tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
30#include <mach/hardware.h>
31
32#define TIMER_FREQ CLOCK_TICK_RATE
33#define RTC_DEF_DIVIDER (32768 - 1)
34#define RTC_DEF_TRIM 0
35#define MAXFREQ_PERIODIC 1000
36
37/*
38 * PXA Registers and bits definitions
39 */
40#define RTSR_PICE (1 << 15) /* Periodic interrupt count enable */
41#define RTSR_PIALE (1 << 14) /* Periodic interrupt Alarm enable */
42#define RTSR_PIAL (1 << 13) /* Periodic interrupt detected */
43#define RTSR_SWALE2 (1 << 11) /* RTC stopwatch alarm2 enable */
44#define RTSR_SWAL2 (1 << 10) /* RTC stopwatch alarm2 detected */
45#define RTSR_SWALE1 (1 << 9) /* RTC stopwatch alarm1 enable */
46#define RTSR_SWAL1 (1 << 8) /* RTC stopwatch alarm1 detected */
47#define RTSR_RDALE2 (1 << 7) /* RTC alarm2 enable */
48#define RTSR_RDAL2 (1 << 6) /* RTC alarm2 detected */
49#define RTSR_RDALE1 (1 << 5) /* RTC alarm1 enable */
50#define RTSR_RDAL1 (1 << 4) /* RTC alarm1 detected */
51#define RTSR_HZE (1 << 3) /* HZ interrupt enable */
52#define RTSR_ALE (1 << 2) /* RTC alarm interrupt enable */
53#define RTSR_HZ (1 << 1) /* HZ rising-edge detected */
54#define RTSR_AL (1 << 0) /* RTC alarm detected */
55#define RTSR_TRIG_MASK (RTSR_AL | RTSR_HZ | RTSR_RDAL1 | RTSR_RDAL2\
56 | RTSR_SWAL1 | RTSR_SWAL2)
57#define RYxR_YEAR_S 9
58#define RYxR_YEAR_MASK (0xfff << RYxR_YEAR_S)
59#define RYxR_MONTH_S 5
60#define RYxR_MONTH_MASK (0xf << RYxR_MONTH_S)
61#define RYxR_DAY_MASK 0x1f
62#define RDxR_HOUR_S 12
63#define RDxR_HOUR_MASK (0x1f << RDxR_HOUR_S)
64#define RDxR_MIN_S 6
65#define RDxR_MIN_MASK (0x3f << RDxR_MIN_S)
66#define RDxR_SEC_MASK 0x3f
67
68#define RTSR 0x08
69#define RTTR 0x0c
70#define RDCR 0x10
71#define RYCR 0x14
72#define RDAR1 0x18
73#define RYAR1 0x1c
74#define RTCPICR 0x34
75#define PIAR 0x38
76
77#define rtc_readl(pxa_rtc, reg) \
78 __raw_readl((pxa_rtc)->base + (reg))
79#define rtc_writel(pxa_rtc, reg, value) \
80 __raw_writel((value), (pxa_rtc)->base + (reg))
81
82struct pxa_rtc {
83 struct resource *ress;
84 void __iomem *base;
85 int irq_1Hz;
86 int irq_Alrm;
87 struct rtc_device *rtc;
88 spinlock_t lock; /* Protects this structure */
89 struct rtc_time rtc_alarm;
90};
91
92static 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
99static 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
105static 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
115static 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
125static 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
135static 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
172static 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, IRQF_DISABLED,
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, IRQF_DISABLED,
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
194err_irq_Alrm:
195 free_irq(pxa_rtc->irq_1Hz, dev);
196err_irq_1Hz:
197 return ret;
198}
199
200static 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
212static int pxa_periodic_irq_set_freq(struct device *dev, int freq)
213{
214 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
215 int period_ms;
216
217 if (freq < 1 || freq > MAXFREQ_PERIODIC)
218 return -EINVAL;
219
220 period_ms = 1000 / freq;
221 rtc_writel(pxa_rtc, PIAR, period_ms);
222
223 return 0;
224}
225
226static int pxa_periodic_irq_set_state(struct device *dev, int enabled)
227{
228 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
229
230 if (enabled)
231 rtsr_set_bits(pxa_rtc, RTSR_PIALE | RTSR_PICE);
232 else
233 rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_PICE);
234
235 return 0;
236}
237
238static int pxa_rtc_ioctl(struct device *dev, unsigned int cmd,
239 unsigned long arg)
240{
241 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
242 int ret = 0;
243
244 spin_lock_irq(&pxa_rtc->lock);
245 switch (cmd) {
246 case RTC_AIE_OFF:
247 rtsr_clear_bits(pxa_rtc, RTSR_RDALE1);
248 break;
249 case RTC_AIE_ON:
250 rtsr_set_bits(pxa_rtc, RTSR_RDALE1);
251 break;
252 case RTC_UIE_OFF:
253 rtsr_clear_bits(pxa_rtc, RTSR_HZE);
254 break;
255 case RTC_UIE_ON:
256 rtsr_set_bits(pxa_rtc, RTSR_HZE);
257 break;
258 default:
259 ret = -ENOIOCTLCMD;
260 }
261
262 spin_unlock_irq(&pxa_rtc->lock);
263 return ret;
264}
265
266static int pxa_rtc_read_time(struct device *dev, struct rtc_time *tm)
267{
268 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
269 u32 rycr, rdcr;
270
271 rycr = rtc_readl(pxa_rtc, RYCR);
272 rdcr = rtc_readl(pxa_rtc, RDCR);
273
274 tm_calc(rycr, rdcr, tm);
275 return 0;
276}
277
278static int pxa_rtc_set_time(struct device *dev, struct rtc_time *tm)
279{
280 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
281
282 rtc_writel(pxa_rtc, RYCR, ryxr_calc(tm));
283 rtc_writel(pxa_rtc, RDCR, rdxr_calc(tm));
284
285 return 0;
286}
287
288static int pxa_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
289{
290 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
291 u32 rtsr, ryar, rdar;
292
293 ryar = rtc_readl(pxa_rtc, RYAR1);
294 rdar = rtc_readl(pxa_rtc, RDAR1);
295 tm_calc(ryar, rdar, &alrm->time);
296
297 rtsr = rtc_readl(pxa_rtc, RTSR);
298 alrm->enabled = (rtsr & RTSR_RDALE1) ? 1 : 0;
299 alrm->pending = (rtsr & RTSR_RDAL1) ? 1 : 0;
300 return 0;
301}
302
303static int pxa_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
304{
305 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
306 u32 rtsr;
307
308 spin_lock_irq(&pxa_rtc->lock);
309
310 rtc_writel(pxa_rtc, RYAR1, ryxr_calc(&alrm->time));
311 rtc_writel(pxa_rtc, RDAR1, rdxr_calc(&alrm->time));
312
313 rtsr = rtc_readl(pxa_rtc, RTSR);
314 if (alrm->enabled)
315 rtsr |= RTSR_RDALE1;
316 else
317 rtsr &= ~RTSR_RDALE1;
318 rtc_writel(pxa_rtc, RTSR, rtsr);
319
320 spin_unlock_irq(&pxa_rtc->lock);
321
322 return 0;
323}
324
325static int pxa_rtc_proc(struct device *dev, struct seq_file *seq)
326{
327 struct pxa_rtc *pxa_rtc = dev_get_drvdata(dev);
328
329 seq_printf(seq, "trim/divider\t: 0x%08x\n", rtc_readl(pxa_rtc, RTTR));
330 seq_printf(seq, "update_IRQ\t: %s\n",
331 (rtc_readl(pxa_rtc, RTSR) & RTSR_HZE) ? "yes" : "no");
332 seq_printf(seq, "periodic_IRQ\t: %s\n",
333 (rtc_readl(pxa_rtc, RTSR) & RTSR_PIALE) ? "yes" : "no");
334 seq_printf(seq, "periodic_freq\t: %u\n", rtc_readl(pxa_rtc, PIAR));
335
336 return 0;
337}
338
339static const struct rtc_class_ops pxa_rtc_ops = {
340 .open = pxa_rtc_open,
341 .release = pxa_rtc_release,
342 .ioctl = pxa_rtc_ioctl,
343 .read_time = pxa_rtc_read_time,
344 .set_time = pxa_rtc_set_time,
345 .read_alarm = pxa_rtc_read_alarm,
346 .set_alarm = pxa_rtc_set_alarm,
347 .proc = pxa_rtc_proc,
348 .irq_set_state = pxa_periodic_irq_set_state,
349 .irq_set_freq = pxa_periodic_irq_set_freq,
350};
351
352static int __init pxa_rtc_probe(struct platform_device *pdev)
353{
354 struct device *dev = &pdev->dev;
355 struct pxa_rtc *pxa_rtc;
356 int ret;
357 u32 rttr;
358
359 pxa_rtc = kzalloc(sizeof(struct pxa_rtc), GFP_KERNEL);
360 if (!pxa_rtc)
361 return -ENOMEM;
362
363 spin_lock_init(&pxa_rtc->lock);
364 platform_set_drvdata(pdev, pxa_rtc);
365
366 ret = -ENXIO;
367 pxa_rtc->ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
368 if (!pxa_rtc->ress) {
369 dev_err(dev, "No I/O memory resource defined\n");
370 goto err_ress;
371 }
372
373 pxa_rtc->irq_1Hz = platform_get_irq(pdev, 0);
374 if (pxa_rtc->irq_1Hz < 0) {
375 dev_err(dev, "No 1Hz IRQ resource defined\n");
376 goto err_ress;
377 }
378 pxa_rtc->irq_Alrm = platform_get_irq(pdev, 1);
379 if (pxa_rtc->irq_Alrm < 0) {
380 dev_err(dev, "No alarm IRQ resource defined\n");
381 goto err_ress;
382 }
383
384 ret = -ENOMEM;
385 pxa_rtc->base = ioremap(pxa_rtc->ress->start,
386 resource_size(pxa_rtc->ress));
387 if (!pxa_rtc->base) {
388 dev_err(&pdev->dev, "Unable to map pxa RTC I/O memory\n");
389 goto err_map;
390 }
391
392 /*
393 * If the clock divider is uninitialized then reset it to the
394 * default value to get the 1Hz clock.
395 */
396 if (rtc_readl(pxa_rtc, RTTR) == 0) {
397 rttr = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
398 rtc_writel(pxa_rtc, RTTR, rttr);
399 dev_warn(dev, "warning: initializing default clock"
400 " divider/trim value\n");
401 }
402
403 rtsr_clear_bits(pxa_rtc, RTSR_PIALE | RTSR_RDALE1 | RTSR_HZE);
404
405 pxa_rtc->rtc = rtc_device_register("pxa-rtc", &pdev->dev, &pxa_rtc_ops,
406 THIS_MODULE);
407 ret = PTR_ERR(pxa_rtc->rtc);
408 if (IS_ERR(pxa_rtc->rtc)) {
409 dev_err(dev, "Failed to register RTC device -> %d\n", ret);
410 goto err_rtc_reg;
411 }
412
413 device_init_wakeup(dev, 1);
414
415 return 0;
416
417err_rtc_reg:
418 iounmap(pxa_rtc->base);
419err_ress:
420err_map:
421 kfree(pxa_rtc);
422 return ret;
423}
424
425static int __exit pxa_rtc_remove(struct platform_device *pdev)
426{
427 struct pxa_rtc *pxa_rtc = platform_get_drvdata(pdev);
428
429 rtc_device_unregister(pxa_rtc->rtc);
430
431 spin_lock_irq(&pxa_rtc->lock);
432 iounmap(pxa_rtc->base);
433 spin_unlock_irq(&pxa_rtc->lock);
434
435 kfree(pxa_rtc);
436
437 return 0;
438}
439
440#ifdef CONFIG_PM
441static int pxa_rtc_suspend(struct platform_device *pdev, pm_message_t state)
442{
443 struct pxa_rtc *pxa_rtc = platform_get_drvdata(pdev);
444
445 if (device_may_wakeup(&pdev->dev))
446 enable_irq_wake(pxa_rtc->irq_Alrm);
447 return 0;
448}
449
450static int pxa_rtc_resume(struct platform_device *pdev)
451{
452 struct pxa_rtc *pxa_rtc = platform_get_drvdata(pdev);
453
454 if (device_may_wakeup(&pdev->dev))
455 disable_irq_wake(pxa_rtc->irq_Alrm);
456 return 0;
457}
458#else
459#define pxa_rtc_suspend NULL
460#define pxa_rtc_resume NULL
461#endif
462
463static struct platform_driver pxa_rtc_driver = {
464 .remove = __exit_p(pxa_rtc_remove),
465 .suspend = pxa_rtc_suspend,
466 .resume = pxa_rtc_resume,
467 .driver = {
468 .name = "pxa-rtc",
469 },
470};
471
472static int __init pxa_rtc_init(void)
473{
474 if (cpu_is_pxa27x() || cpu_is_pxa3xx())
475 return platform_driver_probe(&pxa_rtc_driver, pxa_rtc_probe);
476
477 return -ENODEV;
478}
479
480static void __exit pxa_rtc_exit(void)
481{
482 platform_driver_unregister(&pxa_rtc_driver);
483}
484
485module_init(pxa_rtc_init);
486module_exit(pxa_rtc_exit);
487
488MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
489MODULE_DESCRIPTION("PXA27x/PXA3xx Realtime Clock Driver (RTC)");
490MODULE_LICENSE("GPL");
491MODULE_ALIAS("platform:pxa-rtc");