ext4: fix possible use-after-free in ext4_remove_li_request()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / rtc / rtc-vr41xx.c
blob769190ac6d11ec8e9401dba1735de6d8cc9c4196
1 /*
2 * Driver for NEC VR4100 series Real Time Clock unit.
4 * Copyright (C) 2003-2008 Yoichi Yuasa <yuasa@linux-mips.org>
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.
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.
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
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>
32 #include <asm/div64.h>
33 #include <asm/io.h>
34 #include <asm/uaccess.h>
36 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
37 MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
38 MODULE_LICENSE("GPL v2");
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
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
70 #define RTC_FREQUENCY 32768
71 #define MAX_PERIODIC_RATE 6553
73 static void __iomem *rtc1_base;
74 static void __iomem *rtc2_base;
76 #define rtc1_read(offset) readw(rtc1_base + (offset))
77 #define rtc1_write(offset, value) writew((value), rtc1_base + (offset))
79 #define rtc2_read(offset) readw(rtc2_base + (offset))
80 #define rtc2_write(offset, value) writew((value), rtc2_base + (offset))
82 static unsigned long epoch = 1970; /* Jan 1 1970 00:00:00 */
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;
91 static inline unsigned long read_elapsed_second(void)
94 unsigned long first_low, first_mid, first_high;
96 unsigned long second_low, second_mid, second_high;
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);
108 return (first_high << 17) | (first_mid << 1) | (first_low >> 15);
111 static inline void write_elapsed_second(unsigned long sec)
113 spin_lock_irq(&rtc_lock);
115 rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
116 rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
117 rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
119 spin_unlock_irq(&rtc_lock);
122 static void vr41xx_rtc_release(struct device *dev)
125 spin_lock_irq(&rtc_lock);
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);
133 spin_unlock_irq(&rtc_lock);
135 disable_irq(aie_irq);
136 disable_irq(pie_irq);
139 static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
141 unsigned long epoch_sec, elapsed_sec;
143 epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
144 elapsed_sec = read_elapsed_second();
146 rtc_time_to_tm(epoch_sec + elapsed_sec, time);
148 return 0;
151 static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time)
153 unsigned long epoch_sec, current_sec;
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);
159 write_elapsed_second(current_sec - epoch_sec);
161 return 0;
164 static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
166 unsigned long low, mid, high;
167 struct rtc_time *time = &wkalrm->time;
169 spin_lock_irq(&rtc_lock);
171 low = rtc1_read(ECMPLREG);
172 mid = rtc1_read(ECMPMREG);
173 high = rtc1_read(ECMPHREG);
174 wkalrm->enabled = alarm_enabled;
176 spin_unlock_irq(&rtc_lock);
178 rtc_time_to_tm((high << 17) | (mid << 1) | (low >> 15), time);
180 return 0;
183 static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
185 unsigned long alarm_sec;
186 struct rtc_time *time = &wkalrm->time;
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);
191 spin_lock_irq(&rtc_lock);
193 if (alarm_enabled)
194 disable_irq(aie_irq);
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));
200 if (wkalrm->enabled)
201 enable_irq(aie_irq);
203 alarm_enabled = wkalrm->enabled;
205 spin_unlock_irq(&rtc_lock);
207 return 0;
210 static int vr41xx_rtc_irq_set_freq(struct device *dev, int freq)
212 u64 count;
214 if (!is_power_of_2(freq))
215 return -EINVAL;
216 count = RTC_FREQUENCY;
217 do_div(count, freq);
219 spin_lock_irq(&rtc_lock);
221 periodic_count = count;
222 rtc1_write(RTCL1LREG, periodic_count);
223 rtc1_write(RTCL1HREG, periodic_count >> 16);
225 spin_unlock_irq(&rtc_lock);
227 return 0;
230 static int vr41xx_rtc_irq_set_state(struct device *dev, int enabled)
232 if (enabled)
233 enable_irq(pie_irq);
234 else
235 disable_irq(pie_irq);
237 return 0;
240 static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
242 switch (cmd) {
243 case RTC_EPOCH_READ:
244 return put_user(epoch, (unsigned long __user *)arg);
245 case RTC_EPOCH_SET:
246 /* Doesn't support before 1900 */
247 if (arg < 1900)
248 return -EINVAL;
249 epoch = arg;
250 break;
251 default:
252 return -ENOIOCTLCMD;
255 return 0;
258 static int vr41xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
260 spin_lock_irq(&rtc_lock);
261 if (enabled) {
262 if (!alarm_enabled) {
263 enable_irq(aie_irq);
264 alarm_enabled = 1;
266 } else {
267 if (alarm_enabled) {
268 disable_irq(aie_irq);
269 alarm_enabled = 0;
272 spin_unlock_irq(&rtc_lock);
273 return 0;
276 static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id)
278 struct platform_device *pdev = (struct platform_device *)dev_id;
279 struct rtc_device *rtc = platform_get_drvdata(pdev);
281 rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
283 rtc_update_irq(rtc, 1, RTC_AF);
285 return IRQ_HANDLED;
288 static irqreturn_t rtclong1_interrupt(int irq, void *dev_id)
290 struct platform_device *pdev = (struct platform_device *)dev_id;
291 struct rtc_device *rtc = platform_get_drvdata(pdev);
292 unsigned long count = periodic_count;
294 rtc2_write(RTCINTREG, RTCLONG1_INT);
296 rtc1_write(RTCL1LREG, count);
297 rtc1_write(RTCL1HREG, count >> 16);
299 rtc_update_irq(rtc, 1, RTC_PF);
301 return IRQ_HANDLED;
304 static const struct rtc_class_ops vr41xx_rtc_ops = {
305 .release = vr41xx_rtc_release,
306 .ioctl = vr41xx_rtc_ioctl,
307 .read_time = vr41xx_rtc_read_time,
308 .set_time = vr41xx_rtc_set_time,
309 .read_alarm = vr41xx_rtc_read_alarm,
310 .set_alarm = vr41xx_rtc_set_alarm,
311 .irq_set_freq = vr41xx_rtc_irq_set_freq,
312 .irq_set_state = vr41xx_rtc_irq_set_state,
315 static int __devinit rtc_probe(struct platform_device *pdev)
317 struct resource *res;
318 struct rtc_device *rtc;
319 int retval;
321 if (pdev->num_resources != 4)
322 return -EBUSY;
324 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
325 if (!res)
326 return -EBUSY;
328 rtc1_base = ioremap(res->start, resource_size(res));
329 if (!rtc1_base)
330 return -EBUSY;
332 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
333 if (!res) {
334 retval = -EBUSY;
335 goto err_rtc1_iounmap;
338 rtc2_base = ioremap(res->start, resource_size(res));
339 if (!rtc2_base) {
340 retval = -EBUSY;
341 goto err_rtc1_iounmap;
344 rtc = rtc_device_register(rtc_name, &pdev->dev, &vr41xx_rtc_ops, THIS_MODULE);
345 if (IS_ERR(rtc)) {
346 retval = PTR_ERR(rtc);
347 goto err_iounmap_all;
350 rtc->max_user_freq = MAX_PERIODIC_RATE;
352 spin_lock_irq(&rtc_lock);
354 rtc1_write(ECMPLREG, 0);
355 rtc1_write(ECMPMREG, 0);
356 rtc1_write(ECMPHREG, 0);
357 rtc1_write(RTCL1LREG, 0);
358 rtc1_write(RTCL1HREG, 0);
360 spin_unlock_irq(&rtc_lock);
362 aie_irq = platform_get_irq(pdev, 0);
363 if (aie_irq <= 0) {
364 retval = -EBUSY;
365 goto err_device_unregister;
368 retval = request_irq(aie_irq, elapsedtime_interrupt, IRQF_DISABLED,
369 "elapsed_time", pdev);
370 if (retval < 0)
371 goto err_device_unregister;
373 pie_irq = platform_get_irq(pdev, 1);
374 if (pie_irq <= 0)
375 goto err_free_irq;
377 retval = request_irq(pie_irq, rtclong1_interrupt, IRQF_DISABLED,
378 "rtclong1", pdev);
379 if (retval < 0)
380 goto err_free_irq;
382 platform_set_drvdata(pdev, rtc);
384 disable_irq(aie_irq);
385 disable_irq(pie_irq);
387 printk(KERN_INFO "rtc: Real Time Clock of NEC VR4100 series\n");
389 return 0;
391 err_free_irq:
392 free_irq(aie_irq, pdev);
394 err_device_unregister:
395 rtc_device_unregister(rtc);
397 err_iounmap_all:
398 iounmap(rtc2_base);
399 rtc2_base = NULL;
401 err_rtc1_iounmap:
402 iounmap(rtc1_base);
403 rtc1_base = NULL;
405 return retval;
408 static int __devexit rtc_remove(struct platform_device *pdev)
410 struct rtc_device *rtc;
412 rtc = platform_get_drvdata(pdev);
413 if (rtc)
414 rtc_device_unregister(rtc);
416 platform_set_drvdata(pdev, NULL);
418 free_irq(aie_irq, pdev);
419 free_irq(pie_irq, pdev);
420 if (rtc1_base)
421 iounmap(rtc1_base);
422 if (rtc2_base)
423 iounmap(rtc2_base);
425 return 0;
428 /* work with hotplug and coldplug */
429 MODULE_ALIAS("platform:RTC");
431 static struct platform_driver rtc_platform_driver = {
432 .probe = rtc_probe,
433 .remove = __devexit_p(rtc_remove),
434 .driver = {
435 .name = rtc_name,
436 .owner = THIS_MODULE,
440 static int __init vr41xx_rtc_init(void)
442 return platform_driver_register(&rtc_platform_driver);
445 static void __exit vr41xx_rtc_exit(void)
447 platform_driver_unregister(&rtc_platform_driver);
450 module_init(vr41xx_rtc_init);
451 module_exit(vr41xx_rtc_exit);