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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 */
37enum {
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};
60static 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};
83static 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/*----------------------------------------------------------------------*/
135static u8 *rtc_reg_map;
136
137/*
138 * Supports 1 byte read from TWL RTC register.
139 */
140static 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 */
154static 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 */
169static unsigned char rtc_irq_bits;
170
171/*
172 * Enable 1/second update and/or alarm interrupts.
173 */
174static 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 */
191static 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
204static 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 */
225static 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
259static 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
294out:
295 return ret;
296}
297
298/*
299 * Gets current TWL RTC alarm time.
300 */
301static 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
328static 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);
354out:
355 return ret;
356}
357
358static 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;
406out:
407 return ret;
408}
409
410static 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
420static 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
490out2:
491 rtc_device_unregister(rtc);
492out1:
493 return ret;
494}
495
496/*
497 * Disable all TWL RTC module interrupts.
498 * Sets status flag to free.
499 */
500static 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
523static 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
532static unsigned char irqstat;
533
534static 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
542static 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
553MODULE_ALIAS("platform:twl_rtc");
554
555static 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
567static 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}
576module_init(twl_rtc_init);
577
578static void __exit twl_rtc_exit(void)
579{
580 platform_driver_unregister(&twl4030rtc_driver);
581}
582module_exit(twl_rtc_exit);
583
584MODULE_AUTHOR("Texas Instruments, MontaVista Software");
585MODULE_LICENSE("GPL");
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/kernel.h>
24#include <linux/errno.h>
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/types.h>
28#include <linux/rtc.h>
29#include <linux/bcd.h>
30#include <linux/platform_device.h>
31#include <linux/interrupt.h>
32#include <linux/of.h>
33
34#include <linux/i2c/twl.h>
35
36
37/*
38 * RTC block register offsets (use TWL_MODULE_RTC)
39 */
40enum {
41 REG_SECONDS_REG = 0,
42 REG_MINUTES_REG,
43 REG_HOURS_REG,
44 REG_DAYS_REG,
45 REG_MONTHS_REG,
46 REG_YEARS_REG,
47 REG_WEEKS_REG,
48
49 REG_ALARM_SECONDS_REG,
50 REG_ALARM_MINUTES_REG,
51 REG_ALARM_HOURS_REG,
52 REG_ALARM_DAYS_REG,
53 REG_ALARM_MONTHS_REG,
54 REG_ALARM_YEARS_REG,
55
56 REG_RTC_CTRL_REG,
57 REG_RTC_STATUS_REG,
58 REG_RTC_INTERRUPTS_REG,
59
60 REG_RTC_COMP_LSB_REG,
61 REG_RTC_COMP_MSB_REG,
62};
63static const u8 twl4030_rtc_reg_map[] = {
64 [REG_SECONDS_REG] = 0x00,
65 [REG_MINUTES_REG] = 0x01,
66 [REG_HOURS_REG] = 0x02,
67 [REG_DAYS_REG] = 0x03,
68 [REG_MONTHS_REG] = 0x04,
69 [REG_YEARS_REG] = 0x05,
70 [REG_WEEKS_REG] = 0x06,
71
72 [REG_ALARM_SECONDS_REG] = 0x07,
73 [REG_ALARM_MINUTES_REG] = 0x08,
74 [REG_ALARM_HOURS_REG] = 0x09,
75 [REG_ALARM_DAYS_REG] = 0x0A,
76 [REG_ALARM_MONTHS_REG] = 0x0B,
77 [REG_ALARM_YEARS_REG] = 0x0C,
78
79 [REG_RTC_CTRL_REG] = 0x0D,
80 [REG_RTC_STATUS_REG] = 0x0E,
81 [REG_RTC_INTERRUPTS_REG] = 0x0F,
82
83 [REG_RTC_COMP_LSB_REG] = 0x10,
84 [REG_RTC_COMP_MSB_REG] = 0x11,
85};
86static const u8 twl6030_rtc_reg_map[] = {
87 [REG_SECONDS_REG] = 0x00,
88 [REG_MINUTES_REG] = 0x01,
89 [REG_HOURS_REG] = 0x02,
90 [REG_DAYS_REG] = 0x03,
91 [REG_MONTHS_REG] = 0x04,
92 [REG_YEARS_REG] = 0x05,
93 [REG_WEEKS_REG] = 0x06,
94
95 [REG_ALARM_SECONDS_REG] = 0x08,
96 [REG_ALARM_MINUTES_REG] = 0x09,
97 [REG_ALARM_HOURS_REG] = 0x0A,
98 [REG_ALARM_DAYS_REG] = 0x0B,
99 [REG_ALARM_MONTHS_REG] = 0x0C,
100 [REG_ALARM_YEARS_REG] = 0x0D,
101
102 [REG_RTC_CTRL_REG] = 0x10,
103 [REG_RTC_STATUS_REG] = 0x11,
104 [REG_RTC_INTERRUPTS_REG] = 0x12,
105
106 [REG_RTC_COMP_LSB_REG] = 0x13,
107 [REG_RTC_COMP_MSB_REG] = 0x14,
108};
109
110/* RTC_CTRL_REG bitfields */
111#define BIT_RTC_CTRL_REG_STOP_RTC_M 0x01
112#define BIT_RTC_CTRL_REG_ROUND_30S_M 0x02
113#define BIT_RTC_CTRL_REG_AUTO_COMP_M 0x04
114#define BIT_RTC_CTRL_REG_MODE_12_24_M 0x08
115#define BIT_RTC_CTRL_REG_TEST_MODE_M 0x10
116#define BIT_RTC_CTRL_REG_SET_32_COUNTER_M 0x20
117#define BIT_RTC_CTRL_REG_GET_TIME_M 0x40
118#define BIT_RTC_CTRL_REG_RTC_V_OPT 0x80
119
120/* RTC_STATUS_REG bitfields */
121#define BIT_RTC_STATUS_REG_RUN_M 0x02
122#define BIT_RTC_STATUS_REG_1S_EVENT_M 0x04
123#define BIT_RTC_STATUS_REG_1M_EVENT_M 0x08
124#define BIT_RTC_STATUS_REG_1H_EVENT_M 0x10
125#define BIT_RTC_STATUS_REG_1D_EVENT_M 0x20
126#define BIT_RTC_STATUS_REG_ALARM_M 0x40
127#define BIT_RTC_STATUS_REG_POWER_UP_M 0x80
128
129/* RTC_INTERRUPTS_REG bitfields */
130#define BIT_RTC_INTERRUPTS_REG_EVERY_M 0x03
131#define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M 0x04
132#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M 0x08
133
134
135/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
136#define ALL_TIME_REGS 6
137
138/*----------------------------------------------------------------------*/
139static u8 *rtc_reg_map;
140
141/*
142 * Supports 1 byte read from TWL RTC register.
143 */
144static int twl_rtc_read_u8(u8 *data, u8 reg)
145{
146 int ret;
147
148 ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg]));
149 if (ret < 0)
150 pr_err("Could not read TWL register %X - error %d\n", reg, ret);
151 return ret;
152}
153
154/*
155 * Supports 1 byte write to TWL RTC registers.
156 */
157static int twl_rtc_write_u8(u8 data, u8 reg)
158{
159 int ret;
160
161 ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg]));
162 if (ret < 0)
163 pr_err("Could not write TWL register %X - error %d\n",
164 reg, ret);
165 return ret;
166}
167
168/*
169 * Cache the value for timer/alarm interrupts register; this is
170 * only changed by callers holding rtc ops lock (or resume).
171 */
172static unsigned char rtc_irq_bits;
173
174/*
175 * Enable 1/second update and/or alarm interrupts.
176 */
177static int set_rtc_irq_bit(unsigned char bit)
178{
179 unsigned char val;
180 int ret;
181
182 /* if the bit is set, return from here */
183 if (rtc_irq_bits & bit)
184 return 0;
185
186 val = rtc_irq_bits | bit;
187 val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
188 ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
189 if (ret == 0)
190 rtc_irq_bits = val;
191
192 return ret;
193}
194
195/*
196 * Disable update and/or alarm interrupts.
197 */
198static int mask_rtc_irq_bit(unsigned char bit)
199{
200 unsigned char val;
201 int ret;
202
203 /* if the bit is clear, return from here */
204 if (!(rtc_irq_bits & bit))
205 return 0;
206
207 val = rtc_irq_bits & ~bit;
208 ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
209 if (ret == 0)
210 rtc_irq_bits = val;
211
212 return ret;
213}
214
215static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
216{
217 struct platform_device *pdev = to_platform_device(dev);
218 int irq = platform_get_irq(pdev, 0);
219 static bool twl_rtc_wake_enabled;
220 int ret;
221
222 if (enabled) {
223 ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
224 if (device_can_wakeup(dev) && !twl_rtc_wake_enabled) {
225 enable_irq_wake(irq);
226 twl_rtc_wake_enabled = true;
227 }
228 } else {
229 ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
230 if (twl_rtc_wake_enabled) {
231 disable_irq_wake(irq);
232 twl_rtc_wake_enabled = false;
233 }
234 }
235
236 return ret;
237}
238
239/*
240 * Gets current TWL RTC time and date parameters.
241 *
242 * The RTC's time/alarm representation is not what gmtime(3) requires
243 * Linux to use:
244 *
245 * - Months are 1..12 vs Linux 0-11
246 * - Years are 0..99 vs Linux 1900..N (we assume 21st century)
247 */
248static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
249{
250 unsigned char rtc_data[ALL_TIME_REGS];
251 int ret;
252 u8 save_control;
253 u8 rtc_control;
254
255 ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
256 if (ret < 0) {
257 dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret);
258 return ret;
259 }
260 /* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
261 if (twl_class_is_6030()) {
262 if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) {
263 save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M;
264 ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
265 if (ret < 0) {
266 dev_err(dev, "%s clr GET_TIME, error %d\n",
267 __func__, ret);
268 return ret;
269 }
270 }
271 }
272
273 /* Copy RTC counting registers to static registers or latches */
274 rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M;
275
276 /* for twl6030/32 enable read access to static shadowed registers */
277 if (twl_class_is_6030())
278 rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT;
279
280 ret = twl_rtc_write_u8(rtc_control, REG_RTC_CTRL_REG);
281 if (ret < 0) {
282 dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret);
283 return ret;
284 }
285
286 ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
287 (rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
288
289 if (ret < 0) {
290 dev_err(dev, "%s: reading data, error %d\n", __func__, ret);
291 return ret;
292 }
293
294 /* for twl6030 restore original state of rtc control register */
295 if (twl_class_is_6030()) {
296 ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
297 if (ret < 0) {
298 dev_err(dev, "%s: restore CTRL_REG, error %d\n",
299 __func__, ret);
300 return ret;
301 }
302 }
303
304 tm->tm_sec = bcd2bin(rtc_data[0]);
305 tm->tm_min = bcd2bin(rtc_data[1]);
306 tm->tm_hour = bcd2bin(rtc_data[2]);
307 tm->tm_mday = bcd2bin(rtc_data[3]);
308 tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
309 tm->tm_year = bcd2bin(rtc_data[5]) + 100;
310
311 return ret;
312}
313
314static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm)
315{
316 unsigned char save_control;
317 unsigned char rtc_data[ALL_TIME_REGS];
318 int ret;
319
320 rtc_data[0] = bin2bcd(tm->tm_sec);
321 rtc_data[1] = bin2bcd(tm->tm_min);
322 rtc_data[2] = bin2bcd(tm->tm_hour);
323 rtc_data[3] = bin2bcd(tm->tm_mday);
324 rtc_data[4] = bin2bcd(tm->tm_mon + 1);
325 rtc_data[5] = bin2bcd(tm->tm_year - 100);
326
327 /* Stop RTC while updating the TC registers */
328 ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
329 if (ret < 0)
330 goto out;
331
332 save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
333 ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
334 if (ret < 0)
335 goto out;
336
337 /* update all the time registers in one shot */
338 ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
339 (rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
340 if (ret < 0) {
341 dev_err(dev, "rtc_set_time error %d\n", ret);
342 goto out;
343 }
344
345 /* Start back RTC */
346 save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
347 ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
348
349out:
350 return ret;
351}
352
353/*
354 * Gets current TWL RTC alarm time.
355 */
356static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
357{
358 unsigned char rtc_data[ALL_TIME_REGS];
359 int ret;
360
361 ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
362 (rtc_reg_map[REG_ALARM_SECONDS_REG]), ALL_TIME_REGS);
363 if (ret < 0) {
364 dev_err(dev, "rtc_read_alarm error %d\n", ret);
365 return ret;
366 }
367
368 /* some of these fields may be wildcard/"match all" */
369 alm->time.tm_sec = bcd2bin(rtc_data[0]);
370 alm->time.tm_min = bcd2bin(rtc_data[1]);
371 alm->time.tm_hour = bcd2bin(rtc_data[2]);
372 alm->time.tm_mday = bcd2bin(rtc_data[3]);
373 alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
374 alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
375
376 /* report cached alarm enable state */
377 if (rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
378 alm->enabled = 1;
379
380 return ret;
381}
382
383static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
384{
385 unsigned char alarm_data[ALL_TIME_REGS];
386 int ret;
387
388 ret = twl_rtc_alarm_irq_enable(dev, 0);
389 if (ret)
390 goto out;
391
392 alarm_data[0] = bin2bcd(alm->time.tm_sec);
393 alarm_data[1] = bin2bcd(alm->time.tm_min);
394 alarm_data[2] = bin2bcd(alm->time.tm_hour);
395 alarm_data[3] = bin2bcd(alm->time.tm_mday);
396 alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
397 alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
398
399 /* update all the alarm registers in one shot */
400 ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
401 (rtc_reg_map[REG_ALARM_SECONDS_REG]), ALL_TIME_REGS);
402 if (ret) {
403 dev_err(dev, "rtc_set_alarm error %d\n", ret);
404 goto out;
405 }
406
407 if (alm->enabled)
408 ret = twl_rtc_alarm_irq_enable(dev, 1);
409out:
410 return ret;
411}
412
413static irqreturn_t twl_rtc_interrupt(int irq, void *rtc)
414{
415 unsigned long events;
416 int ret = IRQ_NONE;
417 int res;
418 u8 rd_reg;
419
420 res = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
421 if (res)
422 goto out;
423 /*
424 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
425 * only one (ALARM or RTC) interrupt source may be enabled
426 * at time, we also could check our results
427 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
428 */
429 if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
430 events = RTC_IRQF | RTC_AF;
431 else
432 events = RTC_IRQF | RTC_PF;
433
434 res = twl_rtc_write_u8(BIT_RTC_STATUS_REG_ALARM_M,
435 REG_RTC_STATUS_REG);
436 if (res)
437 goto out;
438
439 if (twl_class_is_4030()) {
440 /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
441 * needs 2 reads to clear the interrupt. One read is done in
442 * do_twl_pwrirq(). Doing the second read, to clear
443 * the bit.
444 *
445 * FIXME the reason PWR_ISR1 needs an extra read is that
446 * RTC_IF retriggered until we cleared REG_ALARM_M above.
447 * But re-reading like this is a bad hack; by doing so we
448 * risk wrongly clearing status for some other IRQ (losing
449 * the interrupt). Be smarter about handling RTC_UF ...
450 */
451 res = twl_i2c_read_u8(TWL4030_MODULE_INT,
452 &rd_reg, TWL4030_INT_PWR_ISR1);
453 if (res)
454 goto out;
455 }
456
457 /* Notify RTC core on event */
458 rtc_update_irq(rtc, 1, events);
459
460 ret = IRQ_HANDLED;
461out:
462 return ret;
463}
464
465static struct rtc_class_ops twl_rtc_ops = {
466 .read_time = twl_rtc_read_time,
467 .set_time = twl_rtc_set_time,
468 .read_alarm = twl_rtc_read_alarm,
469 .set_alarm = twl_rtc_set_alarm,
470 .alarm_irq_enable = twl_rtc_alarm_irq_enable,
471};
472
473/*----------------------------------------------------------------------*/
474
475static int twl_rtc_probe(struct platform_device *pdev)
476{
477 struct rtc_device *rtc;
478 int ret = -EINVAL;
479 int irq = platform_get_irq(pdev, 0);
480 u8 rd_reg;
481
482 if (irq <= 0)
483 return ret;
484
485 /* Initialize the register map */
486 if (twl_class_is_4030())
487 rtc_reg_map = (u8 *)twl4030_rtc_reg_map;
488 else
489 rtc_reg_map = (u8 *)twl6030_rtc_reg_map;
490
491 ret = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
492 if (ret < 0)
493 return ret;
494
495 if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
496 dev_warn(&pdev->dev, "Power up reset detected.\n");
497
498 if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
499 dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
500
501 /* Clear RTC Power up reset and pending alarm interrupts */
502 ret = twl_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
503 if (ret < 0)
504 return ret;
505
506 if (twl_class_is_6030()) {
507 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
508 REG_INT_MSK_LINE_A);
509 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
510 REG_INT_MSK_STS_A);
511 }
512
513 dev_info(&pdev->dev, "Enabling TWL-RTC\n");
514 ret = twl_rtc_write_u8(BIT_RTC_CTRL_REG_STOP_RTC_M, REG_RTC_CTRL_REG);
515 if (ret < 0)
516 return ret;
517
518 /* ensure interrupts are disabled, bootloaders can be strange */
519 ret = twl_rtc_write_u8(0, REG_RTC_INTERRUPTS_REG);
520 if (ret < 0)
521 dev_warn(&pdev->dev, "unable to disable interrupt\n");
522
523 /* init cached IRQ enable bits */
524 ret = twl_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG);
525 if (ret < 0)
526 return ret;
527
528 device_init_wakeup(&pdev->dev, 1);
529
530 rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
531 &twl_rtc_ops, THIS_MODULE);
532 if (IS_ERR(rtc)) {
533 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
534 PTR_ERR(rtc));
535 return PTR_ERR(rtc);
536 }
537
538 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
539 twl_rtc_interrupt,
540 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
541 dev_name(&rtc->dev), rtc);
542 if (ret < 0) {
543 dev_err(&pdev->dev, "IRQ is not free.\n");
544 return ret;
545 }
546
547 platform_set_drvdata(pdev, rtc);
548 return 0;
549}
550
551/*
552 * Disable all TWL RTC module interrupts.
553 * Sets status flag to free.
554 */
555static int twl_rtc_remove(struct platform_device *pdev)
556{
557 /* leave rtc running, but disable irqs */
558 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
559 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
560 if (twl_class_is_6030()) {
561 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
562 REG_INT_MSK_LINE_A);
563 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
564 REG_INT_MSK_STS_A);
565 }
566
567 return 0;
568}
569
570static void twl_rtc_shutdown(struct platform_device *pdev)
571{
572 /* mask timer interrupts, but leave alarm interrupts on to enable
573 power-on when alarm is triggered */
574 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
575}
576
577#ifdef CONFIG_PM_SLEEP
578static unsigned char irqstat;
579
580static int twl_rtc_suspend(struct device *dev)
581{
582 irqstat = rtc_irq_bits;
583
584 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
585 return 0;
586}
587
588static int twl_rtc_resume(struct device *dev)
589{
590 set_rtc_irq_bit(irqstat);
591 return 0;
592}
593#endif
594
595static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops, twl_rtc_suspend, twl_rtc_resume);
596
597#ifdef CONFIG_OF
598static const struct of_device_id twl_rtc_of_match[] = {
599 {.compatible = "ti,twl4030-rtc", },
600 { },
601};
602MODULE_DEVICE_TABLE(of, twl_rtc_of_match);
603#endif
604
605MODULE_ALIAS("platform:twl_rtc");
606
607static struct platform_driver twl4030rtc_driver = {
608 .probe = twl_rtc_probe,
609 .remove = twl_rtc_remove,
610 .shutdown = twl_rtc_shutdown,
611 .driver = {
612 .name = "twl_rtc",
613 .pm = &twl_rtc_pm_ops,
614 .of_match_table = of_match_ptr(twl_rtc_of_match),
615 },
616};
617
618module_platform_driver(twl4030rtc_driver);
619
620MODULE_AUTHOR("Texas Instruments, MontaVista Software");
621MODULE_LICENSE("GPL");