1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * An I2C and SPI driver for the NXP PCF2127/29 RTC
4 * Copyright 2013 Til-Technologies
5 *
6 * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
7 *
8 * Watchdog and tamper functions
9 * Author: Bruno Thomsen <bruno.thomsen@gmail.com>
10 *
11 * based on the other drivers in this same directory.
12 *
13 * Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf
14 */
15
16 #include <linux/i2c.h>
17 #include <linux/spi/spi.h>
18 #include <linux/bcd.h>
19 #include <linux/rtc.h>
20 #include <linux/slab.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/regmap.h>
24 #include <linux/watchdog.h>
25
26 /* Control register 1 */
27 #define PCF2127_REG_CTRL1 0x00
28 #define PCF2127_BIT_CTRL1_TSF1 BIT(4)
29 /* Control register 2 */
30 #define PCF2127_REG_CTRL2 0x01
31 #define PCF2127_BIT_CTRL2_TSIE BIT(2)
32 #define PCF2127_BIT_CTRL2_TSF2 BIT(5)
33 /* Control register 3 */
34 #define PCF2127_REG_CTRL3 0x02
35 #define PCF2127_BIT_CTRL3_BLIE BIT(0)
36 #define PCF2127_BIT_CTRL3_BIE BIT(1)
37 #define PCF2127_BIT_CTRL3_BLF BIT(2)
38 #define PCF2127_BIT_CTRL3_BF BIT(3)
39 #define PCF2127_BIT_CTRL3_BTSE BIT(4)
40 /* Time and date registers */
41 #define PCF2127_REG_SC 0x03
42 #define PCF2127_BIT_SC_OSF BIT(7)
43 #define PCF2127_REG_MN 0x04
44 #define PCF2127_REG_HR 0x05
45 #define PCF2127_REG_DM 0x06
46 #define PCF2127_REG_DW 0x07
47 #define PCF2127_REG_MO 0x08
48 #define PCF2127_REG_YR 0x09
49 /* Watchdog registers */
50 #define PCF2127_REG_WD_CTL 0x10
51 #define PCF2127_BIT_WD_CTL_TF0 BIT(0)
52 #define PCF2127_BIT_WD_CTL_TF1 BIT(1)
53 #define PCF2127_BIT_WD_CTL_CD0 BIT(6)
54 #define PCF2127_BIT_WD_CTL_CD1 BIT(7)
55 #define PCF2127_REG_WD_VAL 0x11
56 /* Tamper timestamp registers */
57 #define PCF2127_REG_TS_CTRL 0x12
58 #define PCF2127_BIT_TS_CTRL_TSOFF BIT(6)
59 #define PCF2127_BIT_TS_CTRL_TSM BIT(7)
60 #define PCF2127_REG_TS_SC 0x13
61 #define PCF2127_REG_TS_MN 0x14
62 #define PCF2127_REG_TS_HR 0x15
63 #define PCF2127_REG_TS_DM 0x16
64 #define PCF2127_REG_TS_MO 0x17
65 #define PCF2127_REG_TS_YR 0x18
66 /*
67 * RAM registers
68 * PCF2127 has 512 bytes general-purpose static RAM (SRAM) that is
69 * battery backed and can survive a power outage.
70 * PCF2129 doesn't have this feature.
71 */
72 #define PCF2127_REG_RAM_ADDR_MSB 0x1A
73 #define PCF2127_REG_RAM_WRT_CMD 0x1C
74 #define PCF2127_REG_RAM_RD_CMD 0x1D
75
76 /* Watchdog timer value constants */
77 #define PCF2127_WD_VAL_STOP 0
78 #define PCF2127_WD_VAL_MIN 2
79 #define PCF2127_WD_VAL_MAX 255
80 #define PCF2127_WD_VAL_DEFAULT 60
81
82 struct pcf2127 {
83 struct rtc_device *rtc;
84 struct watchdog_device wdd;
85 struct regmap *regmap;
86 };
87
88 /*
89 * In the routines that deal directly with the pcf2127 hardware, we use
90 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
91 */
pcf2127_rtc_read_time(struct device * dev,struct rtc_time * tm)92 static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
93 {
94 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
95 unsigned char buf[10];
96 int ret;
97
98 /*
99 * Avoid reading CTRL2 register as it causes WD_VAL register
100 * value to reset to 0 which means watchdog is stopped.
101 */
102 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL3,
103 (buf + PCF2127_REG_CTRL3),
104 ARRAY_SIZE(buf) - PCF2127_REG_CTRL3);
105 if (ret) {
106 dev_err(dev, "%s: read error\n", __func__);
107 return ret;
108 }
109
110 if (buf[PCF2127_REG_CTRL3] & PCF2127_BIT_CTRL3_BLF)
111 dev_info(dev,
112 "low voltage detected, check/replace RTC battery.\n");
113
114 /* Clock integrity is not guaranteed when OSF flag is set. */
115 if (buf[PCF2127_REG_SC] & PCF2127_BIT_SC_OSF) {
116 /*
117 * no need clear the flag here,
118 * it will be cleared once the new date is saved
119 */
120 dev_warn(dev,
121 "oscillator stop detected, date/time is not reliable\n");
122 return -EINVAL;
123 }
124
125 dev_dbg(dev,
126 "%s: raw data is cr3=%02x, sec=%02x, min=%02x, hr=%02x, "
127 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
128 __func__, buf[PCF2127_REG_CTRL3], buf[PCF2127_REG_SC],
129 buf[PCF2127_REG_MN], buf[PCF2127_REG_HR],
130 buf[PCF2127_REG_DM], buf[PCF2127_REG_DW],
131 buf[PCF2127_REG_MO], buf[PCF2127_REG_YR]);
132
133 tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
134 tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
135 tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
136 tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
137 tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
138 tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
139 tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
140 if (tm->tm_year < 70)
141 tm->tm_year += 100; /* assume we are in 1970...2069 */
142
143 dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
144 "mday=%d, mon=%d, year=%d, wday=%d\n",
145 __func__,
146 tm->tm_sec, tm->tm_min, tm->tm_hour,
147 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
148
149 return 0;
150 }
151
pcf2127_rtc_set_time(struct device * dev,struct rtc_time * tm)152 static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
153 {
154 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
155 unsigned char buf[7];
156 int i = 0, err;
157
158 dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
159 "mday=%d, mon=%d, year=%d, wday=%d\n",
160 __func__,
161 tm->tm_sec, tm->tm_min, tm->tm_hour,
162 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
163
164 /* hours, minutes and seconds */
165 buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
166 buf[i++] = bin2bcd(tm->tm_min);
167 buf[i++] = bin2bcd(tm->tm_hour);
168 buf[i++] = bin2bcd(tm->tm_mday);
169 buf[i++] = tm->tm_wday & 0x07;
170
171 /* month, 1 - 12 */
172 buf[i++] = bin2bcd(tm->tm_mon + 1);
173
174 /* year */
175 buf[i++] = bin2bcd(tm->tm_year % 100);
176
177 /* write register's data */
178 err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
179 if (err) {
180 dev_err(dev,
181 "%s: err=%d", __func__, err);
182 return err;
183 }
184
185 return 0;
186 }
187
188 #ifdef CONFIG_RTC_INTF_DEV
pcf2127_rtc_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)189 static int pcf2127_rtc_ioctl(struct device *dev,
190 unsigned int cmd, unsigned long arg)
191 {
192 struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
193 int touser;
194 int ret;
195
196 switch (cmd) {
197 case RTC_VL_READ:
198 ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser);
199 if (ret)
200 return ret;
201
202 touser = touser & PCF2127_BIT_CTRL3_BLF ? 1 : 0;
203
204 if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
205 return -EFAULT;
206 return 0;
207 default:
208 return -ENOIOCTLCMD;
209 }
210 }
211 #else
212 #define pcf2127_rtc_ioctl NULL
213 #endif
214
215 static const struct rtc_class_ops pcf2127_rtc_ops = {
216 .ioctl = pcf2127_rtc_ioctl,
217 .read_time = pcf2127_rtc_read_time,
218 .set_time = pcf2127_rtc_set_time,
219 };
220
pcf2127_nvmem_read(void * priv,unsigned int offset,void * val,size_t bytes)221 static int pcf2127_nvmem_read(void *priv, unsigned int offset,
222 void *val, size_t bytes)
223 {
224 struct pcf2127 *pcf2127 = priv;
225 int ret;
226 unsigned char offsetbuf[] = { offset >> 8, offset };
227
228 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
229 offsetbuf, 2);
230 if (ret)
231 return ret;
232
233 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_RD_CMD,
234 val, bytes);
235
236 return ret ?: bytes;
237 }
238
pcf2127_nvmem_write(void * priv,unsigned int offset,void * val,size_t bytes)239 static int pcf2127_nvmem_write(void *priv, unsigned int offset,
240 void *val, size_t bytes)
241 {
242 struct pcf2127 *pcf2127 = priv;
243 int ret;
244 unsigned char offsetbuf[] = { offset >> 8, offset };
245
246 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
247 offsetbuf, 2);
248 if (ret)
249 return ret;
250
251 ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_WRT_CMD,
252 val, bytes);
253
254 return ret ?: bytes;
255 }
256
257 /* watchdog driver */
258
pcf2127_wdt_ping(struct watchdog_device * wdd)259 static int pcf2127_wdt_ping(struct watchdog_device *wdd)
260 {
261 struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
262
263 return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL, wdd->timeout);
264 }
265
266 /*
267 * Restart watchdog timer if feature is active.
268 *
269 * Note: Reading CTRL2 register causes watchdog to stop which is unfortunate,
270 * since register also contain control/status flags for other features.
271 * Always call this function after reading CTRL2 register.
272 */
pcf2127_wdt_active_ping(struct watchdog_device * wdd)273 static int pcf2127_wdt_active_ping(struct watchdog_device *wdd)
274 {
275 int ret = 0;
276
277 if (watchdog_active(wdd)) {
278 ret = pcf2127_wdt_ping(wdd);
279 if (ret)
280 dev_err(wdd->parent,
281 "%s: watchdog restart failed, ret=%d\n",
282 __func__, ret);
283 }
284
285 return ret;
286 }
287
pcf2127_wdt_start(struct watchdog_device * wdd)288 static int pcf2127_wdt_start(struct watchdog_device *wdd)
289 {
290 return pcf2127_wdt_ping(wdd);
291 }
292
pcf2127_wdt_stop(struct watchdog_device * wdd)293 static int pcf2127_wdt_stop(struct watchdog_device *wdd)
294 {
295 struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
296
297 return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL,
298 PCF2127_WD_VAL_STOP);
299 }
300
pcf2127_wdt_set_timeout(struct watchdog_device * wdd,unsigned int new_timeout)301 static int pcf2127_wdt_set_timeout(struct watchdog_device *wdd,
302 unsigned int new_timeout)
303 {
304 dev_dbg(wdd->parent, "new watchdog timeout: %is (old: %is)\n",
305 new_timeout, wdd->timeout);
306
307 wdd->timeout = new_timeout;
308
309 return pcf2127_wdt_active_ping(wdd);
310 }
311
312 static const struct watchdog_info pcf2127_wdt_info = {
313 .identity = "NXP PCF2127/PCF2129 Watchdog",
314 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
315 };
316
317 static const struct watchdog_ops pcf2127_watchdog_ops = {
318 .owner = THIS_MODULE,
319 .start = pcf2127_wdt_start,
320 .stop = pcf2127_wdt_stop,
321 .ping = pcf2127_wdt_ping,
322 .set_timeout = pcf2127_wdt_set_timeout,
323 };
324
325 /* sysfs interface */
326
timestamp0_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)327 static ssize_t timestamp0_store(struct device *dev,
328 struct device_attribute *attr,
329 const char *buf, size_t count)
330 {
331 struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
332 int ret;
333
334 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
335 PCF2127_BIT_CTRL1_TSF1, 0);
336 if (ret) {
337 dev_err(dev, "%s: update ctrl1 ret=%d\n", __func__, ret);
338 return ret;
339 }
340
341 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
342 PCF2127_BIT_CTRL2_TSF2, 0);
343 if (ret) {
344 dev_err(dev, "%s: update ctrl2 ret=%d\n", __func__, ret);
345 return ret;
346 }
347
348 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
349 if (ret)
350 return ret;
351
352 return count;
353 };
354
timestamp0_show(struct device * dev,struct device_attribute * attr,char * buf)355 static ssize_t timestamp0_show(struct device *dev,
356 struct device_attribute *attr, char *buf)
357 {
358 struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
359 struct rtc_time tm;
360 int ret;
361 unsigned char data[25];
362
363 ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, data,
364 sizeof(data));
365 if (ret) {
366 dev_err(dev, "%s: read error ret=%d\n", __func__, ret);
367 return ret;
368 }
369
370 dev_dbg(dev,
371 "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, ts_sc=%02x, "
372 "ts_mn=%02x, ts_hr=%02x, ts_dm=%02x, ts_mo=%02x, ts_yr=%02x\n",
373 __func__, data[PCF2127_REG_CTRL1], data[PCF2127_REG_CTRL2],
374 data[PCF2127_REG_CTRL3], data[PCF2127_REG_TS_SC],
375 data[PCF2127_REG_TS_MN], data[PCF2127_REG_TS_HR],
376 data[PCF2127_REG_TS_DM], data[PCF2127_REG_TS_MO],
377 data[PCF2127_REG_TS_YR]);
378
379 ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
380 if (ret)
381 return ret;
382
383 if (!(data[PCF2127_REG_CTRL1] & PCF2127_BIT_CTRL1_TSF1) &&
384 !(data[PCF2127_REG_CTRL2] & PCF2127_BIT_CTRL2_TSF2))
385 return 0;
386
387 tm.tm_sec = bcd2bin(data[PCF2127_REG_TS_SC] & 0x7F);
388 tm.tm_min = bcd2bin(data[PCF2127_REG_TS_MN] & 0x7F);
389 tm.tm_hour = bcd2bin(data[PCF2127_REG_TS_HR] & 0x3F);
390 tm.tm_mday = bcd2bin(data[PCF2127_REG_TS_DM] & 0x3F);
391 /* TS_MO register (month) value range: 1-12 */
392 tm.tm_mon = bcd2bin(data[PCF2127_REG_TS_MO] & 0x1F) - 1;
393 tm.tm_year = bcd2bin(data[PCF2127_REG_TS_YR]);
394 if (tm.tm_year < 70)
395 tm.tm_year += 100; /* assume we are in 1970...2069 */
396
397 ret = rtc_valid_tm(&tm);
398 if (ret)
399 return ret;
400
401 return sprintf(buf, "%llu\n",
402 (unsigned long long)rtc_tm_to_time64(&tm));
403 };
404
405 static DEVICE_ATTR_RW(timestamp0);
406
407 static struct attribute *pcf2127_attrs[] = {
408 &dev_attr_timestamp0.attr,
409 NULL
410 };
411
412 static const struct attribute_group pcf2127_attr_group = {
413 .attrs = pcf2127_attrs,
414 };
415
pcf2127_probe(struct device * dev,struct regmap * regmap,const char * name,bool has_nvmem)416 static int pcf2127_probe(struct device *dev, struct regmap *regmap,
417 const char *name, bool has_nvmem)
418 {
419 struct pcf2127 *pcf2127;
420 int ret = 0;
421
422 dev_dbg(dev, "%s\n", __func__);
423
424 pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
425 if (!pcf2127)
426 return -ENOMEM;
427
428 pcf2127->regmap = regmap;
429
430 dev_set_drvdata(dev, pcf2127);
431
432 pcf2127->rtc = devm_rtc_allocate_device(dev);
433 if (IS_ERR(pcf2127->rtc))
434 return PTR_ERR(pcf2127->rtc);
435
436 pcf2127->rtc->ops = &pcf2127_rtc_ops;
437
438 pcf2127->wdd.parent = dev;
439 pcf2127->wdd.info = &pcf2127_wdt_info;
440 pcf2127->wdd.ops = &pcf2127_watchdog_ops;
441 pcf2127->wdd.min_timeout = PCF2127_WD_VAL_MIN;
442 pcf2127->wdd.max_timeout = PCF2127_WD_VAL_MAX;
443 pcf2127->wdd.timeout = PCF2127_WD_VAL_DEFAULT;
444 pcf2127->wdd.min_hw_heartbeat_ms = 500;
445
446 watchdog_set_drvdata(&pcf2127->wdd, pcf2127);
447
448 if (has_nvmem) {
449 struct nvmem_config nvmem_cfg = {
450 .priv = pcf2127,
451 .reg_read = pcf2127_nvmem_read,
452 .reg_write = pcf2127_nvmem_write,
453 .size = 512,
454 };
455
456 ret = rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg);
457 }
458
459 /*
460 * Watchdog timer enabled and reset pin /RST activated when timed out.
461 * Select 1Hz clock source for watchdog timer.
462 * Timer is not started until WD_VAL is loaded with a valid value.
463 * Note: Countdown timer disabled and not available.
464 */
465 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_WD_CTL,
466 PCF2127_BIT_WD_CTL_CD1 |
467 PCF2127_BIT_WD_CTL_CD0 |
468 PCF2127_BIT_WD_CTL_TF1 |
469 PCF2127_BIT_WD_CTL_TF0,
470 PCF2127_BIT_WD_CTL_CD1 |
471 PCF2127_BIT_WD_CTL_CD0 |
472 PCF2127_BIT_WD_CTL_TF1);
473 if (ret) {
474 dev_err(dev, "%s: watchdog config (wd_ctl) failed\n", __func__);
475 return ret;
476 }
477
478 #ifdef CONFIG_WATCHDOG
479 ret = devm_watchdog_register_device(dev, &pcf2127->wdd);
480 if (ret)
481 return ret;
482 #endif /* CONFIG_WATCHDOG */
483
484 /*
485 * Disable battery low/switch-over timestamp and interrupts.
486 * Clear battery interrupt flags which can block new trigger events.
487 * Note: This is the default chip behaviour but added to ensure
488 * correct tamper timestamp and interrupt function.
489 */
490 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
491 PCF2127_BIT_CTRL3_BTSE |
492 PCF2127_BIT_CTRL3_BF |
493 PCF2127_BIT_CTRL3_BIE |
494 PCF2127_BIT_CTRL3_BLIE, 0);
495 if (ret) {
496 dev_err(dev, "%s: interrupt config (ctrl3) failed\n",
497 __func__);
498 return ret;
499 }
500
501 /*
502 * Enable timestamp function and store timestamp of first trigger
503 * event until TSF1 and TFS2 interrupt flags are cleared.
504 */
505 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_TS_CTRL,
506 PCF2127_BIT_TS_CTRL_TSOFF |
507 PCF2127_BIT_TS_CTRL_TSM,
508 PCF2127_BIT_TS_CTRL_TSM);
509 if (ret) {
510 dev_err(dev, "%s: tamper detection config (ts_ctrl) failed\n",
511 __func__);
512 return ret;
513 }
514
515 /*
516 * Enable interrupt generation when TSF1 or TSF2 timestamp flags
517 * are set. Interrupt signal is an open-drain output and can be
518 * left floating if unused.
519 */
520 ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
521 PCF2127_BIT_CTRL2_TSIE,
522 PCF2127_BIT_CTRL2_TSIE);
523 if (ret) {
524 dev_err(dev, "%s: tamper detection config (ctrl2) failed\n",
525 __func__);
526 return ret;
527 }
528
529 ret = rtc_add_group(pcf2127->rtc, &pcf2127_attr_group);
530 if (ret) {
531 dev_err(dev, "%s: tamper sysfs registering failed\n",
532 __func__);
533 return ret;
534 }
535
536 return rtc_register_device(pcf2127->rtc);
537 }
538
539 #ifdef CONFIG_OF
540 static const struct of_device_id pcf2127_of_match[] = {
541 { .compatible = "nxp,pcf2127" },
542 { .compatible = "nxp,pcf2129" },
543 {}
544 };
545 MODULE_DEVICE_TABLE(of, pcf2127_of_match);
546 #endif
547
548 #if IS_ENABLED(CONFIG_I2C)
549
pcf2127_i2c_write(void * context,const void * data,size_t count)550 static int pcf2127_i2c_write(void *context, const void *data, size_t count)
551 {
552 struct device *dev = context;
553 struct i2c_client *client = to_i2c_client(dev);
554 int ret;
555
556 ret = i2c_master_send(client, data, count);
557 if (ret != count)
558 return ret < 0 ? ret : -EIO;
559
560 return 0;
561 }
562
pcf2127_i2c_gather_write(void * context,const void * reg,size_t reg_size,const void * val,size_t val_size)563 static int pcf2127_i2c_gather_write(void *context,
564 const void *reg, size_t reg_size,
565 const void *val, size_t val_size)
566 {
567 struct device *dev = context;
568 struct i2c_client *client = to_i2c_client(dev);
569 int ret;
570 void *buf;
571
572 if (WARN_ON(reg_size != 1))
573 return -EINVAL;
574
575 buf = kmalloc(val_size + 1, GFP_KERNEL);
576 if (!buf)
577 return -ENOMEM;
578
579 memcpy(buf, reg, 1);
580 memcpy(buf + 1, val, val_size);
581
582 ret = i2c_master_send(client, buf, val_size + 1);
583
584 kfree(buf);
585
586 if (ret != val_size + 1)
587 return ret < 0 ? ret : -EIO;
588
589 return 0;
590 }
591
pcf2127_i2c_read(void * context,const void * reg,size_t reg_size,void * val,size_t val_size)592 static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
593 void *val, size_t val_size)
594 {
595 struct device *dev = context;
596 struct i2c_client *client = to_i2c_client(dev);
597 int ret;
598
599 if (WARN_ON(reg_size != 1))
600 return -EINVAL;
601
602 ret = i2c_master_send(client, reg, 1);
603 if (ret != 1)
604 return ret < 0 ? ret : -EIO;
605
606 ret = i2c_master_recv(client, val, val_size);
607 if (ret != val_size)
608 return ret < 0 ? ret : -EIO;
609
610 return 0;
611 }
612
613 /*
614 * The reason we need this custom regmap_bus instead of using regmap_init_i2c()
615 * is that the STOP condition is required between set register address and
616 * read register data when reading from registers.
617 */
618 static const struct regmap_bus pcf2127_i2c_regmap = {
619 .write = pcf2127_i2c_write,
620 .gather_write = pcf2127_i2c_gather_write,
621 .read = pcf2127_i2c_read,
622 };
623
624 static struct i2c_driver pcf2127_i2c_driver;
625
pcf2127_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)626 static int pcf2127_i2c_probe(struct i2c_client *client,
627 const struct i2c_device_id *id)
628 {
629 struct regmap *regmap;
630 static const struct regmap_config config = {
631 .reg_bits = 8,
632 .val_bits = 8,
633 };
634
635 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
636 return -ENODEV;
637
638 regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
639 &client->dev, &config);
640 if (IS_ERR(regmap)) {
641 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
642 __func__, PTR_ERR(regmap));
643 return PTR_ERR(regmap);
644 }
645
646 return pcf2127_probe(&client->dev, regmap,
647 pcf2127_i2c_driver.driver.name, id->driver_data);
648 }
649
650 static const struct i2c_device_id pcf2127_i2c_id[] = {
651 { "pcf2127", 1 },
652 { "pcf2129", 0 },
653 { }
654 };
655 MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
656
657 static struct i2c_driver pcf2127_i2c_driver = {
658 .driver = {
659 .name = "rtc-pcf2127-i2c",
660 .of_match_table = of_match_ptr(pcf2127_of_match),
661 },
662 .probe = pcf2127_i2c_probe,
663 .id_table = pcf2127_i2c_id,
664 };
665
pcf2127_i2c_register_driver(void)666 static int pcf2127_i2c_register_driver(void)
667 {
668 return i2c_add_driver(&pcf2127_i2c_driver);
669 }
670
pcf2127_i2c_unregister_driver(void)671 static void pcf2127_i2c_unregister_driver(void)
672 {
673 i2c_del_driver(&pcf2127_i2c_driver);
674 }
675
676 #else
677
pcf2127_i2c_register_driver(void)678 static int pcf2127_i2c_register_driver(void)
679 {
680 return 0;
681 }
682
pcf2127_i2c_unregister_driver(void)683 static void pcf2127_i2c_unregister_driver(void)
684 {
685 }
686
687 #endif
688
689 #if IS_ENABLED(CONFIG_SPI_MASTER)
690
691 static struct spi_driver pcf2127_spi_driver;
692
pcf2127_spi_probe(struct spi_device * spi)693 static int pcf2127_spi_probe(struct spi_device *spi)
694 {
695 static const struct regmap_config config = {
696 .reg_bits = 8,
697 .val_bits = 8,
698 .read_flag_mask = 0xa0,
699 .write_flag_mask = 0x20,
700 };
701 struct regmap *regmap;
702
703 regmap = devm_regmap_init_spi(spi, &config);
704 if (IS_ERR(regmap)) {
705 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
706 __func__, PTR_ERR(regmap));
707 return PTR_ERR(regmap);
708 }
709
710 return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name,
711 spi_get_device_id(spi)->driver_data);
712 }
713
714 static const struct spi_device_id pcf2127_spi_id[] = {
715 { "pcf2127", 1 },
716 { "pcf2129", 0 },
717 { }
718 };
719 MODULE_DEVICE_TABLE(spi, pcf2127_spi_id);
720
721 static struct spi_driver pcf2127_spi_driver = {
722 .driver = {
723 .name = "rtc-pcf2127-spi",
724 .of_match_table = of_match_ptr(pcf2127_of_match),
725 },
726 .probe = pcf2127_spi_probe,
727 .id_table = pcf2127_spi_id,
728 };
729
pcf2127_spi_register_driver(void)730 static int pcf2127_spi_register_driver(void)
731 {
732 return spi_register_driver(&pcf2127_spi_driver);
733 }
734
pcf2127_spi_unregister_driver(void)735 static void pcf2127_spi_unregister_driver(void)
736 {
737 spi_unregister_driver(&pcf2127_spi_driver);
738 }
739
740 #else
741
pcf2127_spi_register_driver(void)742 static int pcf2127_spi_register_driver(void)
743 {
744 return 0;
745 }
746
pcf2127_spi_unregister_driver(void)747 static void pcf2127_spi_unregister_driver(void)
748 {
749 }
750
751 #endif
752
pcf2127_init(void)753 static int __init pcf2127_init(void)
754 {
755 int ret;
756
757 ret = pcf2127_i2c_register_driver();
758 if (ret) {
759 pr_err("Failed to register pcf2127 i2c driver: %d\n", ret);
760 return ret;
761 }
762
763 ret = pcf2127_spi_register_driver();
764 if (ret) {
765 pr_err("Failed to register pcf2127 spi driver: %d\n", ret);
766 pcf2127_i2c_unregister_driver();
767 }
768
769 return ret;
770 }
module_init(pcf2127_init)771 module_init(pcf2127_init)
772
773 static void __exit pcf2127_exit(void)
774 {
775 pcf2127_spi_unregister_driver();
776 pcf2127_i2c_unregister_driver();
777 }
778 module_exit(pcf2127_exit)
779
780 MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
781 MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver");
782 MODULE_LICENSE("GPL v2");
783
