rtc-m48t59 driver NO_IRQ mode fixup
[linux-2.6.git] / drivers / rtc / rtc-omap.c
1 /*
2  * TI OMAP1 Real Time Clock interface for Linux
3  *
4  * Copyright (C) 2003 MontaVista Software, Inc.
5  * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
6  *
7  * Copyright (C) 2006 David Brownell (new RTC framework)
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/ioport.h>
19 #include <linux/delay.h>
20 #include <linux/rtc.h>
21 #include <linux/bcd.h>
22 #include <linux/platform_device.h>
23
24 #include <asm/io.h>
25 #include <asm/mach/time.h>
26
27
28 /* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
29  * with century-range alarm matching, driven by the 32kHz clock.
30  *
31  * The main user-visible ways it differs from PC RTCs are by omitting
32  * "don't care" alarm fields and sub-second periodic IRQs, and having
33  * an autoadjust mechanism to calibrate to the true oscillator rate.
34  *
35  * Board-specific wiring options include using split power mode with
36  * RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
37  * and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
38  * low power modes).  See the BOARD-SPECIFIC CUSTOMIZATION comment.
39  */
40
41 #define OMAP_RTC_BASE                   0xfffb4800
42
43 /* RTC registers */
44 #define OMAP_RTC_SECONDS_REG            0x00
45 #define OMAP_RTC_MINUTES_REG            0x04
46 #define OMAP_RTC_HOURS_REG              0x08
47 #define OMAP_RTC_DAYS_REG               0x0C
48 #define OMAP_RTC_MONTHS_REG             0x10
49 #define OMAP_RTC_YEARS_REG              0x14
50 #define OMAP_RTC_WEEKS_REG              0x18
51
52 #define OMAP_RTC_ALARM_SECONDS_REG      0x20
53 #define OMAP_RTC_ALARM_MINUTES_REG      0x24
54 #define OMAP_RTC_ALARM_HOURS_REG        0x28
55 #define OMAP_RTC_ALARM_DAYS_REG         0x2c
56 #define OMAP_RTC_ALARM_MONTHS_REG       0x30
57 #define OMAP_RTC_ALARM_YEARS_REG        0x34
58
59 #define OMAP_RTC_CTRL_REG               0x40
60 #define OMAP_RTC_STATUS_REG             0x44
61 #define OMAP_RTC_INTERRUPTS_REG         0x48
62
63 #define OMAP_RTC_COMP_LSB_REG           0x4c
64 #define OMAP_RTC_COMP_MSB_REG           0x50
65 #define OMAP_RTC_OSC_REG                0x54
66
67 /* OMAP_RTC_CTRL_REG bit fields: */
68 #define OMAP_RTC_CTRL_SPLIT             (1<<7)
69 #define OMAP_RTC_CTRL_DISABLE           (1<<6)
70 #define OMAP_RTC_CTRL_SET_32_COUNTER    (1<<5)
71 #define OMAP_RTC_CTRL_TEST              (1<<4)
72 #define OMAP_RTC_CTRL_MODE_12_24        (1<<3)
73 #define OMAP_RTC_CTRL_AUTO_COMP         (1<<2)
74 #define OMAP_RTC_CTRL_ROUND_30S         (1<<1)
75 #define OMAP_RTC_CTRL_STOP              (1<<0)
76
77 /* OMAP_RTC_STATUS_REG bit fields: */
78 #define OMAP_RTC_STATUS_POWER_UP        (1<<7)
79 #define OMAP_RTC_STATUS_ALARM           (1<<6)
80 #define OMAP_RTC_STATUS_1D_EVENT        (1<<5)
81 #define OMAP_RTC_STATUS_1H_EVENT        (1<<4)
82 #define OMAP_RTC_STATUS_1M_EVENT        (1<<3)
83 #define OMAP_RTC_STATUS_1S_EVENT        (1<<2)
84 #define OMAP_RTC_STATUS_RUN             (1<<1)
85 #define OMAP_RTC_STATUS_BUSY            (1<<0)
86
87 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
88 #define OMAP_RTC_INTERRUPTS_IT_ALARM    (1<<3)
89 #define OMAP_RTC_INTERRUPTS_IT_TIMER    (1<<2)
90
91
92 #define rtc_read(addr)          omap_readb(OMAP_RTC_BASE + (addr))
93 #define rtc_write(val, addr)    omap_writeb(val, OMAP_RTC_BASE + (addr))
94
95
96 /* platform_bus isn't hotpluggable, so for static linkage it'd be safe
97  * to get rid of probe() and remove() code ... too bad the driver struct
98  * remembers probe(), that's about 25% of the runtime footprint!!
99  */
100 #ifndef MODULE
101 #undef  __devexit
102 #undef  __devexit_p
103 #define __devexit       __exit
104 #define __devexit_p     __exit_p
105 #endif
106
107
108 /* we rely on the rtc framework to handle locking (rtc->ops_lock),
109  * so the only other requirement is that register accesses which
110  * require BUSY to be clear are made with IRQs locally disabled
111  */
112 static void rtc_wait_not_busy(void)
113 {
114         int     count = 0;
115         u8      status;
116
117         /* BUSY may stay active for 1/32768 second (~30 usec) */
118         for (count = 0; count < 50; count++) {
119                 status = rtc_read(OMAP_RTC_STATUS_REG);
120                 if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
121                         break;
122                 udelay(1);
123         }
124         /* now we have ~15 usec to read/write various registers */
125 }
126
127 static irqreturn_t rtc_irq(int irq, void *rtc)
128 {
129         unsigned long           events = 0;
130         u8                      irq_data;
131
132         irq_data = rtc_read(OMAP_RTC_STATUS_REG);
133
134         /* alarm irq? */
135         if (irq_data & OMAP_RTC_STATUS_ALARM) {
136                 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
137                 events |= RTC_IRQF | RTC_AF;
138         }
139
140         /* 1/sec periodic/update irq? */
141         if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
142                 events |= RTC_IRQF | RTC_UF;
143
144         rtc_update_irq(rtc, 1, events);
145
146         return IRQ_HANDLED;
147 }
148
149 #ifdef  CONFIG_RTC_INTF_DEV
150
151 static int
152 omap_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
153 {
154         u8 reg;
155
156         switch (cmd) {
157         case RTC_AIE_OFF:
158         case RTC_AIE_ON:
159         case RTC_UIE_OFF:
160         case RTC_UIE_ON:
161                 break;
162         default:
163                 return -ENOIOCTLCMD;
164         }
165
166         local_irq_disable();
167         rtc_wait_not_busy();
168         reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
169         switch (cmd) {
170         /* AIE = Alarm Interrupt Enable */
171         case RTC_AIE_OFF:
172                 reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
173                 break;
174         case RTC_AIE_ON:
175                 reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
176                 break;
177         /* UIE = Update Interrupt Enable (1/second) */
178         case RTC_UIE_OFF:
179                 reg &= ~OMAP_RTC_INTERRUPTS_IT_TIMER;
180                 break;
181         case RTC_UIE_ON:
182                 reg |= OMAP_RTC_INTERRUPTS_IT_TIMER;
183                 break;
184         }
185         rtc_wait_not_busy();
186         rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
187         local_irq_enable();
188
189         return 0;
190 }
191
192 #else
193 #define omap_rtc_ioctl  NULL
194 #endif
195
196 /* this hardware doesn't support "don't care" alarm fields */
197 static int tm2bcd(struct rtc_time *tm)
198 {
199         if (rtc_valid_tm(tm) != 0)
200                 return -EINVAL;
201
202         tm->tm_sec = BIN2BCD(tm->tm_sec);
203         tm->tm_min = BIN2BCD(tm->tm_min);
204         tm->tm_hour = BIN2BCD(tm->tm_hour);
205         tm->tm_mday = BIN2BCD(tm->tm_mday);
206
207         tm->tm_mon = BIN2BCD(tm->tm_mon + 1);
208
209         /* epoch == 1900 */
210         if (tm->tm_year < 100 || tm->tm_year > 199)
211                 return -EINVAL;
212         tm->tm_year = BIN2BCD(tm->tm_year - 100);
213
214         return 0;
215 }
216
217 static void bcd2tm(struct rtc_time *tm)
218 {
219         tm->tm_sec = BCD2BIN(tm->tm_sec);
220         tm->tm_min = BCD2BIN(tm->tm_min);
221         tm->tm_hour = BCD2BIN(tm->tm_hour);
222         tm->tm_mday = BCD2BIN(tm->tm_mday);
223         tm->tm_mon = BCD2BIN(tm->tm_mon) - 1;
224         /* epoch == 1900 */
225         tm->tm_year = BCD2BIN(tm->tm_year) + 100;
226 }
227
228
229 static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
230 {
231         /* we don't report wday/yday/isdst ... */
232         local_irq_disable();
233         rtc_wait_not_busy();
234
235         tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
236         tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
237         tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
238         tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
239         tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
240         tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
241
242         local_irq_enable();
243
244         bcd2tm(tm);
245         return 0;
246 }
247
248 static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
249 {
250         if (tm2bcd(tm) < 0)
251                 return -EINVAL;
252         local_irq_disable();
253         rtc_wait_not_busy();
254
255         rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
256         rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
257         rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
258         rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
259         rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
260         rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
261
262         local_irq_enable();
263
264         return 0;
265 }
266
267 static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
268 {
269         local_irq_disable();
270         rtc_wait_not_busy();
271
272         alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
273         alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
274         alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
275         alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
276         alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
277         alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
278
279         local_irq_enable();
280
281         bcd2tm(&alm->time);
282         alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
283                         & OMAP_RTC_INTERRUPTS_IT_ALARM);
284
285         return 0;
286 }
287
288 static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
289 {
290         u8 reg;
291
292         if (tm2bcd(&alm->time) < 0)
293                 return -EINVAL;
294
295         local_irq_disable();
296         rtc_wait_not_busy();
297
298         rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
299         rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
300         rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
301         rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
302         rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
303         rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
304
305         reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
306         if (alm->enabled)
307                 reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
308         else
309                 reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
310         rtc_write(reg, OMAP_RTC_INTERRUPTS_REG);
311
312         local_irq_enable();
313
314         return 0;
315 }
316
317 static struct rtc_class_ops omap_rtc_ops = {
318         .ioctl          = omap_rtc_ioctl,
319         .read_time      = omap_rtc_read_time,
320         .set_time       = omap_rtc_set_time,
321         .read_alarm     = omap_rtc_read_alarm,
322         .set_alarm      = omap_rtc_set_alarm,
323 };
324
325 static int omap_rtc_alarm;
326 static int omap_rtc_timer;
327
328 static int __devinit omap_rtc_probe(struct platform_device *pdev)
329 {
330         struct resource         *res, *mem;
331         struct rtc_device       *rtc;
332         u8                      reg, new_ctrl;
333
334         omap_rtc_timer = platform_get_irq(pdev, 0);
335         if (omap_rtc_timer <= 0) {
336                 pr_debug("%s: no update irq?\n", pdev->name);
337                 return -ENOENT;
338         }
339
340         omap_rtc_alarm = platform_get_irq(pdev, 1);
341         if (omap_rtc_alarm <= 0) {
342                 pr_debug("%s: no alarm irq?\n", pdev->name);
343                 return -ENOENT;
344         }
345
346         /* NOTE:  using static mapping for RTC registers */
347         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
348         if (res && res->start != OMAP_RTC_BASE) {
349                 pr_debug("%s: RTC registers at %08x, expected %08x\n",
350                         pdev->name, (unsigned) res->start, OMAP_RTC_BASE);
351                 return -ENOENT;
352         }
353
354         if (res)
355                 mem = request_mem_region(res->start,
356                                 res->end - res->start + 1,
357                                 pdev->name);
358         else
359                 mem = NULL;
360         if (!mem) {
361                 pr_debug("%s: RTC registers at %08x are not free\n",
362                         pdev->name, OMAP_RTC_BASE);
363                 return -EBUSY;
364         }
365
366         rtc = rtc_device_register(pdev->name, &pdev->dev,
367                         &omap_rtc_ops, THIS_MODULE);
368         if (IS_ERR(rtc)) {
369                 pr_debug("%s: can't register RTC device, err %ld\n",
370                         pdev->name, PTR_ERR(rtc));
371                 goto fail;
372         }
373         platform_set_drvdata(pdev, rtc);
374         dev_set_drvdata(&rtc->dev, mem);
375
376         /* clear pending irqs, and set 1/second periodic,
377          * which we'll use instead of update irqs
378          */
379         rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
380
381         /* clear old status */
382         reg = rtc_read(OMAP_RTC_STATUS_REG);
383         if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
384                 pr_info("%s: RTC power up reset detected\n",
385                         pdev->name);
386                 rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
387         }
388         if (reg & (u8) OMAP_RTC_STATUS_ALARM)
389                 rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
390
391         /* handle periodic and alarm irqs */
392         if (request_irq(omap_rtc_timer, rtc_irq, IRQF_DISABLED,
393                         rtc->dev.bus_id, rtc)) {
394                 pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
395                         pdev->name, omap_rtc_timer);
396                 goto fail0;
397         }
398         if (request_irq(omap_rtc_alarm, rtc_irq, IRQF_DISABLED,
399                         rtc->dev.bus_id, rtc)) {
400                 pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
401                         pdev->name, omap_rtc_alarm);
402                 goto fail1;
403         }
404
405         /* On boards with split power, RTC_ON_NOFF won't reset the RTC */
406         reg = rtc_read(OMAP_RTC_CTRL_REG);
407         if (reg & (u8) OMAP_RTC_CTRL_STOP)
408                 pr_info("%s: already running\n", pdev->name);
409
410         /* force to 24 hour mode */
411         new_ctrl = reg & ~(OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
412         new_ctrl |= OMAP_RTC_CTRL_STOP;
413
414         /* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
415          *
416          *  - Boards wired so that RTC_WAKE_INT does something, and muxed
417          *    right (W13_1610_RTC_WAKE_INT is the default after chip reset),
418          *    should initialize the device wakeup flag appropriately.
419          *
420          *  - Boards wired so RTC_ON_nOFF is used as the reset signal,
421          *    rather than nPWRON_RESET, should forcibly enable split
422          *    power mode.  (Some chip errata report that RTC_CTRL_SPLIT
423          *    is write-only, and always reads as zero...)
424          */
425         device_init_wakeup(&pdev->dev, 0);
426
427         if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
428                 pr_info("%s: split power mode\n", pdev->name);
429
430         if (reg != new_ctrl)
431                 rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
432
433         return 0;
434
435 fail1:
436         free_irq(omap_rtc_timer, NULL);
437 fail0:
438         rtc_device_unregister(rtc);
439 fail:
440         release_resource(mem);
441         return -EIO;
442 }
443
444 static int __devexit omap_rtc_remove(struct platform_device *pdev)
445 {
446         struct rtc_device       *rtc = platform_get_drvdata(pdev);;
447
448         device_init_wakeup(&pdev->dev, 0);
449
450         /* leave rtc running, but disable irqs */
451         rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
452
453         free_irq(omap_rtc_timer, rtc);
454         free_irq(omap_rtc_alarm, rtc);
455
456         release_resource(dev_get_drvdata(&rtc->dev));
457         rtc_device_unregister(rtc);
458         return 0;
459 }
460
461 #ifdef CONFIG_PM
462
463 static u8 irqstat;
464
465 static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
466 {
467         irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
468
469         /* FIXME the RTC alarm is not currently acting as a wakeup event
470          * source, and in fact this enable() call is just saving a flag
471          * that's never used...
472          */
473         if (device_may_wakeup(&pdev->dev))
474                 enable_irq_wake(omap_rtc_alarm);
475         else
476                 rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
477
478         return 0;
479 }
480
481 static int omap_rtc_resume(struct platform_device *pdev)
482 {
483         if (device_may_wakeup(&pdev->dev))
484                 disable_irq_wake(omap_rtc_alarm);
485         else
486                 rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
487         return 0;
488 }
489
490 #else
491 #define omap_rtc_suspend NULL
492 #define omap_rtc_resume  NULL
493 #endif
494
495 static void omap_rtc_shutdown(struct platform_device *pdev)
496 {
497         rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
498 }
499
500 MODULE_ALIAS("omap_rtc");
501 static struct platform_driver omap_rtc_driver = {
502         .probe          = omap_rtc_probe,
503         .remove         = __devexit_p(omap_rtc_remove),
504         .suspend        = omap_rtc_suspend,
505         .resume         = omap_rtc_resume,
506         .shutdown       = omap_rtc_shutdown,
507         .driver         = {
508                 .name   = "omap_rtc",
509                 .owner  = THIS_MODULE,
510         },
511 };
512
513 static int __init rtc_init(void)
514 {
515         return platform_driver_register(&omap_rtc_driver);
516 }
517 module_init(rtc_init);
518
519 static void __exit rtc_exit(void)
520 {
521         platform_driver_unregister(&omap_rtc_driver);
522 }
523 module_exit(rtc_exit);
524
525 MODULE_AUTHOR("George G. Davis (and others)");
526 MODULE_LICENSE("GPL");