rtc: tps6591x: Enable alarm interrupt for RTC_WKALM_SET ioctl
[linux-2.6.git] / drivers / rtc / rtc-tps6591x.c
1 /*
2  * drivers/rtc/rtc_tps6591x.c
3  *
4  * RTC driver for TI TPS6591x
5  *
6  * Copyright (c) 2011-2012, NVIDIA Corporation.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  *
18  * You should have received a copy of the GNU General Public License along
19  * with this program; if not, write to the Free Software Foundation, Inc.,
20  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
21  */
22
23 /* #define DEBUG                1 */
24 /* #define VERBOSE_DEBUG        1 */
25
26 #include <linux/device.h>
27 #include <linux/err.h>
28 #include <linux/init.h>
29 #include <linux/kernel.h>
30 #include <linux/mfd/tps6591x.h>
31 #include <linux/platform_device.h>
32 #include <linux/rtc.h>
33 #include <linux/slab.h>
34
35 #define RTC_CTRL                0x10
36 #define RTC_STATUS              0x11
37 #define RTC_SECONDS_REG         0x0
38 #define RTC_ALARM               0x8
39 #define RTC_INT                 0x12
40 #define RTC_RESET_STATUS        0x16
41 #define RTC_BBCH_REG            0x39
42
43 #define RTC_BBCH_SEL            0x02
44 #define RTC_BBCH_EN             0x01
45 #define ENABLE_ALARM_INT 0x8
46 #define RTC_RESET_VALUE 0x80
47 #define ALARM_INT_STATUS 0x40
48
49 /*
50 Linux RTC driver refers 1900 as base year in many calculations.
51 (e.g. refer drivers/rtc/rtc-lib.c)
52 */
53 #define OS_REF_YEAR 1900
54
55 /*
56         PMU RTC have only 2 nibbles to store year information, so using an offset
57         of 100 to set the base year as 2000 for our driver.
58 */
59 #define RTC_YEAR_OFFSET 100
60
61 struct tps6591x_rtc {
62         unsigned long           epoch_start;
63         int                     irq;
64         struct rtc_device       *rtc;
65         bool                    irq_en;
66 };
67
68 static int tps6591x_read_regs(struct device *dev, int reg, int len,
69         uint8_t *val)
70 {
71         int ret;
72
73         /* dummy read of STATUS_REG as per data sheet */
74         ret = tps6591x_reads(dev->parent, RTC_STATUS, 1, val);
75         if (ret < 0) {
76                 dev_err(dev->parent, "\n %s failed reading from RTC_STATUS\n",
77                         __func__);
78                 WARN_ON(1);
79                 return ret;
80         }
81
82         ret = tps6591x_reads(dev->parent, reg, len, val);
83         if (ret < 0) {
84                 dev_err(dev->parent, "\n %s failed reading from 0x%02x\n",
85                         __func__, reg);
86                 WARN_ON(1);
87                 return ret;
88         }
89         return 0;
90 }
91
92 static int tps6591x_write_regs(struct device *dev, int reg, int len,
93         uint8_t *val)
94 {
95         int ret;
96         ret = tps6591x_writes(dev->parent, reg, len, val);
97         if (ret < 0) {
98                 dev_err(dev->parent, "\n %s failed writing\n", __func__);
99                 WARN_ON(1);
100                 return ret;
101         }
102
103         return 0;
104 }
105
106 static int tps6591x_rtc_valid_tm(struct rtc_time *tm)
107 {
108         if (tm->tm_year >= (RTC_YEAR_OFFSET + 99)
109                 || tm->tm_mon >= 12
110                 || tm->tm_mday < 1
111                 || tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + OS_REF_YEAR)
112                 || tm->tm_hour >= 24
113                 || tm->tm_min >= 60
114                 || tm->tm_sec >= 60)
115                 return -EINVAL;
116         return 0;
117 }
118
119 static u8 dec2bcd(u8 dec)
120 {
121         return ((dec/10)<<4)+(dec%10);
122 }
123
124 static u8 bcd2dec(u8 bcd)
125 {
126         return (bcd >> 4)*10+(bcd & 0xF);
127 }
128
129 static void convert_bcd_to_decimal(u8 *buf, u8 len)
130 {
131         int i = 0;
132         for (i = 0; i < len; i++)
133                 buf[i] = bcd2dec(buf[i]);
134 }
135
136 static void convert_decimal_to_bcd(u8 *buf, u8 len)
137 {
138         int i = 0;
139         for (i = 0; i < len; i++)
140                 buf[i] = dec2bcd(buf[i]);
141 }
142
143 static void print_time(struct device *dev, struct rtc_time *tm)
144 {
145         dev_info(dev, "RTC Time : %d/%d/%d %d:%d:%d\n",
146                 (tm->tm_mon + 1), tm->tm_mday, (tm->tm_year + OS_REF_YEAR),
147                 tm->tm_hour, tm->tm_min , tm->tm_sec);
148 }
149
150 static int tps6591x_rtc_read_time(struct device *dev, struct rtc_time *tm)
151 {
152         u8 buff[7];
153         int err;
154         err = tps6591x_read_regs(dev, RTC_SECONDS_REG, sizeof(buff), buff);
155         if (err < 0) {
156                 dev_err(dev, "\n %s :: failed to read time\n", __FILE__);
157                 return err;
158         }
159         convert_bcd_to_decimal(buff, sizeof(buff));
160         tm->tm_sec = buff[0];
161         tm->tm_min = buff[1];
162         tm->tm_hour = buff[2];
163         tm->tm_mday = buff[3];
164         tm->tm_mon = buff[4] - 1;
165         tm->tm_year = buff[5];
166         tm->tm_wday = buff[6];
167         print_time(dev, tm);
168         return tps6591x_rtc_valid_tm(tm);
169 }
170
171 static int tps6591x_rtc_stop(struct device *dev)
172 {
173         u8 reg = 0;
174         u8 retries = 0;
175         int err;
176         do {
177                 err = tps6591x_read_regs(dev, RTC_CTRL, 1, &reg);
178                 if (err < 0) {
179                         dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
180                         return err;
181                 }
182
183                 /* clear STOP bit alone */
184                 reg &= ~0x1;
185
186                 err = tps6591x_write_regs(dev, RTC_CTRL, 1, &reg);
187                 if (err < 0) {
188                         dev_err(dev->parent, "\n failed to program RTC_CTRL reg\n");
189                         return err;
190                 }
191
192                 err = tps6591x_read_regs(dev, RTC_STATUS, 1, &reg);
193                 if (err < 0) {
194                         dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
195                         return err;
196                 }
197                 /* FixMe: Is allowing up to 5 retries sufficient?? */
198                 if (retries++ == 5) {
199                         dev_err(dev->parent, "\n failed to stop RTC\n");
200                         return -EBUSY;
201                 }
202         }       while (reg & 2);
203         return 0;
204 }
205
206 static int tps6591x_rtc_start(struct device *dev)
207 {
208         u8 reg = 0;
209         u8 retries = 0;
210         int err;
211
212         do {
213                 err = tps6591x_read_regs(dev, RTC_CTRL, 1, &reg);
214                 if (err < 0) {
215                         dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
216                         return err;
217                 }
218
219                 /* set STOP bit alone */
220                 reg |= 0x1;
221
222                 err = tps6591x_write_regs(dev, RTC_CTRL, 1, &reg);
223                 if (err < 0) {
224                         dev_err(dev->parent, "\n failed to program RTC_CTRL reg\n");
225                         return err;
226                 }
227
228                 err = tps6591x_read_regs(dev, RTC_STATUS, 1, &reg);
229                 if (err < 0) {
230                         dev_err(dev->parent, "\n failed to read RTC_CTRL reg\n");
231                         return err;
232                 }
233                 /* FixMe: Is allowing up to 5 retries sufficient?? */
234                 if (retries++ == 5) {
235                         dev_err(dev->parent, "\n failed to stop RTC\n");
236                         return -EBUSY;
237                 }
238         }       while (!(reg & 2));
239         return 0;
240 }
241
242
243 static int tps6591x_rtc_set_time(struct device *dev, struct rtc_time *tm)
244 {
245         u8 buff[7];
246         int err;
247
248         buff[0] = tm->tm_sec;
249         buff[1] = tm->tm_min;
250         buff[2] = tm->tm_hour;
251         buff[3] = tm->tm_mday;
252         buff[4] = tm->tm_mon + 1;
253         buff[5] = tm->tm_year;
254         buff[6] = tm->tm_wday;
255
256         print_time(dev, tm);
257         convert_decimal_to_bcd(buff, sizeof(buff));
258         err = tps6591x_rtc_stop(dev);
259         if (err < 0) {
260                 dev_err(dev->parent, "\n failed to clear RTC_ENABLE\n");
261                 return err;
262         }
263
264         err = tps6591x_write_regs(dev, RTC_SECONDS_REG, sizeof(buff), buff);
265         if (err < 0) {
266                 dev_err(dev->parent, "\n failed to program new time\n");
267                 return err;
268         }
269
270         err = tps6591x_rtc_start(dev);
271         if (err < 0) {
272                 dev_err(dev->parent, "\n failed to set RTC_ENABLE\n");
273                 return err;
274         }
275
276         return 0;
277 }
278
279 static int tps6591x_rtc_alarm_irq_enable(struct device *dev,
280                                          unsigned int enable)
281 {
282         struct tps6591x_rtc *rtc = dev_get_drvdata(dev);
283         u8 reg;
284         int err;
285
286         if (rtc->irq == -1)
287                 return -EIO;
288
289         if (enable) {
290                 if (rtc->irq_en == true)
291                         return 0;
292                 err = tps6591x_read_regs(dev, RTC_INT, 1, &reg);
293                 if (err)
294                         return err;
295                 reg |= 0x8;
296                 err = tps6591x_write_regs(dev, RTC_INT, 1, &reg);
297                 if (err)
298                         return err;
299                 rtc->irq_en = true;
300         } else {
301                 if (rtc->irq_en == false)
302                         return 0;
303                 err = tps6591x_read_regs(dev, RTC_INT, 1, &reg);
304                 if (err)
305                         return err;
306                 reg &= ~0x8;
307                 err = tps6591x_write_regs(dev, RTC_INT, 1, &reg);
308                 if (err)
309                         return err;
310                 rtc->irq_en = false;
311         }
312         return 0;
313 }
314
315 static int tps6591x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
316 {
317         struct tps6591x_rtc *rtc = dev_get_drvdata(dev);
318         unsigned long seconds;
319         u8 buff[6];
320         int err;
321         struct rtc_time tm;
322
323         if (rtc->irq == -1)
324                 return -EIO;
325
326         dev_info(dev->parent, "\n setting alarm to requested time::\n");
327         print_time(dev->parent, &alrm->time);
328         rtc_tm_to_time(&alrm->time, &seconds);
329         tps6591x_rtc_read_time(dev, &tm);
330         rtc_tm_to_time(&tm, &rtc->epoch_start);
331
332         if (WARN_ON(alrm->enabled && (seconds < rtc->epoch_start))) {
333                 dev_err(dev->parent, "\n can't set alarm to requested time\n");
334                 return -EINVAL;
335         }
336
337         err = tps6591x_rtc_alarm_irq_enable(dev, alrm->enabled);
338         if(err) {
339                 dev_err(dev->parent, "\n can't set alarm irq\n");
340                 return err;
341         }
342
343         buff[0] = alrm->time.tm_sec;
344         buff[1] = alrm->time.tm_min;
345         buff[2] = alrm->time.tm_hour;
346         buff[3] = alrm->time.tm_mday;
347         buff[4] = alrm->time.tm_mon + 1;
348         buff[5] = alrm->time.tm_year;
349         convert_decimal_to_bcd(buff, sizeof(buff));
350         err = tps6591x_write_regs(dev, RTC_ALARM, sizeof(buff), buff);
351         if (err)
352                 dev_err(dev->parent, "\n unable to program alarm\n");
353
354         return err;
355 }
356
357 static int tps6591x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
358 {
359         u8 buff[6];
360         int err;
361
362         err = tps6591x_read_regs(dev, RTC_ALARM, sizeof(buff), buff);
363         if (err)
364                 return err;
365         convert_bcd_to_decimal(buff, sizeof(buff));
366
367         alrm->time.tm_sec = buff[0];
368         alrm->time.tm_min = buff[1];
369         alrm->time.tm_hour = buff[2];
370         alrm->time.tm_mday = buff[3];
371         alrm->time.tm_mon = buff[4] - 1;
372         alrm->time.tm_year = buff[5];
373
374         dev_info(dev->parent, "\n getting alarm time::\n");
375         print_time(dev, &alrm->time);
376
377         return 0;
378 }
379
380 static const struct rtc_class_ops tps6591x_rtc_ops = {
381         .read_time      = tps6591x_rtc_read_time,
382         .set_time       = tps6591x_rtc_set_time,
383         .set_alarm      = tps6591x_rtc_set_alarm,
384         .read_alarm     = tps6591x_rtc_read_alarm,
385         .alarm_irq_enable = tps6591x_rtc_alarm_irq_enable,
386 };
387
388 static irqreturn_t tps6591x_rtc_irq(int irq, void *data)
389 {
390         struct device *dev = data;
391         struct tps6591x_rtc *rtc = dev_get_drvdata(dev);
392         u8 reg;
393         int err;
394
395         /* clear Alarm status bits.*/
396         err = tps6591x_read_regs(dev, RTC_STATUS, 1, &reg);
397         if (err) {
398                 dev_err(dev->parent, "unable to read RTC_STATUS reg\n");
399                 return -EBUSY;
400         }
401
402         reg = ALARM_INT_STATUS;
403         err = tps6591x_write_regs(dev, RTC_STATUS, 1, &reg);
404         if (err) {
405                 dev_err(dev->parent, "unable to program RTC_STATUS reg\n");
406                 return -EBUSY;
407         }
408
409         rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
410         return IRQ_HANDLED;
411 }
412
413 static int __devinit tps6591x_rtc_probe(struct platform_device *pdev)
414 {
415         struct tps6591x_rtc_platform_data *pdata = pdev->dev.platform_data;
416         struct tps6591x_rtc *rtc;
417         struct rtc_time tm;
418         int err;
419         u8 reg;
420
421         rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
422
423         if (!rtc)
424                 return -ENOMEM;
425
426         rtc->irq = -1;
427
428         if (!pdata) {
429                 dev_err(&pdev->dev, "no platform_data specified\n");
430                 return -EINVAL;
431         }
432
433         if (pdata->irq < 0)
434                 dev_err(&pdev->dev, "\n no IRQ specified, wakeup is disabled\n");
435
436         dev_set_drvdata(&pdev->dev, rtc);
437         device_init_wakeup(&pdev->dev, 1);
438         rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
439                                        &tps6591x_rtc_ops, THIS_MODULE);
440
441         if (IS_ERR(rtc->rtc)) {
442                 err = PTR_ERR(rtc->rtc);
443                 goto fail;
444         }
445
446         if ((int)pdev && (int)&pdev->dev)
447                 err = tps6591x_read_regs(&pdev->dev, RTC_STATUS, 1, &reg);
448         else {
449                 dev_err(&pdev->dev, "\n %s Input params incorrect\n", __func__);
450                 return -EBUSY;
451         }
452         if (err) {
453                 dev_err(&pdev->dev, "\n %s unable to read status\n", __func__);
454                 return -EBUSY;
455         }
456
457         reg = RTC_BBCH_SEL | RTC_BBCH_EN;
458         tps6591x_write_regs(&pdev->dev, RTC_BBCH_REG, 1, &reg);
459         if (err) {
460                 dev_err(&pdev->dev, "unable to program Charger reg\n");
461                 return -EBUSY;
462         }
463
464         tps6591x_rtc_read_time(&pdev->dev, &tm);
465         if ((tm.tm_year < RTC_YEAR_OFFSET || tm.tm_year > (RTC_YEAR_OFFSET + 99))){
466                 if (pdata->time.tm_year < 2000 || pdata->time.tm_year > 2100)   {
467                         memset(&pdata->time, 0, sizeof(pdata->time));
468                         pdata->time.tm_year = RTC_YEAR_OFFSET;
469                         pdata->time.tm_mday = 1;
470                 } else
471                 pdata->time.tm_year -= OS_REF_YEAR;
472                 tps6591x_rtc_set_time(&pdev->dev, &pdata->time);
473         }
474
475         reg = ALARM_INT_STATUS;
476         err = tps6591x_write_regs(&pdev->dev, RTC_STATUS, 1, &reg);
477         if (err) {
478                 dev_err(&pdev->dev, "unable to program RTC_STATUS reg\n");
479                 return -EBUSY;
480         }
481
482         reg = ENABLE_ALARM_INT;
483         tps6591x_write_regs(&pdev->dev, RTC_INT, 1, &reg);
484         if (err) {
485                 dev_err(&pdev->dev, "unable to program Interrupt Mask reg\n");
486                 return -EBUSY;
487         }
488
489         if (pdata && (pdata->irq >= 0)) {
490                 rtc->irq = pdata->irq;
491                 err = request_threaded_irq(pdata->irq, NULL, tps6591x_rtc_irq,
492                                         IRQF_ONESHOT, "rtc_tps6591x",
493                                         &pdev->dev);
494                 if (err) {
495                         dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq);
496                         rtc->irq = -1;
497                 } else {
498                         device_init_wakeup(&pdev->dev, 1);
499                         enable_irq_wake(rtc->irq);
500                 }
501         }
502         return 0;
503
504 fail:
505         if (!IS_ERR_OR_NULL(rtc->rtc))
506                 rtc_device_unregister(rtc->rtc);
507         kfree(rtc);
508         return err;
509 }
510
511 static int __devexit tps6591x_rtc_remove(struct platform_device *pdev)
512 {
513         struct tps6591x_rtc *rtc = dev_get_drvdata(&pdev->dev);
514
515         if (rtc->irq != -1)
516                 free_irq(rtc->irq, rtc);
517         rtc_device_unregister(rtc->rtc);
518         kfree(rtc);
519         return 0;
520 }
521
522 static struct platform_driver tps6591x_rtc_driver = {
523         .driver = {
524                 .name   = "rtc_tps6591x",
525                 .owner  = THIS_MODULE,
526         },
527         .probe  = tps6591x_rtc_probe,
528         .remove = __devexit_p(tps6591x_rtc_remove),
529 };
530
531 static int __init tps6591x_rtc_init(void)
532 {
533         return platform_driver_register(&tps6591x_rtc_driver);
534 }
535 module_init(tps6591x_rtc_init);
536
537 static void __exit tps6591x_rtc_exit(void)
538 {
539         platform_driver_unregister(&tps6591x_rtc_driver);
540 }
541 module_exit(tps6591x_rtc_exit);
542
543 MODULE_DESCRIPTION("TI TPS6591x RTC driver");
544 MODULE_AUTHOR("NVIDIA Corporation");
545 MODULE_LICENSE("GPL");
546 MODULE_ALIAS("platform:rtc_tps6591x");