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Linux 4.18.10
[linux/fpc-iii.git] / drivers / rtc / rtc-spear.c
blob0567944fd4f89ada811158b0315e2eb473ce4f48
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 void tm2bcd(struct rtc_time *tm)
174 {
175 tm->tm_sec = bin2bcd(tm->tm_sec);
176 tm->tm_min = bin2bcd(tm->tm_min);
177 tm->tm_hour = bin2bcd(tm->tm_hour);
178 tm->tm_mday = bin2bcd(tm->tm_mday);
179 tm->tm_mon = bin2bcd(tm->tm_mon + 1);
180 tm->tm_year = bin2bcd(tm->tm_year);
181 }
182
183 static void bcd2tm(struct rtc_time *tm)
184 {
185 tm->tm_sec = bcd2bin(tm->tm_sec);
186 tm->tm_min = bcd2bin(tm->tm_min);
187 tm->tm_hour = bcd2bin(tm->tm_hour);
188 tm->tm_mday = bcd2bin(tm->tm_mday);
189 tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
190 /* epoch == 1900 */
191 tm->tm_year = bcd2bin(tm->tm_year);
192 }
193
194 /*
195 * spear_rtc_read_time - set the time
196 * @dev: rtc device in use
197 * @tm: holds date and time
198 *
199 * This function read time and date. On success it will return 0
200 * otherwise -ve error is returned.
201 */
202 static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
203 {
204 struct spear_rtc_config *config = dev_get_drvdata(dev);
205 unsigned int time, date;
206
207 /* we don't report wday/yday/isdst ... */
208 rtc_wait_not_busy(config);
209
210 time = readl(config->ioaddr + TIME_REG);
211 date = readl(config->ioaddr + DATE_REG);
212 tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
213 tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
214 tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
215 tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
216 tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
217 tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
218
219 bcd2tm(tm);
220 return 0;
221 }
222
223 /*
224 * spear_rtc_set_time - set the time
225 * @dev: rtc device in use
226 * @tm: holds date and time
227 *
228 * This function set time and date. On success it will return 0
229 * otherwise -ve error is returned.
230 */
231 static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)
232 {
233 struct spear_rtc_config *config = dev_get_drvdata(dev);
234 unsigned int time, date;
235
236 tm2bcd(tm);
237
238 rtc_wait_not_busy(config);
239 time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |
240 (tm->tm_hour << HOUR_SHIFT);
241 date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |
242 (tm->tm_year << YEAR_SHIFT);
243 writel(time, config->ioaddr + TIME_REG);
244 writel(date, config->ioaddr + DATE_REG);
245
246 return is_write_complete(config);
247 }
248
249 /*
250 * spear_rtc_read_alarm - read the alarm time
251 * @dev: rtc device in use
252 * @alm: holds alarm date and time
253 *
254 * This function read alarm time and date. On success it will return 0
255 * otherwise -ve error is returned.
256 */
257 static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
258 {
259 struct spear_rtc_config *config = dev_get_drvdata(dev);
260 unsigned int time, date;
261
262 rtc_wait_not_busy(config);
263
264 time = readl(config->ioaddr + ALARM_TIME_REG);
265 date = readl(config->ioaddr + ALARM_DATE_REG);
266 alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
267 alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
268 alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
269 alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
270 alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
271 alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
272
273 bcd2tm(&alm->time);
274 alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE;
275
276 return 0;
277 }
278
279 /*
280 * spear_rtc_set_alarm - set the alarm time
281 * @dev: rtc device in use
282 * @alm: holds alarm date and time
283 *
284 * This function set alarm time and date. On success it will return 0
285 * otherwise -ve error is returned.
286 */
287 static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
288 {
289 struct spear_rtc_config *config = dev_get_drvdata(dev);
290 unsigned int time, date;
291 int err;
292
293 tm2bcd(&alm->time);
294
295 rtc_wait_not_busy(config);
296
297 time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min <<
298 MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT);
299 date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon <<
300 MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT);
301
302 writel(time, config->ioaddr + ALARM_TIME_REG);
303 writel(date, config->ioaddr + ALARM_DATE_REG);
304 err = is_write_complete(config);
305 if (err < 0)
306 return err;
307
308 if (alm->enabled)
309 spear_rtc_enable_interrupt(config);
310 else
311 spear_rtc_disable_interrupt(config);
312
313 return 0;
314 }
315
316 static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled)
317 {
318 struct spear_rtc_config *config = dev_get_drvdata(dev);
319 int ret = 0;
320
321 spear_rtc_clear_interrupt(config);
322
323 switch (enabled) {
324 case 0:
325 /* alarm off */
326 spear_rtc_disable_interrupt(config);
327 break;
328 case 1:
329 /* alarm on */
330 spear_rtc_enable_interrupt(config);
331 break;
332 default:
333 ret = -EINVAL;
334 break;
335 }
336
337 return ret;
338 }
339
340 static const struct rtc_class_ops spear_rtc_ops = {
341 .read_time = spear_rtc_read_time,
342 .set_time = spear_rtc_set_time,
343 .read_alarm = spear_rtc_read_alarm,
344 .set_alarm = spear_rtc_set_alarm,
345 .alarm_irq_enable = spear_alarm_irq_enable,
346 };
347
348 static int spear_rtc_probe(struct platform_device *pdev)
349 {
350 struct resource *res;
351 struct spear_rtc_config *config;
352 int status = 0;
353 int irq;
354
355 config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
356 if (!config)
357 return -ENOMEM;
358
359 /* alarm irqs */
360 irq = platform_get_irq(pdev, 0);
361 if (irq < 0) {
362 dev_err(&pdev->dev, "no update irq?\n");
363 return irq;
364 }
365
366 status = devm_request_irq(&pdev->dev, irq, spear_rtc_irq, 0, pdev->name,
367 config);
368 if (status) {
369 dev_err(&pdev->dev, "Alarm interrupt IRQ%d already claimed\n",
370 irq);
371 return status;
372 }
373
374 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
375 config->ioaddr = devm_ioremap_resource(&pdev->dev, res);
376 if (IS_ERR(config->ioaddr))
377 return PTR_ERR(config->ioaddr);
378
379 config->clk = devm_clk_get(&pdev->dev, NULL);
380 if (IS_ERR(config->clk))
381 return PTR_ERR(config->clk);
382
383 status = clk_prepare_enable(config->clk);
384 if (status < 0)
385 return status;
386
387 spin_lock_init(&config->lock);
388 platform_set_drvdata(pdev, config);
389
390 config->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
391 &spear_rtc_ops, THIS_MODULE);
392 if (IS_ERR(config->rtc)) {
393 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
394 PTR_ERR(config->rtc));
395 status = PTR_ERR(config->rtc);
396 goto err_disable_clock;
397 }
398
399 config->rtc->uie_unsupported = 1;
400
401 if (!device_can_wakeup(&pdev->dev))
402 device_init_wakeup(&pdev->dev, 1);
403
404 return 0;
405
406 err_disable_clock:
407 clk_disable_unprepare(config->clk);
408
409 return status;
410 }
411
412 static int spear_rtc_remove(struct platform_device *pdev)
413 {
414 struct spear_rtc_config *config = platform_get_drvdata(pdev);
415
416 spear_rtc_disable_interrupt(config);
417 clk_disable_unprepare(config->clk);
418 device_init_wakeup(&pdev->dev, 0);
419
420 return 0;
421 }
422
423 #ifdef CONFIG_PM_SLEEP
424 static int spear_rtc_suspend(struct device *dev)
425 {
426 struct platform_device *pdev = to_platform_device(dev);
427 struct spear_rtc_config *config = platform_get_drvdata(pdev);
428 int irq;
429
430 irq = platform_get_irq(pdev, 0);
431 if (device_may_wakeup(&pdev->dev)) {
432 if (!enable_irq_wake(irq))
433 config->irq_wake = 1;
434 } else {
435 spear_rtc_disable_interrupt(config);
436 clk_disable(config->clk);
437 }
438
439 return 0;
440 }
441
442 static int spear_rtc_resume(struct device *dev)
443 {
444 struct platform_device *pdev = to_platform_device(dev);
445 struct spear_rtc_config *config = platform_get_drvdata(pdev);
446 int irq;
447
448 irq = platform_get_irq(pdev, 0);
449
450 if (device_may_wakeup(&pdev->dev)) {
451 if (config->irq_wake) {
452 disable_irq_wake(irq);
453 config->irq_wake = 0;
454 }
455 } else {
456 clk_enable(config->clk);
457 spear_rtc_enable_interrupt(config);
458 }
459
460 return 0;
461 }
462 #endif
463
464 static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume);
465
466 static void spear_rtc_shutdown(struct platform_device *pdev)
467 {
468 struct spear_rtc_config *config = platform_get_drvdata(pdev);
469
470 spear_rtc_disable_interrupt(config);
471 clk_disable(config->clk);
472 }
473
474 #ifdef CONFIG_OF
475 static const struct of_device_id spear_rtc_id_table[] = {
476 { .compatible = "st,spear600-rtc" },
477 {}
478 };
479 MODULE_DEVICE_TABLE(of, spear_rtc_id_table);
480 #endif
481
482 static struct platform_driver spear_rtc_driver = {
483 .probe = spear_rtc_probe,
484 .remove = spear_rtc_remove,
485 .shutdown = spear_rtc_shutdown,
486 .driver = {
487 .name = "rtc-spear",
488 .pm = &spear_rtc_pm_ops,
489 .of_match_table = of_match_ptr(spear_rtc_id_table),
490 },
491 };
492
493 module_platform_driver(spear_rtc_driver);
494
495 MODULE_ALIAS("platform:rtc-spear");
496 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
497 MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
498 MODULE_LICENSE("GPL");
Linux with added FPC-III support