1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Driver for the Epson RTC module RX-6110 SA |
4 | * |
5 | * Copyright(C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de> |
6 | * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved. |
7 | */ |
8 | |
9 | #include <linux/bcd.h> |
10 | #include <linux/init.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> |
13 | #include <linux/regmap.h> |
14 | #include <linux/rtc.h> |
15 | #include <linux/of.h> |
16 | #include <linux/spi/spi.h> |
17 | #include <linux/i2c.h> |
18 | |
19 | /* RX-6110 Register definitions */ |
20 | #define RX6110_REG_SEC 0x10 |
21 | #define RX6110_REG_MIN 0x11 |
22 | #define RX6110_REG_HOUR 0x12 |
23 | #define RX6110_REG_WDAY 0x13 |
24 | #define RX6110_REG_MDAY 0x14 |
25 | #define RX6110_REG_MONTH 0x15 |
26 | #define RX6110_REG_YEAR 0x16 |
27 | #define RX6110_REG_RES1 0x17 |
28 | #define RX6110_REG_ALMIN 0x18 |
29 | #define RX6110_REG_ALHOUR 0x19 |
30 | #define RX6110_REG_ALWDAY 0x1A |
31 | #define RX6110_REG_TCOUNT0 0x1B |
32 | #define RX6110_REG_TCOUNT1 0x1C |
33 | #define RX6110_REG_EXT 0x1D |
34 | #define RX6110_REG_FLAG 0x1E |
35 | #define RX6110_REG_CTRL 0x1F |
36 | #define RX6110_REG_USER0 0x20 |
37 | #define RX6110_REG_USER1 0x21 |
38 | #define RX6110_REG_USER2 0x22 |
39 | #define RX6110_REG_USER3 0x23 |
40 | #define RX6110_REG_USER4 0x24 |
41 | #define RX6110_REG_USER5 0x25 |
42 | #define RX6110_REG_USER6 0x26 |
43 | #define RX6110_REG_USER7 0x27 |
44 | #define RX6110_REG_USER8 0x28 |
45 | #define RX6110_REG_USER9 0x29 |
46 | #define RX6110_REG_USERA 0x2A |
47 | #define RX6110_REG_USERB 0x2B |
48 | #define RX6110_REG_USERC 0x2C |
49 | #define RX6110_REG_USERD 0x2D |
50 | #define RX6110_REG_USERE 0x2E |
51 | #define RX6110_REG_USERF 0x2F |
52 | #define RX6110_REG_RES2 0x30 |
53 | #define RX6110_REG_RES3 0x31 |
54 | #define RX6110_REG_IRQ 0x32 |
55 | |
56 | #define RX6110_BIT_ALARM_EN BIT(7) |
57 | |
58 | /* Extension Register (1Dh) bit positions */ |
59 | #define RX6110_BIT_EXT_TSEL0 BIT(0) |
60 | #define RX6110_BIT_EXT_TSEL1 BIT(1) |
61 | #define RX6110_BIT_EXT_TSEL2 BIT(2) |
62 | #define RX6110_BIT_EXT_WADA BIT(3) |
63 | #define RX6110_BIT_EXT_TE BIT(4) |
64 | #define RX6110_BIT_EXT_USEL BIT(5) |
65 | #define RX6110_BIT_EXT_FSEL0 BIT(6) |
66 | #define RX6110_BIT_EXT_FSEL1 BIT(7) |
67 | |
68 | /* Flag Register (1Eh) bit positions */ |
69 | #define RX6110_BIT_FLAG_VLF BIT(1) |
70 | #define RX6110_BIT_FLAG_AF BIT(3) |
71 | #define RX6110_BIT_FLAG_TF BIT(4) |
72 | #define RX6110_BIT_FLAG_UF BIT(5) |
73 | |
74 | /* Control Register (1Fh) bit positions */ |
75 | #define RX6110_BIT_CTRL_TBKE BIT(0) |
76 | #define RX6110_BIT_CTRL_TBKON BIT(1) |
77 | #define RX6110_BIT_CTRL_TSTP BIT(2) |
78 | #define RX6110_BIT_CTRL_AIE BIT(3) |
79 | #define RX6110_BIT_CTRL_TIE BIT(4) |
80 | #define RX6110_BIT_CTRL_UIE BIT(5) |
81 | #define RX6110_BIT_CTRL_STOP BIT(6) |
82 | #define RX6110_BIT_CTRL_TEST BIT(7) |
83 | |
84 | enum { |
85 | RTC_SEC = 0, |
86 | RTC_MIN, |
87 | RTC_HOUR, |
88 | RTC_WDAY, |
89 | RTC_MDAY, |
90 | RTC_MONTH, |
91 | RTC_YEAR, |
92 | RTC_NR_TIME |
93 | }; |
94 | |
95 | #define RX6110_DRIVER_NAME "rx6110" |
96 | |
97 | struct rx6110_data { |
98 | struct rtc_device *rtc; |
99 | struct regmap *regmap; |
100 | }; |
101 | |
102 | /** |
103 | * rx6110_rtc_tm_to_data - convert rtc_time to native time encoding |
104 | * |
105 | * @tm: holds date and time |
106 | * @data: holds the encoding in rx6110 native form |
107 | */ |
108 | static int rx6110_rtc_tm_to_data(struct rtc_time *tm, u8 *data) |
109 | { |
110 | pr_debug("%s: date %ptRr\n" , __func__, tm); |
111 | |
112 | /* |
113 | * The year in the RTC is a value between 0 and 99. |
114 | * Assume that this represents the current century |
115 | * and disregard all other values. |
116 | */ |
117 | if (tm->tm_year < 100 || tm->tm_year >= 200) |
118 | return -EINVAL; |
119 | |
120 | data[RTC_SEC] = bin2bcd(tm->tm_sec); |
121 | data[RTC_MIN] = bin2bcd(tm->tm_min); |
122 | data[RTC_HOUR] = bin2bcd(tm->tm_hour); |
123 | data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday)); |
124 | data[RTC_MDAY] = bin2bcd(tm->tm_mday); |
125 | data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1); |
126 | data[RTC_YEAR] = bin2bcd(tm->tm_year % 100); |
127 | |
128 | return 0; |
129 | } |
130 | |
131 | /** |
132 | * rx6110_data_to_rtc_tm - convert native time encoding to rtc_time |
133 | * |
134 | * @data: holds the encoding in rx6110 native form |
135 | * @tm: holds date and time |
136 | */ |
137 | static int rx6110_data_to_rtc_tm(u8 *data, struct rtc_time *tm) |
138 | { |
139 | tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f); |
140 | tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f); |
141 | /* only 24-hour clock */ |
142 | tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f); |
143 | tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f); |
144 | tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f); |
145 | tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1; |
146 | tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100; |
147 | |
148 | pr_debug("%s: date %ptRr\n" , __func__, tm); |
149 | |
150 | /* |
151 | * The year in the RTC is a value between 0 and 99. |
152 | * Assume that this represents the current century |
153 | * and disregard all other values. |
154 | */ |
155 | if (tm->tm_year < 100 || tm->tm_year >= 200) |
156 | return -EINVAL; |
157 | |
158 | return 0; |
159 | } |
160 | |
161 | /** |
162 | * rx6110_set_time - set the current time in the rx6110 registers |
163 | * |
164 | * @dev: the rtc device in use |
165 | * @tm: holds date and time |
166 | * |
167 | * BUG: The HW assumes every year that is a multiple of 4 to be a leap |
168 | * year. Next time this is wrong is 2100, which will not be a leap year |
169 | * |
170 | * Note: If STOP is not set/cleared, the clock will start when the seconds |
171 | * register is written |
172 | * |
173 | */ |
174 | static int rx6110_set_time(struct device *dev, struct rtc_time *tm) |
175 | { |
176 | struct rx6110_data *rx6110 = dev_get_drvdata(dev); |
177 | u8 data[RTC_NR_TIME]; |
178 | int ret; |
179 | |
180 | ret = rx6110_rtc_tm_to_data(tm, data); |
181 | if (ret < 0) |
182 | return ret; |
183 | |
184 | /* set STOP bit before changing clock/calendar */ |
185 | ret = regmap_update_bits(map: rx6110->regmap, RX6110_REG_CTRL, |
186 | RX6110_BIT_CTRL_STOP, RX6110_BIT_CTRL_STOP); |
187 | if (ret) |
188 | return ret; |
189 | |
190 | ret = regmap_bulk_write(map: rx6110->regmap, RX6110_REG_SEC, val: data, |
191 | val_count: RTC_NR_TIME); |
192 | if (ret) |
193 | return ret; |
194 | |
195 | /* The time in the RTC is valid. Be sure to have VLF cleared. */ |
196 | ret = regmap_update_bits(map: rx6110->regmap, RX6110_REG_FLAG, |
197 | RX6110_BIT_FLAG_VLF, val: 0); |
198 | if (ret) |
199 | return ret; |
200 | |
201 | /* clear STOP bit after changing clock/calendar */ |
202 | ret = regmap_update_bits(map: rx6110->regmap, RX6110_REG_CTRL, |
203 | RX6110_BIT_CTRL_STOP, val: 0); |
204 | |
205 | return ret; |
206 | } |
207 | |
208 | /** |
209 | * rx6110_get_time - get the current time from the rx6110 registers |
210 | * @dev: the rtc device in use |
211 | * @tm: holds date and time |
212 | */ |
213 | static int rx6110_get_time(struct device *dev, struct rtc_time *tm) |
214 | { |
215 | struct rx6110_data *rx6110 = dev_get_drvdata(dev); |
216 | u8 data[RTC_NR_TIME]; |
217 | int flags; |
218 | int ret; |
219 | |
220 | ret = regmap_read(map: rx6110->regmap, RX6110_REG_FLAG, val: &flags); |
221 | if (ret) |
222 | return -EINVAL; |
223 | |
224 | /* check for VLF Flag (set at power-on) */ |
225 | if ((flags & RX6110_BIT_FLAG_VLF)) { |
226 | dev_warn(dev, "Voltage low, data is invalid.\n" ); |
227 | return -EINVAL; |
228 | } |
229 | |
230 | /* read registers to date */ |
231 | ret = regmap_bulk_read(map: rx6110->regmap, RX6110_REG_SEC, val: data, |
232 | val_count: RTC_NR_TIME); |
233 | if (ret) |
234 | return ret; |
235 | |
236 | ret = rx6110_data_to_rtc_tm(data, tm); |
237 | if (ret) |
238 | return ret; |
239 | |
240 | dev_dbg(dev, "%s: date %ptRr\n" , __func__, tm); |
241 | |
242 | return 0; |
243 | } |
244 | |
245 | static const struct reg_sequence rx6110_default_regs[] = { |
246 | { RX6110_REG_RES1, 0xB8 }, |
247 | { RX6110_REG_RES2, 0x00 }, |
248 | { RX6110_REG_RES3, 0x10 }, |
249 | { RX6110_REG_IRQ, 0x00 }, |
250 | { RX6110_REG_ALMIN, 0x00 }, |
251 | { RX6110_REG_ALHOUR, 0x00 }, |
252 | { RX6110_REG_ALWDAY, 0x00 }, |
253 | }; |
254 | |
255 | /** |
256 | * rx6110_init - initialize the rx6110 registers |
257 | * |
258 | * @rx6110: pointer to the rx6110 struct in use |
259 | * |
260 | */ |
261 | static int rx6110_init(struct rx6110_data *rx6110) |
262 | { |
263 | struct rtc_device *rtc = rx6110->rtc; |
264 | int flags; |
265 | int ret; |
266 | |
267 | ret = regmap_update_bits(map: rx6110->regmap, RX6110_REG_EXT, |
268 | RX6110_BIT_EXT_TE, val: 0); |
269 | if (ret) |
270 | return ret; |
271 | |
272 | ret = regmap_register_patch(map: rx6110->regmap, regs: rx6110_default_regs, |
273 | ARRAY_SIZE(rx6110_default_regs)); |
274 | if (ret) |
275 | return ret; |
276 | |
277 | ret = regmap_read(map: rx6110->regmap, RX6110_REG_FLAG, val: &flags); |
278 | if (ret) |
279 | return ret; |
280 | |
281 | /* check for VLF Flag (set at power-on) */ |
282 | if ((flags & RX6110_BIT_FLAG_VLF)) |
283 | dev_warn(&rtc->dev, "Voltage low, data loss detected.\n" ); |
284 | |
285 | /* check for Alarm Flag */ |
286 | if (flags & RX6110_BIT_FLAG_AF) |
287 | dev_warn(&rtc->dev, "An alarm may have been missed.\n" ); |
288 | |
289 | /* check for Periodic Timer Flag */ |
290 | if (flags & RX6110_BIT_FLAG_TF) |
291 | dev_warn(&rtc->dev, "Periodic timer was detected\n" ); |
292 | |
293 | /* check for Update Timer Flag */ |
294 | if (flags & RX6110_BIT_FLAG_UF) |
295 | dev_warn(&rtc->dev, "Update timer was detected\n" ); |
296 | |
297 | /* clear all flags BUT VLF */ |
298 | ret = regmap_update_bits(map: rx6110->regmap, RX6110_REG_FLAG, |
299 | RX6110_BIT_FLAG_AF | |
300 | RX6110_BIT_FLAG_UF | |
301 | RX6110_BIT_FLAG_TF, |
302 | val: 0); |
303 | |
304 | return ret; |
305 | } |
306 | |
307 | static const struct rtc_class_ops rx6110_rtc_ops = { |
308 | .read_time = rx6110_get_time, |
309 | .set_time = rx6110_set_time, |
310 | }; |
311 | |
312 | static int rx6110_probe(struct rx6110_data *rx6110, struct device *dev) |
313 | { |
314 | int err; |
315 | |
316 | rx6110->rtc = devm_rtc_device_register(dev, |
317 | RX6110_DRIVER_NAME, |
318 | ops: &rx6110_rtc_ops, THIS_MODULE); |
319 | |
320 | if (IS_ERR(ptr: rx6110->rtc)) |
321 | return PTR_ERR(ptr: rx6110->rtc); |
322 | |
323 | err = rx6110_init(rx6110); |
324 | if (err) |
325 | return err; |
326 | |
327 | rx6110->rtc->max_user_freq = 1; |
328 | |
329 | return 0; |
330 | } |
331 | |
332 | #if IS_ENABLED(CONFIG_SPI_MASTER) |
333 | static struct regmap_config regmap_spi_config = { |
334 | .reg_bits = 8, |
335 | .val_bits = 8, |
336 | .max_register = RX6110_REG_IRQ, |
337 | .read_flag_mask = 0x80, |
338 | }; |
339 | |
340 | /** |
341 | * rx6110_spi_probe - initialize rtc driver |
342 | * @spi: pointer to spi device |
343 | */ |
344 | static int rx6110_spi_probe(struct spi_device *spi) |
345 | { |
346 | struct rx6110_data *rx6110; |
347 | |
348 | if ((spi->bits_per_word && spi->bits_per_word != 8) || |
349 | (spi->max_speed_hz > 2000000) || |
350 | (spi->mode != (SPI_CS_HIGH | SPI_CPOL | SPI_CPHA))) { |
351 | dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n" , |
352 | spi->bits_per_word, spi->max_speed_hz, spi->mode); |
353 | dev_warn(&spi->dev, "driving device in an unsupported mode" ); |
354 | } |
355 | |
356 | rx6110 = devm_kzalloc(dev: &spi->dev, size: sizeof(*rx6110), GFP_KERNEL); |
357 | if (!rx6110) |
358 | return -ENOMEM; |
359 | |
360 | rx6110->regmap = devm_regmap_init_spi(spi, ®map_spi_config); |
361 | if (IS_ERR(ptr: rx6110->regmap)) { |
362 | dev_err(&spi->dev, "regmap init failed for rtc rx6110\n" ); |
363 | return PTR_ERR(ptr: rx6110->regmap); |
364 | } |
365 | |
366 | spi_set_drvdata(spi, data: rx6110); |
367 | |
368 | return rx6110_probe(rx6110, dev: &spi->dev); |
369 | } |
370 | |
371 | static const struct spi_device_id rx6110_spi_id[] = { |
372 | { "rx6110" , 0 }, |
373 | { } |
374 | }; |
375 | MODULE_DEVICE_TABLE(spi, rx6110_spi_id); |
376 | |
377 | static const __maybe_unused struct of_device_id rx6110_spi_of_match[] = { |
378 | { .compatible = "epson,rx6110" }, |
379 | { }, |
380 | }; |
381 | MODULE_DEVICE_TABLE(of, rx6110_spi_of_match); |
382 | |
383 | static struct spi_driver rx6110_spi_driver = { |
384 | .driver = { |
385 | .name = RX6110_DRIVER_NAME, |
386 | .of_match_table = of_match_ptr(rx6110_spi_of_match), |
387 | }, |
388 | .probe = rx6110_spi_probe, |
389 | .id_table = rx6110_spi_id, |
390 | }; |
391 | |
392 | static int rx6110_spi_register(void) |
393 | { |
394 | return spi_register_driver(&rx6110_spi_driver); |
395 | } |
396 | |
397 | static void rx6110_spi_unregister(void) |
398 | { |
399 | spi_unregister_driver(sdrv: &rx6110_spi_driver); |
400 | } |
401 | #else |
402 | static int rx6110_spi_register(void) |
403 | { |
404 | return 0; |
405 | } |
406 | |
407 | static void rx6110_spi_unregister(void) |
408 | { |
409 | } |
410 | #endif /* CONFIG_SPI_MASTER */ |
411 | |
412 | #if IS_ENABLED(CONFIG_I2C) |
413 | static struct regmap_config regmap_i2c_config = { |
414 | .reg_bits = 8, |
415 | .val_bits = 8, |
416 | .max_register = RX6110_REG_IRQ, |
417 | .read_flag_mask = 0x80, |
418 | }; |
419 | |
420 | static int rx6110_i2c_probe(struct i2c_client *client) |
421 | { |
422 | struct i2c_adapter *adapter = client->adapter; |
423 | struct rx6110_data *rx6110; |
424 | |
425 | if (!i2c_check_functionality(adap: adapter, I2C_FUNC_SMBUS_BYTE_DATA |
426 | | I2C_FUNC_SMBUS_I2C_BLOCK)) { |
427 | dev_err(&adapter->dev, |
428 | "doesn't support required functionality\n" ); |
429 | return -EIO; |
430 | } |
431 | |
432 | rx6110 = devm_kzalloc(dev: &client->dev, size: sizeof(*rx6110), GFP_KERNEL); |
433 | if (!rx6110) |
434 | return -ENOMEM; |
435 | |
436 | rx6110->regmap = devm_regmap_init_i2c(client, ®map_i2c_config); |
437 | if (IS_ERR(ptr: rx6110->regmap)) { |
438 | dev_err(&client->dev, "regmap init failed for rtc rx6110\n" ); |
439 | return PTR_ERR(ptr: rx6110->regmap); |
440 | } |
441 | |
442 | i2c_set_clientdata(client, data: rx6110); |
443 | |
444 | return rx6110_probe(rx6110, dev: &client->dev); |
445 | } |
446 | |
447 | static const struct acpi_device_id rx6110_i2c_acpi_match[] = { |
448 | { "SECC6110" }, |
449 | { } |
450 | }; |
451 | MODULE_DEVICE_TABLE(acpi, rx6110_i2c_acpi_match); |
452 | |
453 | static const struct i2c_device_id rx6110_i2c_id[] = { |
454 | { "rx6110" , 0 }, |
455 | { } |
456 | }; |
457 | MODULE_DEVICE_TABLE(i2c, rx6110_i2c_id); |
458 | |
459 | static struct i2c_driver rx6110_i2c_driver = { |
460 | .driver = { |
461 | .name = RX6110_DRIVER_NAME, |
462 | .acpi_match_table = rx6110_i2c_acpi_match, |
463 | }, |
464 | .probe = rx6110_i2c_probe, |
465 | .id_table = rx6110_i2c_id, |
466 | }; |
467 | |
468 | static int rx6110_i2c_register(void) |
469 | { |
470 | return i2c_add_driver(&rx6110_i2c_driver); |
471 | } |
472 | |
473 | static void rx6110_i2c_unregister(void) |
474 | { |
475 | i2c_del_driver(driver: &rx6110_i2c_driver); |
476 | } |
477 | #else |
478 | static int rx6110_i2c_register(void) |
479 | { |
480 | return 0; |
481 | } |
482 | |
483 | static void rx6110_i2c_unregister(void) |
484 | { |
485 | } |
486 | #endif /* CONFIG_I2C */ |
487 | |
488 | static int __init rx6110_module_init(void) |
489 | { |
490 | int ret; |
491 | |
492 | ret = rx6110_spi_register(); |
493 | if (ret) |
494 | return ret; |
495 | |
496 | ret = rx6110_i2c_register(); |
497 | if (ret) |
498 | rx6110_spi_unregister(); |
499 | |
500 | return ret; |
501 | } |
502 | module_init(rx6110_module_init); |
503 | |
504 | static void __exit rx6110_module_exit(void) |
505 | { |
506 | rx6110_spi_unregister(); |
507 | rx6110_i2c_unregister(); |
508 | } |
509 | module_exit(rx6110_module_exit); |
510 | |
511 | MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>" ); |
512 | MODULE_DESCRIPTION("RX-6110 SA RTC driver" ); |
513 | MODULE_LICENSE("GPL" ); |
514 | |