Merge branch 'fixes' of git://git.linaro.org/people/arnd/arm-soc
[pandora-kernel.git] / drivers / rtc / rtc-twl.c
1 /*
2  * rtc-twl.c -- TWL Real Time Clock interface
3  *
4  * Copyright (C) 2007 MontaVista Software, Inc
5  * Author: Alexandre Rusev <source@mvista.com>
6  *
7  * Based on original TI driver twl4030-rtc.c
8  *   Copyright (C) 2006 Texas Instruments, Inc.
9  *
10  * Based on rtc-omap.c
11  *   Copyright (C) 2003 MontaVista Software, Inc.
12  *   Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
13  *   Copyright (C) 2006 David Brownell
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License
17  * as published by the Free Software Foundation; either version
18  * 2 of the License, or (at your option) any later version.
19  */
20
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/rtc.h>
27 #include <linux/bcd.h>
28 #include <linux/platform_device.h>
29 #include <linux/interrupt.h>
30
31 #include <linux/i2c/twl.h>
32
33
34 /*
35  * RTC block register offsets (use TWL_MODULE_RTC)
36  */
37 enum {
38         REG_SECONDS_REG = 0,
39         REG_MINUTES_REG,
40         REG_HOURS_REG,
41         REG_DAYS_REG,
42         REG_MONTHS_REG,
43         REG_YEARS_REG,
44         REG_WEEKS_REG,
45
46         REG_ALARM_SECONDS_REG,
47         REG_ALARM_MINUTES_REG,
48         REG_ALARM_HOURS_REG,
49         REG_ALARM_DAYS_REG,
50         REG_ALARM_MONTHS_REG,
51         REG_ALARM_YEARS_REG,
52
53         REG_RTC_CTRL_REG,
54         REG_RTC_STATUS_REG,
55         REG_RTC_INTERRUPTS_REG,
56
57         REG_RTC_COMP_LSB_REG,
58         REG_RTC_COMP_MSB_REG,
59 };
60 static const u8 twl4030_rtc_reg_map[] = {
61         [REG_SECONDS_REG] = 0x00,
62         [REG_MINUTES_REG] = 0x01,
63         [REG_HOURS_REG] = 0x02,
64         [REG_DAYS_REG] = 0x03,
65         [REG_MONTHS_REG] = 0x04,
66         [REG_YEARS_REG] = 0x05,
67         [REG_WEEKS_REG] = 0x06,
68
69         [REG_ALARM_SECONDS_REG] = 0x07,
70         [REG_ALARM_MINUTES_REG] = 0x08,
71         [REG_ALARM_HOURS_REG] = 0x09,
72         [REG_ALARM_DAYS_REG] = 0x0A,
73         [REG_ALARM_MONTHS_REG] = 0x0B,
74         [REG_ALARM_YEARS_REG] = 0x0C,
75
76         [REG_RTC_CTRL_REG] = 0x0D,
77         [REG_RTC_STATUS_REG] = 0x0E,
78         [REG_RTC_INTERRUPTS_REG] = 0x0F,
79
80         [REG_RTC_COMP_LSB_REG] = 0x10,
81         [REG_RTC_COMP_MSB_REG] = 0x11,
82 };
83 static const u8 twl6030_rtc_reg_map[] = {
84         [REG_SECONDS_REG] = 0x00,
85         [REG_MINUTES_REG] = 0x01,
86         [REG_HOURS_REG] = 0x02,
87         [REG_DAYS_REG] = 0x03,
88         [REG_MONTHS_REG] = 0x04,
89         [REG_YEARS_REG] = 0x05,
90         [REG_WEEKS_REG] = 0x06,
91
92         [REG_ALARM_SECONDS_REG] = 0x08,
93         [REG_ALARM_MINUTES_REG] = 0x09,
94         [REG_ALARM_HOURS_REG] = 0x0A,
95         [REG_ALARM_DAYS_REG] = 0x0B,
96         [REG_ALARM_MONTHS_REG] = 0x0C,
97         [REG_ALARM_YEARS_REG] = 0x0D,
98
99         [REG_RTC_CTRL_REG] = 0x10,
100         [REG_RTC_STATUS_REG] = 0x11,
101         [REG_RTC_INTERRUPTS_REG] = 0x12,
102
103         [REG_RTC_COMP_LSB_REG] = 0x13,
104         [REG_RTC_COMP_MSB_REG] = 0x14,
105 };
106
107 /* RTC_CTRL_REG bitfields */
108 #define BIT_RTC_CTRL_REG_STOP_RTC_M              0x01
109 #define BIT_RTC_CTRL_REG_ROUND_30S_M             0x02
110 #define BIT_RTC_CTRL_REG_AUTO_COMP_M             0x04
111 #define BIT_RTC_CTRL_REG_MODE_12_24_M            0x08
112 #define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
113 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
114 #define BIT_RTC_CTRL_REG_GET_TIME_M              0x40
115
116 /* RTC_STATUS_REG bitfields */
117 #define BIT_RTC_STATUS_REG_RUN_M                 0x02
118 #define BIT_RTC_STATUS_REG_1S_EVENT_M            0x04
119 #define BIT_RTC_STATUS_REG_1M_EVENT_M            0x08
120 #define BIT_RTC_STATUS_REG_1H_EVENT_M            0x10
121 #define BIT_RTC_STATUS_REG_1D_EVENT_M            0x20
122 #define BIT_RTC_STATUS_REG_ALARM_M               0x40
123 #define BIT_RTC_STATUS_REG_POWER_UP_M            0x80
124
125 /* RTC_INTERRUPTS_REG bitfields */
126 #define BIT_RTC_INTERRUPTS_REG_EVERY_M           0x03
127 #define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M        0x04
128 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M        0x08
129
130
131 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
132 #define ALL_TIME_REGS           6
133
134 /*----------------------------------------------------------------------*/
135 static u8  *rtc_reg_map;
136
137 /*
138  * Supports 1 byte read from TWL RTC register.
139  */
140 static int twl_rtc_read_u8(u8 *data, u8 reg)
141 {
142         int ret;
143
144         ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg]));
145         if (ret < 0)
146                 pr_err("twl_rtc: Could not read TWL"
147                        "register %X - error %d\n", reg, ret);
148         return ret;
149 }
150
151 /*
152  * Supports 1 byte write to TWL RTC registers.
153  */
154 static int twl_rtc_write_u8(u8 data, u8 reg)
155 {
156         int ret;
157
158         ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg]));
159         if (ret < 0)
160                 pr_err("twl_rtc: Could not write TWL"
161                        "register %X - error %d\n", reg, ret);
162         return ret;
163 }
164
165 /*
166  * Cache the value for timer/alarm interrupts register; this is
167  * only changed by callers holding rtc ops lock (or resume).
168  */
169 static unsigned char rtc_irq_bits;
170
171 /*
172  * Enable 1/second update and/or alarm interrupts.
173  */
174 static int set_rtc_irq_bit(unsigned char bit)
175 {
176         unsigned char val;
177         int ret;
178
179         val = rtc_irq_bits | bit;
180         val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
181         ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
182         if (ret == 0)
183                 rtc_irq_bits = val;
184
185         return ret;
186 }
187
188 /*
189  * Disable update and/or alarm interrupts.
190  */
191 static int mask_rtc_irq_bit(unsigned char bit)
192 {
193         unsigned char val;
194         int ret;
195
196         val = rtc_irq_bits & ~bit;
197         ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
198         if (ret == 0)
199                 rtc_irq_bits = val;
200
201         return ret;
202 }
203
204 static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
205 {
206         int ret;
207
208         if (enabled)
209                 ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
210         else
211                 ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
212
213         return ret;
214 }
215
216 /*
217  * Gets current TWL RTC time and date parameters.
218  *
219  * The RTC's time/alarm representation is not what gmtime(3) requires
220  * Linux to use:
221  *
222  *  - Months are 1..12 vs Linux 0-11
223  *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
224  */
225 static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
226 {
227         unsigned char rtc_data[ALL_TIME_REGS + 1];
228         int ret;
229         u8 save_control;
230
231         ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
232         if (ret < 0)
233                 return ret;
234
235         save_control |= BIT_RTC_CTRL_REG_GET_TIME_M;
236
237         ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
238         if (ret < 0)
239                 return ret;
240
241         ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
242                         (rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
243
244         if (ret < 0) {
245                 dev_err(dev, "rtc_read_time error %d\n", ret);
246                 return ret;
247         }
248
249         tm->tm_sec = bcd2bin(rtc_data[0]);
250         tm->tm_min = bcd2bin(rtc_data[1]);
251         tm->tm_hour = bcd2bin(rtc_data[2]);
252         tm->tm_mday = bcd2bin(rtc_data[3]);
253         tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
254         tm->tm_year = bcd2bin(rtc_data[5]) + 100;
255
256         return ret;
257 }
258
259 static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm)
260 {
261         unsigned char save_control;
262         unsigned char rtc_data[ALL_TIME_REGS + 1];
263         int ret;
264
265         rtc_data[1] = bin2bcd(tm->tm_sec);
266         rtc_data[2] = bin2bcd(tm->tm_min);
267         rtc_data[3] = bin2bcd(tm->tm_hour);
268         rtc_data[4] = bin2bcd(tm->tm_mday);
269         rtc_data[5] = bin2bcd(tm->tm_mon + 1);
270         rtc_data[6] = bin2bcd(tm->tm_year - 100);
271
272         /* Stop RTC while updating the TC registers */
273         ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
274         if (ret < 0)
275                 goto out;
276
277         save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
278         ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
279         if (ret < 0)
280                 goto out;
281
282         /* update all the time registers in one shot */
283         ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
284                 (rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
285         if (ret < 0) {
286                 dev_err(dev, "rtc_set_time error %d\n", ret);
287                 goto out;
288         }
289
290         /* Start back RTC */
291         save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
292         ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
293
294 out:
295         return ret;
296 }
297
298 /*
299  * Gets current TWL RTC alarm time.
300  */
301 static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
302 {
303         unsigned char rtc_data[ALL_TIME_REGS + 1];
304         int ret;
305
306         ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
307                         (rtc_reg_map[REG_ALARM_SECONDS_REG]), ALL_TIME_REGS);
308         if (ret < 0) {
309                 dev_err(dev, "rtc_read_alarm error %d\n", ret);
310                 return ret;
311         }
312
313         /* some of these fields may be wildcard/"match all" */
314         alm->time.tm_sec = bcd2bin(rtc_data[0]);
315         alm->time.tm_min = bcd2bin(rtc_data[1]);
316         alm->time.tm_hour = bcd2bin(rtc_data[2]);
317         alm->time.tm_mday = bcd2bin(rtc_data[3]);
318         alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
319         alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
320
321         /* report cached alarm enable state */
322         if (rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
323                 alm->enabled = 1;
324
325         return ret;
326 }
327
328 static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
329 {
330         unsigned char alarm_data[ALL_TIME_REGS + 1];
331         int ret;
332
333         ret = twl_rtc_alarm_irq_enable(dev, 0);
334         if (ret)
335                 goto out;
336
337         alarm_data[1] = bin2bcd(alm->time.tm_sec);
338         alarm_data[2] = bin2bcd(alm->time.tm_min);
339         alarm_data[3] = bin2bcd(alm->time.tm_hour);
340         alarm_data[4] = bin2bcd(alm->time.tm_mday);
341         alarm_data[5] = bin2bcd(alm->time.tm_mon + 1);
342         alarm_data[6] = bin2bcd(alm->time.tm_year - 100);
343
344         /* update all the alarm registers in one shot */
345         ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
346                 (rtc_reg_map[REG_ALARM_SECONDS_REG]), ALL_TIME_REGS);
347         if (ret) {
348                 dev_err(dev, "rtc_set_alarm error %d\n", ret);
349                 goto out;
350         }
351
352         if (alm->enabled)
353                 ret = twl_rtc_alarm_irq_enable(dev, 1);
354 out:
355         return ret;
356 }
357
358 static irqreturn_t twl_rtc_interrupt(int irq, void *rtc)
359 {
360         unsigned long events = 0;
361         int ret = IRQ_NONE;
362         int res;
363         u8 rd_reg;
364
365         res = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
366         if (res)
367                 goto out;
368         /*
369          * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
370          * only one (ALARM or RTC) interrupt source may be enabled
371          * at time, we also could check our results
372          * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
373          */
374         if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
375                 events |= RTC_IRQF | RTC_AF;
376         else
377                 events |= RTC_IRQF | RTC_UF;
378
379         res = twl_rtc_write_u8(rd_reg | BIT_RTC_STATUS_REG_ALARM_M,
380                                    REG_RTC_STATUS_REG);
381         if (res)
382                 goto out;
383
384         if (twl_class_is_4030()) {
385                 /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
386                  * needs 2 reads to clear the interrupt. One read is done in
387                  * do_twl_pwrirq(). Doing the second read, to clear
388                  * the bit.
389                  *
390                  * FIXME the reason PWR_ISR1 needs an extra read is that
391                  * RTC_IF retriggered until we cleared REG_ALARM_M above.
392                  * But re-reading like this is a bad hack; by doing so we
393                  * risk wrongly clearing status for some other IRQ (losing
394                  * the interrupt).  Be smarter about handling RTC_UF ...
395                  */
396                 res = twl_i2c_read_u8(TWL4030_MODULE_INT,
397                         &rd_reg, TWL4030_INT_PWR_ISR1);
398                 if (res)
399                         goto out;
400         }
401
402         /* Notify RTC core on event */
403         rtc_update_irq(rtc, 1, events);
404
405         ret = IRQ_HANDLED;
406 out:
407         return ret;
408 }
409
410 static struct rtc_class_ops twl_rtc_ops = {
411         .read_time      = twl_rtc_read_time,
412         .set_time       = twl_rtc_set_time,
413         .read_alarm     = twl_rtc_read_alarm,
414         .set_alarm      = twl_rtc_set_alarm,
415         .alarm_irq_enable = twl_rtc_alarm_irq_enable,
416 };
417
418 /*----------------------------------------------------------------------*/
419
420 static int __devinit twl_rtc_probe(struct platform_device *pdev)
421 {
422         struct rtc_device *rtc;
423         int ret = -EINVAL;
424         int irq = platform_get_irq(pdev, 0);
425         u8 rd_reg;
426
427         if (irq <= 0)
428                 goto out1;
429
430         ret = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
431         if (ret < 0)
432                 goto out1;
433
434         if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
435                 dev_warn(&pdev->dev, "Power up reset detected.\n");
436
437         if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
438                 dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
439
440         /* Clear RTC Power up reset and pending alarm interrupts */
441         ret = twl_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
442         if (ret < 0)
443                 goto out1;
444
445         if (twl_class_is_6030()) {
446                 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
447                         REG_INT_MSK_LINE_A);
448                 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
449                         REG_INT_MSK_STS_A);
450         }
451
452         /* Check RTC module status, Enable if it is off */
453         ret = twl_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG);
454         if (ret < 0)
455                 goto out1;
456
457         if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) {
458                 dev_info(&pdev->dev, "Enabling TWL-RTC.\n");
459                 rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M;
460                 ret = twl_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG);
461                 if (ret < 0)
462                         goto out1;
463         }
464
465         /* init cached IRQ enable bits */
466         ret = twl_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG);
467         if (ret < 0)
468                 goto out1;
469
470         rtc = rtc_device_register(pdev->name,
471                                   &pdev->dev, &twl_rtc_ops, THIS_MODULE);
472         if (IS_ERR(rtc)) {
473                 ret = PTR_ERR(rtc);
474                 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
475                         PTR_ERR(rtc));
476                 goto out1;
477         }
478
479         ret = request_threaded_irq(irq, NULL, twl_rtc_interrupt,
480                                    IRQF_TRIGGER_RISING,
481                                    dev_name(&rtc->dev), rtc);
482         if (ret < 0) {
483                 dev_err(&pdev->dev, "IRQ is not free.\n");
484                 goto out2;
485         }
486
487         platform_set_drvdata(pdev, rtc);
488         return 0;
489
490 out2:
491         rtc_device_unregister(rtc);
492 out1:
493         return ret;
494 }
495
496 /*
497  * Disable all TWL RTC module interrupts.
498  * Sets status flag to free.
499  */
500 static int __devexit twl_rtc_remove(struct platform_device *pdev)
501 {
502         /* leave rtc running, but disable irqs */
503         struct rtc_device *rtc = platform_get_drvdata(pdev);
504         int irq = platform_get_irq(pdev, 0);
505
506         mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
507         mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
508         if (twl_class_is_6030()) {
509                 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
510                         REG_INT_MSK_LINE_A);
511                 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
512                         REG_INT_MSK_STS_A);
513         }
514
515
516         free_irq(irq, rtc);
517
518         rtc_device_unregister(rtc);
519         platform_set_drvdata(pdev, NULL);
520         return 0;
521 }
522
523 static void twl_rtc_shutdown(struct platform_device *pdev)
524 {
525         /* mask timer interrupts, but leave alarm interrupts on to enable
526            power-on when alarm is triggered */
527         mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
528 }
529
530 #ifdef CONFIG_PM
531
532 static unsigned char irqstat;
533
534 static int twl_rtc_suspend(struct platform_device *pdev, pm_message_t state)
535 {
536         irqstat = rtc_irq_bits;
537
538         mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
539         return 0;
540 }
541
542 static int twl_rtc_resume(struct platform_device *pdev)
543 {
544         set_rtc_irq_bit(irqstat);
545         return 0;
546 }
547
548 #else
549 #define twl_rtc_suspend NULL
550 #define twl_rtc_resume  NULL
551 #endif
552
553 MODULE_ALIAS("platform:twl_rtc");
554
555 static struct platform_driver twl4030rtc_driver = {
556         .probe          = twl_rtc_probe,
557         .remove         = __devexit_p(twl_rtc_remove),
558         .shutdown       = twl_rtc_shutdown,
559         .suspend        = twl_rtc_suspend,
560         .resume         = twl_rtc_resume,
561         .driver         = {
562                 .owner  = THIS_MODULE,
563                 .name   = "twl_rtc",
564         },
565 };
566
567 static int __init twl_rtc_init(void)
568 {
569         if (twl_class_is_4030())
570                 rtc_reg_map = (u8 *) twl4030_rtc_reg_map;
571         else
572                 rtc_reg_map = (u8 *) twl6030_rtc_reg_map;
573
574         return platform_driver_register(&twl4030rtc_driver);
575 }
576 module_init(twl_rtc_init);
577
578 static void __exit twl_rtc_exit(void)
579 {
580         platform_driver_unregister(&twl4030rtc_driver);
581 }
582 module_exit(twl_rtc_exit);
583
584 MODULE_AUTHOR("Texas Instruments, MontaVista Software");
585 MODULE_LICENSE("GPL");