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MAINTAINERS: add myself as co-maintainer of the iwlwifi driver
[linux/fpc-iii.git] / drivers / rtc / rtc-spear.c
blobf05ef8568480429f912bf47f72349eb331d214ca
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/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/rtc.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24
25 /* RTC registers */
26 #define TIME_REG 0x00
27 #define DATE_REG 0x04
28 #define ALARM_TIME_REG 0x08
29 #define ALARM_DATE_REG 0x0C
30 #define CTRL_REG 0x10
31 #define STATUS_REG 0x14
32
33 /* TIME_REG & ALARM_TIME_REG */
34 #define SECONDS_UNITS (0xf<<0) /* seconds units position */
35 #define SECONDS_TENS (0x7<<4) /* seconds tens position */
36 #define MINUTES_UNITS (0xf<<8) /* minutes units position */
37 #define MINUTES_TENS (0x7<<12) /* minutes tens position */
38 #define HOURS_UNITS (0xf<<16) /* hours units position */
39 #define HOURS_TENS (0x3<<20) /* hours tens position */
40
41 /* DATE_REG & ALARM_DATE_REG */
42 #define DAYS_UNITS (0xf<<0) /* days units position */
43 #define DAYS_TENS (0x3<<4) /* days tens position */
44 #define MONTHS_UNITS (0xf<<8) /* months units position */
45 #define MONTHS_TENS (0x1<<12) /* months tens position */
46 #define YEARS_UNITS (0xf<<16) /* years units position */
47 #define YEARS_TENS (0xf<<20) /* years tens position */
48 #define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */
49 #define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */
50
51 /* MASK SHIFT TIME_REG & ALARM_TIME_REG*/
52 #define SECOND_SHIFT 0x00 /* seconds units */
53 #define MINUTE_SHIFT 0x08 /* minutes units position */
54 #define HOUR_SHIFT 0x10 /* hours units position */
55 #define MDAY_SHIFT 0x00 /* Month day shift */
56 #define MONTH_SHIFT 0x08 /* Month shift */
57 #define YEAR_SHIFT 0x10 /* Year shift */
58
59 #define SECOND_MASK 0x7F
60 #define MIN_MASK 0x7F
61 #define HOUR_MASK 0x3F
62 #define DAY_MASK 0x3F
63 #define MONTH_MASK 0x7F
64 #define YEAR_MASK 0xFFFF
65
66 /* date reg equal to time reg, for debug only */
67 #define TIME_BYP (1<<9)
68 #define INT_ENABLE (1<<31) /* interrupt enable */
69
70 /* STATUS_REG */
71 #define CLK_UNCONNECTED (1<<0)
72 #define PEND_WR_TIME (1<<2)
73 #define PEND_WR_DATE (1<<3)
74 #define LOST_WR_TIME (1<<4)
75 #define LOST_WR_DATE (1<<5)
76 #define RTC_INT_MASK (1<<31)
77 #define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE)
78 #define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE)
79
80 struct spear_rtc_config {
81 struct rtc_device *rtc;
82 struct clk *clk;
83 spinlock_t lock;
84 void __iomem *ioaddr;
85 unsigned int irq_wake;
86 };
87
88 static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config)
89 {
90 unsigned int val;
91 unsigned long flags;
92
93 spin_lock_irqsave(&config->lock, flags);
94 val = readl(config->ioaddr + STATUS_REG);
95 val |= RTC_INT_MASK;
96 writel(val, config->ioaddr + STATUS_REG);
97 spin_unlock_irqrestore(&config->lock, flags);
98 }
99
100 static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config)
101 {
102 unsigned int val;
103
104 val = readl(config->ioaddr + CTRL_REG);
105 if (!(val & INT_ENABLE)) {
106 spear_rtc_clear_interrupt(config);
107 val |= INT_ENABLE;
108 writel(val, config->ioaddr + CTRL_REG);
109 }
110 }
111
112 static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config)
113 {
114 unsigned int val;
115
116 val = readl(config->ioaddr + CTRL_REG);
117 if (val & INT_ENABLE) {
118 val &= ~INT_ENABLE;
119 writel(val, config->ioaddr + CTRL_REG);
120 }
121 }
122
123 static inline int is_write_complete(struct spear_rtc_config *config)
124 {
125 int ret = 0;
126 unsigned long flags;
127
128 spin_lock_irqsave(&config->lock, flags);
129 if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL)
130 ret = -EIO;
131 spin_unlock_irqrestore(&config->lock, flags);
132
133 return ret;
134 }
135
136 static void rtc_wait_not_busy(struct spear_rtc_config *config)
137 {
138 int status, count = 0;
139 unsigned long flags;
140
141 /* Assuming BUSY may stay active for 80 msec) */
142 for (count = 0; count < 80; count++) {
143 spin_lock_irqsave(&config->lock, flags);
144 status = readl(config->ioaddr + STATUS_REG);
145 spin_unlock_irqrestore(&config->lock, flags);
146 if ((status & STATUS_BUSY) == 0)
147 break;
148 /* check status busy, after each msec */
149 msleep(1);
150 }
151 }
152
153 static irqreturn_t spear_rtc_irq(int irq, void *dev_id)
154 {
155 struct spear_rtc_config *config = dev_id;
156 unsigned long flags, events = 0;
157 unsigned int irq_data;
158
159 spin_lock_irqsave(&config->lock, flags);
160 irq_data = readl(config->ioaddr + STATUS_REG);
161 spin_unlock_irqrestore(&config->lock, flags);
162
163 if ((irq_data & RTC_INT_MASK)) {
164 spear_rtc_clear_interrupt(config);
165 events = RTC_IRQF | RTC_AF;
166 rtc_update_irq(config->rtc, 1, events);
167 return IRQ_HANDLED;
168 } else
169 return IRQ_NONE;
170
171 }
172
173 static int tm2bcd(struct rtc_time *tm)
174 {
175 if (rtc_valid_tm(tm) != 0)
176 return -EINVAL;
177 tm->tm_sec = bin2bcd(tm->tm_sec);
178 tm->tm_min = bin2bcd(tm->tm_min);
179 tm->tm_hour = bin2bcd(tm->tm_hour);
180 tm->tm_mday = bin2bcd(tm->tm_mday);
181 tm->tm_mon = bin2bcd(tm->tm_mon + 1);
182 tm->tm_year = bin2bcd(tm->tm_year);
183
184 return 0;
185 }
186
187 static void bcd2tm(struct rtc_time *tm)
188 {
189 tm->tm_sec = bcd2bin(tm->tm_sec);
190 tm->tm_min = bcd2bin(tm->tm_min);
191 tm->tm_hour = bcd2bin(tm->tm_hour);
192 tm->tm_mday = bcd2bin(tm->tm_mday);
193 tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
194 /* epoch == 1900 */
195 tm->tm_year = bcd2bin(tm->tm_year);
196 }
197
198 /*
199 * spear_rtc_read_time - set the time
200 * @dev: rtc device in use
201 * @tm: holds date and time
202 *
203 * This function read time and date. On success it will return 0
204 * otherwise -ve error is returned.
205 */
206 static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
207 {
208 struct spear_rtc_config *config = dev_get_drvdata(dev);
209 unsigned int time, date;
210
211 /* we don't report wday/yday/isdst ... */
212 rtc_wait_not_busy(config);
213
214 time = readl(config->ioaddr + TIME_REG);
215 date = readl(config->ioaddr + DATE_REG);
216 tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
217 tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
218 tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
219 tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
220 tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
221 tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
222
223 bcd2tm(tm);
224 return 0;
225 }
226
227 /*
228 * spear_rtc_set_time - set the time
229 * @dev: rtc device in use
230 * @tm: holds date and time
231 *
232 * This function set time and date. On success it will return 0
233 * otherwise -ve error is returned.
234 */
235 static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)
236 {
237 struct spear_rtc_config *config = dev_get_drvdata(dev);
238 unsigned int time, date;
239
240 if (tm2bcd(tm) < 0)
241 return -EINVAL;
242
243 rtc_wait_not_busy(config);
244 time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |
245 (tm->tm_hour << HOUR_SHIFT);
246 date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |
247 (tm->tm_year << YEAR_SHIFT);
248 writel(time, config->ioaddr + TIME_REG);
249 writel(date, config->ioaddr + DATE_REG);
250
251 return is_write_complete(config);
252 }
253
254 /*
255 * spear_rtc_read_alarm - read the alarm time
256 * @dev: rtc device in use
257 * @alm: holds alarm date and time
258 *
259 * This function read alarm time and date. On success it will return 0
260 * otherwise -ve error is returned.
261 */
262 static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
263 {
264 struct spear_rtc_config *config = dev_get_drvdata(dev);
265 unsigned int time, date;
266
267 rtc_wait_not_busy(config);
268
269 time = readl(config->ioaddr + ALARM_TIME_REG);
270 date = readl(config->ioaddr + ALARM_DATE_REG);
271 alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
272 alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
273 alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
274 alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
275 alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
276 alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
277
278 bcd2tm(&alm->time);
279 alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE;
280
281 return 0;
282 }
283
284 /*
285 * spear_rtc_set_alarm - set the alarm time
286 * @dev: rtc device in use
287 * @alm: holds alarm date and time
288 *
289 * This function set alarm time and date. On success it will return 0
290 * otherwise -ve error is returned.
291 */
292 static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
293 {
294 struct spear_rtc_config *config = dev_get_drvdata(dev);
295 unsigned int time, date;
296 int err;
297
298 if (tm2bcd(&alm->time) < 0)
299 return -EINVAL;
300
301 rtc_wait_not_busy(config);
302
303 time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min <<
304 MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT);
305 date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon <<
306 MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT);
307
308 writel(time, config->ioaddr + ALARM_TIME_REG);
309 writel(date, config->ioaddr + ALARM_DATE_REG);
310 err = is_write_complete(config);
311 if (err < 0)
312 return err;
313
314 if (alm->enabled)
315 spear_rtc_enable_interrupt(config);
316 else
317 spear_rtc_disable_interrupt(config);
318
319 return 0;
320 }
321
322 static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled)
323 {
324 struct spear_rtc_config *config = dev_get_drvdata(dev);
325 int ret = 0;
326
327 spear_rtc_clear_interrupt(config);
328
329 switch (enabled) {
330 case 0:
331 /* alarm off */
332 spear_rtc_disable_interrupt(config);
333 break;
334 case 1:
335 /* alarm on */
336 spear_rtc_enable_interrupt(config);
337 break;
338 default:
339 ret = -EINVAL;
340 break;
341 }
342
343 return ret;
344 }
345
346 static struct rtc_class_ops spear_rtc_ops = {
347 .read_time = spear_rtc_read_time,
348 .set_time = spear_rtc_set_time,
349 .read_alarm = spear_rtc_read_alarm,
350 .set_alarm = spear_rtc_set_alarm,
351 .alarm_irq_enable = spear_alarm_irq_enable,
352 };
353
354 static int spear_rtc_probe(struct platform_device *pdev)
355 {
356 struct resource *res;
357 struct spear_rtc_config *config;
358 int status = 0;
359 int irq;
360
361 config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
362 if (!config)
363 return -ENOMEM;
364
365 /* alarm irqs */
366 irq = platform_get_irq(pdev, 0);
367 if (irq < 0) {
368 dev_err(&pdev->dev, "no update irq?\n");
369 return irq;
370 }
371
372 status = devm_request_irq(&pdev->dev, irq, spear_rtc_irq, 0, pdev->name,
373 config);
374 if (status) {
375 dev_err(&pdev->dev, "Alarm interrupt IRQ%d already claimed\n",
376 irq);
377 return status;
378 }
379
380 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
381 config->ioaddr = devm_ioremap_resource(&pdev->dev, res);
382 if (IS_ERR(config->ioaddr))
383 return PTR_ERR(config->ioaddr);
384
385 config->clk = devm_clk_get(&pdev->dev, NULL);
386 if (IS_ERR(config->clk))
387 return PTR_ERR(config->clk);
388
389 status = clk_prepare_enable(config->clk);
390 if (status < 0)
391 return status;
392
393 spin_lock_init(&config->lock);
394 platform_set_drvdata(pdev, config);
395
396 config->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
397 &spear_rtc_ops, THIS_MODULE);
398 if (IS_ERR(config->rtc)) {
399 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
400 PTR_ERR(config->rtc));
401 status = PTR_ERR(config->rtc);
402 goto err_disable_clock;
403 }
404
405 config->rtc->uie_unsupported = 1;
406
407 if (!device_can_wakeup(&pdev->dev))
408 device_init_wakeup(&pdev->dev, 1);
409
410 return 0;
411
412 err_disable_clock:
413 clk_disable_unprepare(config->clk);
414
415 return status;
416 }
417
418 static int spear_rtc_remove(struct platform_device *pdev)
419 {
420 struct spear_rtc_config *config = platform_get_drvdata(pdev);
421
422 spear_rtc_disable_interrupt(config);
423 clk_disable_unprepare(config->clk);
424 device_init_wakeup(&pdev->dev, 0);
425
426 return 0;
427 }
428
429 #ifdef CONFIG_PM_SLEEP
430 static int spear_rtc_suspend(struct device *dev)
431 {
432 struct platform_device *pdev = to_platform_device(dev);
433 struct spear_rtc_config *config = platform_get_drvdata(pdev);
434 int irq;
435
436 irq = platform_get_irq(pdev, 0);
437 if (device_may_wakeup(&pdev->dev)) {
438 if (!enable_irq_wake(irq))
439 config->irq_wake = 1;
440 } else {
441 spear_rtc_disable_interrupt(config);
442 clk_disable(config->clk);
443 }
444
445 return 0;
446 }
447
448 static int spear_rtc_resume(struct device *dev)
449 {
450 struct platform_device *pdev = to_platform_device(dev);
451 struct spear_rtc_config *config = platform_get_drvdata(pdev);
452 int irq;
453
454 irq = platform_get_irq(pdev, 0);
455
456 if (device_may_wakeup(&pdev->dev)) {
457 if (config->irq_wake) {
458 disable_irq_wake(irq);
459 config->irq_wake = 0;
460 }
461 } else {
462 clk_enable(config->clk);
463 spear_rtc_enable_interrupt(config);
464 }
465
466 return 0;
467 }
468 #endif
469
470 static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume);
471
472 static void spear_rtc_shutdown(struct platform_device *pdev)
473 {
474 struct spear_rtc_config *config = platform_get_drvdata(pdev);
475
476 spear_rtc_disable_interrupt(config);
477 clk_disable(config->clk);
478 }
479
480 #ifdef CONFIG_OF
481 static const struct of_device_id spear_rtc_id_table[] = {
482 { .compatible = "st,spear600-rtc" },
483 {}
484 };
485 MODULE_DEVICE_TABLE(of, spear_rtc_id_table);
486 #endif
487
488 static struct platform_driver spear_rtc_driver = {
489 .probe = spear_rtc_probe,
490 .remove = spear_rtc_remove,
491 .shutdown = spear_rtc_shutdown,
492 .driver = {
493 .name = "rtc-spear",
494 .pm = &spear_rtc_pm_ops,
495 .of_match_table = of_match_ptr(spear_rtc_id_table),
496 },
497 };
498
499 module_platform_driver(spear_rtc_driver);
500
501 MODULE_ALIAS("platform:rtc-spear");
502 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
503 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
504 MODULE_LICENSE("GPL");
Linux with added FPC-III support