Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / drivers / rtc / rtc-wm8350.c
1 /*
2  *      Real Time Clock driver for Wolfson Microelectronics WM8350
3  *
4  *      Copyright (C) 2007, 2008 Wolfson Microelectronics PLC.
5  *
6  *  Author: Liam Girdwood
7  *          linux@wolfsonmicro.com
8  *
9  *  This program is free software; you can redistribute  it and/or modify it
10  *  under  the terms of  the GNU General  Public License as published by the
11  *  Free Software Foundation;  either version 2 of the  License, or (at your
12  *  option) any later version.
13  *
14  */
15
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/time.h>
19 #include <linux/rtc.h>
20 #include <linux/bcd.h>
21 #include <linux/interrupt.h>
22 #include <linux/ioctl.h>
23 #include <linux/completion.h>
24 #include <linux/mfd/wm8350/rtc.h>
25 #include <linux/mfd/wm8350/core.h>
26 #include <linux/delay.h>
27 #include <linux/platform_device.h>
28
29 #define WM8350_SET_ALM_RETRIES  5
30 #define WM8350_SET_TIME_RETRIES 5
31 #define WM8350_GET_TIME_RETRIES 5
32
33 #define to_wm8350_from_rtc_dev(d) container_of(d, struct wm8350, rtc.pdev.dev)
34
35 /*
36  * Read current time and date in RTC
37  */
38 static int wm8350_rtc_readtime(struct device *dev, struct rtc_time *tm)
39 {
40         struct wm8350 *wm8350 = dev_get_drvdata(dev);
41         u16 time1[4], time2[4];
42         int retries = WM8350_GET_TIME_RETRIES, ret;
43
44         /*
45          * Read the time twice and compare.
46          * If time1 == time2, then time is valid else retry.
47          */
48         do {
49                 ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
50                                         4, time1);
51                 if (ret < 0)
52                         return ret;
53                 ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
54                                         4, time2);
55                 if (ret < 0)
56                         return ret;
57
58                 if (memcmp(time1, time2, sizeof(time1)) == 0) {
59                         tm->tm_sec = time1[0] & WM8350_RTC_SECS_MASK;
60
61                         tm->tm_min = (time1[0] & WM8350_RTC_MINS_MASK)
62                             >> WM8350_RTC_MINS_SHIFT;
63
64                         tm->tm_hour = time1[1] & WM8350_RTC_HRS_MASK;
65
66                         tm->tm_wday = ((time1[1] >> WM8350_RTC_DAY_SHIFT)
67                                        & 0x7) - 1;
68
69                         tm->tm_mon = ((time1[2] & WM8350_RTC_MTH_MASK)
70                                       >> WM8350_RTC_MTH_SHIFT) - 1;
71
72                         tm->tm_mday = (time1[2] & WM8350_RTC_DATE_MASK);
73
74                         tm->tm_year = ((time1[3] & WM8350_RTC_YHUNDREDS_MASK)
75                                        >> WM8350_RTC_YHUNDREDS_SHIFT) * 100;
76                         tm->tm_year += time1[3] & WM8350_RTC_YUNITS_MASK;
77
78                         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,
79                                                     tm->tm_year);
80                         tm->tm_year -= 1900;
81
82                         dev_dbg(dev, "Read (%d left): %04x %04x %04x %04x\n",
83                                 retries,
84                                 time1[0], time1[1], time1[2], time1[3]);
85
86                         return 0;
87                 }
88         } while (retries--);
89
90         dev_err(dev, "timed out reading RTC time\n");
91         return -EIO;
92 }
93
94 /*
95  * Set current time and date in RTC
96  */
97 static int wm8350_rtc_settime(struct device *dev, struct rtc_time *tm)
98 {
99         struct wm8350 *wm8350 = dev_get_drvdata(dev);
100         u16 time[4];
101         u16 rtc_ctrl;
102         int ret, retries = WM8350_SET_TIME_RETRIES;
103
104         time[0] = tm->tm_sec;
105         time[0] |= tm->tm_min << WM8350_RTC_MINS_SHIFT;
106         time[1] = tm->tm_hour;
107         time[1] |= (tm->tm_wday + 1) << WM8350_RTC_DAY_SHIFT;
108         time[2] = tm->tm_mday;
109         time[2] |= (tm->tm_mon + 1) << WM8350_RTC_MTH_SHIFT;
110         time[3] = ((tm->tm_year + 1900) / 100) << WM8350_RTC_YHUNDREDS_SHIFT;
111         time[3] |= (tm->tm_year + 1900) % 100;
112
113         dev_dbg(dev, "Setting: %04x %04x %04x %04x\n",
114                 time[0], time[1], time[2], time[3]);
115
116         /* Set RTC_SET to stop the clock */
117         ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, WM8350_RTC_SET);
118         if (ret < 0)
119                 return ret;
120
121         /* Wait until confirmation of stopping */
122         do {
123                 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
124                 schedule_timeout_uninterruptible(msecs_to_jiffies(1));
125         } while (--retries && !(rtc_ctrl & WM8350_RTC_STS));
126
127         if (!retries) {
128                 dev_err(dev, "timed out on set confirmation\n");
129                 return -EIO;
130         }
131
132         /* Write time to RTC */
133         ret = wm8350_block_write(wm8350, WM8350_RTC_SECONDS_MINUTES, 4, time);
134         if (ret < 0)
135                 return ret;
136
137         /* Clear RTC_SET to start the clock */
138         ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
139                                 WM8350_RTC_SET);
140         return ret;
141 }
142
143 /*
144  * Read alarm time and date in RTC
145  */
146 static int wm8350_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
147 {
148         struct wm8350 *wm8350 = dev_get_drvdata(dev);
149         struct rtc_time *tm = &alrm->time;
150         u16 time[4];
151         int ret;
152
153         ret = wm8350_block_read(wm8350, WM8350_ALARM_SECONDS_MINUTES, 4, time);
154         if (ret < 0)
155                 return ret;
156
157         tm->tm_sec = time[0] & WM8350_RTC_ALMSECS_MASK;
158         if (tm->tm_sec == WM8350_RTC_ALMSECS_MASK)
159                 tm->tm_sec = -1;
160
161         tm->tm_min = time[0] & WM8350_RTC_ALMMINS_MASK;
162         if (tm->tm_min == WM8350_RTC_ALMMINS_MASK)
163                 tm->tm_min = -1;
164         else
165                 tm->tm_min >>= WM8350_RTC_ALMMINS_SHIFT;
166
167         tm->tm_hour = time[1] & WM8350_RTC_ALMHRS_MASK;
168         if (tm->tm_hour == WM8350_RTC_ALMHRS_MASK)
169                 tm->tm_hour = -1;
170
171         tm->tm_wday = ((time[1] >> WM8350_RTC_ALMDAY_SHIFT) & 0x7) - 1;
172         if (tm->tm_wday > 7)
173                 tm->tm_wday = -1;
174
175         tm->tm_mon = time[2] & WM8350_RTC_ALMMTH_MASK;
176         if (tm->tm_mon == WM8350_RTC_ALMMTH_MASK)
177                 tm->tm_mon = -1;
178         else
179                 tm->tm_mon = (tm->tm_mon >> WM8350_RTC_ALMMTH_SHIFT) - 1;
180
181         tm->tm_mday = (time[2] & WM8350_RTC_ALMDATE_MASK);
182         if (tm->tm_mday == WM8350_RTC_ALMDATE_MASK)
183                 tm->tm_mday = -1;
184
185         tm->tm_year = -1;
186
187         alrm->enabled = !(time[3] & WM8350_RTC_ALMSTS);
188
189         return 0;
190 }
191
192 static int wm8350_rtc_stop_alarm(struct wm8350 *wm8350)
193 {
194         int retries = WM8350_SET_ALM_RETRIES;
195         u16 rtc_ctrl;
196         int ret;
197
198         /* Set RTC_SET to stop the clock */
199         ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
200                               WM8350_RTC_ALMSET);
201         if (ret < 0)
202                 return ret;
203
204         /* Wait until confirmation of stopping */
205         do {
206                 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
207                 schedule_timeout_uninterruptible(msecs_to_jiffies(1));
208         } while (retries-- && !(rtc_ctrl & WM8350_RTC_ALMSTS));
209
210         if (!(rtc_ctrl & WM8350_RTC_ALMSTS))
211                 return -ETIMEDOUT;
212
213         return 0;
214 }
215
216 static int wm8350_rtc_start_alarm(struct wm8350 *wm8350)
217 {
218         int ret;
219         int retries = WM8350_SET_ALM_RETRIES;
220         u16 rtc_ctrl;
221
222         ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
223                                 WM8350_RTC_ALMSET);
224         if (ret < 0)
225                 return ret;
226
227         /* Wait until confirmation */
228         do {
229                 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
230                 schedule_timeout_uninterruptible(msecs_to_jiffies(1));
231         } while (retries-- && rtc_ctrl & WM8350_RTC_ALMSTS);
232
233         if (rtc_ctrl & WM8350_RTC_ALMSTS)
234                 return -ETIMEDOUT;
235
236         return 0;
237 }
238
239 static int wm8350_rtc_alarm_irq_enable(struct device *dev,
240                                        unsigned int enabled)
241 {
242         struct wm8350 *wm8350 = dev_get_drvdata(dev);
243
244         if (enabled)
245                 return wm8350_rtc_start_alarm(wm8350);
246         else
247                 return wm8350_rtc_stop_alarm(wm8350);
248 }
249
250 static int wm8350_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
251 {
252         struct wm8350 *wm8350 = dev_get_drvdata(dev);
253         struct rtc_time *tm = &alrm->time;
254         u16 time[3];
255         int ret;
256
257         memset(time, 0, sizeof(time));
258
259         if (tm->tm_sec != -1)
260                 time[0] |= tm->tm_sec;
261         else
262                 time[0] |= WM8350_RTC_ALMSECS_MASK;
263
264         if (tm->tm_min != -1)
265                 time[0] |= tm->tm_min << WM8350_RTC_ALMMINS_SHIFT;
266         else
267                 time[0] |= WM8350_RTC_ALMMINS_MASK;
268
269         if (tm->tm_hour != -1)
270                 time[1] |= tm->tm_hour;
271         else
272                 time[1] |= WM8350_RTC_ALMHRS_MASK;
273
274         if (tm->tm_wday != -1)
275                 time[1] |= (tm->tm_wday + 1) << WM8350_RTC_ALMDAY_SHIFT;
276         else
277                 time[1] |= WM8350_RTC_ALMDAY_MASK;
278
279         if (tm->tm_mday != -1)
280                 time[2] |= tm->tm_mday;
281         else
282                 time[2] |= WM8350_RTC_ALMDATE_MASK;
283
284         if (tm->tm_mon != -1)
285                 time[2] |= (tm->tm_mon + 1) << WM8350_RTC_ALMMTH_SHIFT;
286         else
287                 time[2] |= WM8350_RTC_ALMMTH_MASK;
288
289         ret = wm8350_rtc_stop_alarm(wm8350);
290         if (ret < 0)
291                 return ret;
292
293         /* Write time to RTC */
294         ret = wm8350_block_write(wm8350, WM8350_ALARM_SECONDS_MINUTES,
295                                  3, time);
296         if (ret < 0)
297                 return ret;
298
299         if (alrm->enabled)
300                 ret = wm8350_rtc_start_alarm(wm8350);
301
302         return ret;
303 }
304
305 static int wm8350_rtc_update_irq_enable(struct device *dev,
306                                         unsigned int enabled)
307 {
308         struct wm8350 *wm8350 = dev_get_drvdata(dev);
309
310         /* Suppress duplicate changes since genirq nests enable and
311          * disable calls. */
312         if (enabled == wm8350->rtc.update_enabled)
313                 return 0;
314
315         if (enabled)
316                 wm8350_unmask_irq(wm8350, WM8350_IRQ_RTC_SEC);
317         else
318                 wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC);
319
320         wm8350->rtc.update_enabled = enabled;
321
322         return 0;
323 }
324
325 static irqreturn_t wm8350_rtc_alarm_handler(int irq, void *data)
326 {
327         struct wm8350 *wm8350 = data;
328         struct rtc_device *rtc = wm8350->rtc.rtc;
329         int ret;
330
331         rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
332
333         /* Make it one shot */
334         ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
335                               WM8350_RTC_ALMSET);
336         if (ret != 0) {
337                 dev_err(&(wm8350->rtc.pdev->dev),
338                         "Failed to disable alarm: %d\n", ret);
339         }
340
341         return IRQ_HANDLED;
342 }
343
344 static irqreturn_t wm8350_rtc_update_handler(int irq, void *data)
345 {
346         struct wm8350 *wm8350 = data;
347         struct rtc_device *rtc = wm8350->rtc.rtc;
348
349         rtc_update_irq(rtc, 1, RTC_IRQF | RTC_UF);
350
351         return IRQ_HANDLED;
352 }
353
354 static const struct rtc_class_ops wm8350_rtc_ops = {
355         .read_time = wm8350_rtc_readtime,
356         .set_time = wm8350_rtc_settime,
357         .read_alarm = wm8350_rtc_readalarm,
358         .set_alarm = wm8350_rtc_setalarm,
359         .alarm_irq_enable = wm8350_rtc_alarm_irq_enable,
360         .update_irq_enable = wm8350_rtc_update_irq_enable,
361 };
362
363 #ifdef CONFIG_PM
364 static int wm8350_rtc_suspend(struct device *dev)
365 {
366         struct platform_device *pdev = to_platform_device(dev);
367         struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev);
368         int ret = 0;
369         u16 reg;
370
371         reg = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
372
373         if (device_may_wakeup(&wm8350->rtc.pdev->dev) &&
374             reg & WM8350_RTC_ALMSTS) {
375                 ret = wm8350_rtc_stop_alarm(wm8350);
376                 if (ret != 0)
377                         dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n",
378                                 ret);
379         }
380
381         return ret;
382 }
383
384 static int wm8350_rtc_resume(struct device *dev)
385 {
386         struct platform_device *pdev = to_platform_device(dev);
387         struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev);
388         int ret;
389
390         if (wm8350->rtc.alarm_enabled) {
391                 ret = wm8350_rtc_start_alarm(wm8350);
392                 if (ret != 0)
393                         dev_err(&pdev->dev,
394                                 "Failed to restart RTC alarm: %d\n", ret);
395         }
396
397         return 0;
398 }
399
400 #else
401 #define wm8350_rtc_suspend NULL
402 #define wm8350_rtc_resume NULL
403 #endif
404
405 static int wm8350_rtc_probe(struct platform_device *pdev)
406 {
407         struct wm8350 *wm8350 = platform_get_drvdata(pdev);
408         struct wm8350_rtc *wm_rtc = &wm8350->rtc;
409         int ret = 0;
410         u16 timectl, power5;
411
412         timectl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
413         if (timectl & WM8350_RTC_BCD) {
414                 dev_err(&pdev->dev, "RTC BCD mode not supported\n");
415                 return -EINVAL;
416         }
417         if (timectl & WM8350_RTC_12HR) {
418                 dev_err(&pdev->dev, "RTC 12 hour mode not supported\n");
419                 return -EINVAL;
420         }
421
422         /* enable the RTC if it's not already enabled */
423         power5 = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);
424         if (!(power5 &  WM8350_RTC_TICK_ENA)) {
425                 dev_info(wm8350->dev, "Starting RTC\n");
426
427                 wm8350_reg_unlock(wm8350);
428
429                 ret = wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5,
430                                       WM8350_RTC_TICK_ENA);
431                 if (ret < 0) {
432                         dev_err(&pdev->dev, "failed to enable RTC: %d\n", ret);
433                         return ret;
434                 }
435
436                 wm8350_reg_lock(wm8350);
437         }
438
439         if (timectl & WM8350_RTC_STS) {
440                 int retries;
441
442                 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
443                                         WM8350_RTC_SET);
444                 if (ret < 0) {
445                         dev_err(&pdev->dev, "failed to start: %d\n", ret);
446                         return ret;
447                 }
448
449                 retries = WM8350_SET_TIME_RETRIES;
450                 do {
451                         timectl = wm8350_reg_read(wm8350,
452                                                   WM8350_RTC_TIME_CONTROL);
453                 } while (timectl & WM8350_RTC_STS && --retries);
454
455                 if (retries == 0) {
456                         dev_err(&pdev->dev, "failed to start: timeout\n");
457                         return -ENODEV;
458                 }
459         }
460
461         device_init_wakeup(&pdev->dev, 1);
462
463         wm_rtc->rtc = rtc_device_register("wm8350", &pdev->dev,
464                                           &wm8350_rtc_ops, THIS_MODULE);
465         if (IS_ERR(wm_rtc->rtc)) {
466                 ret = PTR_ERR(wm_rtc->rtc);
467                 dev_err(&pdev->dev, "failed to register RTC: %d\n", ret);
468                 return ret;
469         }
470
471         wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC,
472                             wm8350_rtc_update_handler, 0,
473                             "RTC Seconds", wm8350);
474         wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC);
475
476         wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM,
477                             wm8350_rtc_alarm_handler, 0,
478                             "RTC Alarm", wm8350);
479
480         return 0;
481 }
482
483 static int __devexit wm8350_rtc_remove(struct platform_device *pdev)
484 {
485         struct wm8350 *wm8350 = platform_get_drvdata(pdev);
486         struct wm8350_rtc *wm_rtc = &wm8350->rtc;
487
488         wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);
489         wm8350_free_irq(wm8350, WM8350_IRQ_RTC_ALM, wm8350);
490
491         rtc_device_unregister(wm_rtc->rtc);
492
493         return 0;
494 }
495
496 static struct dev_pm_ops wm8350_rtc_pm_ops = {
497         .suspend = wm8350_rtc_suspend,
498         .resume = wm8350_rtc_resume,
499 };
500
501 static struct platform_driver wm8350_rtc_driver = {
502         .probe = wm8350_rtc_probe,
503         .remove = __devexit_p(wm8350_rtc_remove),
504         .driver = {
505                 .name = "wm8350-rtc",
506                 .pm = &wm8350_rtc_pm_ops,
507         },
508 };
509
510 static int __init wm8350_rtc_init(void)
511 {
512         return platform_driver_register(&wm8350_rtc_driver);
513 }
514 module_init(wm8350_rtc_init);
515
516 static void __exit wm8350_rtc_exit(void)
517 {
518         platform_driver_unregister(&wm8350_rtc_driver);
519 }
520 module_exit(wm8350_rtc_exit);
521
522 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
523 MODULE_DESCRIPTION("RTC driver for the WM8350");
524 MODULE_LICENSE("GPL");
525 MODULE_ALIAS("platform:wm8350-rtc");