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nfsd: make V4ROOT exports read-only
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / rtc / rtc-mxc.c
blob6bd5072d4eb7f4056c226e7982972080fb4f18ff
1 /*
2 * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
3 *
4 * The code contained herein is licensed under the GNU General Public
5 * License. You may obtain a copy of the GNU General Public License
6 * Version 2 or later at the following locations:
7 *
8 * http://www.opensource.org/licenses/gpl-license.html
9 * http://www.gnu.org/copyleft/gpl.html
10 */
11
12 #include <linux/io.h>
13 #include <linux/rtc.h>
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/clk.h>
18
19 #include <mach/hardware.h>
20
21 #define RTC_INPUT_CLK_32768HZ (0x00 << 5)
22 #define RTC_INPUT_CLK_32000HZ (0x01 << 5)
23 #define RTC_INPUT_CLK_38400HZ (0x02 << 5)
24
25 #define RTC_SW_BIT (1 << 0)
26 #define RTC_ALM_BIT (1 << 2)
27 #define RTC_1HZ_BIT (1 << 4)
28 #define RTC_2HZ_BIT (1 << 7)
29 #define RTC_SAM0_BIT (1 << 8)
30 #define RTC_SAM1_BIT (1 << 9)
31 #define RTC_SAM2_BIT (1 << 10)
32 #define RTC_SAM3_BIT (1 << 11)
33 #define RTC_SAM4_BIT (1 << 12)
34 #define RTC_SAM5_BIT (1 << 13)
35 #define RTC_SAM6_BIT (1 << 14)
36 #define RTC_SAM7_BIT (1 << 15)
37 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
38 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
39 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
40
41 #define RTC_ENABLE_BIT (1 << 7)
42
43 #define MAX_PIE_NUM 9
44 #define MAX_PIE_FREQ 512
45 static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = {
46 { 2, RTC_2HZ_BIT },
47 { 4, RTC_SAM0_BIT },
48 { 8, RTC_SAM1_BIT },
49 { 16, RTC_SAM2_BIT },
50 { 32, RTC_SAM3_BIT },
51 { 64, RTC_SAM4_BIT },
52 { 128, RTC_SAM5_BIT },
53 { 256, RTC_SAM6_BIT },
54 { MAX_PIE_FREQ, RTC_SAM7_BIT },
55 };
56
57 /* Those are the bits from a classic RTC we want to mimic */
58 #define RTC_IRQF 0x80 /* any of the following 3 is active */
59 #define RTC_PF 0x40 /* Periodic interrupt */
60 #define RTC_AF 0x20 /* Alarm interrupt */
61 #define RTC_UF 0x10 /* Update interrupt for 1Hz RTC */
62
63 #define MXC_RTC_TIME 0
64 #define MXC_RTC_ALARM 1
65
66 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
67 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
68 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
69 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
70 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
71 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
72 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
73 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
74 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
75 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
76 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
77 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
78 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
79
80 struct rtc_plat_data {
81 struct rtc_device *rtc;
82 void __iomem *ioaddr;
83 int irq;
84 struct clk *clk;
85 unsigned int irqen;
86 int alrm_sec;
87 int alrm_min;
88 int alrm_hour;
89 int alrm_mday;
90 struct timespec mxc_rtc_delta;
91 struct rtc_time g_rtc_alarm;
92 };
93
94 /*
95 * This function is used to obtain the RTC time or the alarm value in
96 * second.
97 */
98 static u32 get_alarm_or_time(struct device *dev, int time_alarm)
99 {
100 struct platform_device *pdev = to_platform_device(dev);
101 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
102 void __iomem *ioaddr = pdata->ioaddr;
103 u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
104
105 switch (time_alarm) {
106 case MXC_RTC_TIME:
107 day = readw(ioaddr + RTC_DAYR);
108 hr_min = readw(ioaddr + RTC_HOURMIN);
109 sec = readw(ioaddr + RTC_SECOND);
110 break;
111 case MXC_RTC_ALARM:
112 day = readw(ioaddr + RTC_DAYALARM);
113 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
114 sec = readw(ioaddr + RTC_ALRM_SEC);
115 break;
116 }
117
118 hr = hr_min >> 8;
119 min = hr_min & 0xff;
120
121 return (((day * 24 + hr) * 60) + min) * 60 + sec;
122 }
123
124 /*
125 * This function sets the RTC alarm value or the time value.
126 */
127 static void set_alarm_or_time(struct device *dev, int time_alarm, u32 time)
128 {
129 u32 day, hr, min, sec, temp;
130 struct platform_device *pdev = to_platform_device(dev);
131 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
132 void __iomem *ioaddr = pdata->ioaddr;
133
134 day = time / 86400;
135 time -= day * 86400;
136
137 /* time is within a day now */
138 hr = time / 3600;
139 time -= hr * 3600;
140
141 /* time is within an hour now */
142 min = time / 60;
143 sec = time - min * 60;
144
145 temp = (hr << 8) + min;
146
147 switch (time_alarm) {
148 case MXC_RTC_TIME:
149 writew(day, ioaddr + RTC_DAYR);
150 writew(sec, ioaddr + RTC_SECOND);
151 writew(temp, ioaddr + RTC_HOURMIN);
152 break;
153 case MXC_RTC_ALARM:
154 writew(day, ioaddr + RTC_DAYALARM);
155 writew(sec, ioaddr + RTC_ALRM_SEC);
156 writew(temp, ioaddr + RTC_ALRM_HM);
157 break;
158 }
159 }
160
161 /*
162 * This function updates the RTC alarm registers and then clears all the
163 * interrupt status bits.
164 */
165 static int rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
166 {
167 struct rtc_time alarm_tm, now_tm;
168 unsigned long now, time;
169 int ret;
170 struct platform_device *pdev = to_platform_device(dev);
171 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
172 void __iomem *ioaddr = pdata->ioaddr;
173
174 now = get_alarm_or_time(dev, MXC_RTC_TIME);
175 rtc_time_to_tm(now, &now_tm);
176 alarm_tm.tm_year = now_tm.tm_year;
177 alarm_tm.tm_mon = now_tm.tm_mon;
178 alarm_tm.tm_mday = now_tm.tm_mday;
179 alarm_tm.tm_hour = alrm->tm_hour;
180 alarm_tm.tm_min = alrm->tm_min;
181 alarm_tm.tm_sec = alrm->tm_sec;
182 rtc_tm_to_time(&now_tm, &now);
183 rtc_tm_to_time(&alarm_tm, &time);
184
185 if (time < now) {
186 time += 60 * 60 * 24;
187 rtc_time_to_tm(time, &alarm_tm);
188 }
189
190 ret = rtc_tm_to_time(&alarm_tm, &time);
191
192 /* clear all the interrupt status bits */
193 writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
194 set_alarm_or_time(dev, MXC_RTC_ALARM, time);
195
196 return ret;
197 }
198
199 /* This function is the RTC interrupt service routine. */
200 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
201 {
202 struct platform_device *pdev = dev_id;
203 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
204 void __iomem *ioaddr = pdata->ioaddr;
205 u32 status;
206 u32 events = 0;
207
208 spin_lock_irq(&pdata->rtc->irq_lock);
209 status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
210 /* clear interrupt sources */
211 writew(status, ioaddr + RTC_RTCISR);
212
213 /* clear alarm interrupt if it has occurred */
214 if (status & RTC_ALM_BIT)
215 status &= ~RTC_ALM_BIT;
216
217 /* update irq data & counter */
218 if (status & RTC_ALM_BIT)
219 events |= (RTC_AF | RTC_IRQF);
220
221 if (status & RTC_1HZ_BIT)
222 events |= (RTC_UF | RTC_IRQF);
223
224 if (status & PIT_ALL_ON)
225 events |= (RTC_PF | RTC_IRQF);
226
227 if ((status & RTC_ALM_BIT) && rtc_valid_tm(&pdata->g_rtc_alarm))
228 rtc_update_alarm(&pdev->dev, &pdata->g_rtc_alarm);
229
230 rtc_update_irq(pdata->rtc, 1, events);
231 spin_unlock_irq(&pdata->rtc->irq_lock);
232
233 return IRQ_HANDLED;
234 }
235
236 /*
237 * Clear all interrupts and release the IRQ
238 */
239 static void mxc_rtc_release(struct device *dev)
240 {
241 struct platform_device *pdev = to_platform_device(dev);
242 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
243 void __iomem *ioaddr = pdata->ioaddr;
244
245 spin_lock_irq(&pdata->rtc->irq_lock);
246
247 /* Disable all rtc interrupts */
248 writew(0, ioaddr + RTC_RTCIENR);
249
250 /* Clear all interrupt status */
251 writew(0xffffffff, ioaddr + RTC_RTCISR);
252
253 spin_unlock_irq(&pdata->rtc->irq_lock);
254 }
255
256 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
257 unsigned int enabled)
258 {
259 struct platform_device *pdev = to_platform_device(dev);
260 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
261 void __iomem *ioaddr = pdata->ioaddr;
262 u32 reg;
263
264 spin_lock_irq(&pdata->rtc->irq_lock);
265 reg = readw(ioaddr + RTC_RTCIENR);
266
267 if (enabled)
268 reg |= bit;
269 else
270 reg &= ~bit;
271
272 writew(reg, ioaddr + RTC_RTCIENR);
273 spin_unlock_irq(&pdata->rtc->irq_lock);
274 }
275
276 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
277 {
278 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
279 return 0;
280 }
281
282 static int mxc_rtc_update_irq_enable(struct device *dev, unsigned int enabled)
283 {
284 mxc_rtc_irq_enable(dev, RTC_1HZ_BIT, enabled);
285 return 0;
286 }
287
288 /*
289 * This function reads the current RTC time into tm in Gregorian date.
290 */
291 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
292 {
293 u32 val;
294
295 /* Avoid roll-over from reading the different registers */
296 do {
297 val = get_alarm_or_time(dev, MXC_RTC_TIME);
298 } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
299
300 rtc_time_to_tm(val, tm);
301
302 return 0;
303 }
304
305 /*
306 * This function sets the internal RTC time based on tm in Gregorian date.
307 */
308 static int mxc_rtc_set_mmss(struct device *dev, unsigned long time)
309 {
310 /* Avoid roll-over from reading the different registers */
311 do {
312 set_alarm_or_time(dev, MXC_RTC_TIME, time);
313 } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
314
315 return 0;
316 }
317
318 /*
319 * This function reads the current alarm value into the passed in 'alrm'
320 * argument. It updates the alrm's pending field value based on the whether
321 * an alarm interrupt occurs or not.
322 */
323 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
324 {
325 struct platform_device *pdev = to_platform_device(dev);
326 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
327 void __iomem *ioaddr = pdata->ioaddr;
328
329 rtc_time_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
330 alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
331
332 return 0;
333 }
334
335 /*
336 * This function sets the RTC alarm based on passed in alrm.
337 */
338 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
339 {
340 struct platform_device *pdev = to_platform_device(dev);
341 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
342 int ret;
343
344 if (rtc_valid_tm(&alrm->time)) {
345 if (alrm->time.tm_sec > 59 ||
346 alrm->time.tm_hour > 23 ||
347 alrm->time.tm_min > 59)
348 return -EINVAL;
349
350 ret = rtc_update_alarm(dev, &alrm->time);
351 } else {
352 ret = rtc_valid_tm(&alrm->time);
353 if (ret)
354 return ret;
355
356 ret = rtc_update_alarm(dev, &alrm->time);
357 }
358
359 if (ret)
360 return ret;
361
362 memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
363 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
364
365 return 0;
366 }
367
368 /* RTC layer */
369 static struct rtc_class_ops mxc_rtc_ops = {
370 .release = mxc_rtc_release,
371 .read_time = mxc_rtc_read_time,
372 .set_mmss = mxc_rtc_set_mmss,
373 .read_alarm = mxc_rtc_read_alarm,
374 .set_alarm = mxc_rtc_set_alarm,
375 .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
376 .update_irq_enable = mxc_rtc_update_irq_enable,
377 };
378
379 static int __init mxc_rtc_probe(struct platform_device *pdev)
380 {
381 struct clk *clk;
382 struct resource *res;
383 struct rtc_device *rtc;
384 struct rtc_plat_data *pdata = NULL;
385 u32 reg;
386 int ret, rate;
387
388 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
389 if (!res)
390 return -ENODEV;
391
392 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
393 if (!pdata)
394 return -ENOMEM;
395
396 pdata->ioaddr = ioremap(res->start, resource_size(res));
397
398 clk = clk_get(&pdev->dev, "ckil");
399 if (IS_ERR(clk))
400 return PTR_ERR(clk);
401
402 rate = clk_get_rate(clk);
403 clk_put(clk);
404
405 if (rate == 32768)
406 reg = RTC_INPUT_CLK_32768HZ;
407 else if (rate == 32000)
408 reg = RTC_INPUT_CLK_32000HZ;
409 else if (rate == 38400)
410 reg = RTC_INPUT_CLK_38400HZ;
411 else {
412 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n",
413 clk_get_rate(clk));
414 ret = -EINVAL;
415 goto exit_free_pdata;
416 }
417
418 reg |= RTC_ENABLE_BIT;
419 writew(reg, (pdata->ioaddr + RTC_RTCCTL));
420 if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
421 dev_err(&pdev->dev, "hardware module can't be enabled!\n");
422 ret = -EIO;
423 goto exit_free_pdata;
424 }
425
426 pdata->clk = clk_get(&pdev->dev, "rtc");
427 if (IS_ERR(pdata->clk)) {
428 dev_err(&pdev->dev, "unable to get clock!\n");
429 ret = PTR_ERR(pdata->clk);
430 goto exit_free_pdata;
431 }
432
433 clk_enable(pdata->clk);
434
435 rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
436 THIS_MODULE);
437 if (IS_ERR(rtc)) {
438 ret = PTR_ERR(rtc);
439 goto exit_put_clk;
440 }
441
442 pdata->rtc = rtc;
443 platform_set_drvdata(pdev, pdata);
444
445 /* Configure and enable the RTC */
446 pdata->irq = platform_get_irq(pdev, 0);
447
448 if (pdata->irq >= 0 &&
449 request_irq(pdata->irq, mxc_rtc_interrupt, IRQF_SHARED,
450 pdev->name, pdev) < 0) {
451 dev_warn(&pdev->dev, "interrupt not available.\n");
452 pdata->irq = -1;
453 }
454
455 return 0;
456
457 exit_put_clk:
458 clk_put(pdata->clk);
459
460 exit_free_pdata:
461 kfree(pdata);
462
463 return ret;
464 }
465
466 static int __exit mxc_rtc_remove(struct platform_device *pdev)
467 {
468 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
469
470 rtc_device_unregister(pdata->rtc);
471
472 if (pdata->irq >= 0)
473 free_irq(pdata->irq, pdev);
474
475 clk_disable(pdata->clk);
476 clk_put(pdata->clk);
477 kfree(pdata);
478 platform_set_drvdata(pdev, NULL);
479
480 return 0;
481 }
482
483 static struct platform_driver mxc_rtc_driver = {
484 .driver = {
485 .name = "mxc_rtc",
486 .owner = THIS_MODULE,
487 },
488 .remove = __exit_p(mxc_rtc_remove),
489 };
490
491 static int __init mxc_rtc_init(void)
492 {
493 return platform_driver_probe(&mxc_rtc_driver, mxc_rtc_probe);
494 }
495
496 static void __exit mxc_rtc_exit(void)
497 {
498 platform_driver_unregister(&mxc_rtc_driver);
499 }
500
501 module_init(mxc_rtc_init);
502 module_exit(mxc_rtc_exit);
503
504 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
505 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
506 MODULE_LICENSE("GPL");
507
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