clk: bcm: dvp: Add MODULE_DEVICE_TABLE()
[linux-2.6-microblaze.git] / drivers / rtc / rtc-ds1511.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * An rtc driver for the Dallas DS1511
4  *
5  * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
6  * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
7  *
8  * Real time clock driver for the Dallas 1511 chip, which also
9  * contains a watchdog timer.  There is a tiny amount of code that
10  * platform code could use to mess with the watchdog device a little
11  * bit, but not a full watchdog driver.
12  */
13
14 #include <linux/bcd.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/gfp.h>
18 #include <linux/delay.h>
19 #include <linux/interrupt.h>
20 #include <linux/rtc.h>
21 #include <linux/platform_device.h>
22 #include <linux/io.h>
23 #include <linux/module.h>
24
25 enum ds1511reg {
26         DS1511_SEC = 0x0,
27         DS1511_MIN = 0x1,
28         DS1511_HOUR = 0x2,
29         DS1511_DOW = 0x3,
30         DS1511_DOM = 0x4,
31         DS1511_MONTH = 0x5,
32         DS1511_YEAR = 0x6,
33         DS1511_CENTURY = 0x7,
34         DS1511_AM1_SEC = 0x8,
35         DS1511_AM2_MIN = 0x9,
36         DS1511_AM3_HOUR = 0xa,
37         DS1511_AM4_DATE = 0xb,
38         DS1511_WD_MSEC = 0xc,
39         DS1511_WD_SEC = 0xd,
40         DS1511_CONTROL_A = 0xe,
41         DS1511_CONTROL_B = 0xf,
42         DS1511_RAMADDR_LSB = 0x10,
43         DS1511_RAMDATA = 0x13
44 };
45
46 #define DS1511_BLF1     0x80
47 #define DS1511_BLF2     0x40
48 #define DS1511_PRS      0x20
49 #define DS1511_PAB      0x10
50 #define DS1511_TDF      0x08
51 #define DS1511_KSF      0x04
52 #define DS1511_WDF      0x02
53 #define DS1511_IRQF     0x01
54 #define DS1511_TE       0x80
55 #define DS1511_CS       0x40
56 #define DS1511_BME      0x20
57 #define DS1511_TPE      0x10
58 #define DS1511_TIE      0x08
59 #define DS1511_KIE      0x04
60 #define DS1511_WDE      0x02
61 #define DS1511_WDS      0x01
62 #define DS1511_RAM_MAX  0x100
63
64 #define RTC_CMD         DS1511_CONTROL_B
65 #define RTC_CMD1        DS1511_CONTROL_A
66
67 #define RTC_ALARM_SEC   DS1511_AM1_SEC
68 #define RTC_ALARM_MIN   DS1511_AM2_MIN
69 #define RTC_ALARM_HOUR  DS1511_AM3_HOUR
70 #define RTC_ALARM_DATE  DS1511_AM4_DATE
71
72 #define RTC_SEC         DS1511_SEC
73 #define RTC_MIN         DS1511_MIN
74 #define RTC_HOUR        DS1511_HOUR
75 #define RTC_DOW         DS1511_DOW
76 #define RTC_DOM         DS1511_DOM
77 #define RTC_MON         DS1511_MONTH
78 #define RTC_YEAR        DS1511_YEAR
79 #define RTC_CENTURY     DS1511_CENTURY
80
81 #define RTC_TIE DS1511_TIE
82 #define RTC_TE  DS1511_TE
83
84 struct rtc_plat_data {
85         struct rtc_device *rtc;
86         void __iomem *ioaddr;           /* virtual base address */
87         int irq;
88         unsigned int irqen;
89         int alrm_sec;
90         int alrm_min;
91         int alrm_hour;
92         int alrm_mday;
93         spinlock_t lock;
94 };
95
96 static DEFINE_SPINLOCK(ds1511_lock);
97
98 static __iomem char *ds1511_base;
99 static u32 reg_spacing = 1;
100
101 static noinline void
102 rtc_write(uint8_t val, uint32_t reg)
103 {
104         writeb(val, ds1511_base + (reg * reg_spacing));
105 }
106
107 static inline void
108 rtc_write_alarm(uint8_t val, enum ds1511reg reg)
109 {
110         rtc_write((val | 0x80), reg);
111 }
112
113 static noinline uint8_t
114 rtc_read(enum ds1511reg reg)
115 {
116         return readb(ds1511_base + (reg * reg_spacing));
117 }
118
119 static inline void
120 rtc_disable_update(void)
121 {
122         rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
123 }
124
125 static void
126 rtc_enable_update(void)
127 {
128         rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD);
129 }
130
131 /*
132  * #define DS1511_WDOG_RESET_SUPPORT
133  *
134  * Uncomment this if you want to use these routines in
135  * some platform code.
136  */
137 #ifdef DS1511_WDOG_RESET_SUPPORT
138 /*
139  * just enough code to set the watchdog timer so that it
140  * will reboot the system
141  */
142 void
143 ds1511_wdog_set(unsigned long deciseconds)
144 {
145         /*
146          * the wdog timer can take 99.99 seconds
147          */
148         deciseconds %= 10000;
149         /*
150          * set the wdog values in the wdog registers
151          */
152         rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
153         rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
154         /*
155          * set wdog enable and wdog 'steering' bit to issue a reset
156          */
157         rtc_write(rtc_read(RTC_CMD) | DS1511_WDE | DS1511_WDS, RTC_CMD);
158 }
159
160 void
161 ds1511_wdog_disable(void)
162 {
163         /*
164          * clear wdog enable and wdog 'steering' bits
165          */
166         rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD);
167         /*
168          * clear the wdog counter
169          */
170         rtc_write(0, DS1511_WD_MSEC);
171         rtc_write(0, DS1511_WD_SEC);
172 }
173 #endif
174
175 /*
176  * set the rtc chip's idea of the time.
177  * stupidly, some callers call with year unmolested;
178  * and some call with  year = year - 1900.  thanks.
179  */
180 static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
181 {
182         u8 mon, day, dow, hrs, min, sec, yrs, cen;
183         unsigned long flags;
184
185         /*
186          * won't have to change this for a while
187          */
188         if (rtc_tm->tm_year < 1900)
189                 rtc_tm->tm_year += 1900;
190
191         if (rtc_tm->tm_year < 1970)
192                 return -EINVAL;
193
194         yrs = rtc_tm->tm_year % 100;
195         cen = rtc_tm->tm_year / 100;
196         mon = rtc_tm->tm_mon + 1;   /* tm_mon starts at zero */
197         day = rtc_tm->tm_mday;
198         dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
199         hrs = rtc_tm->tm_hour;
200         min = rtc_tm->tm_min;
201         sec = rtc_tm->tm_sec;
202
203         if ((mon > 12) || (day == 0))
204                 return -EINVAL;
205
206         if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year))
207                 return -EINVAL;
208
209         if ((hrs >= 24) || (min >= 60) || (sec >= 60))
210                 return -EINVAL;
211
212         /*
213          * each register is a different number of valid bits
214          */
215         sec = bin2bcd(sec) & 0x7f;
216         min = bin2bcd(min) & 0x7f;
217         hrs = bin2bcd(hrs) & 0x3f;
218         day = bin2bcd(day) & 0x3f;
219         mon = bin2bcd(mon) & 0x1f;
220         yrs = bin2bcd(yrs) & 0xff;
221         cen = bin2bcd(cen) & 0xff;
222
223         spin_lock_irqsave(&ds1511_lock, flags);
224         rtc_disable_update();
225         rtc_write(cen, RTC_CENTURY);
226         rtc_write(yrs, RTC_YEAR);
227         rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON);
228         rtc_write(day, RTC_DOM);
229         rtc_write(hrs, RTC_HOUR);
230         rtc_write(min, RTC_MIN);
231         rtc_write(sec, RTC_SEC);
232         rtc_write(dow, RTC_DOW);
233         rtc_enable_update();
234         spin_unlock_irqrestore(&ds1511_lock, flags);
235
236         return 0;
237 }
238
239 static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
240 {
241         unsigned int century;
242         unsigned long flags;
243
244         spin_lock_irqsave(&ds1511_lock, flags);
245         rtc_disable_update();
246
247         rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
248         rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
249         rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
250         rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
251         rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
252         rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
253         rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
254         century = rtc_read(RTC_CENTURY);
255
256         rtc_enable_update();
257         spin_unlock_irqrestore(&ds1511_lock, flags);
258
259         rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
260         rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
261         rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
262         rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
263         rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
264         rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
265         rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
266         century = bcd2bin(century) * 100;
267
268         /*
269          * Account for differences between how the RTC uses the values
270          * and how they are defined in a struct rtc_time;
271          */
272         century += rtc_tm->tm_year;
273         rtc_tm->tm_year = century - 1900;
274
275         rtc_tm->tm_mon--;
276
277         return 0;
278 }
279
280 /*
281  * write the alarm register settings
282  *
283  * we only have the use to interrupt every second, otherwise
284  * known as the update interrupt, or the interrupt if the whole
285  * date/hours/mins/secs matches.  the ds1511 has many more
286  * permutations, but the kernel doesn't.
287  */
288 static void
289 ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
290 {
291         unsigned long flags;
292
293         spin_lock_irqsave(&pdata->lock, flags);
294         rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
295                0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
296                RTC_ALARM_DATE);
297         rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
298                0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
299                RTC_ALARM_HOUR);
300         rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
301                0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
302                RTC_ALARM_MIN);
303         rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
304                0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
305                RTC_ALARM_SEC);
306         rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
307         rtc_read(RTC_CMD1);     /* clear interrupts */
308         spin_unlock_irqrestore(&pdata->lock, flags);
309 }
310
311 static int
312 ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
313 {
314         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
315
316         if (pdata->irq <= 0)
317                 return -EINVAL;
318
319         pdata->alrm_mday = alrm->time.tm_mday;
320         pdata->alrm_hour = alrm->time.tm_hour;
321         pdata->alrm_min = alrm->time.tm_min;
322         pdata->alrm_sec = alrm->time.tm_sec;
323         if (alrm->enabled)
324                 pdata->irqen |= RTC_AF;
325
326         ds1511_rtc_update_alarm(pdata);
327         return 0;
328 }
329
330 static int
331 ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
332 {
333         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
334
335         if (pdata->irq <= 0)
336                 return -EINVAL;
337
338         alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
339         alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
340         alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
341         alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
342         alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
343         return 0;
344 }
345
346 static irqreturn_t
347 ds1511_interrupt(int irq, void *dev_id)
348 {
349         struct platform_device *pdev = dev_id;
350         struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
351         unsigned long events = 0;
352
353         spin_lock(&pdata->lock);
354         /*
355          * read and clear interrupt
356          */
357         if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
358                 events = RTC_IRQF;
359                 if (rtc_read(RTC_ALARM_SEC) & 0x80)
360                         events |= RTC_UF;
361                 else
362                         events |= RTC_AF;
363                 rtc_update_irq(pdata->rtc, 1, events);
364         }
365         spin_unlock(&pdata->lock);
366         return events ? IRQ_HANDLED : IRQ_NONE;
367 }
368
369 static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
370 {
371         struct rtc_plat_data *pdata = dev_get_drvdata(dev);
372
373         if (pdata->irq <= 0)
374                 return -EINVAL;
375         if (enabled)
376                 pdata->irqen |= RTC_AF;
377         else
378                 pdata->irqen &= ~RTC_AF;
379         ds1511_rtc_update_alarm(pdata);
380         return 0;
381 }
382
383 static const struct rtc_class_ops ds1511_rtc_ops = {
384         .read_time              = ds1511_rtc_read_time,
385         .set_time               = ds1511_rtc_set_time,
386         .read_alarm             = ds1511_rtc_read_alarm,
387         .set_alarm              = ds1511_rtc_set_alarm,
388         .alarm_irq_enable       = ds1511_rtc_alarm_irq_enable,
389 };
390
391 static int ds1511_nvram_read(void *priv, unsigned int pos, void *buf,
392                              size_t size)
393 {
394         int i;
395
396         rtc_write(pos, DS1511_RAMADDR_LSB);
397         for (i = 0; i < size; i++)
398                 *(char *)buf++ = rtc_read(DS1511_RAMDATA);
399
400         return 0;
401 }
402
403 static int ds1511_nvram_write(void *priv, unsigned int pos, void *buf,
404                               size_t size)
405 {
406         int i;
407
408         rtc_write(pos, DS1511_RAMADDR_LSB);
409         for (i = 0; i < size; i++)
410                 rtc_write(*(char *)buf++, DS1511_RAMDATA);
411
412         return 0;
413 }
414
415 static int ds1511_rtc_probe(struct platform_device *pdev)
416 {
417         struct rtc_plat_data *pdata;
418         int ret = 0;
419         struct nvmem_config ds1511_nvmem_cfg = {
420                 .name = "ds1511_nvram",
421                 .word_size = 1,
422                 .stride = 1,
423                 .size = DS1511_RAM_MAX,
424                 .reg_read = ds1511_nvram_read,
425                 .reg_write = ds1511_nvram_write,
426                 .priv = &pdev->dev,
427         };
428
429         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
430         if (!pdata)
431                 return -ENOMEM;
432
433         ds1511_base = devm_platform_ioremap_resource(pdev, 0);
434         if (IS_ERR(ds1511_base))
435                 return PTR_ERR(ds1511_base);
436         pdata->ioaddr = ds1511_base;
437         pdata->irq = platform_get_irq(pdev, 0);
438
439         /*
440          * turn on the clock and the crystal, etc.
441          */
442         rtc_write(DS1511_BME, RTC_CMD);
443         rtc_write(0, RTC_CMD1);
444         /*
445          * clear the wdog counter
446          */
447         rtc_write(0, DS1511_WD_MSEC);
448         rtc_write(0, DS1511_WD_SEC);
449         /*
450          * start the clock
451          */
452         rtc_enable_update();
453
454         /*
455          * check for a dying bat-tree
456          */
457         if (rtc_read(RTC_CMD1) & DS1511_BLF1)
458                 dev_warn(&pdev->dev, "voltage-low detected.\n");
459
460         spin_lock_init(&pdata->lock);
461         platform_set_drvdata(pdev, pdata);
462
463         pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
464         if (IS_ERR(pdata->rtc))
465                 return PTR_ERR(pdata->rtc);
466
467         pdata->rtc->ops = &ds1511_rtc_ops;
468
469         pdata->rtc->nvram_old_abi = true;
470
471         ret = rtc_register_device(pdata->rtc);
472         if (ret)
473                 return ret;
474
475         rtc_nvmem_register(pdata->rtc, &ds1511_nvmem_cfg);
476
477         /*
478          * if the platform has an interrupt in mind for this device,
479          * then by all means, set it
480          */
481         if (pdata->irq > 0) {
482                 rtc_read(RTC_CMD1);
483                 if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
484                         IRQF_SHARED, pdev->name, pdev) < 0) {
485
486                         dev_warn(&pdev->dev, "interrupt not available.\n");
487                         pdata->irq = 0;
488                 }
489         }
490
491         return 0;
492 }
493
494 /* work with hotplug and coldplug */
495 MODULE_ALIAS("platform:ds1511");
496
497 static struct platform_driver ds1511_rtc_driver = {
498         .probe          = ds1511_rtc_probe,
499         .driver         = {
500                 .name   = "ds1511",
501         },
502 };
503
504 module_platform_driver(ds1511_rtc_driver);
505
506 MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
507 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
508 MODULE_LICENSE("GPL");