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