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Yoichi Yuasa8417eb72006-04-10 22:54:47 -07001/*
2 * Driver for NEC VR4100 series Real Time Clock unit.
3 *
Yoichi Yuasaada8e952009-07-03 00:39:38 +09004 * Copyright (C) 2003-2008 Yoichi Yuasa <yuasa@linux-mips.org>
Yoichi Yuasa8417eb72006-04-10 22:54:47 -07005 *
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 */
Yoichi Yuasabd0765092007-05-11 21:18:48 +090020#include <linux/err.h>
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070021#include <linux/fs.h>
22#include <linux/init.h>
23#include <linux/ioport.h>
Yoichi Yuasabd0765092007-05-11 21:18:48 +090024#include <linux/interrupt.h>
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070025#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>
Jonathan Cameron5d2a5032009-01-06 14:42:12 -080030#include <linux/log2.h>
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070031
32#include <asm/div64.h>
33#include <asm/io.h>
34#include <asm/uaccess.h>
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070035
Yoichi Yuasaada8e952009-07-03 00:39:38 +090036MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070037MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
Yoichi Yuasa4cad4432008-07-23 21:30:48 -070038MODULE_LICENSE("GPL v2");
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070039
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070040/* 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
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070072
73static void __iomem *rtc1_base;
74static 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
82static unsigned long epoch = 1970; /* Jan 1 1970 00:00:00 */
83
Ingo Molnar34af9462006-06-27 02:53:55 -070084static DEFINE_SPINLOCK(rtc_lock);
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070085static char rtc_name[] = "RTC";
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070086static unsigned long periodic_count;
Yoichi Yuasa9b5ef642007-05-08 00:33:50 -070087static unsigned int alarm_enabled;
Anton Vorontsov2fac6672009-01-06 14:42:11 -080088static int aie_irq;
89static int pie_irq;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -070090
91static 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
111static 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
122static 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
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900135 disable_irq(aie_irq);
136 disable_irq(pie_irq);
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700137}
138
139static 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
151static 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
164static 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);
Yoichi Yuasa9b5ef642007-05-08 00:33:50 -0700174 wkalrm->enabled = alarm_enabled;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700175
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
183static 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
Yoichi Yuasa9b5ef642007-05-08 00:33:50 -0700193 if (alarm_enabled)
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900194 disable_irq(aie_irq);
Yoichi Yuasa9b5ef642007-05-08 00:33:50 -0700195
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700196 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
Yoichi Yuasa9b5ef642007-05-08 00:33:50 -0700200 if (wkalrm->enabled)
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900201 enable_irq(aie_irq);
Yoichi Yuasa9b5ef642007-05-08 00:33:50 -0700202
203 alarm_enabled = wkalrm->enabled;
204
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700205 spin_unlock_irq(&rtc_lock);
206
207 return 0;
208}
209
Yoichi Yuasa4cad4432008-07-23 21:30:48 -0700210static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
211{
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700212 switch (cmd) {
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700213 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;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700219 epoch = arg;
220 break;
221 default:
Alessandro Zummob3969e52006-05-20 15:00:29 -0700222 return -ENOIOCTLCMD;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700223 }
224
225 return 0;
226}
227
John Stultz16380c12011-02-02 17:02:41 -0800228static 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
David Howells7d12e782006-10-05 14:55:46 +0100246static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700247{
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
David Brownellab6a2d72007-05-08 00:33:30 -0700253 rtc_update_irq(rtc, 1, RTC_AF);
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700254
255 return IRQ_HANDLED;
256}
257
David Howells7d12e782006-10-05 14:55:46 +0100258static irqreturn_t rtclong1_interrupt(int irq, void *dev_id)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700259{
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
David Brownellab6a2d72007-05-08 00:33:30 -0700269 rtc_update_irq(rtc, 1, RTC_PF);
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700270
271 return IRQ_HANDLED;
272}
273
David Brownellff8371a2006-09-30 23:28:17 -0700274static const struct rtc_class_ops vr41xx_rtc_ops = {
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700275 .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
283static int __devinit rtc_probe(struct platform_device *pdev)
284{
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900285 struct resource *res;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700286 struct rtc_device *rtc;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700287 int retval;
288
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900289 if (pdev->num_resources != 4)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700290 return -EBUSY;
291
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900292 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
293 if (!res)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700294 return -EBUSY;
295
Yoichi Yuasaa91912f2009-12-15 16:46:15 -0800296 rtc1_base = ioremap(res->start, resource_size(res));
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900297 if (!rtc1_base)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700298 return -EBUSY;
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900299
300 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
301 if (!res) {
302 retval = -EBUSY;
303 goto err_rtc1_iounmap;
304 }
305
Yoichi Yuasaa91912f2009-12-15 16:46:15 -0800306 rtc2_base = ioremap(res->start, resource_size(res));
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900307 if (!rtc2_base) {
308 retval = -EBUSY;
309 goto err_rtc1_iounmap;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700310 }
311
312 rtc = rtc_device_register(rtc_name, &pdev->dev, &vr41xx_rtc_ops, THIS_MODULE);
313 if (IS_ERR(rtc)) {
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900314 retval = PTR_ERR(rtc);
315 goto err_iounmap_all;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700316 }
317
Yoichi Yuasa4cad4432008-07-23 21:30:48 -0700318 rtc->max_user_freq = MAX_PERIODIC_RATE;
319
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700320 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
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900330 aie_irq = platform_get_irq(pdev, 0);
Anton Vorontsov2fac6672009-01-06 14:42:11 -0800331 if (aie_irq <= 0) {
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900332 retval = -EBUSY;
333 goto err_device_unregister;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700334 }
335
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900336 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);
Anton Vorontsov2fac6672009-01-06 14:42:11 -0800342 if (pie_irq <= 0)
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900343 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;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700349
350 platform_set_drvdata(pdev, rtc);
351
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900352 disable_irq(aie_irq);
353 disable_irq(pie_irq);
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700354
355 printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
356
357 return 0;
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900358
359err_free_irq:
360 free_irq(aie_irq, pdev);
361
362err_device_unregister:
363 rtc_device_unregister(rtc);
364
365err_iounmap_all:
366 iounmap(rtc2_base);
367 rtc2_base = NULL;
368
369err_rtc1_iounmap:
370 iounmap(rtc1_base);
371 rtc1_base = NULL;
372
373 return retval;
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700374}
375
376static int __devexit rtc_remove(struct platform_device *pdev)
377{
378 struct rtc_device *rtc;
379
380 rtc = platform_get_drvdata(pdev);
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900381 if (rtc)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700382 rtc_device_unregister(rtc);
383
384 platform_set_drvdata(pdev, NULL);
385
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900386 free_irq(aie_irq, pdev);
387 free_irq(pie_irq, pdev);
388 if (rtc1_base)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700389 iounmap(rtc1_base);
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900390 if (rtc2_base)
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700391 iounmap(rtc2_base);
392
393 return 0;
394}
395
Kay Sieversad28a072008-04-10 21:29:25 -0700396/* work with hotplug and coldplug */
397MODULE_ALIAS("platform:RTC");
398
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700399static 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
408static int __init vr41xx_rtc_init(void)
409{
Yoichi Yuasabd0765092007-05-11 21:18:48 +0900410 return platform_driver_register(&rtc_platform_driver);
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700411}
412
413static void __exit vr41xx_rtc_exit(void)
414{
415 platform_driver_unregister(&rtc_platform_driver);
Yoichi Yuasa8417eb72006-04-10 22:54:47 -0700416}
417
418module_init(vr41xx_rtc_init);
419module_exit(vr41xx_rtc_exit);