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rtc: ds1307: comment and format cleanup
[deliverable/linux.git] / drivers / rtc / rtc-spear.c
1 /*
2 * drivers/rtc/rtc-spear.c
3 *
4 * Copyright (C) 2010 ST Microelectronics
5 * Rajeev Kumar<rajeev-dlh.kumar@st.com>
6 *
7 * This file is licensed under the terms of the GNU General Public
8 * License version 2. This program is licensed "as is" without any
9 * warranty of any kind, whether express or implied.
10 */
11
12 #include <linux/bcd.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/init.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/rtc.h>
21 #include <linux/slab.h>
22 #include <linux/spinlock.h>
23
24 /* RTC registers */
25 #define TIME_REG 0x00
26 #define DATE_REG 0x04
27 #define ALARM_TIME_REG 0x08
28 #define ALARM_DATE_REG 0x0C
29 #define CTRL_REG 0x10
30 #define STATUS_REG 0x14
31
32 /* TIME_REG & ALARM_TIME_REG */
33 #define SECONDS_UNITS (0xf<<0) /* seconds units position */
34 #define SECONDS_TENS (0x7<<4) /* seconds tens position */
35 #define MINUTES_UNITS (0xf<<8) /* minutes units position */
36 #define MINUTES_TENS (0x7<<12) /* minutes tens position */
37 #define HOURS_UNITS (0xf<<16) /* hours units position */
38 #define HOURS_TENS (0x3<<20) /* hours tens position */
39
40 /* DATE_REG & ALARM_DATE_REG */
41 #define DAYS_UNITS (0xf<<0) /* days units position */
42 #define DAYS_TENS (0x3<<4) /* days tens position */
43 #define MONTHS_UNITS (0xf<<8) /* months units position */
44 #define MONTHS_TENS (0x1<<12) /* months tens position */
45 #define YEARS_UNITS (0xf<<16) /* years units position */
46 #define YEARS_TENS (0xf<<20) /* years tens position */
47 #define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */
48 #define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */
49
50 /* MASK SHIFT TIME_REG & ALARM_TIME_REG*/
51 #define SECOND_SHIFT 0x00 /* seconds units */
52 #define MINUTE_SHIFT 0x08 /* minutes units position */
53 #define HOUR_SHIFT 0x10 /* hours units position */
54 #define MDAY_SHIFT 0x00 /* Month day shift */
55 #define MONTH_SHIFT 0x08 /* Month shift */
56 #define YEAR_SHIFT 0x10 /* Year shift */
57
58 #define SECOND_MASK 0x7F
59 #define MIN_MASK 0x7F
60 #define HOUR_MASK 0x3F
61 #define DAY_MASK 0x3F
62 #define MONTH_MASK 0x7F
63 #define YEAR_MASK 0xFFFF
64
65 /* date reg equal to time reg, for debug only */
66 #define TIME_BYP (1<<9)
67 #define INT_ENABLE (1<<31) /* interrupt enable */
68
69 /* STATUS_REG */
70 #define CLK_UNCONNECTED (1<<0)
71 #define PEND_WR_TIME (1<<2)
72 #define PEND_WR_DATE (1<<3)
73 #define LOST_WR_TIME (1<<4)
74 #define LOST_WR_DATE (1<<5)
75 #define RTC_INT_MASK (1<<31)
76 #define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE)
77 #define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE)
78
79 struct spear_rtc_config {
80 struct rtc_device *rtc;
81 struct clk *clk;
82 spinlock_t lock;
83 void __iomem *ioaddr;
84 unsigned int irq_wake;
85 };
86
87 static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config)
88 {
89 unsigned int val;
90 unsigned long flags;
91
92 spin_lock_irqsave(&config->lock, flags);
93 val = readl(config->ioaddr + STATUS_REG);
94 val |= RTC_INT_MASK;
95 writel(val, config->ioaddr + STATUS_REG);
96 spin_unlock_irqrestore(&config->lock, flags);
97 }
98
99 static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config)
100 {
101 unsigned int val;
102
103 val = readl(config->ioaddr + CTRL_REG);
104 if (!(val & INT_ENABLE)) {
105 spear_rtc_clear_interrupt(config);
106 val |= INT_ENABLE;
107 writel(val, config->ioaddr + CTRL_REG);
108 }
109 }
110
111 static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config)
112 {
113 unsigned int val;
114
115 val = readl(config->ioaddr + CTRL_REG);
116 if (val & INT_ENABLE) {
117 val &= ~INT_ENABLE;
118 writel(val, config->ioaddr + CTRL_REG);
119 }
120 }
121
122 static inline int is_write_complete(struct spear_rtc_config *config)
123 {
124 int ret = 0;
125 unsigned long flags;
126
127 spin_lock_irqsave(&config->lock, flags);
128 if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL)
129 ret = -EIO;
130 spin_unlock_irqrestore(&config->lock, flags);
131
132 return ret;
133 }
134
135 static void rtc_wait_not_busy(struct spear_rtc_config *config)
136 {
137 int status, count = 0;
138 unsigned long flags;
139
140 /* Assuming BUSY may stay active for 80 msec) */
141 for (count = 0; count < 80; count++) {
142 spin_lock_irqsave(&config->lock, flags);
143 status = readl(config->ioaddr + STATUS_REG);
144 spin_unlock_irqrestore(&config->lock, flags);
145 if ((status & STATUS_BUSY) == 0)
146 break;
147 /* check status busy, after each msec */
148 msleep(1);
149 }
150 }
151
152 static irqreturn_t spear_rtc_irq(int irq, void *dev_id)
153 {
154 struct spear_rtc_config *config = dev_id;
155 unsigned long flags, events = 0;
156 unsigned int irq_data;
157
158 spin_lock_irqsave(&config->lock, flags);
159 irq_data = readl(config->ioaddr + STATUS_REG);
160 spin_unlock_irqrestore(&config->lock, flags);
161
162 if ((irq_data & RTC_INT_MASK)) {
163 spear_rtc_clear_interrupt(config);
164 events = RTC_IRQF | RTC_AF;
165 rtc_update_irq(config->rtc, 1, events);
166 return IRQ_HANDLED;
167 } else
168 return IRQ_NONE;
169
170 }
171
172 static int tm2bcd(struct rtc_time *tm)
173 {
174 if (rtc_valid_tm(tm) != 0)
175 return -EINVAL;
176 tm->tm_sec = bin2bcd(tm->tm_sec);
177 tm->tm_min = bin2bcd(tm->tm_min);
178 tm->tm_hour = bin2bcd(tm->tm_hour);
179 tm->tm_mday = bin2bcd(tm->tm_mday);
180 tm->tm_mon = bin2bcd(tm->tm_mon + 1);
181 tm->tm_year = bin2bcd(tm->tm_year);
182
183 return 0;
184 }
185
186 static void bcd2tm(struct rtc_time *tm)
187 {
188 tm->tm_sec = bcd2bin(tm->tm_sec);
189 tm->tm_min = bcd2bin(tm->tm_min);
190 tm->tm_hour = bcd2bin(tm->tm_hour);
191 tm->tm_mday = bcd2bin(tm->tm_mday);
192 tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
193 /* epoch == 1900 */
194 tm->tm_year = bcd2bin(tm->tm_year);
195 }
196
197 /*
198 * spear_rtc_read_time - set the time
199 * @dev: rtc device in use
200 * @tm: holds date and time
201 *
202 * This function read time and date. On success it will return 0
203 * otherwise -ve error is returned.
204 */
205 static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
206 {
207 struct spear_rtc_config *config = dev_get_drvdata(dev);
208 unsigned int time, date;
209
210 /* we don't report wday/yday/isdst ... */
211 rtc_wait_not_busy(config);
212
213 time = readl(config->ioaddr + TIME_REG);
214 date = readl(config->ioaddr + DATE_REG);
215 tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
216 tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
217 tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
218 tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
219 tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
220 tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
221
222 bcd2tm(tm);
223 return 0;
224 }
225
226 /*
227 * spear_rtc_set_time - set the time
228 * @dev: rtc device in use
229 * @tm: holds date and time
230 *
231 * This function set time and date. On success it will return 0
232 * otherwise -ve error is returned.
233 */
234 static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)
235 {
236 struct spear_rtc_config *config = dev_get_drvdata(dev);
237 unsigned int time, date, err = 0;
238
239 if (tm2bcd(tm) < 0)
240 return -EINVAL;
241
242 rtc_wait_not_busy(config);
243 time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |
244 (tm->tm_hour << HOUR_SHIFT);
245 date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |
246 (tm->tm_year << YEAR_SHIFT);
247 writel(time, config->ioaddr + TIME_REG);
248 writel(date, config->ioaddr + DATE_REG);
249 err = is_write_complete(config);
250 if (err < 0)
251 return err;
252
253 return 0;
254 }
255
256 /*
257 * spear_rtc_read_alarm - read the alarm time
258 * @dev: rtc device in use
259 * @alm: holds alarm date and time
260 *
261 * This function read alarm time and date. On success it will return 0
262 * otherwise -ve error is returned.
263 */
264 static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
265 {
266 struct spear_rtc_config *config = dev_get_drvdata(dev);
267 unsigned int time, date;
268
269 rtc_wait_not_busy(config);
270
271 time = readl(config->ioaddr + ALARM_TIME_REG);
272 date = readl(config->ioaddr + ALARM_DATE_REG);
273 alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
274 alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
275 alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
276 alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
277 alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
278 alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
279
280 bcd2tm(&alm->time);
281 alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE;
282
283 return 0;
284 }
285
286 /*
287 * spear_rtc_set_alarm - set the alarm time
288 * @dev: rtc device in use
289 * @alm: holds alarm date and time
290 *
291 * This function set alarm time and date. On success it will return 0
292 * otherwise -ve error is returned.
293 */
294 static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
295 {
296 struct spear_rtc_config *config = dev_get_drvdata(dev);
297 unsigned int time, date, err = 0;
298
299 if (tm2bcd(&alm->time) < 0)
300 return -EINVAL;
301
302 rtc_wait_not_busy(config);
303
304 time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min <<
305 MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT);
306 date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon <<
307 MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT);
308
309 writel(time, config->ioaddr + ALARM_TIME_REG);
310 writel(date, config->ioaddr + ALARM_DATE_REG);
311 err = is_write_complete(config);
312 if (err < 0)
313 return err;
314
315 if (alm->enabled)
316 spear_rtc_enable_interrupt(config);
317 else
318 spear_rtc_disable_interrupt(config);
319
320 return 0;
321 }
322
323 static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled)
324 {
325 struct spear_rtc_config *config = dev_get_drvdata(dev);
326 int ret = 0;
327
328 spear_rtc_clear_interrupt(config);
329
330 switch (enabled) {
331 case 0:
332 /* alarm off */
333 spear_rtc_disable_interrupt(config);
334 break;
335 case 1:
336 /* alarm on */
337 spear_rtc_enable_interrupt(config);
338 break;
339 default:
340 ret = -EINVAL;
341 break;
342 }
343
344 return ret;
345 }
346
347 static struct rtc_class_ops spear_rtc_ops = {
348 .read_time = spear_rtc_read_time,
349 .set_time = spear_rtc_set_time,
350 .read_alarm = spear_rtc_read_alarm,
351 .set_alarm = spear_rtc_set_alarm,
352 .alarm_irq_enable = spear_alarm_irq_enable,
353 };
354
355 static int __devinit spear_rtc_probe(struct platform_device *pdev)
356 {
357 struct resource *res;
358 struct spear_rtc_config *config;
359 unsigned int status = 0;
360 int irq;
361
362 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
363 if (!res) {
364 dev_err(&pdev->dev, "no resource defined\n");
365 return -EBUSY;
366 }
367 if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
368 dev_err(&pdev->dev, "rtc region already claimed\n");
369 return -EBUSY;
370 }
371
372 config = kzalloc(sizeof(*config), GFP_KERNEL);
373 if (!config) {
374 dev_err(&pdev->dev, "out of memory\n");
375 status = -ENOMEM;
376 goto err_release_region;
377 }
378
379 config->clk = clk_get(&pdev->dev, NULL);
380 if (IS_ERR(config->clk)) {
381 status = PTR_ERR(config->clk);
382 goto err_kfree;
383 }
384
385 status = clk_enable(config->clk);
386 if (status < 0)
387 goto err_clk_put;
388
389 config->ioaddr = ioremap(res->start, resource_size(res));
390 if (!config->ioaddr) {
391 dev_err(&pdev->dev, "ioremap fail\n");
392 status = -ENOMEM;
393 goto err_disable_clock;
394 }
395
396 spin_lock_init(&config->lock);
397 platform_set_drvdata(pdev, config);
398
399 config->rtc = rtc_device_register(pdev->name, &pdev->dev,
400 &spear_rtc_ops, THIS_MODULE);
401 if (IS_ERR(config->rtc)) {
402 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
403 PTR_ERR(config->rtc));
404 status = PTR_ERR(config->rtc);
405 goto err_iounmap;
406 }
407
408 /* alarm irqs */
409 irq = platform_get_irq(pdev, 0);
410 if (irq < 0) {
411 dev_err(&pdev->dev, "no update irq?\n");
412 status = irq;
413 goto err_clear_platdata;
414 }
415
416 status = request_irq(irq, spear_rtc_irq, 0, pdev->name, config);
417 if (status) {
418 dev_err(&pdev->dev, "Alarm interrupt IRQ%d already \
419 claimed\n", irq);
420 goto err_clear_platdata;
421 }
422
423 if (!device_can_wakeup(&pdev->dev))
424 device_init_wakeup(&pdev->dev, 1);
425
426 return 0;
427
428 err_clear_platdata:
429 platform_set_drvdata(pdev, NULL);
430 rtc_device_unregister(config->rtc);
431 err_iounmap:
432 iounmap(config->ioaddr);
433 err_disable_clock:
434 clk_disable(config->clk);
435 err_clk_put:
436 clk_put(config->clk);
437 err_kfree:
438 kfree(config);
439 err_release_region:
440 release_mem_region(res->start, resource_size(res));
441
442 return status;
443 }
444
445 static int __devexit spear_rtc_remove(struct platform_device *pdev)
446 {
447 struct spear_rtc_config *config = platform_get_drvdata(pdev);
448 int irq;
449 struct resource *res;
450
451 /* leave rtc running, but disable irqs */
452 spear_rtc_disable_interrupt(config);
453 device_init_wakeup(&pdev->dev, 0);
454 irq = platform_get_irq(pdev, 0);
455 if (irq)
456 free_irq(irq, pdev);
457 clk_disable(config->clk);
458 clk_put(config->clk);
459 iounmap(config->ioaddr);
460 kfree(config);
461 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
462 if (res)
463 release_mem_region(res->start, resource_size(res));
464 platform_set_drvdata(pdev, NULL);
465 rtc_device_unregister(config->rtc);
466
467 return 0;
468 }
469
470 #ifdef CONFIG_PM
471
472 static int spear_rtc_suspend(struct platform_device *pdev, pm_message_t state)
473 {
474 struct spear_rtc_config *config = platform_get_drvdata(pdev);
475 int irq;
476
477 irq = platform_get_irq(pdev, 0);
478 if (device_may_wakeup(&pdev->dev)) {
479 if (!enable_irq_wake(irq))
480 config->irq_wake = 1;
481 } else {
482 spear_rtc_disable_interrupt(config);
483 clk_disable(config->clk);
484 }
485
486 return 0;
487 }
488
489 static int spear_rtc_resume(struct platform_device *pdev)
490 {
491 struct spear_rtc_config *config = platform_get_drvdata(pdev);
492 int irq;
493
494 irq = platform_get_irq(pdev, 0);
495
496 if (device_may_wakeup(&pdev->dev)) {
497 if (config->irq_wake) {
498 disable_irq_wake(irq);
499 config->irq_wake = 0;
500 }
501 } else {
502 clk_enable(config->clk);
503 spear_rtc_enable_interrupt(config);
504 }
505
506 return 0;
507 }
508
509 #else
510 #define spear_rtc_suspend NULL
511 #define spear_rtc_resume NULL
512 #endif
513
514 static void spear_rtc_shutdown(struct platform_device *pdev)
515 {
516 struct spear_rtc_config *config = platform_get_drvdata(pdev);
517
518 spear_rtc_disable_interrupt(config);
519 clk_disable(config->clk);
520 }
521
522 static struct platform_driver spear_rtc_driver = {
523 .probe = spear_rtc_probe,
524 .remove = __devexit_p(spear_rtc_remove),
525 .suspend = spear_rtc_suspend,
526 .resume = spear_rtc_resume,
527 .shutdown = spear_rtc_shutdown,
528 .driver = {
529 .name = "rtc-spear",
530 },
531 };
532
533 module_platform_driver(spear_rtc_driver);
534
535 MODULE_ALIAS("platform:rtc-spear");
536 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
537 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
538 MODULE_LICENSE("GPL");
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