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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
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
34#define SECONDS_UNITS (0xf<<0)
35#define SECONDS_TENS (0x7<<4)
36#define MINUTES_UNITS (0xf<<8)
37#define MINUTES_TENS (0x7<<12)
38#define HOURS_UNITS (0xf<<16)
39#define HOURS_TENS (0x3<<20)
40
41
42#define DAYS_UNITS (0xf<<0)
43#define DAYS_TENS (0x3<<4)
44#define MONTHS_UNITS (0xf<<8)
45#define MONTHS_TENS (0x1<<12)
46#define YEARS_UNITS (0xf<<16)
47#define YEARS_TENS (0xf<<20)
48#define YEARS_HUNDREDS (0xf<<24)
49#define YEARS_MILLENIUMS (0xf<<28)
50
51
52#define SECOND_SHIFT 0x00
53#define MINUTE_SHIFT 0x08
54#define HOUR_SHIFT 0x10
55#define MDAY_SHIFT 0x00
56#define MONTH_SHIFT 0x08
57#define YEAR_SHIFT 0x10
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
67#define TIME_BYP (1<<9)
68#define INT_ENABLE (1<<31)
69
70
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
80struct 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
88static 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
100static 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
112static 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
123static 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
136static void rtc_wait_not_busy(struct spear_rtc_config *config)
137{
138 int status, count = 0;
139 unsigned long flags;
140
141
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
149 msleep(1);
150 }
151}
152
153static 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
173static 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
183static 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
191 tm->tm_year = bcd2bin(tm->tm_year);
192}
193
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200
201
202static 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
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
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229
230
231static 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
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253
254
255
256
257static 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
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283
284
285
286
287static 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
316static 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
326 spear_rtc_disable_interrupt(config);
327 break;
328 case 1:
329
330 spear_rtc_enable_interrupt(config);
331 break;
332 default:
333 ret = -EINVAL;
334 break;
335 }
336
337 return ret;
338}
339
340static 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
348static 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
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
406err_disable_clock:
407 clk_disable_unprepare(config->clk);
408
409 return status;
410}
411
412static 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
424static 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
442static 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
464static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume);
465
466static 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
475static const struct of_device_id spear_rtc_id_table[] = {
476 { .compatible = "st,spear600-rtc" },
477 {}
478};
479MODULE_DEVICE_TABLE(of, spear_rtc_id_table);
480#endif
481
482static 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
493module_platform_driver(spear_rtc_driver);
494
495MODULE_ALIAS("platform:rtc-spear");
496MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
497MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)");
498MODULE_LICENSE("GPL");
499
