Alessandro Zummo | e824290 | 2006-03-27 01:16:41 -0800 | [diff] [blame] | 1 | /* |
| 2 | * RTC subsystem, dev interface |
| 3 | * |
| 4 | * Copyright (C) 2005 Tower Technologies |
| 5 | * Author: Alessandro Zummo <a.zummo@towertech.it> |
| 6 | * |
| 7 | * based on arch/arm/common/rtctime.c |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/rtc.h> |
| 16 | |
| 17 | static struct class *rtc_dev_class; |
| 18 | static dev_t rtc_devt; |
| 19 | |
| 20 | #define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */ |
| 21 | |
| 22 | static int rtc_dev_open(struct inode *inode, struct file *file) |
| 23 | { |
| 24 | int err; |
| 25 | struct rtc_device *rtc = container_of(inode->i_cdev, |
| 26 | struct rtc_device, char_dev); |
| 27 | struct rtc_class_ops *ops = rtc->ops; |
| 28 | |
| 29 | /* We keep the lock as long as the device is in use |
| 30 | * and return immediately if busy |
| 31 | */ |
| 32 | if (!(mutex_trylock(&rtc->char_lock))) |
| 33 | return -EBUSY; |
| 34 | |
| 35 | file->private_data = &rtc->class_dev; |
| 36 | |
| 37 | err = ops->open ? ops->open(rtc->class_dev.dev) : 0; |
| 38 | if (err == 0) { |
| 39 | spin_lock_irq(&rtc->irq_lock); |
| 40 | rtc->irq_data = 0; |
| 41 | spin_unlock_irq(&rtc->irq_lock); |
| 42 | |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | /* something has gone wrong, release the lock */ |
| 47 | mutex_unlock(&rtc->char_lock); |
| 48 | return err; |
| 49 | } |
| 50 | |
| 51 | |
| 52 | static ssize_t |
| 53 | rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
| 54 | { |
| 55 | struct rtc_device *rtc = to_rtc_device(file->private_data); |
| 56 | |
| 57 | DECLARE_WAITQUEUE(wait, current); |
| 58 | unsigned long data; |
| 59 | ssize_t ret; |
| 60 | |
Atsushi Nemoto | 3418ff7 | 2006-05-01 12:16:16 -0700 | [diff] [blame] | 61 | if (count != sizeof(unsigned int) && count < sizeof(unsigned long)) |
Alessandro Zummo | e824290 | 2006-03-27 01:16:41 -0800 | [diff] [blame] | 62 | return -EINVAL; |
| 63 | |
| 64 | add_wait_queue(&rtc->irq_queue, &wait); |
| 65 | do { |
| 66 | __set_current_state(TASK_INTERRUPTIBLE); |
| 67 | |
| 68 | spin_lock_irq(&rtc->irq_lock); |
| 69 | data = rtc->irq_data; |
| 70 | rtc->irq_data = 0; |
| 71 | spin_unlock_irq(&rtc->irq_lock); |
| 72 | |
| 73 | if (data != 0) { |
| 74 | ret = 0; |
| 75 | break; |
| 76 | } |
| 77 | if (file->f_flags & O_NONBLOCK) { |
| 78 | ret = -EAGAIN; |
| 79 | break; |
| 80 | } |
| 81 | if (signal_pending(current)) { |
| 82 | ret = -ERESTARTSYS; |
| 83 | break; |
| 84 | } |
| 85 | schedule(); |
| 86 | } while (1); |
| 87 | set_current_state(TASK_RUNNING); |
| 88 | remove_wait_queue(&rtc->irq_queue, &wait); |
| 89 | |
| 90 | if (ret == 0) { |
| 91 | /* Check for any data updates */ |
| 92 | if (rtc->ops->read_callback) |
Atsushi Nemoto | 3418ff7 | 2006-05-01 12:16:16 -0700 | [diff] [blame] | 93 | data = rtc->ops->read_callback(rtc->class_dev.dev, |
| 94 | data); |
Alessandro Zummo | e824290 | 2006-03-27 01:16:41 -0800 | [diff] [blame] | 95 | |
Atsushi Nemoto | 3418ff7 | 2006-05-01 12:16:16 -0700 | [diff] [blame] | 96 | if (sizeof(int) != sizeof(long) && |
| 97 | count == sizeof(unsigned int)) |
| 98 | ret = put_user(data, (unsigned int __user *)buf) ?: |
| 99 | sizeof(unsigned int); |
| 100 | else |
| 101 | ret = put_user(data, (unsigned long __user *)buf) ?: |
| 102 | sizeof(unsigned long); |
Alessandro Zummo | e824290 | 2006-03-27 01:16:41 -0800 | [diff] [blame] | 103 | } |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | static unsigned int rtc_dev_poll(struct file *file, poll_table *wait) |
| 108 | { |
| 109 | struct rtc_device *rtc = to_rtc_device(file->private_data); |
| 110 | unsigned long data; |
| 111 | |
| 112 | poll_wait(file, &rtc->irq_queue, wait); |
| 113 | |
| 114 | data = rtc->irq_data; |
| 115 | |
| 116 | return (data != 0) ? (POLLIN | POLLRDNORM) : 0; |
| 117 | } |
| 118 | |
| 119 | static int rtc_dev_ioctl(struct inode *inode, struct file *file, |
| 120 | unsigned int cmd, unsigned long arg) |
| 121 | { |
| 122 | int err = 0; |
| 123 | struct class_device *class_dev = file->private_data; |
| 124 | struct rtc_device *rtc = to_rtc_device(class_dev); |
| 125 | struct rtc_class_ops *ops = rtc->ops; |
| 126 | struct rtc_time tm; |
| 127 | struct rtc_wkalrm alarm; |
| 128 | void __user *uarg = (void __user *) arg; |
| 129 | |
| 130 | /* avoid conflicting IRQ users */ |
| 131 | if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) { |
| 132 | spin_lock(&rtc->irq_task_lock); |
| 133 | if (rtc->irq_task) |
| 134 | err = -EBUSY; |
| 135 | spin_unlock(&rtc->irq_task_lock); |
| 136 | |
| 137 | if (err < 0) |
| 138 | return err; |
| 139 | } |
| 140 | |
| 141 | /* try the driver's ioctl interface */ |
| 142 | if (ops->ioctl) { |
| 143 | err = ops->ioctl(class_dev->dev, cmd, arg); |
Alessandro Zummo | b3969e5 | 2006-05-20 15:00:29 -0700 | [diff] [blame^] | 144 | if (err != -ENOIOCTLCMD) |
Alessandro Zummo | e824290 | 2006-03-27 01:16:41 -0800 | [diff] [blame] | 145 | return err; |
| 146 | } |
| 147 | |
| 148 | /* if the driver does not provide the ioctl interface |
| 149 | * or if that particular ioctl was not implemented |
Alessandro Zummo | b3969e5 | 2006-05-20 15:00:29 -0700 | [diff] [blame^] | 150 | * (-ENOIOCTLCMD), we will try to emulate here. |
Alessandro Zummo | e824290 | 2006-03-27 01:16:41 -0800 | [diff] [blame] | 151 | */ |
| 152 | |
| 153 | switch (cmd) { |
| 154 | case RTC_ALM_READ: |
| 155 | err = rtc_read_alarm(class_dev, &alarm); |
| 156 | if (err < 0) |
| 157 | return err; |
| 158 | |
| 159 | if (copy_to_user(uarg, &alarm.time, sizeof(tm))) |
| 160 | return -EFAULT; |
| 161 | break; |
| 162 | |
| 163 | case RTC_ALM_SET: |
| 164 | if (copy_from_user(&alarm.time, uarg, sizeof(tm))) |
| 165 | return -EFAULT; |
| 166 | |
| 167 | alarm.enabled = 0; |
| 168 | alarm.pending = 0; |
| 169 | alarm.time.tm_mday = -1; |
| 170 | alarm.time.tm_mon = -1; |
| 171 | alarm.time.tm_year = -1; |
| 172 | alarm.time.tm_wday = -1; |
| 173 | alarm.time.tm_yday = -1; |
| 174 | alarm.time.tm_isdst = -1; |
| 175 | err = rtc_set_alarm(class_dev, &alarm); |
| 176 | break; |
| 177 | |
| 178 | case RTC_RD_TIME: |
| 179 | err = rtc_read_time(class_dev, &tm); |
| 180 | if (err < 0) |
| 181 | return err; |
| 182 | |
| 183 | if (copy_to_user(uarg, &tm, sizeof(tm))) |
| 184 | return -EFAULT; |
| 185 | break; |
| 186 | |
| 187 | case RTC_SET_TIME: |
| 188 | if (!capable(CAP_SYS_TIME)) |
| 189 | return -EACCES; |
| 190 | |
| 191 | if (copy_from_user(&tm, uarg, sizeof(tm))) |
| 192 | return -EFAULT; |
| 193 | |
| 194 | err = rtc_set_time(class_dev, &tm); |
| 195 | break; |
| 196 | #if 0 |
| 197 | case RTC_EPOCH_SET: |
| 198 | #ifndef rtc_epoch |
| 199 | /* |
| 200 | * There were no RTC clocks before 1900. |
| 201 | */ |
| 202 | if (arg < 1900) { |
| 203 | err = -EINVAL; |
| 204 | break; |
| 205 | } |
| 206 | if (!capable(CAP_SYS_TIME)) { |
| 207 | err = -EACCES; |
| 208 | break; |
| 209 | } |
| 210 | rtc_epoch = arg; |
| 211 | err = 0; |
| 212 | #endif |
| 213 | break; |
| 214 | |
| 215 | case RTC_EPOCH_READ: |
| 216 | err = put_user(rtc_epoch, (unsigned long __user *)uarg); |
| 217 | break; |
| 218 | #endif |
| 219 | case RTC_WKALM_SET: |
| 220 | if (copy_from_user(&alarm, uarg, sizeof(alarm))) |
| 221 | return -EFAULT; |
| 222 | |
| 223 | err = rtc_set_alarm(class_dev, &alarm); |
| 224 | break; |
| 225 | |
| 226 | case RTC_WKALM_RD: |
| 227 | err = rtc_read_alarm(class_dev, &alarm); |
| 228 | if (err < 0) |
| 229 | return err; |
| 230 | |
| 231 | if (copy_to_user(uarg, &alarm, sizeof(alarm))) |
| 232 | return -EFAULT; |
| 233 | break; |
| 234 | |
| 235 | default: |
Alessandro Zummo | b3969e5 | 2006-05-20 15:00:29 -0700 | [diff] [blame^] | 236 | err = -ENOTTY; |
Alessandro Zummo | e824290 | 2006-03-27 01:16:41 -0800 | [diff] [blame] | 237 | break; |
| 238 | } |
| 239 | |
| 240 | return err; |
| 241 | } |
| 242 | |
| 243 | static int rtc_dev_release(struct inode *inode, struct file *file) |
| 244 | { |
| 245 | struct rtc_device *rtc = to_rtc_device(file->private_data); |
| 246 | |
| 247 | if (rtc->ops->release) |
| 248 | rtc->ops->release(rtc->class_dev.dev); |
| 249 | |
| 250 | mutex_unlock(&rtc->char_lock); |
| 251 | return 0; |
| 252 | } |
| 253 | |
| 254 | static int rtc_dev_fasync(int fd, struct file *file, int on) |
| 255 | { |
| 256 | struct rtc_device *rtc = to_rtc_device(file->private_data); |
| 257 | return fasync_helper(fd, file, on, &rtc->async_queue); |
| 258 | } |
| 259 | |
| 260 | static struct file_operations rtc_dev_fops = { |
| 261 | .owner = THIS_MODULE, |
| 262 | .llseek = no_llseek, |
| 263 | .read = rtc_dev_read, |
| 264 | .poll = rtc_dev_poll, |
| 265 | .ioctl = rtc_dev_ioctl, |
| 266 | .open = rtc_dev_open, |
| 267 | .release = rtc_dev_release, |
| 268 | .fasync = rtc_dev_fasync, |
| 269 | }; |
| 270 | |
| 271 | /* insertion/removal hooks */ |
| 272 | |
| 273 | static int rtc_dev_add_device(struct class_device *class_dev, |
| 274 | struct class_interface *class_intf) |
| 275 | { |
| 276 | int err = 0; |
| 277 | struct rtc_device *rtc = to_rtc_device(class_dev); |
| 278 | |
| 279 | if (rtc->id >= RTC_DEV_MAX) { |
| 280 | dev_err(class_dev->dev, "too many RTCs\n"); |
| 281 | return -EINVAL; |
| 282 | } |
| 283 | |
| 284 | mutex_init(&rtc->char_lock); |
| 285 | spin_lock_init(&rtc->irq_lock); |
| 286 | init_waitqueue_head(&rtc->irq_queue); |
| 287 | |
| 288 | cdev_init(&rtc->char_dev, &rtc_dev_fops); |
| 289 | rtc->char_dev.owner = rtc->owner; |
| 290 | |
| 291 | if (cdev_add(&rtc->char_dev, MKDEV(MAJOR(rtc_devt), rtc->id), 1)) { |
| 292 | cdev_del(&rtc->char_dev); |
| 293 | dev_err(class_dev->dev, |
| 294 | "failed to add char device %d:%d\n", |
| 295 | MAJOR(rtc_devt), rtc->id); |
| 296 | return -ENODEV; |
| 297 | } |
| 298 | |
| 299 | rtc->rtc_dev = class_device_create(rtc_dev_class, NULL, |
| 300 | MKDEV(MAJOR(rtc_devt), rtc->id), |
| 301 | class_dev->dev, "rtc%d", rtc->id); |
| 302 | if (IS_ERR(rtc->rtc_dev)) { |
| 303 | dev_err(class_dev->dev, "cannot create rtc_dev device\n"); |
| 304 | err = PTR_ERR(rtc->rtc_dev); |
| 305 | goto err_cdev_del; |
| 306 | } |
| 307 | |
| 308 | dev_info(class_dev->dev, "rtc intf: dev (%d:%d)\n", |
| 309 | MAJOR(rtc->rtc_dev->devt), |
| 310 | MINOR(rtc->rtc_dev->devt)); |
| 311 | |
| 312 | return 0; |
| 313 | |
| 314 | err_cdev_del: |
| 315 | |
| 316 | cdev_del(&rtc->char_dev); |
| 317 | return err; |
| 318 | } |
| 319 | |
| 320 | static void rtc_dev_remove_device(struct class_device *class_dev, |
| 321 | struct class_interface *class_intf) |
| 322 | { |
| 323 | struct rtc_device *rtc = to_rtc_device(class_dev); |
| 324 | |
| 325 | if (rtc->rtc_dev) { |
| 326 | dev_dbg(class_dev->dev, "removing char %d:%d\n", |
| 327 | MAJOR(rtc->rtc_dev->devt), |
| 328 | MINOR(rtc->rtc_dev->devt)); |
| 329 | |
| 330 | class_device_unregister(rtc->rtc_dev); |
| 331 | cdev_del(&rtc->char_dev); |
| 332 | } |
| 333 | } |
| 334 | |
| 335 | /* interface registration */ |
| 336 | |
| 337 | static struct class_interface rtc_dev_interface = { |
| 338 | .add = &rtc_dev_add_device, |
| 339 | .remove = &rtc_dev_remove_device, |
| 340 | }; |
| 341 | |
| 342 | static int __init rtc_dev_init(void) |
| 343 | { |
| 344 | int err; |
| 345 | |
| 346 | rtc_dev_class = class_create(THIS_MODULE, "rtc-dev"); |
| 347 | if (IS_ERR(rtc_dev_class)) |
| 348 | return PTR_ERR(rtc_dev_class); |
| 349 | |
| 350 | err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); |
| 351 | if (err < 0) { |
| 352 | printk(KERN_ERR "%s: failed to allocate char dev region\n", |
| 353 | __FILE__); |
| 354 | goto err_destroy_class; |
| 355 | } |
| 356 | |
| 357 | err = rtc_interface_register(&rtc_dev_interface); |
| 358 | if (err < 0) { |
| 359 | printk(KERN_ERR "%s: failed to register the interface\n", |
| 360 | __FILE__); |
| 361 | goto err_unregister_chrdev; |
| 362 | } |
| 363 | |
| 364 | return 0; |
| 365 | |
| 366 | err_unregister_chrdev: |
| 367 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); |
| 368 | |
| 369 | err_destroy_class: |
| 370 | class_destroy(rtc_dev_class); |
| 371 | |
| 372 | return err; |
| 373 | } |
| 374 | |
| 375 | static void __exit rtc_dev_exit(void) |
| 376 | { |
| 377 | class_interface_unregister(&rtc_dev_interface); |
| 378 | class_destroy(rtc_dev_class); |
| 379 | unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); |
| 380 | } |
| 381 | |
| 382 | module_init(rtc_dev_init); |
| 383 | module_exit(rtc_dev_exit); |
| 384 | |
| 385 | MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); |
| 386 | MODULE_DESCRIPTION("RTC class dev interface"); |
| 387 | MODULE_LICENSE("GPL"); |