Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Raw serio device providing access to a raw byte stream from underlying |
| 3 | * serio port. Closely emulates behavior of pre-2.6 /dev/psaux device |
| 4 | * |
| 5 | * Copyright (c) 2004 Dmitry Torokhov |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify it |
| 8 | * under the terms of the GNU General Public License version 2 as published by |
| 9 | * the Free Software Foundation. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/poll.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/serio.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/major.h> |
| 18 | #include <linux/device.h> |
| 19 | #include <linux/devfs_fs_kernel.h> |
| 20 | #include <linux/miscdevice.h> |
| 21 | #include <linux/wait.h> |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 22 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | #define DRIVER_DESC "Raw serio driver" |
| 25 | |
| 26 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); |
| 27 | MODULE_DESCRIPTION(DRIVER_DESC); |
| 28 | MODULE_LICENSE("GPL"); |
| 29 | |
| 30 | #define SERIO_RAW_QUEUE_LEN 64 |
| 31 | struct serio_raw { |
| 32 | unsigned char queue[SERIO_RAW_QUEUE_LEN]; |
| 33 | unsigned int tail, head; |
| 34 | |
| 35 | char name[16]; |
| 36 | unsigned int refcnt; |
| 37 | struct serio *serio; |
| 38 | struct miscdevice dev; |
| 39 | wait_queue_head_t wait; |
| 40 | struct list_head list; |
| 41 | struct list_head node; |
| 42 | }; |
| 43 | |
| 44 | struct serio_raw_list { |
| 45 | struct fasync_struct *fasync; |
| 46 | struct serio_raw *serio_raw; |
| 47 | struct list_head node; |
| 48 | }; |
| 49 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 50 | static DEFINE_MUTEX(serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | static LIST_HEAD(serio_raw_list); |
| 52 | static unsigned int serio_raw_no; |
| 53 | |
| 54 | /********************************************************************* |
| 55 | * Interface with userspace (file operations) * |
| 56 | *********************************************************************/ |
| 57 | |
| 58 | static int serio_raw_fasync(int fd, struct file *file, int on) |
| 59 | { |
| 60 | struct serio_raw_list *list = file->private_data; |
| 61 | int retval; |
| 62 | |
| 63 | retval = fasync_helper(fd, file, on, &list->fasync); |
| 64 | return retval < 0 ? retval : 0; |
| 65 | } |
| 66 | |
| 67 | static struct serio_raw *serio_raw_locate(int minor) |
| 68 | { |
| 69 | struct serio_raw *serio_raw; |
| 70 | |
| 71 | list_for_each_entry(serio_raw, &serio_raw_list, node) { |
| 72 | if (serio_raw->dev.minor == minor) |
| 73 | return serio_raw; |
| 74 | } |
| 75 | |
| 76 | return NULL; |
| 77 | } |
| 78 | |
| 79 | static int serio_raw_open(struct inode *inode, struct file *file) |
| 80 | { |
| 81 | struct serio_raw *serio_raw; |
| 82 | struct serio_raw_list *list; |
| 83 | int retval = 0; |
| 84 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 85 | retval = mutex_lock_interruptible(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | if (retval) |
| 87 | return retval; |
| 88 | |
| 89 | if (!(serio_raw = serio_raw_locate(iminor(inode)))) { |
| 90 | retval = -ENODEV; |
| 91 | goto out; |
| 92 | } |
| 93 | |
| 94 | if (!serio_raw->serio) { |
| 95 | retval = -ENODEV; |
| 96 | goto out; |
| 97 | } |
| 98 | |
Eric Sesterhenn | b39787a | 2006-03-14 00:09:16 -0500 | [diff] [blame] | 99 | if (!(list = kzalloc(sizeof(struct serio_raw_list), GFP_KERNEL))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | retval = -ENOMEM; |
| 101 | goto out; |
| 102 | } |
| 103 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | list->serio_raw = serio_raw; |
| 105 | file->private_data = list; |
| 106 | |
| 107 | serio_raw->refcnt++; |
| 108 | list_add_tail(&list->node, &serio_raw->list); |
| 109 | |
| 110 | out: |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 111 | mutex_unlock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | return retval; |
| 113 | } |
| 114 | |
| 115 | static int serio_raw_cleanup(struct serio_raw *serio_raw) |
| 116 | { |
| 117 | if (--serio_raw->refcnt == 0) { |
| 118 | misc_deregister(&serio_raw->dev); |
| 119 | list_del_init(&serio_raw->node); |
| 120 | kfree(serio_raw); |
| 121 | |
| 122 | return 1; |
| 123 | } |
| 124 | |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static int serio_raw_release(struct inode *inode, struct file *file) |
| 129 | { |
| 130 | struct serio_raw_list *list = file->private_data; |
| 131 | struct serio_raw *serio_raw = list->serio_raw; |
| 132 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 133 | mutex_lock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | |
| 135 | serio_raw_fasync(-1, file, 0); |
| 136 | serio_raw_cleanup(serio_raw); |
| 137 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 138 | mutex_unlock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c) |
| 143 | { |
| 144 | unsigned long flags; |
| 145 | int empty; |
| 146 | |
| 147 | spin_lock_irqsave(&serio_raw->serio->lock, flags); |
| 148 | |
| 149 | empty = serio_raw->head == serio_raw->tail; |
| 150 | if (!empty) { |
| 151 | *c = serio_raw->queue[serio_raw->tail]; |
| 152 | serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN; |
| 153 | } |
| 154 | |
| 155 | spin_unlock_irqrestore(&serio_raw->serio->lock, flags); |
| 156 | |
| 157 | return !empty; |
| 158 | } |
| 159 | |
| 160 | static ssize_t serio_raw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) |
| 161 | { |
| 162 | struct serio_raw_list *list = file->private_data; |
| 163 | struct serio_raw *serio_raw = list->serio_raw; |
| 164 | char c; |
| 165 | ssize_t retval = 0; |
| 166 | |
| 167 | if (!serio_raw->serio) |
| 168 | return -ENODEV; |
| 169 | |
| 170 | if (serio_raw->head == serio_raw->tail && (file->f_flags & O_NONBLOCK)) |
| 171 | return -EAGAIN; |
| 172 | |
| 173 | retval = wait_event_interruptible(list->serio_raw->wait, |
| 174 | serio_raw->head != serio_raw->tail || !serio_raw->serio); |
| 175 | if (retval) |
| 176 | return retval; |
| 177 | |
| 178 | if (!serio_raw->serio) |
| 179 | return -ENODEV; |
| 180 | |
| 181 | while (retval < count && serio_raw_fetch_byte(serio_raw, &c)) { |
| 182 | if (put_user(c, buffer++)) |
| 183 | return -EFAULT; |
| 184 | retval++; |
| 185 | } |
| 186 | |
| 187 | return retval; |
| 188 | } |
| 189 | |
| 190 | static ssize_t serio_raw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) |
| 191 | { |
| 192 | struct serio_raw_list *list = file->private_data; |
| 193 | ssize_t written = 0; |
| 194 | int retval; |
| 195 | unsigned char c; |
| 196 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 197 | retval = mutex_lock_interruptible(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | if (retval) |
| 199 | return retval; |
| 200 | |
| 201 | if (!list->serio_raw->serio) { |
| 202 | retval = -ENODEV; |
| 203 | goto out; |
| 204 | } |
| 205 | |
| 206 | if (count > 32) |
| 207 | count = 32; |
| 208 | |
| 209 | while (count--) { |
| 210 | if (get_user(c, buffer++)) { |
| 211 | retval = -EFAULT; |
| 212 | goto out; |
| 213 | } |
| 214 | if (serio_write(list->serio_raw->serio, c)) { |
| 215 | retval = -EIO; |
| 216 | goto out; |
| 217 | } |
| 218 | written++; |
| 219 | }; |
| 220 | |
| 221 | out: |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 222 | mutex_unlock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | return written; |
| 224 | } |
| 225 | |
| 226 | static unsigned int serio_raw_poll(struct file *file, poll_table *wait) |
| 227 | { |
| 228 | struct serio_raw_list *list = file->private_data; |
| 229 | |
| 230 | poll_wait(file, &list->serio_raw->wait, wait); |
| 231 | |
| 232 | if (list->serio_raw->head != list->serio_raw->tail) |
| 233 | return POLLIN | POLLRDNORM; |
| 234 | |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | static struct file_operations serio_raw_fops = { |
| 239 | .owner = THIS_MODULE, |
| 240 | .open = serio_raw_open, |
| 241 | .release = serio_raw_release, |
| 242 | .read = serio_raw_read, |
| 243 | .write = serio_raw_write, |
| 244 | .poll = serio_raw_poll, |
| 245 | .fasync = serio_raw_fasync, |
| 246 | }; |
| 247 | |
| 248 | |
| 249 | /********************************************************************* |
| 250 | * Interface with serio port * |
| 251 | *********************************************************************/ |
| 252 | |
| 253 | static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data, |
| 254 | unsigned int dfl, struct pt_regs *regs) |
| 255 | { |
| 256 | struct serio_raw *serio_raw = serio_get_drvdata(serio); |
| 257 | struct serio_raw_list *list; |
| 258 | unsigned int head = serio_raw->head; |
| 259 | |
| 260 | /* we are holding serio->lock here so we are prootected */ |
| 261 | serio_raw->queue[head] = data; |
| 262 | head = (head + 1) % SERIO_RAW_QUEUE_LEN; |
| 263 | if (likely(head != serio_raw->tail)) { |
| 264 | serio_raw->head = head; |
| 265 | list_for_each_entry(list, &serio_raw->list, node) |
| 266 | kill_fasync(&list->fasync, SIGIO, POLL_IN); |
| 267 | wake_up_interruptible(&serio_raw->wait); |
| 268 | } |
| 269 | |
| 270 | return IRQ_HANDLED; |
| 271 | } |
| 272 | |
| 273 | static int serio_raw_connect(struct serio *serio, struct serio_driver *drv) |
| 274 | { |
| 275 | struct serio_raw *serio_raw; |
| 276 | int err; |
| 277 | |
Eric Sesterhenn | b39787a | 2006-03-14 00:09:16 -0500 | [diff] [blame] | 278 | if (!(serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | printk(KERN_ERR "serio_raw.c: can't allocate memory for a device\n"); |
| 280 | return -ENOMEM; |
| 281 | } |
| 282 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 283 | mutex_lock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%d", serio_raw_no++); |
| 286 | serio_raw->refcnt = 1; |
| 287 | serio_raw->serio = serio; |
| 288 | INIT_LIST_HEAD(&serio_raw->list); |
| 289 | init_waitqueue_head(&serio_raw->wait); |
| 290 | |
| 291 | serio_set_drvdata(serio, serio_raw); |
| 292 | |
| 293 | err = serio_open(serio, drv); |
| 294 | if (err) |
| 295 | goto out_free; |
| 296 | |
| 297 | list_add_tail(&serio_raw->node, &serio_raw_list); |
| 298 | |
| 299 | serio_raw->dev.minor = PSMOUSE_MINOR; |
| 300 | serio_raw->dev.name = serio_raw->name; |
Dmitry Torokhov | dc1e97b | 2005-07-11 01:02:16 -0500 | [diff] [blame] | 301 | serio_raw->dev.dev = &serio->dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | serio_raw->dev.fops = &serio_raw_fops; |
| 303 | |
| 304 | err = misc_register(&serio_raw->dev); |
| 305 | if (err) { |
| 306 | serio_raw->dev.minor = MISC_DYNAMIC_MINOR; |
| 307 | err = misc_register(&serio_raw->dev); |
| 308 | } |
| 309 | |
| 310 | if (err) { |
| 311 | printk(KERN_INFO "serio_raw: failed to register raw access device for %s\n", |
| 312 | serio->phys); |
| 313 | goto out_close; |
| 314 | } |
| 315 | |
| 316 | printk(KERN_INFO "serio_raw: raw access enabled on %s (%s, minor %d)\n", |
| 317 | serio->phys, serio_raw->name, serio_raw->dev.minor); |
| 318 | goto out; |
| 319 | |
| 320 | out_close: |
| 321 | serio_close(serio); |
| 322 | list_del_init(&serio_raw->node); |
| 323 | out_free: |
| 324 | serio_set_drvdata(serio, NULL); |
| 325 | kfree(serio_raw); |
| 326 | out: |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 327 | mutex_unlock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | return err; |
| 329 | } |
| 330 | |
| 331 | static int serio_raw_reconnect(struct serio *serio) |
| 332 | { |
| 333 | struct serio_raw *serio_raw = serio_get_drvdata(serio); |
| 334 | struct serio_driver *drv = serio->drv; |
| 335 | |
| 336 | if (!drv || !serio_raw) { |
| 337 | printk(KERN_DEBUG "serio_raw: reconnect request, but serio is disconnected, ignoring...\n"); |
| 338 | return -1; |
| 339 | } |
| 340 | |
| 341 | /* |
| 342 | * Nothing needs to be done here, we just need this method to |
| 343 | * keep the same device. |
| 344 | */ |
| 345 | return 0; |
| 346 | } |
| 347 | |
| 348 | static void serio_raw_disconnect(struct serio *serio) |
| 349 | { |
| 350 | struct serio_raw *serio_raw; |
| 351 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 352 | mutex_lock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | |
| 354 | serio_raw = serio_get_drvdata(serio); |
| 355 | |
| 356 | serio_close(serio); |
| 357 | serio_set_drvdata(serio, NULL); |
| 358 | |
| 359 | serio_raw->serio = NULL; |
| 360 | if (!serio_raw_cleanup(serio_raw)) |
| 361 | wake_up_interruptible(&serio_raw->wait); |
| 362 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 363 | mutex_unlock(&serio_raw_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | } |
| 365 | |
| 366 | static struct serio_device_id serio_raw_serio_ids[] = { |
| 367 | { |
| 368 | .type = SERIO_8042, |
| 369 | .proto = SERIO_ANY, |
| 370 | .id = SERIO_ANY, |
| 371 | .extra = SERIO_ANY, |
| 372 | }, |
| 373 | { 0 } |
| 374 | }; |
| 375 | |
| 376 | MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids); |
| 377 | |
| 378 | static struct serio_driver serio_raw_drv = { |
| 379 | .driver = { |
| 380 | .name = "serio_raw", |
| 381 | }, |
| 382 | .description = DRIVER_DESC, |
| 383 | .id_table = serio_raw_serio_ids, |
| 384 | .interrupt = serio_raw_interrupt, |
| 385 | .connect = serio_raw_connect, |
| 386 | .reconnect = serio_raw_reconnect, |
| 387 | .disconnect = serio_raw_disconnect, |
| 388 | .manual_bind = 1, |
| 389 | }; |
| 390 | |
| 391 | static int __init serio_raw_init(void) |
| 392 | { |
| 393 | serio_register_driver(&serio_raw_drv); |
| 394 | return 0; |
| 395 | } |
| 396 | |
| 397 | static void __exit serio_raw_exit(void) |
| 398 | { |
| 399 | serio_unregister_driver(&serio_raw_drv); |
| 400 | } |
| 401 | |
| 402 | module_init(serio_raw_init); |
| 403 | module_exit(serio_raw_exit); |