1 /*
2 * Real Time Clock interface for XScale PXA27x and PXA3xx
3 *
4 * Copyright (C) 2008 Robert Jarzmik
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22 #include <linux/init.h>
23 #include <linux/platform_device.h>
24 #include <linux/module.h>
25 #include <linux/rtc.h>
26 #include <linux/seq_file.h>
27 #include <linux/interrupt.h>
28 #include <linux/io.h>
29 #include <linux/slab.h>
30
31 #include <mach/hardware.h>
32
33 #define TIMER_FREQ CLOCK_TICK_RATE
34 #define RTC_DEF_DIVIDER (32768 - 1)
35 #define RTC_DEF_TRIM 0
36 #define MAXFREQ_PERIODIC 1000
37
38 /*
39 * PXA Registers and bits definitions
40 */
41 #define RTSR_PICE (1 << 15) /* Periodic interrupt count enable */
42 #define RTSR_PIALE (1 << 14) /* Periodic interrupt Alarm enable */
43 #define RTSR_PIAL (1 << 13) /* Periodic interrupt detected */
44 #define RTSR_SWALE2 (1 << 11) /* RTC stopwatch alarm2 enable */
45 #define RTSR_SWAL2 (1 << 10) /* RTC stopwatch alarm2 detected */
46 #define RTSR_SWALE1 (1 << 9) /* RTC stopwatch alarm1 enable */
47 #define RTSR_SWAL1 (1 << 8) /* RTC stopwatch alarm1 detected */
48 #define RTSR_RDALE2 (1 << 7) /* RTC alarm2 enable */
49 #define RTSR_RDAL2 (1 << 6) /* RTC alarm2 detected */
50 #define RTSR_RDALE1 (1 << 5) /* RTC alarm1 enable */
51 #define RTSR_RDAL1 (1 << 4) /* RTC alarm1 detected */
52 #define RTSR_HZE (1 << 3) /* HZ interrupt enable */
53 #define RTSR_ALE (1 << 2) /* RTC alarm interrupt enable */
54 #define RTSR_HZ (1 << 1) /* HZ rising-edge detected */
55 #define RTSR_AL (1 << 0) /* RTC alarm detected */
56 #define RTSR_TRIG_MASK (RTSR_AL | RTSR_HZ | RTSR_RDAL1 | RTSR_RDAL2\
57 | RTSR_SWAL1 | RTSR_SWAL2)
58 #define RYxR_YEAR_S 9
59 #define RYxR_YEAR_MASK (0xfff << RYxR_YEAR_S)
60 #define RYxR_MONTH_S 5
61 #define RYxR_MONTH_MASK (0xf << RYxR_MONTH_S)
62 #define RYxR_DAY_MASK 0x1f
63 #define RDxR_HOUR_S 12
64 #define RDxR_HOUR_MASK (0x1f << RDxR_HOUR_S)
65 #define RDxR_MIN_S 6
66 #define RDxR_MIN_MASK (0x3f << RDxR_MIN_S)
67 #define RDxR_SEC_MASK 0x3f
68
69 #define RTSR 0x08
70 #define RTTR 0x0c
71 #define RDCR 0x10
72 #define RYCR 0x14
73 #define RDAR1 0x18
74 #define RYAR1 0x1c
75 #define RTCPICR 0x34
76 #define PIAR 0x38
77
78 #define rtc_readl(pxa_rtc, reg) \
79 __raw_readl((pxa_rtc)->base + (reg))
80 #define rtc_writel(pxa_rtc, reg, value) \
81 __raw_writel((value), (pxa_rtc)->base + (reg))
82
83 struct pxa_rtc {
84 struct resource *ress;
85 void __iomem *base;
86 int irq_1Hz;
87 int irq_Alrm;
88 struct rtc_device *rtc;
89 spinlock_t lock; /* Protects this structure */
90 };
91
ryxr_calc(struct rtc_time * tm)92 static u32 ryxr_calc(struct rtc_time *tm)
93 {
94 return ((tm->tm_year + 1900) << RYxR_YEAR_S)
95 | ((tm->tm_mon + 1) << RYxR_MONTH_S)
96 | tm->tm_mday;
97 }
98
rdxr_calc(struct rtc_time * tm)99 static u32 rdxr_calc(struct rtc_time *tm)
100 {
101 return (tm->tm_hour << RDxR_HOUR_S) | (tm->tm_min << RDxR_MIN_S)
102 | tm->tm_sec;
103 }
104
tm_calc(u32 rycr,u32 rdcr,struct rtc_time * tm)105 static void tm_calc(u32 rycr, u32 rdcr, struct rtc_time *tm)
106 {
107 tm->tm_year = ((rycr & RYxR_YEAR_MASK) >> RYxR_YEAR_S) - 1900;
108 tm->tm_mon = (((rycr & RYxR_MONTH_MASK) >> RYxR_MONTH_S)) - 1;
109 tm->tm_mday = (rycr & RYxR_DAY_MASK);
110 tm->tm_hour = (rdcr & RDxR_HOUR_MASK) >> RDxR_HOUR_S;
111 tm->tm_min = (rdcr & RDxR_MIN_MASK) >> RDxR_MIN_S;
112 tm->tm_sec = rdcr & RDxR_SEC_MASK;
113 }
114
rtsr_clear_bits(struct pxa_rtc * pxa_rtc,u32 mask)115 static void rtsr_clear_bits(struct pxa_rtc *pxa_rtc, u32 mask)
116 {
117 u32 rtsr;
118
119 rtsr = rtc_readl(pxa_rtc, RTSR);
120 rtsr &= ~RTSR_TRIG_MASK;
121 rtsr &= ~mask;
122 rtc_writel(pxa_rtc, RTSR, rtsr);
123 }
124
rtsr_set_bits(struct pxa_rtc * pxa_rtc,u32 mask)125 static void rtsr_set_bits(struct pxa_rtc *pxa_rtc, u32 mask)
126 {
127 u32 rtsr;
128
129 rtsr = rtc_readl(pxa_rtc, RTSR);
130 rtsr &= ~RTSR_TRIG_MASK;
131 rtsr |= mask;
132 rtc_writel(pxa_rtc, RTSR, rtsr);
133 }
134
pxa_rtc_irq(int irq,void * dev_id)135 static irqreturn_t pxa_rtc_irq(int irq, void *dev_id)
136 {
137 struct platform_device *pdev = to_platform_device(dev_id);
138 struct pxa_rtc *pxa_rtc = platform_get_drvdata(pdev);
139 u32 rtsr;
140 unsigned long events = 0;
141
142 spin_lock(&pxa_rtc->lock);
143
144 /* clear interrupt sources */
145 rtsr = rtc_readl(pxa_rtc, RTSR);
146 rtc_writel(pxa_rtc, RTSR, rtsr);
147
148 /* temporary disable rtc interrupts */
149 rtsr_clear_bits(pxa_rtc, RTSR_RDALE1 | RTSR_PIALE | RTSR_HZE);
150
151 /* clear alarm interrupt if it has occurred */
152 if (rtsr & RTSR_RDAL1)
153 rtsr &= ~RTSR_RDALE1;
154
155 /* update irq data & counter */
156 if (rtsr & RTSR_RDAL1)
157 events |= RTC_AF | RTC_IRQF;
158 if (rtsr & RTSR_HZ)
159 events |= RTC_UF | RTC_IRQF;
160 if (rtsr & RTSR_PIAL)
161 events |= RTC_PF | RTC_IRQF;
162
163 rtc_update_irq(pxa_rtc->rtc, 1, events);
164
165 /* enable back rtc interrupts */
166 rtc_writel(pxa_rtc, RTSR, rtsr & ~RTSR_TRIG_MASK);
167
168 spin_unlock(&pxa_rtc->lock);
169 return IRQ_HANDLED;
170 }
171
pxa_rtc_open(struct device * dev)172 static int pxa_rtc_open(struct device *dev)
173 {
174 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
175 int ret;
176
177 ret = request_irq(pxa_rtc->irq_1Hz, pxa_rtc_irq, 0,
178 "rtc 1Hz", dev);
179 if (ret < 0) {
180 dev_err(dev, "can't get irq %i, err %d\n", pxa_rtc->irq_1Hz,
181 ret);
182 goto err_irq_1Hz;
183 }
184 ret = request_irq(pxa_rtc->irq_Alrm, pxa_rtc_irq, 0,
185 "rtc Alrm", dev);
186 if (ret < 0) {
187 dev_err(dev, "can't get irq %i, err %d\n", pxa_rtc->irq_Alrm,
188 ret);
189 goto err_irq_Alrm;
190 }
191
192 return 0;
193
194 err_irq_Alrm:
195 free_irq(pxa_rtc->irq_1Hz, dev);
196 err_irq_1Hz:
197 return ret;
198 }
199
pxa_rtc_release(struct device * dev)200 static void pxa_rtc_release(struct device *dev)
201 {
202 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
203
204 spin_lock_irq(&pxa_rtc->lock);
205 rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE);
206 spin_unlock_irq(&pxa_rtc->lock);
207
208 free_irq(pxa_rtc->irq_Alrm, dev);
209 free_irq(pxa_rtc->irq_1Hz, dev);
210 }
211
pxa_alarm_irq_enable(struct device * dev,unsigned int enabled)212 static int pxa_alarm_irq_enable(struct device *dev, unsigned int enabled)
213 {
214 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
215
216 spin_lock_irq(&pxa_rtc->lock);
217
218 if (enabled)
219 rtsr_set_bits(pxa_rtc, RTSR_RDALE1);
220 else
221 rtsr_clear_bits(pxa_rtc, RTSR_RDALE1);
222
223 spin_unlock_irq(&pxa_rtc->lock);
224 return 0;
225 }
226
pxa_rtc_read_time(struct device * dev,struct rtc_time * tm)227 static int pxa_rtc_read_time(struct device *dev, struct rtc_time *tm)
228 {
229 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
230 u32 rycr, rdcr;
231
232 rycr = rtc_readl(pxa_rtc, RYCR);
233 rdcr = rtc_readl(pxa_rtc, RDCR);
234
235 tm_calc(rycr, rdcr, tm);
236 return 0;
237 }
238
pxa_rtc_set_time(struct device * dev,struct rtc_time * tm)239 static int pxa_rtc_set_time(struct device *dev, struct rtc_time *tm)
240 {
241 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
242
243 rtc_writel(pxa_rtc, RYCR, ryxr_calc(tm));
244 rtc_writel(pxa_rtc, RDCR, rdxr_calc(tm));
245
246 return 0;
247 }
248
pxa_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)249 static int pxa_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
250 {
251 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
252 u32 rtsr, ryar, rdar;
253
254 ryar = rtc_readl(pxa_rtc, RYAR1);
255 rdar = rtc_readl(pxa_rtc, RDAR1);
256 tm_calc(ryar, rdar, &alrm->time);
257
258 rtsr = rtc_readl(pxa_rtc, RTSR);
259 alrm->enabled = (rtsr & RTSR_RDALE1) ? 1 : 0;
260 alrm->pending = (rtsr & RTSR_RDAL1) ? 1 : 0;
261 return 0;
262 }
263
pxa_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)264 static int pxa_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
265 {
266 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
267 u32 rtsr;
268
269 spin_lock_irq(&pxa_rtc->lock);
270
271 rtc_writel(pxa_rtc, RYAR1, ryxr_calc(&alrm->time));
272 rtc_writel(pxa_rtc, RDAR1, rdxr_calc(&alrm->time));
273
274 rtsr = rtc_readl(pxa_rtc, RTSR);
275 if (alrm->enabled)
276 rtsr |= RTSR_RDALE1;
277 else
278 rtsr &= ~RTSR_RDALE1;
279 rtc_writel(pxa_rtc, RTSR, rtsr);
280
281 spin_unlock_irq(&pxa_rtc->lock);
282
283 return 0;
284 }
285
pxa_rtc_proc(struct device * dev,struct seq_file * seq)286 static int pxa_rtc_proc(struct device *dev, struct seq_file *seq)
287 {
288 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
289
290 seq_printf(seq, "trim/divider\t: 0x%08x\n", rtc_readl(pxa_rtc, RTTR));
291 seq_printf(seq, "update_IRQ\t: %s\n",
292 (rtc_readl(pxa_rtc, RTSR) & RTSR_HZE) ? "yes" : "no");
293 seq_printf(seq, "periodic_IRQ\t: %s\n",
294 (rtc_readl(pxa_rtc, RTSR) & RTSR_PIALE) ? "yes" : "no");
295 seq_printf(seq, "periodic_freq\t: %u\n", rtc_readl(pxa_rtc, PIAR));
296
297 return 0;
298 }
299
300 static const struct rtc_class_ops pxa_rtc_ops = {
301 .open = pxa_rtc_open,
302 .release = pxa_rtc_release,
303 .read_time = pxa_rtc_read_time,
304 .set_time = pxa_rtc_set_time,
305 .read_alarm = pxa_rtc_read_alarm,
306 .set_alarm = pxa_rtc_set_alarm,
307 .alarm_irq_enable = pxa_alarm_irq_enable,
308 .proc = pxa_rtc_proc,
309 };
310
pxa_rtc_probe(struct platform_device * pdev)311 static int __init pxa_rtc_probe(struct platform_device *pdev)
312 {
313 struct device *dev = &pdev->dev;
314 struct pxa_rtc *pxa_rtc;
315 int ret;
316 u32 rttr;
317
318 pxa_rtc = kzalloc(sizeof(struct pxa_rtc), GFP_KERNEL);
319 if (!pxa_rtc)
320 return -ENOMEM;
321
322 spin_lock_init(&pxa_rtc->lock);
323 platform_set_drvdata(pdev, pxa_rtc);
324
325 ret = -ENXIO;
326 pxa_rtc->ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
327 if (!pxa_rtc->ress) {
328 dev_err(dev, "No I/O memory resource defined\n");
329 goto err_ress;
330 }
331
332 pxa_rtc->irq_1Hz = platform_get_irq(pdev, 0);
333 if (pxa_rtc->irq_1Hz < 0) {
334 dev_err(dev, "No 1Hz IRQ resource defined\n");
335 goto err_ress;
336 }
337 pxa_rtc->irq_Alrm = platform_get_irq(pdev, 1);
338 if (pxa_rtc->irq_Alrm < 0) {
339 dev_err(dev, "No alarm IRQ resource defined\n");
340 goto err_ress;
341 }
342
343 ret = -ENOMEM;
344 pxa_rtc->base = ioremap(pxa_rtc->ress->start,
345 resource_size(pxa_rtc->ress));
346 if (!pxa_rtc->base) {
347 dev_err(&pdev->dev, "Unable to map pxa RTC I/O memory\n");
348 goto err_map;
349 }
350
351 /*
352 * If the clock divider is uninitialized then reset it to the
353 * default value to get the 1Hz clock.
354 */
355 if (rtc_readl(pxa_rtc, RTTR) == 0) {
356 rttr = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
357 rtc_writel(pxa_rtc, RTTR, rttr);
358 dev_warn(dev, "warning: initializing default clock"
359 " divider/trim value\n");
360 }
361
362 rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE);
363
364 pxa_rtc->rtc = rtc_device_register("pxa-rtc", &pdev->dev, &pxa_rtc_ops,
365 THIS_MODULE);
366 ret = PTR_ERR(pxa_rtc->rtc);
367 if (IS_ERR(pxa_rtc->rtc)) {
368 dev_err(dev, "Failed to register RTC device -> %d\n", ret);
369 goto err_rtc_reg;
370 }
371
372 device_init_wakeup(dev, 1);
373
374 return 0;
375
376 err_rtc_reg:
377 iounmap(pxa_rtc->base);
378 err_ress:
379 err_map:
380 kfree(pxa_rtc);
381 return ret;
382 }
383
pxa_rtc_remove(struct platform_device * pdev)384 static int __exit pxa_rtc_remove(struct platform_device *pdev)
385 {
386 struct pxa_rtc *pxa_rtc = platform_get_drvdata(pdev);
387
388 rtc_device_unregister(pxa_rtc->rtc);
389
390 spin_lock_irq(&pxa_rtc->lock);
391 iounmap(pxa_rtc->base);
392 spin_unlock_irq(&pxa_rtc->lock);
393
394 kfree(pxa_rtc);
395
396 return 0;
397 }
398
399 #ifdef CONFIG_PM
pxa_rtc_suspend(struct device * dev)400 static int pxa_rtc_suspend(struct device *dev)
401 {
402 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
403
404 if (device_may_wakeup(dev))
405 enable_irq_wake(pxa_rtc->irq_Alrm);
406 return 0;
407 }
408
pxa_rtc_resume(struct device * dev)409 static int pxa_rtc_resume(struct device *dev)
410 {
411 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
412
413 if (device_may_wakeup(dev))
414 disable_irq_wake(pxa_rtc->irq_Alrm);
415 return 0;
416 }
417
418 static const struct dev_pm_ops pxa_rtc_pm_ops = {
419 .suspend = pxa_rtc_suspend,
420 .resume = pxa_rtc_resume,
421 };
422 #endif
423
424 static struct platform_driver pxa_rtc_driver = {
425 .remove = __exit_p(pxa_rtc_remove),
426 .driver = {
427 .name = "pxa-rtc",
428 #ifdef CONFIG_PM
429 .pm = &pxa_rtc_pm_ops,
430 #endif
431 },
432 };
433
pxa_rtc_init(void)434 static int __init pxa_rtc_init(void)
435 {
436 if (cpu_is_pxa27x() || cpu_is_pxa3xx())
437 return platform_driver_probe(&pxa_rtc_driver, pxa_rtc_probe);
438
439 return -ENODEV;
440 }
441
pxa_rtc_exit(void)442 static void __exit pxa_rtc_exit(void)
443 {
444 platform_driver_unregister(&pxa_rtc_driver);
445 }
446
447 module_init(pxa_rtc_init);
448 module_exit(pxa_rtc_exit);
449
450 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
451 MODULE_DESCRIPTION("PXA27x/PXA3xx Realtime Clock Driver (RTC)");
452 MODULE_LICENSE("GPL");
453 MODULE_ALIAS("platform:pxa-rtc");
454