?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Linux 4.16.11
[linux/fpc-iii.git] / drivers / rtc / rtc-ds1511.c
blob1e95312a6f2eecdce510a7cdd79a2b59fa37f037
1 /*
2 * An rtc driver for the Dallas DS1511
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * Real time clock driver for the Dallas 1511 chip, which also
12 * contains a watchdog timer. There is a tiny amount of code that
13 * platform code could use to mess with the watchdog device a little
14 * bit, but not a full watchdog driver.
15 */
16
17 #include <linux/bcd.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/gfp.h>
21 #include <linux/delay.h>
22 #include <linux/interrupt.h>
23 #include <linux/rtc.h>
24 #include <linux/platform_device.h>
25 #include <linux/io.h>
26 #include <linux/module.h>
27
28 enum ds1511reg {
29 DS1511_SEC = 0x0,
30 DS1511_MIN = 0x1,
31 DS1511_HOUR = 0x2,
32 DS1511_DOW = 0x3,
33 DS1511_DOM = 0x4,
34 DS1511_MONTH = 0x5,
35 DS1511_YEAR = 0x6,
36 DS1511_CENTURY = 0x7,
37 DS1511_AM1_SEC = 0x8,
38 DS1511_AM2_MIN = 0x9,
39 DS1511_AM3_HOUR = 0xa,
40 DS1511_AM4_DATE = 0xb,
41 DS1511_WD_MSEC = 0xc,
42 DS1511_WD_SEC = 0xd,
43 DS1511_CONTROL_A = 0xe,
44 DS1511_CONTROL_B = 0xf,
45 DS1511_RAMADDR_LSB = 0x10,
46 DS1511_RAMDATA = 0x13
47 };
48
49 #define DS1511_BLF1 0x80
50 #define DS1511_BLF2 0x40
51 #define DS1511_PRS 0x20
52 #define DS1511_PAB 0x10
53 #define DS1511_TDF 0x08
54 #define DS1511_KSF 0x04
55 #define DS1511_WDF 0x02
56 #define DS1511_IRQF 0x01
57 #define DS1511_TE 0x80
58 #define DS1511_CS 0x40
59 #define DS1511_BME 0x20
60 #define DS1511_TPE 0x10
61 #define DS1511_TIE 0x08
62 #define DS1511_KIE 0x04
63 #define DS1511_WDE 0x02
64 #define DS1511_WDS 0x01
65 #define DS1511_RAM_MAX 0x100
66
67 #define RTC_CMD DS1511_CONTROL_B
68 #define RTC_CMD1 DS1511_CONTROL_A
69
70 #define RTC_ALARM_SEC DS1511_AM1_SEC
71 #define RTC_ALARM_MIN DS1511_AM2_MIN
72 #define RTC_ALARM_HOUR DS1511_AM3_HOUR
73 #define RTC_ALARM_DATE DS1511_AM4_DATE
74
75 #define RTC_SEC DS1511_SEC
76 #define RTC_MIN DS1511_MIN
77 #define RTC_HOUR DS1511_HOUR
78 #define RTC_DOW DS1511_DOW
79 #define RTC_DOM DS1511_DOM
80 #define RTC_MON DS1511_MONTH
81 #define RTC_YEAR DS1511_YEAR
82 #define RTC_CENTURY DS1511_CENTURY
83
84 #define RTC_TIE DS1511_TIE
85 #define RTC_TE DS1511_TE
86
87 struct rtc_plat_data {
88 struct rtc_device *rtc;
89 void __iomem *ioaddr; /* virtual base address */
90 int irq;
91 unsigned int irqen;
92 int alrm_sec;
93 int alrm_min;
94 int alrm_hour;
95 int alrm_mday;
96 spinlock_t lock;
97 };
98
99 static DEFINE_SPINLOCK(ds1511_lock);
100
101 static __iomem char *ds1511_base;
102 static u32 reg_spacing = 1;
103
104 static noinline void
105 rtc_write(uint8_t val, uint32_t reg)
106 {
107 writeb(val, ds1511_base + (reg * reg_spacing));
108 }
109
110 static inline void
111 rtc_write_alarm(uint8_t val, enum ds1511reg reg)
112 {
113 rtc_write((val | 0x80), reg);
114 }
115
116 static noinline uint8_t
117 rtc_read(enum ds1511reg reg)
118 {
119 return readb(ds1511_base + (reg * reg_spacing));
120 }
121
122 static inline void
123 rtc_disable_update(void)
124 {
125 rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
126 }
127
128 static void
129 rtc_enable_update(void)
130 {
131 rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD);
132 }
133
134 /*
135 * #define DS1511_WDOG_RESET_SUPPORT
136 *
137 * Uncomment this if you want to use these routines in
138 * some platform code.
139 */
140 #ifdef DS1511_WDOG_RESET_SUPPORT
141 /*
142 * just enough code to set the watchdog timer so that it
143 * will reboot the system
144 */
145 void
146 ds1511_wdog_set(unsigned long deciseconds)
147 {
148 /*
149 * the wdog timer can take 99.99 seconds
150 */
151 deciseconds %= 10000;
152 /*
153 * set the wdog values in the wdog registers
154 */
155 rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
156 rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
157 /*
158 * set wdog enable and wdog 'steering' bit to issue a reset
159 */
160 rtc_write(rtc_read(RTC_CMD) | DS1511_WDE | DS1511_WDS, RTC_CMD);
161 }
162
163 void
164 ds1511_wdog_disable(void)
165 {
166 /*
167 * clear wdog enable and wdog 'steering' bits
168 */
169 rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD);
170 /*
171 * clear the wdog counter
172 */
173 rtc_write(0, DS1511_WD_MSEC);
174 rtc_write(0, DS1511_WD_SEC);
175 }
176 #endif
177
178 /*
179 * set the rtc chip's idea of the time.
180 * stupidly, some callers call with year unmolested;
181 * and some call with year = year - 1900. thanks.
182 */
183 static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
184 {
185 u8 mon, day, dow, hrs, min, sec, yrs, cen;
186 unsigned long flags;
187
188 /*
189 * won't have to change this for a while
190 */
191 if (rtc_tm->tm_year < 1900)
192 rtc_tm->tm_year += 1900;
193
194 if (rtc_tm->tm_year < 1970)
195 return -EINVAL;
196
197 yrs = rtc_tm->tm_year % 100;
198 cen = rtc_tm->tm_year / 100;
199 mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
200 day = rtc_tm->tm_mday;
201 dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
202 hrs = rtc_tm->tm_hour;
203 min = rtc_tm->tm_min;
204 sec = rtc_tm->tm_sec;
205
206 if ((mon > 12) || (day == 0))
207 return -EINVAL;
208
209 if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year))
210 return -EINVAL;
211
212 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
213 return -EINVAL;
214
215 /*
216 * each register is a different number of valid bits
217 */
218 sec = bin2bcd(sec) & 0x7f;
219 min = bin2bcd(min) & 0x7f;
220 hrs = bin2bcd(hrs) & 0x3f;
221 day = bin2bcd(day) & 0x3f;
222 mon = bin2bcd(mon) & 0x1f;
223 yrs = bin2bcd(yrs) & 0xff;
224 cen = bin2bcd(cen) & 0xff;
225
226 spin_lock_irqsave(&ds1511_lock, flags);
227 rtc_disable_update();
228 rtc_write(cen, RTC_CENTURY);
229 rtc_write(yrs, RTC_YEAR);
230 rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON);
231 rtc_write(day, RTC_DOM);
232 rtc_write(hrs, RTC_HOUR);
233 rtc_write(min, RTC_MIN);
234 rtc_write(sec, RTC_SEC);
235 rtc_write(dow, RTC_DOW);
236 rtc_enable_update();
237 spin_unlock_irqrestore(&ds1511_lock, flags);
238
239 return 0;
240 }
241
242 static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
243 {
244 unsigned int century;
245 unsigned long flags;
246
247 spin_lock_irqsave(&ds1511_lock, flags);
248 rtc_disable_update();
249
250 rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
251 rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
252 rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
253 rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
254 rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
255 rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
256 rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
257 century = rtc_read(RTC_CENTURY);
258
259 rtc_enable_update();
260 spin_unlock_irqrestore(&ds1511_lock, flags);
261
262 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
263 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
264 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
265 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
266 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
267 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
268 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
269 century = bcd2bin(century) * 100;
270
271 /*
272 * Account for differences between how the RTC uses the values
273 * and how they are defined in a struct rtc_time;
274 */
275 century += rtc_tm->tm_year;
276 rtc_tm->tm_year = century - 1900;
277
278 rtc_tm->tm_mon--;
279
280 if (rtc_valid_tm(rtc_tm) < 0) {
281 dev_err(dev, "retrieved date/time is not valid.\n");
282 rtc_time_to_tm(0, rtc_tm);
283 }
284 return 0;
285 }
286
287 /*
288 * write the alarm register settings
289 *
290 * we only have the use to interrupt every second, otherwise
291 * known as the update interrupt, or the interrupt if the whole
292 * date/hours/mins/secs matches. the ds1511 has many more
293 * permutations, but the kernel doesn't.
294 */
295 static void
296 ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
297 {
298 unsigned long flags;
299
300 spin_lock_irqsave(&pdata->lock, flags);
301 rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
302 0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
303 RTC_ALARM_DATE);
304 rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
305 0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
306 RTC_ALARM_HOUR);
307 rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
308 0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
309 RTC_ALARM_MIN);
310 rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
311 0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
312 RTC_ALARM_SEC);
313 rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
314 rtc_read(RTC_CMD1); /* clear interrupts */
315 spin_unlock_irqrestore(&pdata->lock, flags);
316 }
317
318 static int
319 ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
320 {
321 struct platform_device *pdev = to_platform_device(dev);
322 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
323
324 if (pdata->irq <= 0)
325 return -EINVAL;
326
327 pdata->alrm_mday = alrm->time.tm_mday;
328 pdata->alrm_hour = alrm->time.tm_hour;
329 pdata->alrm_min = alrm->time.tm_min;
330 pdata->alrm_sec = alrm->time.tm_sec;
331 if (alrm->enabled)
332 pdata->irqen |= RTC_AF;
333
334 ds1511_rtc_update_alarm(pdata);
335 return 0;
336 }
337
338 static int
339 ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
340 {
341 struct platform_device *pdev = to_platform_device(dev);
342 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
343
344 if (pdata->irq <= 0)
345 return -EINVAL;
346
347 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
348 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
349 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
350 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
351 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
352 return 0;
353 }
354
355 static irqreturn_t
356 ds1511_interrupt(int irq, void *dev_id)
357 {
358 struct platform_device *pdev = dev_id;
359 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
360 unsigned long events = 0;
361
362 spin_lock(&pdata->lock);
363 /*
364 * read and clear interrupt
365 */
366 if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
367 events = RTC_IRQF;
368 if (rtc_read(RTC_ALARM_SEC) & 0x80)
369 events |= RTC_UF;
370 else
371 events |= RTC_AF;
372 rtc_update_irq(pdata->rtc, 1, events);
373 }
374 spin_unlock(&pdata->lock);
375 return events ? IRQ_HANDLED : IRQ_NONE;
376 }
377
378 static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
379 {
380 struct platform_device *pdev = to_platform_device(dev);
381 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
382
383 if (pdata->irq <= 0)
384 return -EINVAL;
385 if (enabled)
386 pdata->irqen |= RTC_AF;
387 else
388 pdata->irqen &= ~RTC_AF;
389 ds1511_rtc_update_alarm(pdata);
390 return 0;
391 }
392
393 static const struct rtc_class_ops ds1511_rtc_ops = {
394 .read_time = ds1511_rtc_read_time,
395 .set_time = ds1511_rtc_set_time,
396 .read_alarm = ds1511_rtc_read_alarm,
397 .set_alarm = ds1511_rtc_set_alarm,
398 .alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
399 };
400
401 static int ds1511_nvram_read(void *priv, unsigned int pos, void *buf,
402 size_t size)
403 {
404 int i;
405
406 rtc_write(pos, DS1511_RAMADDR_LSB);
407 for (i = 0; i < size; i++)
408 *(char *)buf++ = rtc_read(DS1511_RAMDATA);
409
410 return 0;
411 }
412
413 static int ds1511_nvram_write(void *priv, unsigned int pos, void *buf,
414 size_t size)
415 {
416 int i;
417
418 rtc_write(pos, DS1511_RAMADDR_LSB);
419 for (i = 0; i < size; i++)
420 rtc_write(*(char *)buf++, DS1511_RAMDATA);
421
422 return 0;
423 }
424
425 static struct nvmem_config ds1511_nvmem_cfg = {
426 .name = "ds1511_nvram",
427 .word_size = 1,
428 .stride = 1,
429 .size = DS1511_RAM_MAX,
430 .reg_read = ds1511_nvram_read,
431 .reg_write = ds1511_nvram_write,
432 };
433
434 static int ds1511_rtc_probe(struct platform_device *pdev)
435 {
436 struct resource *res;
437 struct rtc_plat_data *pdata;
438 int ret = 0;
439
440 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
441 if (!pdata)
442 return -ENOMEM;
443
444 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
445 ds1511_base = devm_ioremap_resource(&pdev->dev, res);
446 if (IS_ERR(ds1511_base))
447 return PTR_ERR(ds1511_base);
448 pdata->ioaddr = ds1511_base;
449 pdata->irq = platform_get_irq(pdev, 0);
450
451 /*
452 * turn on the clock and the crystal, etc.
453 */
454 rtc_write(DS1511_BME, RTC_CMD);
455 rtc_write(0, RTC_CMD1);
456 /*
457 * clear the wdog counter
458 */
459 rtc_write(0, DS1511_WD_MSEC);
460 rtc_write(0, DS1511_WD_SEC);
461 /*
462 * start the clock
463 */
464 rtc_enable_update();
465
466 /*
467 * check for a dying bat-tree
468 */
469 if (rtc_read(RTC_CMD1) & DS1511_BLF1)
470 dev_warn(&pdev->dev, "voltage-low detected.\n");
471
472 spin_lock_init(&pdata->lock);
473 platform_set_drvdata(pdev, pdata);
474
475 pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
476 if (IS_ERR(pdata->rtc))
477 return PTR_ERR(pdata->rtc);
478
479 pdata->rtc->ops = &ds1511_rtc_ops;
480
481 ds1511_nvmem_cfg.priv = &pdev->dev;
482 pdata->rtc->nvmem_config = &ds1511_nvmem_cfg;
483 pdata->rtc->nvram_old_abi = true;
484
485 ret = rtc_register_device(pdata->rtc);
486 if (ret)
487 return ret;
488
489 /*
490 * if the platform has an interrupt in mind for this device,
491 * then by all means, set it
492 */
493 if (pdata->irq > 0) {
494 rtc_read(RTC_CMD1);
495 if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
496 IRQF_SHARED, pdev->name, pdev) < 0) {
497
498 dev_warn(&pdev->dev, "interrupt not available.\n");
499 pdata->irq = 0;
500 }
501 }
502
503 return 0;
504 }
505
506 /* work with hotplug and coldplug */
507 MODULE_ALIAS("platform:ds1511");
508
509 static struct platform_driver ds1511_rtc_driver = {
510 .probe = ds1511_rtc_probe,
511 .driver = {
512 .name = "ds1511",
513 },
514 };
515
516 module_platform_driver(ds1511_rtc_driver);
517
518 MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
519 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
520 MODULE_LICENSE("GPL");
Linux with added FPC-III support