1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Driver for the Epson RTC module RX-8010 SJ |
4 | * |
5 | * Copyright(C) Timesys Corporation 2015 |
6 | * Copyright(C) General Electric Company 2015 |
7 | */ |
8 | |
9 | #include <linux/bcd.h> |
10 | #include <linux/bitops.h> |
11 | #include <linux/i2c.h> |
12 | #include <linux/kernel.h> |
13 | #include <linux/module.h> |
14 | #include <linux/regmap.h> |
15 | #include <linux/rtc.h> |
16 | |
17 | #define RX8010_SEC 0x10 |
18 | #define RX8010_MIN 0x11 |
19 | #define RX8010_HOUR 0x12 |
20 | #define RX8010_WDAY 0x13 |
21 | #define RX8010_MDAY 0x14 |
22 | #define RX8010_MONTH 0x15 |
23 | #define RX8010_YEAR 0x16 |
24 | #define RX8010_RESV17 0x17 |
25 | #define RX8010_ALMIN 0x18 |
26 | #define RX8010_ALHOUR 0x19 |
27 | #define RX8010_ALWDAY 0x1A |
28 | #define RX8010_TCOUNT0 0x1B |
29 | #define RX8010_TCOUNT1 0x1C |
30 | #define RX8010_EXT 0x1D |
31 | #define RX8010_FLAG 0x1E |
32 | #define RX8010_CTRL 0x1F |
33 | /* 0x20 to 0x2F are user registers */ |
34 | #define RX8010_RESV30 0x30 |
35 | #define RX8010_RESV31 0x31 |
36 | #define RX8010_IRQ 0x32 |
37 | |
38 | #define RX8010_EXT_WADA BIT(3) |
39 | |
40 | #define RX8010_FLAG_VLF BIT(1) |
41 | #define RX8010_FLAG_AF BIT(3) |
42 | #define RX8010_FLAG_TF BIT(4) |
43 | #define RX8010_FLAG_UF BIT(5) |
44 | |
45 | #define RX8010_CTRL_AIE BIT(3) |
46 | #define RX8010_CTRL_UIE BIT(5) |
47 | #define RX8010_CTRL_STOP BIT(6) |
48 | #define RX8010_CTRL_TEST BIT(7) |
49 | |
50 | #define RX8010_ALARM_AE BIT(7) |
51 | |
52 | static const struct i2c_device_id rx8010_id[] = { |
53 | { "rx8010" , 0 }, |
54 | { } |
55 | }; |
56 | MODULE_DEVICE_TABLE(i2c, rx8010_id); |
57 | |
58 | static const __maybe_unused struct of_device_id rx8010_of_match[] = { |
59 | { .compatible = "epson,rx8010" }, |
60 | { } |
61 | }; |
62 | MODULE_DEVICE_TABLE(of, rx8010_of_match); |
63 | |
64 | struct rx8010_data { |
65 | struct regmap *regs; |
66 | struct rtc_device *rtc; |
67 | u8 ctrlreg; |
68 | }; |
69 | |
70 | static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id) |
71 | { |
72 | struct i2c_client *client = dev_id; |
73 | struct rx8010_data *rx8010 = i2c_get_clientdata(client); |
74 | int flagreg, err; |
75 | |
76 | rtc_lock(rx8010->rtc); |
77 | |
78 | err = regmap_read(map: rx8010->regs, RX8010_FLAG, val: &flagreg); |
79 | if (err) { |
80 | rtc_unlock(rx8010->rtc); |
81 | return IRQ_NONE; |
82 | } |
83 | |
84 | if (flagreg & RX8010_FLAG_VLF) |
85 | dev_warn(&client->dev, "Frequency stop detected\n" ); |
86 | |
87 | if (flagreg & RX8010_FLAG_TF) { |
88 | flagreg &= ~RX8010_FLAG_TF; |
89 | rtc_update_irq(rtc: rx8010->rtc, num: 1, RTC_PF | RTC_IRQF); |
90 | } |
91 | |
92 | if (flagreg & RX8010_FLAG_AF) { |
93 | flagreg &= ~RX8010_FLAG_AF; |
94 | rtc_update_irq(rtc: rx8010->rtc, num: 1, RTC_AF | RTC_IRQF); |
95 | } |
96 | |
97 | if (flagreg & RX8010_FLAG_UF) { |
98 | flagreg &= ~RX8010_FLAG_UF; |
99 | rtc_update_irq(rtc: rx8010->rtc, num: 1, RTC_UF | RTC_IRQF); |
100 | } |
101 | |
102 | err = regmap_write(map: rx8010->regs, RX8010_FLAG, val: flagreg); |
103 | rtc_unlock(rx8010->rtc); |
104 | return err ? IRQ_NONE : IRQ_HANDLED; |
105 | } |
106 | |
107 | static int rx8010_get_time(struct device *dev, struct rtc_time *dt) |
108 | { |
109 | struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
110 | u8 date[RX8010_YEAR - RX8010_SEC + 1]; |
111 | int flagreg, err; |
112 | |
113 | err = regmap_read(map: rx8010->regs, RX8010_FLAG, val: &flagreg); |
114 | if (err) |
115 | return err; |
116 | |
117 | if (flagreg & RX8010_FLAG_VLF) { |
118 | dev_warn(dev, "Frequency stop detected\n" ); |
119 | return -EINVAL; |
120 | } |
121 | |
122 | err = regmap_bulk_read(map: rx8010->regs, RX8010_SEC, val: date, val_count: sizeof(date)); |
123 | if (err) |
124 | return err; |
125 | |
126 | dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f); |
127 | dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f); |
128 | dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f); |
129 | dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f); |
130 | dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1; |
131 | dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100; |
132 | dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f); |
133 | |
134 | return 0; |
135 | } |
136 | |
137 | static int rx8010_set_time(struct device *dev, struct rtc_time *dt) |
138 | { |
139 | struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
140 | u8 date[RX8010_YEAR - RX8010_SEC + 1]; |
141 | int err; |
142 | |
143 | /* set STOP bit before changing clock/calendar */ |
144 | err = regmap_set_bits(map: rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP); |
145 | if (err) |
146 | return err; |
147 | |
148 | date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec); |
149 | date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min); |
150 | date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour); |
151 | date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday); |
152 | date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1); |
153 | date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100); |
154 | date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday); |
155 | |
156 | err = regmap_bulk_write(map: rx8010->regs, RX8010_SEC, val: date, val_count: sizeof(date)); |
157 | if (err) |
158 | return err; |
159 | |
160 | /* clear STOP bit after changing clock/calendar */ |
161 | err = regmap_clear_bits(map: rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP); |
162 | if (err) |
163 | return err; |
164 | |
165 | err = regmap_clear_bits(map: rx8010->regs, RX8010_FLAG, RX8010_FLAG_VLF); |
166 | if (err) |
167 | return err; |
168 | |
169 | return 0; |
170 | } |
171 | |
172 | static int rx8010_init(struct device *dev) |
173 | { |
174 | struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
175 | u8 ctrl[2]; |
176 | int need_clear = 0, err; |
177 | |
178 | /* Initialize reserved registers as specified in datasheet */ |
179 | err = regmap_write(map: rx8010->regs, RX8010_RESV17, val: 0xD8); |
180 | if (err) |
181 | return err; |
182 | |
183 | err = regmap_write(map: rx8010->regs, RX8010_RESV30, val: 0x00); |
184 | if (err) |
185 | return err; |
186 | |
187 | err = regmap_write(map: rx8010->regs, RX8010_RESV31, val: 0x08); |
188 | if (err) |
189 | return err; |
190 | |
191 | err = regmap_write(map: rx8010->regs, RX8010_IRQ, val: 0x00); |
192 | if (err) |
193 | return err; |
194 | |
195 | err = regmap_bulk_read(map: rx8010->regs, RX8010_FLAG, val: ctrl, val_count: 2); |
196 | if (err) |
197 | return err; |
198 | |
199 | if (ctrl[0] & RX8010_FLAG_VLF) |
200 | dev_warn(dev, "Frequency stop was detected\n" ); |
201 | |
202 | if (ctrl[0] & RX8010_FLAG_AF) { |
203 | dev_warn(dev, "Alarm was detected\n" ); |
204 | need_clear = 1; |
205 | } |
206 | |
207 | if (ctrl[0] & RX8010_FLAG_TF) |
208 | need_clear = 1; |
209 | |
210 | if (ctrl[0] & RX8010_FLAG_UF) |
211 | need_clear = 1; |
212 | |
213 | if (need_clear) { |
214 | ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF); |
215 | err = regmap_write(map: rx8010->regs, RX8010_FLAG, val: ctrl[0]); |
216 | if (err) |
217 | return err; |
218 | } |
219 | |
220 | rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST); |
221 | |
222 | return 0; |
223 | } |
224 | |
225 | static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t) |
226 | { |
227 | struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
228 | u8 alarmvals[3]; |
229 | int flagreg, err; |
230 | |
231 | err = regmap_bulk_read(map: rx8010->regs, RX8010_ALMIN, val: alarmvals, val_count: 3); |
232 | if (err) |
233 | return err; |
234 | |
235 | err = regmap_read(map: rx8010->regs, RX8010_FLAG, val: &flagreg); |
236 | if (err) |
237 | return err; |
238 | |
239 | t->time.tm_sec = 0; |
240 | t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); |
241 | t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); |
242 | |
243 | if (!(alarmvals[2] & RX8010_ALARM_AE)) |
244 | t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f); |
245 | |
246 | t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE); |
247 | t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled; |
248 | |
249 | return 0; |
250 | } |
251 | |
252 | static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t) |
253 | { |
254 | struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
255 | u8 alarmvals[3]; |
256 | int err; |
257 | |
258 | if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) { |
259 | rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE); |
260 | err = regmap_write(map: rx8010->regs, RX8010_CTRL, val: rx8010->ctrlreg); |
261 | if (err) |
262 | return err; |
263 | } |
264 | |
265 | err = regmap_clear_bits(map: rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF); |
266 | if (err) |
267 | return err; |
268 | |
269 | alarmvals[0] = bin2bcd(t->time.tm_min); |
270 | alarmvals[1] = bin2bcd(t->time.tm_hour); |
271 | alarmvals[2] = bin2bcd(t->time.tm_mday); |
272 | |
273 | err = regmap_bulk_write(map: rx8010->regs, RX8010_ALMIN, val: alarmvals, val_count: 2); |
274 | if (err) |
275 | return err; |
276 | |
277 | err = regmap_clear_bits(map: rx8010->regs, RX8010_EXT, RX8010_EXT_WADA); |
278 | if (err) |
279 | return err; |
280 | |
281 | if (alarmvals[2] == 0) |
282 | alarmvals[2] |= RX8010_ALARM_AE; |
283 | |
284 | err = regmap_write(map: rx8010->regs, RX8010_ALWDAY, val: alarmvals[2]); |
285 | if (err) |
286 | return err; |
287 | |
288 | if (t->enabled) { |
289 | if (rx8010->rtc->uie_rtctimer.enabled) |
290 | rx8010->ctrlreg |= RX8010_CTRL_UIE; |
291 | if (rx8010->rtc->aie_timer.enabled) |
292 | rx8010->ctrlreg |= |
293 | (RX8010_CTRL_AIE | RX8010_CTRL_UIE); |
294 | |
295 | err = regmap_write(map: rx8010->regs, RX8010_CTRL, val: rx8010->ctrlreg); |
296 | if (err) |
297 | return err; |
298 | } |
299 | |
300 | return 0; |
301 | } |
302 | |
303 | static int rx8010_alarm_irq_enable(struct device *dev, |
304 | unsigned int enabled) |
305 | { |
306 | struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
307 | int err; |
308 | u8 ctrl; |
309 | |
310 | ctrl = rx8010->ctrlreg; |
311 | |
312 | if (enabled) { |
313 | if (rx8010->rtc->uie_rtctimer.enabled) |
314 | ctrl |= RX8010_CTRL_UIE; |
315 | if (rx8010->rtc->aie_timer.enabled) |
316 | ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE); |
317 | } else { |
318 | if (!rx8010->rtc->uie_rtctimer.enabled) |
319 | ctrl &= ~RX8010_CTRL_UIE; |
320 | if (!rx8010->rtc->aie_timer.enabled) |
321 | ctrl &= ~RX8010_CTRL_AIE; |
322 | } |
323 | |
324 | err = regmap_clear_bits(map: rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF); |
325 | if (err) |
326 | return err; |
327 | |
328 | if (ctrl != rx8010->ctrlreg) { |
329 | rx8010->ctrlreg = ctrl; |
330 | err = regmap_write(map: rx8010->regs, RX8010_CTRL, val: rx8010->ctrlreg); |
331 | if (err) |
332 | return err; |
333 | } |
334 | |
335 | return 0; |
336 | } |
337 | |
338 | static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) |
339 | { |
340 | struct rx8010_data *rx8010 = dev_get_drvdata(dev); |
341 | int tmp, flagreg, err; |
342 | |
343 | switch (cmd) { |
344 | case RTC_VL_READ: |
345 | err = regmap_read(map: rx8010->regs, RX8010_FLAG, val: &flagreg); |
346 | if (err) |
347 | return err; |
348 | |
349 | tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0; |
350 | return put_user(tmp, (unsigned int __user *)arg); |
351 | |
352 | default: |
353 | return -ENOIOCTLCMD; |
354 | } |
355 | } |
356 | |
357 | static const struct rtc_class_ops rx8010_rtc_ops = { |
358 | .read_time = rx8010_get_time, |
359 | .set_time = rx8010_set_time, |
360 | .ioctl = rx8010_ioctl, |
361 | .read_alarm = rx8010_read_alarm, |
362 | .set_alarm = rx8010_set_alarm, |
363 | .alarm_irq_enable = rx8010_alarm_irq_enable, |
364 | }; |
365 | |
366 | static const struct regmap_config rx8010_regmap_config = { |
367 | .name = "rx8010-rtc" , |
368 | .reg_bits = 8, |
369 | .val_bits = 8, |
370 | }; |
371 | |
372 | static int rx8010_probe(struct i2c_client *client) |
373 | { |
374 | struct device *dev = &client->dev; |
375 | struct rx8010_data *rx8010; |
376 | int err = 0; |
377 | |
378 | rx8010 = devm_kzalloc(dev, size: sizeof(*rx8010), GFP_KERNEL); |
379 | if (!rx8010) |
380 | return -ENOMEM; |
381 | |
382 | i2c_set_clientdata(client, data: rx8010); |
383 | |
384 | rx8010->regs = devm_regmap_init_i2c(client, &rx8010_regmap_config); |
385 | if (IS_ERR(ptr: rx8010->regs)) |
386 | return PTR_ERR(ptr: rx8010->regs); |
387 | |
388 | err = rx8010_init(dev); |
389 | if (err) |
390 | return err; |
391 | |
392 | rx8010->rtc = devm_rtc_allocate_device(dev); |
393 | if (IS_ERR(ptr: rx8010->rtc)) |
394 | return PTR_ERR(ptr: rx8010->rtc); |
395 | |
396 | if (client->irq > 0) { |
397 | unsigned long irqflags = IRQF_TRIGGER_LOW; |
398 | |
399 | if (dev_fwnode(&client->dev)) |
400 | irqflags = 0; |
401 | |
402 | err = devm_request_threaded_irq(dev, irq: client->irq, NULL, |
403 | thread_fn: rx8010_irq_1_handler, |
404 | irqflags: irqflags | IRQF_ONESHOT, |
405 | devname: "rx8010" , dev_id: client); |
406 | if (err) { |
407 | dev_err(dev, "unable to request IRQ\n" ); |
408 | return err; |
409 | } |
410 | } else { |
411 | clear_bit(RTC_FEATURE_ALARM, addr: rx8010->rtc->features); |
412 | } |
413 | |
414 | rx8010->rtc->ops = &rx8010_rtc_ops; |
415 | rx8010->rtc->max_user_freq = 1; |
416 | rx8010->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; |
417 | rx8010->rtc->range_max = RTC_TIMESTAMP_END_2099; |
418 | |
419 | return devm_rtc_register_device(rx8010->rtc); |
420 | } |
421 | |
422 | static struct i2c_driver rx8010_driver = { |
423 | .driver = { |
424 | .name = "rtc-rx8010" , |
425 | .of_match_table = of_match_ptr(rx8010_of_match), |
426 | }, |
427 | .probe = rx8010_probe, |
428 | .id_table = rx8010_id, |
429 | }; |
430 | |
431 | module_i2c_driver(rx8010_driver); |
432 | |
433 | MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>" ); |
434 | MODULE_DESCRIPTION("Epson RX8010SJ RTC driver" ); |
435 | MODULE_LICENSE("GPL v2" ); |
436 | |