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aufs: policies for multiple writable branches, from aufs2.2-3.0
[zen-stable.git] / drivers / rtc / rtc-pl031.c
bloba952c8de1dd73776b979784752f8587a6d2b4744
1 /*
2 * drivers/rtc/rtc-pl031.c
3 *
4 * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
5 *
6 * Author: Deepak Saxena <dsaxena@plexity.net>
7 *
8 * Copyright 2006 (c) MontaVista Software, Inc.
9 *
10 * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
11 * Copyright 2010 (c) ST-Ericsson AB
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
17 */
18 #include <linux/module.h>
19 #include <linux/rtc.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/amba/bus.h>
23 #include <linux/io.h>
24 #include <linux/bcd.h>
25 #include <linux/delay.h>
26 #include <linux/slab.h>
27
28 /*
29 * Register definitions
30 */
31 #define RTC_DR 0x00 /* Data read register */
32 #define RTC_MR 0x04 /* Match register */
33 #define RTC_LR 0x08 /* Data load register */
34 #define RTC_CR 0x0c /* Control register */
35 #define RTC_IMSC 0x10 /* Interrupt mask and set register */
36 #define RTC_RIS 0x14 /* Raw interrupt status register */
37 #define RTC_MIS 0x18 /* Masked interrupt status register */
38 #define RTC_ICR 0x1c /* Interrupt clear register */
39 /* ST variants have additional timer functionality */
40 #define RTC_TDR 0x20 /* Timer data read register */
41 #define RTC_TLR 0x24 /* Timer data load register */
42 #define RTC_TCR 0x28 /* Timer control register */
43 #define RTC_YDR 0x30 /* Year data read register */
44 #define RTC_YMR 0x34 /* Year match register */
45 #define RTC_YLR 0x38 /* Year data load register */
46
47 #define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */
48
49 #define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */
50
51 /* Common bit definitions for Interrupt status and control registers */
52 #define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */
53 #define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */
54
55 /* Common bit definations for ST v2 for reading/writing time */
56 #define RTC_SEC_SHIFT 0
57 #define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */
58 #define RTC_MIN_SHIFT 6
59 #define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */
60 #define RTC_HOUR_SHIFT 12
61 #define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */
62 #define RTC_WDAY_SHIFT 17
63 #define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */
64 #define RTC_MDAY_SHIFT 20
65 #define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */
66 #define RTC_MON_SHIFT 25
67 #define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */
68
69 #define RTC_TIMER_FREQ 32768
70
71 struct pl031_local {
72 struct rtc_device *rtc;
73 void __iomem *base;
74 u8 hw_designer;
75 u8 hw_revision:4;
76 };
77
78 static int pl031_alarm_irq_enable(struct device *dev,
79 unsigned int enabled)
80 {
81 struct pl031_local *ldata = dev_get_drvdata(dev);
82 unsigned long imsc;
83
84 /* Clear any pending alarm interrupts. */
85 writel(RTC_BIT_AI, ldata->base + RTC_ICR);
86
87 imsc = readl(ldata->base + RTC_IMSC);
88
89 if (enabled == 1)
90 writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC);
91 else
92 writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC);
93
94 return 0;
95 }
96
97 /*
98 * Convert Gregorian date to ST v2 RTC format.
99 */
100 static int pl031_stv2_tm_to_time(struct device *dev,
101 struct rtc_time *tm, unsigned long *st_time,
102 unsigned long *bcd_year)
103 {
104 int year = tm->tm_year + 1900;
105 int wday = tm->tm_wday;
106
107 /* wday masking is not working in hardware so wday must be valid */
108 if (wday < -1 || wday > 6) {
109 dev_err(dev, "invalid wday value %d\n", tm->tm_wday);
110 return -EINVAL;
111 } else if (wday == -1) {
112 /* wday is not provided, calculate it here */
113 unsigned long time;
114 struct rtc_time calc_tm;
115
116 rtc_tm_to_time(tm, &time);
117 rtc_time_to_tm(time, &calc_tm);
118 wday = calc_tm.tm_wday;
119 }
120
121 *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8);
122
123 *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT)
124 | (tm->tm_mday << RTC_MDAY_SHIFT)
125 | ((wday + 1) << RTC_WDAY_SHIFT)
126 | (tm->tm_hour << RTC_HOUR_SHIFT)
127 | (tm->tm_min << RTC_MIN_SHIFT)
128 | (tm->tm_sec << RTC_SEC_SHIFT);
129
130 return 0;
131 }
132
133 /*
134 * Convert ST v2 RTC format to Gregorian date.
135 */
136 static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year,
137 struct rtc_time *tm)
138 {
139 tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100);
140 tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1;
141 tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT);
142 tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1;
143 tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT);
144 tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT);
145 tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT);
146
147 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
148 tm->tm_year -= 1900;
149
150 return 0;
151 }
152
153 static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm)
154 {
155 struct pl031_local *ldata = dev_get_drvdata(dev);
156
157 pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR),
158 readl(ldata->base + RTC_YDR), tm);
159
160 return 0;
161 }
162
163 static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm)
164 {
165 unsigned long time;
166 unsigned long bcd_year;
167 struct pl031_local *ldata = dev_get_drvdata(dev);
168 int ret;
169
170 ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year);
171 if (ret == 0) {
172 writel(bcd_year, ldata->base + RTC_YLR);
173 writel(time, ldata->base + RTC_LR);
174 }
175
176 return ret;
177 }
178
179 static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
180 {
181 struct pl031_local *ldata = dev_get_drvdata(dev);
182 int ret;
183
184 ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR),
185 readl(ldata->base + RTC_YMR), &alarm->time);
186
187 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
188 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
189
190 return ret;
191 }
192
193 static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
194 {
195 struct pl031_local *ldata = dev_get_drvdata(dev);
196 unsigned long time;
197 unsigned long bcd_year;
198 int ret;
199
200 /* At the moment, we can only deal with non-wildcarded alarm times. */
201 ret = rtc_valid_tm(&alarm->time);
202 if (ret == 0) {
203 ret = pl031_stv2_tm_to_time(dev, &alarm->time,
204 &time, &bcd_year);
205 if (ret == 0) {
206 writel(bcd_year, ldata->base + RTC_YMR);
207 writel(time, ldata->base + RTC_MR);
208
209 pl031_alarm_irq_enable(dev, alarm->enabled);
210 }
211 }
212
213 return ret;
214 }
215
216 static irqreturn_t pl031_interrupt(int irq, void *dev_id)
217 {
218 struct pl031_local *ldata = dev_id;
219 unsigned long rtcmis;
220 unsigned long events = 0;
221
222 rtcmis = readl(ldata->base + RTC_MIS);
223 if (rtcmis) {
224 writel(rtcmis, ldata->base + RTC_ICR);
225
226 if (rtcmis & RTC_BIT_AI)
227 events |= (RTC_AF | RTC_IRQF);
228
229 /* Timer interrupt is only available in ST variants */
230 if ((rtcmis & RTC_BIT_PI) &&
231 (ldata->hw_designer == AMBA_VENDOR_ST))
232 events |= (RTC_PF | RTC_IRQF);
233
234 rtc_update_irq(ldata->rtc, 1, events);
235
236 return IRQ_HANDLED;
237 }
238
239 return IRQ_NONE;
240 }
241
242 static int pl031_read_time(struct device *dev, struct rtc_time *tm)
243 {
244 struct pl031_local *ldata = dev_get_drvdata(dev);
245
246 rtc_time_to_tm(readl(ldata->base + RTC_DR), tm);
247
248 return 0;
249 }
250
251 static int pl031_set_time(struct device *dev, struct rtc_time *tm)
252 {
253 unsigned long time;
254 struct pl031_local *ldata = dev_get_drvdata(dev);
255 int ret;
256
257 ret = rtc_tm_to_time(tm, &time);
258
259 if (ret == 0)
260 writel(time, ldata->base + RTC_LR);
261
262 return ret;
263 }
264
265 static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
266 {
267 struct pl031_local *ldata = dev_get_drvdata(dev);
268
269 rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time);
270
271 alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
272 alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
273
274 return 0;
275 }
276
277 static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
278 {
279 struct pl031_local *ldata = dev_get_drvdata(dev);
280 unsigned long time;
281 int ret;
282
283 /* At the moment, we can only deal with non-wildcarded alarm times. */
284 ret = rtc_valid_tm(&alarm->time);
285 if (ret == 0) {
286 ret = rtc_tm_to_time(&alarm->time, &time);
287 if (ret == 0) {
288 writel(time, ldata->base + RTC_MR);
289 pl031_alarm_irq_enable(dev, alarm->enabled);
290 }
291 }
292
293 return ret;
294 }
295
296 static int pl031_remove(struct amba_device *adev)
297 {
298 struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
299
300 amba_set_drvdata(adev, NULL);
301 free_irq(adev->irq[0], ldata->rtc);
302 rtc_device_unregister(ldata->rtc);
303 iounmap(ldata->base);
304 kfree(ldata);
305 amba_release_regions(adev);
306
307 return 0;
308 }
309
310 static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
311 {
312 int ret;
313 struct pl031_local *ldata;
314 struct rtc_class_ops *ops = id->data;
315
316 ret = amba_request_regions(adev, NULL);
317 if (ret)
318 goto err_req;
319
320 ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL);
321 if (!ldata) {
322 ret = -ENOMEM;
323 goto out;
324 }
325
326 ldata->base = ioremap(adev->res.start, resource_size(&adev->res));
327
328 if (!ldata->base) {
329 ret = -ENOMEM;
330 goto out_no_remap;
331 }
332
333 amba_set_drvdata(adev, ldata);
334
335 ldata->hw_designer = amba_manf(adev);
336 ldata->hw_revision = amba_rev(adev);
337
338 dev_dbg(&adev->dev, "designer ID = 0x%02x\n", ldata->hw_designer);
339 dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision);
340
341 /* Enable the clockwatch on ST Variants */
342 if ((ldata->hw_designer == AMBA_VENDOR_ST) &&
343 (ldata->hw_revision > 1))
344 writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN,
345 ldata->base + RTC_CR);
346
347 ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
348 THIS_MODULE);
349 if (IS_ERR(ldata->rtc)) {
350 ret = PTR_ERR(ldata->rtc);
351 goto out_no_rtc;
352 }
353
354 if (request_irq(adev->irq[0], pl031_interrupt,
355 IRQF_DISABLED, "rtc-pl031", ldata)) {
356 ret = -EIO;
357 goto out_no_irq;
358 }
359
360 return 0;
361
362 out_no_irq:
363 rtc_device_unregister(ldata->rtc);
364 out_no_rtc:
365 iounmap(ldata->base);
366 amba_set_drvdata(adev, NULL);
367 out_no_remap:
368 kfree(ldata);
369 out:
370 amba_release_regions(adev);
371 err_req:
372
373 return ret;
374 }
375
376 /* Operations for the original ARM version */
377 static struct rtc_class_ops arm_pl031_ops = {
378 .read_time = pl031_read_time,
379 .set_time = pl031_set_time,
380 .read_alarm = pl031_read_alarm,
381 .set_alarm = pl031_set_alarm,
382 .alarm_irq_enable = pl031_alarm_irq_enable,
383 };
384
385 /* The First ST derivative */
386 static struct rtc_class_ops stv1_pl031_ops = {
387 .read_time = pl031_read_time,
388 .set_time = pl031_set_time,
389 .read_alarm = pl031_read_alarm,
390 .set_alarm = pl031_set_alarm,
391 .alarm_irq_enable = pl031_alarm_irq_enable,
392 };
393
394 /* And the second ST derivative */
395 static struct rtc_class_ops stv2_pl031_ops = {
396 .read_time = pl031_stv2_read_time,
397 .set_time = pl031_stv2_set_time,
398 .read_alarm = pl031_stv2_read_alarm,
399 .set_alarm = pl031_stv2_set_alarm,
400 .alarm_irq_enable = pl031_alarm_irq_enable,
401 };
402
403 static struct amba_id pl031_ids[] = {
404 {
405 .id = 0x00041031,
406 .mask = 0x000fffff,
407 .data = &arm_pl031_ops,
408 },
409 /* ST Micro variants */
410 {
411 .id = 0x00180031,
412 .mask = 0x00ffffff,
413 .data = &stv1_pl031_ops,
414 },
415 {
416 .id = 0x00280031,
417 .mask = 0x00ffffff,
418 .data = &stv2_pl031_ops,
419 },
420 {0, 0},
421 };
422
423 MODULE_DEVICE_TABLE(amba, pl031_ids);
424
425 static struct amba_driver pl031_driver = {
426 .drv = {
427 .name = "rtc-pl031",
428 },
429 .id_table = pl031_ids,
430 .probe = pl031_probe,
431 .remove = pl031_remove,
432 };
433
434 static int __init pl031_init(void)
435 {
436 return amba_driver_register(&pl031_driver);
437 }
438
439 static void __exit pl031_exit(void)
440 {
441 amba_driver_unregister(&pl031_driver);
442 }
443
444 module_init(pl031_init);
445 module_exit(pl031_exit);
446
447 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
448 MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
449 MODULE_LICENSE("GPL");