 }
470
471 static int
isl1208_rtc_read_time(struct device * dev,struct rtc_time * tm)472 isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
473 {
474 return isl1208_i2c_read_time(to_i2c_client(dev), tm);
475 }
476
477 static int
isl1208_i2c_set_time(struct i2c_client * client,struct rtc_time const * tm)478 isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
479 {
480 int sr;
481 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
482
483 /* The clock has an 8 bit wide bcd-coded register (they never learn)
484 * for the year. tm_year is an offset from 1900 and we are interested
485 * in the 2000-2099 range, so any value less than 100 is invalid.
486 */
487 if (tm->tm_year < 100)
488 return -EINVAL;
489
490 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
491 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
492 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
493
494 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
495 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
496 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
497
498 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
499
500 sr = isl1208_i2c_get_sr(client);
501 if (sr < 0) {
502 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
503 return sr;
504 }
505
506 /* set WRTC */
507 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
508 sr | ISL1208_REG_SR_WRTC);
509 if (sr < 0) {
510 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
511 return sr;
512 }
513
514 /* write RTC registers */
515 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
516 if (sr < 0) {
517 dev_err(&client->dev, "%s: writing RTC section failed\n",
518 __func__);
519 return sr;
520 }
521
522 /* clear WRTC again */
523 sr = isl1208_i2c_get_sr(client);
524 if (sr < 0) {
525 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
526 return sr;
527 }
528 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
529 sr & ~ISL1208_REG_SR_WRTC);
530 if (sr < 0) {
531 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
532 return sr;
533 }
534
535 return 0;
536 }
537
538 static int
isl1208_rtc_set_time(struct device * dev,struct rtc_time * tm)539 isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
540 {
541 return isl1208_i2c_set_time(to_i2c_client(dev), tm);
542 }
543
544 static int
isl1208_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)545 isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
546 {
547 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
548 }
549
550 static int
isl1208_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)551 isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
552 {
553 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
554 }
555
timestamp0_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)556 static ssize_t timestamp0_store(struct device *dev,
557 struct device_attribute *attr,
558 const char *buf, size_t count)
559 {
560 struct i2c_client *client = to_i2c_client(dev->parent);
561 int sr;
562
563 sr = isl1208_i2c_get_sr(client);
564 if (sr < 0) {
565 dev_err(dev, "%s: reading SR failed\n", __func__);
566 return sr;
567 }
568
569 sr &= ~ISL1208_REG_SR_EVT;
570
571 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
572 if (sr < 0)
573 dev_err(dev, "%s: writing SR failed\n",
574 __func__);
575
576 return count;
577 };
578
timestamp0_show(struct device * dev,struct device_attribute * attr,char * buf)579 static ssize_t timestamp0_show(struct device *dev,
580 struct device_attribute *attr, char *buf)
581 {
582 struct i2c_client *client = to_i2c_client(dev->parent);
583 u8 regs[ISL1219_EVT_SECTION_LEN] = { 0, };
584 struct rtc_time tm;
585 int sr;
586
587 sr = isl1208_i2c_get_sr(client);
588 if (sr < 0) {
589 dev_err(dev, "%s: reading SR failed\n", __func__);
590 return sr;
591 }
592
593 if (!(sr & ISL1208_REG_SR_EVT))
594 return 0;
595
596 sr = isl1208_i2c_read_regs(client, ISL1219_REG_SCT, regs,
597 ISL1219_EVT_SECTION_LEN);
598 if (sr < 0) {
599 dev_err(dev, "%s: reading event section failed\n",
600 __func__);
601 return 0;
602 }
603
604 /* MSB of each alarm register is an enable bit */
605 tm.tm_sec = bcd2bin(regs[ISL1219_REG_SCT - ISL1219_REG_SCT] & 0x7f);
606 tm.tm_min = bcd2bin(regs[ISL1219_REG_MNT - ISL1219_REG_SCT] & 0x7f);
607 tm.tm_hour = bcd2bin(regs[ISL1219_REG_HRT - ISL1219_REG_SCT] & 0x3f);
608 tm.tm_mday = bcd2bin(regs[ISL1219_REG_DTT - ISL1219_REG_SCT] & 0x3f);
609 tm.tm_mon =
610 bcd2bin(regs[ISL1219_REG_MOT - ISL1219_REG_SCT] & 0x1f) - 1;
611 tm.tm_year = bcd2bin(regs[ISL1219_REG_YRT - ISL1219_REG_SCT]) + 100;
612
613 sr = rtc_valid_tm(&tm);
614 if (sr)
615 return sr;
616
617 return sprintf(buf, "%llu\n",
618 (unsigned long long)rtc_tm_to_time64(&tm));
619 };
620
621 static DEVICE_ATTR_RW(timestamp0);
622
623 static irqreturn_t
isl1208_rtc_interrupt(int irq,void * data)624 isl1208_rtc_interrupt(int irq, void *data)
625 {
626 unsigned long timeout = jiffies + msecs_to_jiffies(1000);
627 struct i2c_client *client = data;
628 struct isl1208_state *isl1208 = i2c_get_clientdata(client);
629 int handled = 0, sr, err;
630
631 /*
632 * I2C reads get NAK'ed if we read straight away after an interrupt?
633 * Using a mdelay/msleep didn't seem to help either, so we work around
634 * this by continually trying to read the register for a short time.
635 */
636 while (1) {
637 sr = isl1208_i2c_get_sr(client);
638 if (sr >= 0)
639 break;
640
641 if (time_after(jiffies, timeout)) {
642 dev_err(&client->dev, "%s: reading SR failed\n",
643 __func__);
644 return sr;
645 }
646 }
647
648 if (sr & ISL1208_REG_SR_ALM) {
649 dev_dbg(&client->dev, "alarm!\n");
650
651 rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF);
652
653 /* Clear the alarm */
654 sr &= ~ISL1208_REG_SR_ALM;
655 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
656 if (sr < 0)
657 dev_err(&client->dev, "%s: writing SR failed\n",
658 __func__);
659 else
660 handled = 1;
661
662 /* Disable the alarm */
663 err = isl1208_rtc_toggle_alarm(client, 0);
664 if (err)
665 return err;
666 }
667
668 if (isl1208->config->has_tamper && (sr & ISL1208_REG_SR_EVT)) {
669 dev_warn(&client->dev, "event detected");
670 handled = 1;
671 if (isl1208->config->has_timestamp)
672 sysfs_notify(&isl1208->rtc->dev.kobj, NULL,
673 dev_attr_timestamp0.attr.name);
674 }
675
676 return handled ? IRQ_HANDLED : IRQ_NONE;
677 }
678
679 static const struct rtc_class_ops isl1208_rtc_ops = {
680 .proc = isl1208_rtc_proc,
681 .read_time = isl1208_rtc_read_time,
682 .set_time = isl1208_rtc_set_time,
683 .read_alarm = isl1208_rtc_read_alarm,
684 .set_alarm = isl1208_rtc_set_alarm,
685 };
686
687 /* sysfs interface */
688
689 static ssize_t
isl1208_sysfs_show_atrim(struct device * dev,struct device_attribute * attr,char * buf)690 isl1208_sysfs_show_atrim(struct device *dev,
691 struct device_attribute *attr, char *buf)
692 {
693 int atr = isl1208_i2c_get_atr(to_i2c_client(dev->parent));
694 if (atr < 0)
695 return atr;
696
697 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
698 }
699
700 static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
701
702 static ssize_t
isl1208_sysfs_show_dtrim(struct device * dev,struct device_attribute * attr,char * buf)703 isl1208_sysfs_show_dtrim(struct device *dev,
704 struct device_attribute *attr, char *buf)
705 {
706 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev->parent));
707 if (dtr < 0)
708 return dtr;
709
710 return sprintf(buf, "%d ppm\n", dtr - 100);
711 }
712
713 static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
714
715 static ssize_t
isl1208_sysfs_show_usr(struct device * dev,struct device_attribute * attr,char * buf)716 isl1208_sysfs_show_usr(struct device *dev,
717 struct device_attribute *attr, char *buf)
718 {
719 int usr = isl1208_i2c_get_usr(to_i2c_client(dev->parent));
720 if (usr < 0)
721 return usr;
722
723 return sprintf(buf, "0x%.4x\n", usr);
724 }
725
726 static ssize_t
isl1208_sysfs_store_usr(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)727 isl1208_sysfs_store_usr(struct device *dev,
728 struct device_attribute *attr,
729 const char *buf, size_t count)
730 {
731 int usr = -1;
732
733 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
734 if (sscanf(buf, "%x", &usr) != 1)
735 return -EINVAL;
736 } else {
737 if (sscanf(buf, "%d", &usr) != 1)
738 return -EINVAL;
739 }
740
741 if (usr < 0 || usr > 0xffff)
742 return -EINVAL;
743
744 if (isl1208_i2c_set_usr(to_i2c_client(dev->parent), usr))
745 return -EIO;
746
747 return count;
748 }
749
750 static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
751 isl1208_sysfs_store_usr);
752
753 static struct attribute *isl1208_rtc_attrs[] = {
754 &dev_attr_atrim.attr,
755 &dev_attr_dtrim.attr,
756 &dev_attr_usr.attr,
757 NULL
758 };
759
760 static const struct attribute_group isl1208_rtc_sysfs_files = {
761 .attrs = isl1208_rtc_attrs,
762 };
763
764 static struct attribute *isl1219_rtc_attrs[] = {
765 &dev_attr_timestamp0.attr,
766 NULL
767 };
768
769 static const struct attribute_group isl1219_rtc_sysfs_files = {
770 .attrs = isl1219_rtc_attrs,
771 };
772
isl1208_nvmem_read(void * priv,unsigned int off,void * buf,size_t count)773 static int isl1208_nvmem_read(void *priv, unsigned int off, void *buf,
774 size_t count)
775 {
776 struct isl1208_state *isl1208 = priv;
777 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
778 int ret;
779
780 /* nvmem sanitizes offset/count for us, but count==0 is possible */
781 if (!count)
782 return count;
783 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1 + off, buf,
784 count);
785 return ret == 0 ? count : ret;
786 }
787
isl1208_nvmem_write(void * priv,unsigned int off,void * buf,size_t count)788 static int isl1208_nvmem_write(void *priv, unsigned int off, void *buf,
789 size_t count)
790 {
791 struct isl1208_state *isl1208 = priv;
792 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent);
793 int ret;
794
795 /* nvmem sanitizes off/count for us, but count==0 is possible */
796 if (!count)
797 return count;
798 ret = isl1208_i2c_set_regs(client, ISL1208_REG_USR1 + off, buf,
799 count);
800
801 return ret == 0 ? count : ret;
802 }
803
804 static const struct nvmem_config isl1208_nvmem_config = {
805 .name = "isl1208_nvram",
806 .word_size = 1,
807 .stride = 1,
808 /* .size from chip specific config */
809 .reg_read = isl1208_nvmem_read,
810 .reg_write = isl1208_nvmem_write,
811 };
812
isl1208_setup_irq(struct i2c_client * client,int irq)813 static int isl1208_setup_irq(struct i2c_client *client, int irq)
814 {
815 int rc = devm_request_threaded_irq(&client->dev, irq, NULL,
816 isl1208_rtc_interrupt,
817 IRQF_SHARED | IRQF_ONESHOT,
818 isl1208_driver.driver.name,
819 client);
820 if (!rc) {
821 device_init_wakeup(&client->dev, 1);
822 enable_irq_wake(irq);
823 } else {
824 dev_err(&client->dev,
825 "Unable to request irq %d, no alarm support\n",
826 irq);
827 }
828 return rc;
829 }
830
831 static int
isl1208_clk_present(struct i2c_client * client,const char * name)832 isl1208_clk_present(struct i2c_client *client, const char *name)
833 {
834 struct clk *clk;
835
836 clk = devm_clk_get_optional(&client->dev, name);
837 if (IS_ERR(clk))
838 return PTR_ERR(clk);
839
840 return !!clk;
841 }
842
843 static int
isl1208_probe(struct i2c_client * client)844 isl1208_probe(struct i2c_client *client)
845 {
846 struct isl1208_state *isl1208;
847 int evdet_irq = -1;
848 int xtosb_val = 0;
849 int rc = 0;
850 int sr;
851
852 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
853 return -ENODEV;
854
855 if (isl1208_i2c_validate_client(client) < 0)
856 return -ENODEV;
857
858 /* Allocate driver state, point i2c client data to it */
859 isl1208 = devm_kzalloc(&client->dev, sizeof(*isl1208), GFP_KERNEL);
860 if (!isl1208)
861 return -ENOMEM;
862 i2c_set_clientdata(client, isl1208);
863
864 /* Determine which chip we have */
865 isl1208->config = i2c_get_match_data(client);
866 if (!isl1208->config)
867 return -ENODEV;
868
869 rc = isl1208_clk_present(client, "xin");
870 if (rc < 0)
871 return rc;
872
873 if (!rc) {
874 rc = isl1208_clk_present(client, "clkin");
875 if (rc < 0)
876 return rc;
877
878 if (rc)
879 xtosb_val = 1;
880 }
881
882 isl1208->rtc = devm_rtc_allocate_device(&client->dev);
883 if (IS_ERR(isl1208->rtc))
884 return PTR_ERR(isl1208->rtc);
885
886 isl1208->rtc->ops = &isl1208_rtc_ops;
887
888 /* Setup nvmem configuration in driver state struct */
889 isl1208->nvmem_config = isl1208_nvmem_config;
890 isl1208->nvmem_config.size = isl1208->config->nvmem_length;
891 isl1208->nvmem_config.priv = isl1208;
892
893 sr = isl1208_i2c_get_sr(client);
894 if (sr < 0) {
895 dev_err(&client->dev, "reading status failed\n");
896 return sr;
897 }
898
899 if (isl1208->config->has_inverted_osc_bit)
900 xtosb_val = !xtosb_val;
901
902 rc = isl1208_set_xtoscb(client, sr, xtosb_val);
903 if (rc)
904 return rc;
905
906 if (sr & ISL1208_REG_SR_RTCF)
907 dev_warn(&client->dev, "rtc power failure detected, "
908 "please set clock.\n");
909
910 if (isl1208->config->has_tamper) {
911 struct device_node *np = client->dev.of_node;
912 u32 evienb;
913
914 rc = i2c_smbus_read_byte_data(client, ISL1219_REG_EV);
915 if (rc < 0) {
916 dev_err(&client->dev, "failed to read EV reg\n");
917 return rc;
918 }
919 rc |= ISL1219_REG_EV_EVEN;
920 if (!of_property_read_u32(np, "isil,ev-evienb", &evienb)) {
921 if (evienb)
922 rc |= ISL1219_REG_EV_EVIENB;
923 else
924 rc &= ~ISL1219_REG_EV_EVIENB;
925 }
926 rc = i2c_smbus_write_byte_data(client, ISL1219_REG_EV, rc);
927 if (rc < 0) {
928 dev_err(&client->dev, "could not enable tamper detection\n");
929 return rc;
930 }
931 evdet_irq = of_irq_get_byname(np, "evdet");
932 }
933 if (isl1208->config->has_timestamp) {
934 rc = rtc_add_group(isl1208->rtc, &isl1219_rtc_sysfs_files);
935 if (rc)
936 return rc;
937 }
938
939 rc = rtc_add_group(isl1208->rtc, &isl1208_rtc_sysfs_files);
940 if (rc)
941 return rc;
942
943 if (client->irq > 0) {
944 rc = isl1208_setup_irq(client, client->irq);
945 if (rc)
946 return rc;
947 } else {
948 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, isl1208->rtc->features);
949 }
950
951 if (evdet_irq > 0 && evdet_irq != client->irq)
952 rc = isl1208_setup_irq(client, evdet_irq);
953 if (rc)
954 return rc;
955
956 rc = devm_rtc_nvmem_register(isl1208->rtc, &isl1208->nvmem_config);
957 if (rc)
958 return rc;
959
960 return devm_rtc_register_device(isl1208->rtc);
961 }
962
963 static struct i2c_driver isl1208_driver = {
964 .driver = {
965 .name = "rtc-isl1208",
966 .of_match_table = of_match_ptr(isl1208_of_match),
967 },
968 .probe = isl1208_probe,
969 .id_table = isl1208_id,
970 };
971
972 module_i2c_driver(isl1208_driver);
973
974 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
975 MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
976 MODULE_LICENSE("GPL");
977