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Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
[linux-btrfs-devel.git] / drivers / rtc / rtc-mxc.c
blob39e41fbdf08ba6de6259347feb0cc5dee76803d7
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 #define MXC_RTC_TIME 0
59 #define MXC_RTC_ALARM 1
60
61 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
62 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
63 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
64 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
65 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
66 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
67 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
68 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
69 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
70 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
71 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
72 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
73 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
74
75 struct rtc_plat_data {
76 struct rtc_device *rtc;
77 void __iomem *ioaddr;
78 int irq;
79 struct clk *clk;
80 struct rtc_time g_rtc_alarm;
81 };
82
83 /*
84 * This function is used to obtain the RTC time or the alarm value in
85 * second.
86 */
87 static u32 get_alarm_or_time(struct device *dev, int time_alarm)
88 {
89 struct platform_device *pdev = to_platform_device(dev);
90 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
91 void __iomem *ioaddr = pdata->ioaddr;
92 u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
93
94 switch (time_alarm) {
95 case MXC_RTC_TIME:
96 day = readw(ioaddr + RTC_DAYR);
97 hr_min = readw(ioaddr + RTC_HOURMIN);
98 sec = readw(ioaddr + RTC_SECOND);
99 break;
100 case MXC_RTC_ALARM:
101 day = readw(ioaddr + RTC_DAYALARM);
102 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
103 sec = readw(ioaddr + RTC_ALRM_SEC);
104 break;
105 }
106
107 hr = hr_min >> 8;
108 min = hr_min & 0xff;
109
110 return (((day * 24 + hr) * 60) + min) * 60 + sec;
111 }
112
113 /*
114 * This function sets the RTC alarm value or the time value.
115 */
116 static void set_alarm_or_time(struct device *dev, int time_alarm, u32 time)
117 {
118 u32 day, hr, min, sec, temp;
119 struct platform_device *pdev = to_platform_device(dev);
120 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
121 void __iomem *ioaddr = pdata->ioaddr;
122
123 day = time / 86400;
124 time -= day * 86400;
125
126 /* time is within a day now */
127 hr = time / 3600;
128 time -= hr * 3600;
129
130 /* time is within an hour now */
131 min = time / 60;
132 sec = time - min * 60;
133
134 temp = (hr << 8) + min;
135
136 switch (time_alarm) {
137 case MXC_RTC_TIME:
138 writew(day, ioaddr + RTC_DAYR);
139 writew(sec, ioaddr + RTC_SECOND);
140 writew(temp, ioaddr + RTC_HOURMIN);
141 break;
142 case MXC_RTC_ALARM:
143 writew(day, ioaddr + RTC_DAYALARM);
144 writew(sec, ioaddr + RTC_ALRM_SEC);
145 writew(temp, ioaddr + RTC_ALRM_HM);
146 break;
147 }
148 }
149
150 /*
151 * This function updates the RTC alarm registers and then clears all the
152 * interrupt status bits.
153 */
154 static int rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
155 {
156 struct rtc_time alarm_tm, now_tm;
157 unsigned long now, time;
158 int ret;
159 struct platform_device *pdev = to_platform_device(dev);
160 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
161 void __iomem *ioaddr = pdata->ioaddr;
162
163 now = get_alarm_or_time(dev, MXC_RTC_TIME);
164 rtc_time_to_tm(now, &now_tm);
165 alarm_tm.tm_year = now_tm.tm_year;
166 alarm_tm.tm_mon = now_tm.tm_mon;
167 alarm_tm.tm_mday = now_tm.tm_mday;
168 alarm_tm.tm_hour = alrm->tm_hour;
169 alarm_tm.tm_min = alrm->tm_min;
170 alarm_tm.tm_sec = alrm->tm_sec;
171 rtc_tm_to_time(&now_tm, &now);
172 rtc_tm_to_time(&alarm_tm, &time);
173
174 if (time < now) {
175 time += 60 * 60 * 24;
176 rtc_time_to_tm(time, &alarm_tm);
177 }
178
179 ret = rtc_tm_to_time(&alarm_tm, &time);
180
181 /* clear all the interrupt status bits */
182 writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
183 set_alarm_or_time(dev, MXC_RTC_ALARM, time);
184
185 return ret;
186 }
187
188 /* This function is the RTC interrupt service routine. */
189 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
190 {
191 struct platform_device *pdev = dev_id;
192 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
193 void __iomem *ioaddr = pdata->ioaddr;
194 u32 status;
195 u32 events = 0;
196
197 spin_lock_irq(&pdata->rtc->irq_lock);
198 status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
199 /* clear interrupt sources */
200 writew(status, ioaddr + RTC_RTCISR);
201
202 /* clear alarm interrupt if it has occurred */
203 if (status & RTC_ALM_BIT)
204 status &= ~RTC_ALM_BIT;
205
206 /* update irq data & counter */
207 if (status & RTC_ALM_BIT)
208 events |= (RTC_AF | RTC_IRQF);
209
210 if (status & RTC_1HZ_BIT)
211 events |= (RTC_UF | RTC_IRQF);
212
213 if (status & PIT_ALL_ON)
214 events |= (RTC_PF | RTC_IRQF);
215
216 if ((status & RTC_ALM_BIT) && rtc_valid_tm(&pdata->g_rtc_alarm))
217 rtc_update_alarm(&pdev->dev, &pdata->g_rtc_alarm);
218
219 rtc_update_irq(pdata->rtc, 1, events);
220 spin_unlock_irq(&pdata->rtc->irq_lock);
221
222 return IRQ_HANDLED;
223 }
224
225 /*
226 * Clear all interrupts and release the IRQ
227 */
228 static void mxc_rtc_release(struct device *dev)
229 {
230 struct platform_device *pdev = to_platform_device(dev);
231 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
232 void __iomem *ioaddr = pdata->ioaddr;
233
234 spin_lock_irq(&pdata->rtc->irq_lock);
235
236 /* Disable all rtc interrupts */
237 writew(0, ioaddr + RTC_RTCIENR);
238
239 /* Clear all interrupt status */
240 writew(0xffffffff, ioaddr + RTC_RTCISR);
241
242 spin_unlock_irq(&pdata->rtc->irq_lock);
243 }
244
245 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
246 unsigned int enabled)
247 {
248 struct platform_device *pdev = to_platform_device(dev);
249 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
250 void __iomem *ioaddr = pdata->ioaddr;
251 u32 reg;
252
253 spin_lock_irq(&pdata->rtc->irq_lock);
254 reg = readw(ioaddr + RTC_RTCIENR);
255
256 if (enabled)
257 reg |= bit;
258 else
259 reg &= ~bit;
260
261 writew(reg, ioaddr + RTC_RTCIENR);
262 spin_unlock_irq(&pdata->rtc->irq_lock);
263 }
264
265 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
266 {
267 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
268 return 0;
269 }
270
271 /*
272 * This function reads the current RTC time into tm in Gregorian date.
273 */
274 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
275 {
276 u32 val;
277
278 /* Avoid roll-over from reading the different registers */
279 do {
280 val = get_alarm_or_time(dev, MXC_RTC_TIME);
281 } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
282
283 rtc_time_to_tm(val, tm);
284
285 return 0;
286 }
287
288 /*
289 * This function sets the internal RTC time based on tm in Gregorian date.
290 */
291 static int mxc_rtc_set_mmss(struct device *dev, unsigned long time)
292 {
293 /* Avoid roll-over from reading the different registers */
294 do {
295 set_alarm_or_time(dev, MXC_RTC_TIME, time);
296 } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
297
298 return 0;
299 }
300
301 /*
302 * This function reads the current alarm value into the passed in 'alrm'
303 * argument. It updates the alrm's pending field value based on the whether
304 * an alarm interrupt occurs or not.
305 */
306 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
307 {
308 struct platform_device *pdev = to_platform_device(dev);
309 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
310 void __iomem *ioaddr = pdata->ioaddr;
311
312 rtc_time_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
313 alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
314
315 return 0;
316 }
317
318 /*
319 * This function sets the RTC alarm based on passed in alrm.
320 */
321 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
322 {
323 struct platform_device *pdev = to_platform_device(dev);
324 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
325 int ret;
326
327 if (rtc_valid_tm(&alrm->time)) {
328 if (alrm->time.tm_sec > 59 ||
329 alrm->time.tm_hour > 23 ||
330 alrm->time.tm_min > 59)
331 return -EINVAL;
332
333 ret = rtc_update_alarm(dev, &alrm->time);
334 } else {
335 ret = rtc_valid_tm(&alrm->time);
336 if (ret)
337 return ret;
338
339 ret = rtc_update_alarm(dev, &alrm->time);
340 }
341
342 if (ret)
343 return ret;
344
345 memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
346 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
347
348 return 0;
349 }
350
351 /* RTC layer */
352 static struct rtc_class_ops mxc_rtc_ops = {
353 .release = mxc_rtc_release,
354 .read_time = mxc_rtc_read_time,
355 .set_mmss = mxc_rtc_set_mmss,
356 .read_alarm = mxc_rtc_read_alarm,
357 .set_alarm = mxc_rtc_set_alarm,
358 .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
359 };
360
361 static int __init mxc_rtc_probe(struct platform_device *pdev)
362 {
363 struct resource *res;
364 struct rtc_device *rtc;
365 struct rtc_plat_data *pdata = NULL;
366 u32 reg;
367 unsigned long rate;
368 int ret;
369
370 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
371 if (!res)
372 return -ENODEV;
373
374 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
375 if (!pdata)
376 return -ENOMEM;
377
378 if (!devm_request_mem_region(&pdev->dev, res->start,
379 resource_size(res), pdev->name))
380 return -EBUSY;
381
382 pdata->ioaddr = devm_ioremap(&pdev->dev, res->start,
383 resource_size(res));
384
385 pdata->clk = clk_get(&pdev->dev, "rtc");
386 if (IS_ERR(pdata->clk)) {
387 dev_err(&pdev->dev, "unable to get clock!\n");
388 ret = PTR_ERR(pdata->clk);
389 goto exit_free_pdata;
390 }
391
392 clk_enable(pdata->clk);
393 rate = clk_get_rate(pdata->clk);
394
395 if (rate == 32768)
396 reg = RTC_INPUT_CLK_32768HZ;
397 else if (rate == 32000)
398 reg = RTC_INPUT_CLK_32000HZ;
399 else if (rate == 38400)
400 reg = RTC_INPUT_CLK_38400HZ;
401 else {
402 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
403 ret = -EINVAL;
404 goto exit_put_clk;
405 }
406
407 reg |= RTC_ENABLE_BIT;
408 writew(reg, (pdata->ioaddr + RTC_RTCCTL));
409 if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
410 dev_err(&pdev->dev, "hardware module can't be enabled!\n");
411 ret = -EIO;
412 goto exit_put_clk;
413 }
414
415 platform_set_drvdata(pdev, pdata);
416
417 /* Configure and enable the RTC */
418 pdata->irq = platform_get_irq(pdev, 0);
419
420 if (pdata->irq >= 0 &&
421 devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
422 IRQF_SHARED, pdev->name, pdev) < 0) {
423 dev_warn(&pdev->dev, "interrupt not available.\n");
424 pdata->irq = -1;
425 }
426
427 rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops,
428 THIS_MODULE);
429 if (IS_ERR(rtc)) {
430 ret = PTR_ERR(rtc);
431 goto exit_clr_drvdata;
432 }
433
434 pdata->rtc = rtc;
435
436 return 0;
437
438 exit_clr_drvdata:
439 platform_set_drvdata(pdev, NULL);
440 exit_put_clk:
441 clk_disable(pdata->clk);
442 clk_put(pdata->clk);
443
444 exit_free_pdata:
445
446 return ret;
447 }
448
449 static int __exit mxc_rtc_remove(struct platform_device *pdev)
450 {
451 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
452
453 rtc_device_unregister(pdata->rtc);
454
455 clk_disable(pdata->clk);
456 clk_put(pdata->clk);
457 platform_set_drvdata(pdev, NULL);
458
459 return 0;
460 }
461
462 static struct platform_driver mxc_rtc_driver = {
463 .driver = {
464 .name = "mxc_rtc",
465 .owner = THIS_MODULE,
466 },
467 .remove = __exit_p(mxc_rtc_remove),
468 };
469
470 static int __init mxc_rtc_init(void)
471 {
472 return platform_driver_probe(&mxc_rtc_driver, mxc_rtc_probe);
473 }
474
475 static void __exit mxc_rtc_exit(void)
476 {
477 platform_driver_unregister(&mxc_rtc_driver);
478 }
479
480 module_init(mxc_rtc_init);
481 module_exit(mxc_rtc_exit);
482
483 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
484 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
485 MODULE_LICENSE("GPL");
486
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