c5698cda366a910a6f16008248c3c78aac62823f
[pandora-kernel.git] / drivers / rtc / rtc-vr41xx.c
1 /*
2  *  Driver for NEC VR4100 series Real Time Clock unit.
3  *
4  *  Copyright (C) 2003-2008  Yoichi Yuasa <yuasa@linux-mips.org>
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 #include <linux/err.h>
21 #include <linux/fs.h>
22 #include <linux/init.h>
23 #include <linux/ioport.h>
24 #include <linux/interrupt.h>
25 #include <linux/module.h>
26 #include <linux/platform_device.h>
27 #include <linux/rtc.h>
28 #include <linux/spinlock.h>
29 #include <linux/types.h>
30 #include <linux/log2.h>
31
32 #include <asm/div64.h>
33 #include <asm/io.h>
34 #include <asm/uaccess.h>
35
36 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
37 MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
38 MODULE_LICENSE("GPL v2");
39
40 /* RTC 1 registers */
41 #define ETIMELREG               0x00
42 #define ETIMEMREG               0x02
43 #define ETIMEHREG               0x04
44 /* RFU */
45 #define ECMPLREG                0x08
46 #define ECMPMREG                0x0a
47 #define ECMPHREG                0x0c
48 /* RFU */
49 #define RTCL1LREG               0x10
50 #define RTCL1HREG               0x12
51 #define RTCL1CNTLREG            0x14
52 #define RTCL1CNTHREG            0x16
53 #define RTCL2LREG               0x18
54 #define RTCL2HREG               0x1a
55 #define RTCL2CNTLREG            0x1c
56 #define RTCL2CNTHREG            0x1e
57
58 /* RTC 2 registers */
59 #define TCLKLREG                0x00
60 #define TCLKHREG                0x02
61 #define TCLKCNTLREG             0x04
62 #define TCLKCNTHREG             0x06
63 /* RFU */
64 #define RTCINTREG               0x1e
65  #define TCLOCK_INT             0x08
66  #define RTCLONG2_INT           0x04
67  #define RTCLONG1_INT           0x02
68  #define ELAPSEDTIME_INT        0x01
69
70 #define RTC_FREQUENCY           32768
71 #define MAX_PERIODIC_RATE       6553
72
73 static void __iomem *rtc1_base;
74 static void __iomem *rtc2_base;
75
76 #define rtc1_read(offset)               readw(rtc1_base + (offset))
77 #define rtc1_write(offset, value)       writew((value), rtc1_base + (offset))
78
79 #define rtc2_read(offset)               readw(rtc2_base + (offset))
80 #define rtc2_write(offset, value)       writew((value), rtc2_base + (offset))
81
82 static unsigned long epoch = 1970;      /* Jan 1 1970 00:00:00 */
83
84 static DEFINE_SPINLOCK(rtc_lock);
85 static char rtc_name[] = "RTC";
86 static unsigned long periodic_count;
87 static unsigned int alarm_enabled;
88 static int aie_irq;
89 static int pie_irq;
90
91 static inline unsigned long read_elapsed_second(void)
92 {
93
94         unsigned long first_low, first_mid, first_high;
95
96         unsigned long second_low, second_mid, second_high;
97
98         do {
99                 first_low = rtc1_read(ETIMELREG);
100                 first_mid = rtc1_read(ETIMEMREG);
101                 first_high = rtc1_read(ETIMEHREG);
102                 second_low = rtc1_read(ETIMELREG);
103                 second_mid = rtc1_read(ETIMEMREG);
104                 second_high = rtc1_read(ETIMEHREG);
105         } while (first_low != second_low || first_mid != second_mid ||
106                  first_high != second_high);
107
108         return (first_high << 17) | (first_mid << 1) | (first_low >> 15);
109 }
110
111 static inline void write_elapsed_second(unsigned long sec)
112 {
113         spin_lock_irq(&rtc_lock);
114
115         rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
116         rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
117         rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
118
119         spin_unlock_irq(&rtc_lock);
120 }
121
122 static void vr41xx_rtc_release(struct device *dev)
123 {
124
125         spin_lock_irq(&rtc_lock);
126
127         rtc1_write(ECMPLREG, 0);
128         rtc1_write(ECMPMREG, 0);
129         rtc1_write(ECMPHREG, 0);
130         rtc1_write(RTCL1LREG, 0);
131         rtc1_write(RTCL1HREG, 0);
132
133         spin_unlock_irq(&rtc_lock);
134
135         disable_irq(aie_irq);
136         disable_irq(pie_irq);
137 }
138
139 static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
140 {
141         unsigned long epoch_sec, elapsed_sec;
142
143         epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
144         elapsed_sec = read_elapsed_second();
145
146         rtc_time_to_tm(epoch_sec + elapsed_sec, time);
147
148         return 0;
149 }
150
151 static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time)
152 {
153         unsigned long epoch_sec, current_sec;
154
155         epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
156         current_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
157                              time->tm_hour, time->tm_min, time->tm_sec);
158
159         write_elapsed_second(current_sec - epoch_sec);
160
161         return 0;
162 }
163
164 static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
165 {
166         unsigned long low, mid, high;
167         struct rtc_time *time = &wkalrm->time;
168
169         spin_lock_irq(&rtc_lock);
170
171         low = rtc1_read(ECMPLREG);
172         mid = rtc1_read(ECMPMREG);
173         high = rtc1_read(ECMPHREG);
174         wkalrm->enabled = alarm_enabled;
175
176         spin_unlock_irq(&rtc_lock);
177
178         rtc_time_to_tm((high << 17) | (mid << 1) | (low >> 15), time);
179
180         return 0;
181 }
182
183 static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
184 {
185         unsigned long alarm_sec;
186         struct rtc_time *time = &wkalrm->time;
187
188         alarm_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
189                            time->tm_hour, time->tm_min, time->tm_sec);
190
191         spin_lock_irq(&rtc_lock);
192
193         if (alarm_enabled)
194                 disable_irq(aie_irq);
195
196         rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
197         rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
198         rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
199
200         if (wkalrm->enabled)
201                 enable_irq(aie_irq);
202
203         alarm_enabled = wkalrm->enabled;
204
205         spin_unlock_irq(&rtc_lock);
206
207         return 0;
208 }
209
210 static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
211 {
212         switch (cmd) {
213         case RTC_EPOCH_READ:
214                 return put_user(epoch, (unsigned long __user *)arg);
215         case RTC_EPOCH_SET:
216                 /* Doesn't support before 1900 */
217                 if (arg < 1900)
218                         return -EINVAL;
219                 epoch = arg;
220                 break;
221         default:
222                 return -ENOIOCTLCMD;
223         }
224
225         return 0;
226 }
227
228 static int vr41xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
229 {
230         spin_lock_irq(&rtc_lock);
231         if (enabled) {
232                 if (!alarm_enabled) {
233                         enable_irq(aie_irq);
234                         alarm_enabled = 1;
235                 }
236         } else {
237                 if (alarm_enabled) {
238                         disable_irq(aie_irq);
239                         alarm_enabled = 0;
240                 }
241         }
242         spin_unlock_irq(&rtc_lock);
243         return 0;
244 }
245
246 static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id)
247 {
248         struct platform_device *pdev = (struct platform_device *)dev_id;
249         struct rtc_device *rtc = platform_get_drvdata(pdev);
250
251         rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
252
253         rtc_update_irq(rtc, 1, RTC_AF);
254
255         return IRQ_HANDLED;
256 }
257
258 static irqreturn_t rtclong1_interrupt(int irq, void *dev_id)
259 {
260         struct platform_device *pdev = (struct platform_device *)dev_id;
261         struct rtc_device *rtc = platform_get_drvdata(pdev);
262         unsigned long count = periodic_count;
263
264         rtc2_write(RTCINTREG, RTCLONG1_INT);
265
266         rtc1_write(RTCL1LREG, count);
267         rtc1_write(RTCL1HREG, count >> 16);
268
269         rtc_update_irq(rtc, 1, RTC_PF);
270
271         return IRQ_HANDLED;
272 }
273
274 static const struct rtc_class_ops vr41xx_rtc_ops = {
275         .release        = vr41xx_rtc_release,
276         .ioctl          = vr41xx_rtc_ioctl,
277         .read_time      = vr41xx_rtc_read_time,
278         .set_time       = vr41xx_rtc_set_time,
279         .read_alarm     = vr41xx_rtc_read_alarm,
280         .set_alarm      = vr41xx_rtc_set_alarm,
281 };
282
283 static int __devinit rtc_probe(struct platform_device *pdev)
284 {
285         struct resource *res;
286         struct rtc_device *rtc;
287         int retval;
288
289         if (pdev->num_resources != 4)
290                 return -EBUSY;
291
292         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
293         if (!res)
294                 return -EBUSY;
295
296         rtc1_base = ioremap(res->start, resource_size(res));
297         if (!rtc1_base)
298                 return -EBUSY;
299
300         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
301         if (!res) {
302                 retval = -EBUSY;
303                 goto err_rtc1_iounmap;
304         }
305
306         rtc2_base = ioremap(res->start, resource_size(res));
307         if (!rtc2_base) {
308                 retval = -EBUSY;
309                 goto err_rtc1_iounmap;
310         }
311
312         rtc = rtc_device_register(rtc_name, &pdev->dev, &vr41xx_rtc_ops, THIS_MODULE);
313         if (IS_ERR(rtc)) {
314                 retval = PTR_ERR(rtc);
315                 goto err_iounmap_all;
316         }
317
318         rtc->max_user_freq = MAX_PERIODIC_RATE;
319
320         spin_lock_irq(&rtc_lock);
321
322         rtc1_write(ECMPLREG, 0);
323         rtc1_write(ECMPMREG, 0);
324         rtc1_write(ECMPHREG, 0);
325         rtc1_write(RTCL1LREG, 0);
326         rtc1_write(RTCL1HREG, 0);
327
328         spin_unlock_irq(&rtc_lock);
329
330         aie_irq = platform_get_irq(pdev, 0);
331         if (aie_irq <= 0) {
332                 retval = -EBUSY;
333                 goto err_device_unregister;
334         }
335
336         retval = request_irq(aie_irq, elapsedtime_interrupt, IRQF_DISABLED,
337                              "elapsed_time", pdev);
338         if (retval < 0)
339                 goto err_device_unregister;
340
341         pie_irq = platform_get_irq(pdev, 1);
342         if (pie_irq <= 0)
343                 goto err_free_irq;
344
345         retval = request_irq(pie_irq, rtclong1_interrupt, IRQF_DISABLED,
346                              "rtclong1", pdev);
347         if (retval < 0)
348                 goto err_free_irq;
349
350         platform_set_drvdata(pdev, rtc);
351
352         disable_irq(aie_irq);
353         disable_irq(pie_irq);
354
355         printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
356
357         return 0;
358
359 err_free_irq:
360         free_irq(aie_irq, pdev);
361
362 err_device_unregister:
363         rtc_device_unregister(rtc);
364
365 err_iounmap_all:
366         iounmap(rtc2_base);
367         rtc2_base = NULL;
368
369 err_rtc1_iounmap:
370         iounmap(rtc1_base);
371         rtc1_base = NULL;
372
373         return retval;
374 }
375
376 static int __devexit rtc_remove(struct platform_device *pdev)
377 {
378         struct rtc_device *rtc;
379
380         rtc = platform_get_drvdata(pdev);
381         if (rtc)
382                 rtc_device_unregister(rtc);
383
384         platform_set_drvdata(pdev, NULL);
385
386         free_irq(aie_irq, pdev);
387         free_irq(pie_irq, pdev);
388         if (rtc1_base)
389                 iounmap(rtc1_base);
390         if (rtc2_base)
391                 iounmap(rtc2_base);
392
393         return 0;
394 }
395
396 /* work with hotplug and coldplug */
397 MODULE_ALIAS("platform:RTC");
398
399 static struct platform_driver rtc_platform_driver = {
400         .probe          = rtc_probe,
401         .remove         = __devexit_p(rtc_remove),
402         .driver         = {
403                 .name   = rtc_name,
404                 .owner  = THIS_MODULE,
405         },
406 };
407
408 static int __init vr41xx_rtc_init(void)
409 {
410         return platform_driver_register(&rtc_platform_driver);
411 }
412
413 static void __exit vr41xx_rtc_exit(void)
414 {
415         platform_driver_unregister(&rtc_platform_driver);
416 }
417
418 module_init(vr41xx_rtc_init);
419 module_exit(vr41xx_rtc_exit);