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Merge branch 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
[linux-2.6.git] / drivers / rtc / rtc-mxc.c
blob0b06c1e03fd5b764d12d482c27e13cb19a00e14a
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/slab.h>
16 #include <linux/interrupt.h>
17 #include <linux/platform_device.h>
18 #include <linux/clk.h>
19
20 #include <mach/hardware.h>
21
22 #define RTC_INPUT_CLK_32768HZ (0x00 << 5)
23 #define RTC_INPUT_CLK_32000HZ (0x01 << 5)
24 #define RTC_INPUT_CLK_38400HZ (0x02 << 5)
25
26 #define RTC_SW_BIT (1 << 0)
27 #define RTC_ALM_BIT (1 << 2)
28 #define RTC_1HZ_BIT (1 << 4)
29 #define RTC_2HZ_BIT (1 << 7)
30 #define RTC_SAM0_BIT (1 << 8)
31 #define RTC_SAM1_BIT (1 << 9)
32 #define RTC_SAM2_BIT (1 << 10)
33 #define RTC_SAM3_BIT (1 << 11)
34 #define RTC_SAM4_BIT (1 << 12)
35 #define RTC_SAM5_BIT (1 << 13)
36 #define RTC_SAM6_BIT (1 << 14)
37 #define RTC_SAM7_BIT (1 << 15)
38 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
39 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
40 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
41
42 #define RTC_ENABLE_BIT (1 << 7)
43
44 #define MAX_PIE_NUM 9
45 #define MAX_PIE_FREQ 512
46 static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = {
47 { 2, RTC_2HZ_BIT },
48 { 4, RTC_SAM0_BIT },
49 { 8, RTC_SAM1_BIT },
50 { 16, RTC_SAM2_BIT },
51 { 32, RTC_SAM3_BIT },
52 { 64, RTC_SAM4_BIT },
53 { 128, RTC_SAM5_BIT },
54 { 256, RTC_SAM6_BIT },
55 { MAX_PIE_FREQ, RTC_SAM7_BIT },
56 };
57
58 /* Those are the bits from a classic RTC we want to mimic */
59 #define RTC_IRQF 0x80 /* any of the following 3 is active */
60 #define RTC_PF 0x40 /* Periodic interrupt */
61 #define RTC_AF 0x20 /* Alarm interrupt */
62 #define RTC_UF 0x10 /* Update interrupt for 1Hz RTC */
63
64 #define MXC_RTC_TIME 0
65 #define MXC_RTC_ALARM 1
66
67 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
68 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
69 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
70 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
71 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
72 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
73 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
74 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
75 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
76 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
77 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
78 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
79 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
80
81 struct rtc_plat_data {
82 struct rtc_device *rtc;
83 void __iomem *ioaddr;
84 int irq;
85 struct clk *clk;
86 struct rtc_time g_rtc_alarm;
87 };
88
89 /*
90 * This function is used to obtain the RTC time or the alarm value in
91 * second.
92 */
93 static u32 get_alarm_or_time(struct device *dev, int time_alarm)
94 {
95 struct platform_device *pdev = to_platform_device(dev);
96 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
97 void __iomem *ioaddr = pdata->ioaddr;
98 u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
99
100 switch (time_alarm) {
101 case MXC_RTC_TIME:
102 day = readw(ioaddr + RTC_DAYR);
103 hr_min = readw(ioaddr + RTC_HOURMIN);
104 sec = readw(ioaddr + RTC_SECOND);
105 break;
106 case MXC_RTC_ALARM:
107 day = readw(ioaddr + RTC_DAYALARM);
108 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
109 sec = readw(ioaddr + RTC_ALRM_SEC);
110 break;
111 }
112
113 hr = hr_min >> 8;
114 min = hr_min & 0xff;
115
116 return (((day * 24 + hr) * 60) + min) * 60 + sec;
117 }
118
119 /*
120 * This function sets the RTC alarm value or the time value.
121 */
122 static void set_alarm_or_time(struct device *dev, int time_alarm, u32 time)
123 {
124 u32 day, hr, min, sec, temp;
125 struct platform_device *pdev = to_platform_device(dev);
126 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
127 void __iomem *ioaddr = pdata->ioaddr;
128
129 day = time / 86400;
130 time -= day * 86400;
131
132 /* time is within a day now */
133 hr = time / 3600;
134 time -= hr * 3600;
135
136 /* time is within an hour now */
137 min = time / 60;
138 sec = time - min * 60;
139
140 temp = (hr << 8) + min;
141
142 switch (time_alarm) {
143 case MXC_RTC_TIME:
144 writew(day, ioaddr + RTC_DAYR);
145 writew(sec, ioaddr + RTC_SECOND);
146 writew(temp, ioaddr + RTC_HOURMIN);
147 break;
148 case MXC_RTC_ALARM:
149 writew(day, ioaddr + RTC_DAYALARM);
150 writew(sec, ioaddr + RTC_ALRM_SEC);
151 writew(temp, ioaddr + RTC_ALRM_HM);
152 break;
153 }
154 }
155
156 /*
157 * This function updates the RTC alarm registers and then clears all the
158 * interrupt status bits.
159 */
160 static int rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
161 {
162 struct rtc_time alarm_tm, now_tm;
163 unsigned long now, time;
164 int ret;
165 struct platform_device *pdev = to_platform_device(dev);
166 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
167 void __iomem *ioaddr = pdata->ioaddr;
168
169 now = get_alarm_or_time(dev, MXC_RTC_TIME);
170 rtc_time_to_tm(now, &now_tm);
171 alarm_tm.tm_year = now_tm.tm_year;
172 alarm_tm.tm_mon = now_tm.tm_mon;
173 alarm_tm.tm_mday = now_tm.tm_mday;
174 alarm_tm.tm_hour = alrm->tm_hour;
175 alarm_tm.tm_min = alrm->tm_min;
176 alarm_tm.tm_sec = alrm->tm_sec;
177 rtc_tm_to_time(&now_tm, &now);
178 rtc_tm_to_time(&alarm_tm, &time);
179
180 if (time < now) {
181 time += 60 * 60 * 24;
182 rtc_time_to_tm(time, &alarm_tm);
183 }
184
185 ret = rtc_tm_to_time(&alarm_tm, &time);
186
187 /* clear all the interrupt status bits */
188 writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
189 set_alarm_or_time(dev, MXC_RTC_ALARM, time);
190
191 return ret;
192 }
193
194 /* This function is the RTC interrupt service routine. */
195 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
196 {
197 struct platform_device *pdev = dev_id;
198 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
199 void __iomem *ioaddr = pdata->ioaddr;
200 u32 status;
201 u32 events = 0;
202
203 spin_lock_irq(&pdata->rtc->irq_lock);
204 status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
205 /* clear interrupt sources */
206 writew(status, ioaddr + RTC_RTCISR);
207
208 /* clear alarm interrupt if it has occurred */
209 if (status & RTC_ALM_BIT)
210 status &= ~RTC_ALM_BIT;
211
212 /* update irq data & counter */
213 if (status & RTC_ALM_BIT)
214 events |= (RTC_AF | RTC_IRQF);
215
216 if (status & RTC_1HZ_BIT)
217 events |= (RTC_UF | RTC_IRQF);
218
219 if (status & PIT_ALL_ON)
220 events |= (RTC_PF | RTC_IRQF);
221
222 if ((status & RTC_ALM_BIT) && rtc_valid_tm(&pdata->g_rtc_alarm))
223 rtc_update_alarm(&pdev->dev, &pdata->g_rtc_alarm);
224
225 rtc_update_irq(pdata->rtc, 1, events);
226 spin_unlock_irq(&pdata->rtc->irq_lock);
227
228 return IRQ_HANDLED;
229 }
230
231 /*
232 * Clear all interrupts and release the IRQ
233 */
234 static void mxc_rtc_release(struct device *dev)
235 {
236 struct platform_device *pdev = to_platform_device(dev);
237 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
238 void __iomem *ioaddr = pdata->ioaddr;
239
240 spin_lock_irq(&pdata->rtc->irq_lock);
241
242 /* Disable all rtc interrupts */
243 writew(0, ioaddr + RTC_RTCIENR);
244
245 /* Clear all interrupt status */
246 writew(0xffffffff, ioaddr + RTC_RTCISR);
247
248 spin_unlock_irq(&pdata->rtc->irq_lock);
249 }
250
251 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
252 unsigned int enabled)
253 {
254 struct platform_device *pdev = to_platform_device(dev);
255 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
256 void __iomem *ioaddr = pdata->ioaddr;
257 u32 reg;
258
259 spin_lock_irq(&pdata->rtc->irq_lock);
260 reg = readw(ioaddr + RTC_RTCIENR);
261
262 if (enabled)
263 reg |= bit;
264 else
265 reg &= ~bit;
266
267 writew(reg, ioaddr + RTC_RTCIENR);
268 spin_unlock_irq(&pdata->rtc->irq_lock);
269 }
270
271 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
272 {
273 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
274 return 0;
275 }
276
277 static int mxc_rtc_update_irq_enable(struct device *dev, unsigned int enabled)
278 {
279 mxc_rtc_irq_enable(dev, RTC_1HZ_BIT, enabled);
280 return 0;
281 }
282
283 /*
284 * This function reads the current RTC time into tm in Gregorian date.
285 */
286 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
287 {
288 u32 val;
289
290 /* Avoid roll-over from reading the different registers */
291 do {
292 val = get_alarm_or_time(dev, MXC_RTC_TIME);
293 } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
294
295 rtc_time_to_tm(val, tm);
296
297 return 0;
298 }
299
300 /*
301 * This function sets the internal RTC time based on tm in Gregorian date.
302 */
303 static int mxc_rtc_set_mmss(struct device *dev, unsigned long time)
304 {
305 /* Avoid roll-over from reading the different registers */
306 do {
307 set_alarm_or_time(dev, MXC_RTC_TIME, time);
308 } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
309
310 return 0;
311 }
312
313 /*
314 * This function reads the current alarm value into the passed in 'alrm'
315 * argument. It updates the alrm's pending field value based on the whether
316 * an alarm interrupt occurs or not.
317 */
318 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
319 {
320 struct platform_device *pdev = to_platform_device(dev);
321 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
322 void __iomem *ioaddr = pdata->ioaddr;
323
324 rtc_time_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
325 alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
326
327 return 0;
328 }
329
330 /*
331 * This function sets the RTC alarm based on passed in alrm.
332 */
333 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
334 {
335 struct platform_device *pdev = to_platform_device(dev);
336 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
337 int ret;
338
339 if (rtc_valid_tm(&alrm->time)) {
340 if (alrm->time.tm_sec > 59 ||
341 alrm->time.tm_hour > 23 ||
342 alrm->time.tm_min > 59)
343 return -EINVAL;
344
345 ret = rtc_update_alarm(dev, &alrm->time);
346 } else {
347 ret = rtc_valid_tm(&alrm->time);
348 if (ret)
349 return ret;
350
351 ret = rtc_update_alarm(dev, &alrm->time);
352 }
353
354 if (ret)
355 return ret;
356
357 memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
358 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
359
360 return 0;
361 }
362
363 /* RTC layer */
364 static struct rtc_class_ops mxc_rtc_ops = {
365 .release = mxc_rtc_release,
366 .read_time = mxc_rtc_read_time,
367 .set_mmss = mxc_rtc_set_mmss,
368 .read_alarm = mxc_rtc_read_alarm,
369 .set_alarm = mxc_rtc_set_alarm,
370 .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
371 .update_irq_enable = mxc_rtc_update_irq_enable,
372 };
373
374 static int __init mxc_rtc_probe(struct platform_device *pdev)
375 {
376 struct resource *res;
377 struct rtc_device *rtc;
378 struct rtc_plat_data *pdata = NULL;
379 u32 reg;
380 unsigned long rate;
381 int ret;
382
383 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
384 if (!res)
385 return -ENODEV;
386
387 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
388 if (!pdata)
389 return -ENOMEM;
390
391 if (!devm_request_mem_region(&pdev->dev, res->start,
392 resource_size(res), pdev->name))
393 return -EBUSY;
394
395 pdata->ioaddr = devm_ioremap(&pdev->dev, res->start,
396 resource_size(res));
397
398 pdata->clk = clk_get(&pdev->dev, "rtc");
399 if (IS_ERR(pdata->clk)) {
400 dev_err(&pdev->dev, "unable to get clock!\n");
401 ret = PTR_ERR(pdata->clk);
402 goto exit_free_pdata;
403 }
404
405 clk_enable(pdata->clk);
406 rate = clk_get_rate(pdata->clk);
407
408 if (rate == 32768)
409 reg = RTC_INPUT_CLK_32768HZ;
410 else if (rate == 32000)
411 reg = RTC_INPUT_CLK_32000HZ;
412 else if (rate == 38400)
413 reg = RTC_INPUT_CLK_38400HZ;
414 else {
415 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
416 ret = -EINVAL;
417 goto exit_put_clk;
418 }
419
420 reg |= RTC_ENABLE_BIT;
421 writew(reg, (pdata->ioaddr + RTC_RTCCTL));
422 if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
423 dev_err(&pdev->dev, "hardware module can't be enabled!\n");
424 ret = -EIO;
425 goto exit_put_clk;
426 }
427
428 rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
429 THIS_MODULE);
430 if (IS_ERR(rtc)) {
431 ret = PTR_ERR(rtc);
432 goto exit_put_clk;
433 }
434
435 pdata->rtc = rtc;
436 platform_set_drvdata(pdev, pdata);
437
438 /* Configure and enable the RTC */
439 pdata->irq = platform_get_irq(pdev, 0);
440
441 if (pdata->irq >= 0 &&
442 devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
443 IRQF_SHARED, pdev->name, pdev) < 0) {
444 dev_warn(&pdev->dev, "interrupt not available.\n");
445 pdata->irq = -1;
446 }
447
448 return 0;
449
450 exit_put_clk:
451 clk_disable(pdata->clk);
452 clk_put(pdata->clk);
453
454 exit_free_pdata:
455
456 return ret;
457 }
458
459 static int __exit mxc_rtc_remove(struct platform_device *pdev)
460 {
461 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
462
463 rtc_device_unregister(pdata->rtc);
464
465 clk_disable(pdata->clk);
466 clk_put(pdata->clk);
467 platform_set_drvdata(pdev, NULL);
468
469 return 0;
470 }
471
472 static struct platform_driver mxc_rtc_driver = {
473 .driver = {
474 .name = "mxc_rtc",
475 .owner = THIS_MODULE,
476 },
477 .remove = __exit_p(mxc_rtc_remove),
478 };
479
480 static int __init mxc_rtc_init(void)
481 {
482 return platform_driver_probe(&mxc_rtc_driver, mxc_rtc_probe);
483 }
484
485 static void __exit mxc_rtc_exit(void)
486 {
487 platform_driver_unregister(&mxc_rtc_driver);
488 }
489
490 module_init(mxc_rtc_init);
491 module_exit(mxc_rtc_exit);
492
493 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
494 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
495 MODULE_LICENSE("GPL");
496
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