drivers/media/dvb-core/dvbdev.c

   1 /*
   2  * dvbdev.c
   3  *
   4  * Copyright (C) 2000 Ralph  Metzler <ralph@convergence.de>
   5  *                  & Marcus Metzler <marcus@convergence.de>
   6  *                    for convergence integrated media GmbH
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 2.1
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21  *
  22  */
  23
  24 #include <linux/types.h>
  25 #include <linux/errno.h>
  26 #include <linux/string.h>
  27 #include <linux/module.h>
  28 #include <linux/kernel.h>
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/device.h>
  32 #include <linux/fs.h>
  33 #include <linux/cdev.h>
  34 #include <linux/mutex.h>
  35 #include "dvbdev.h"
  36
  37 static DEFINE_MUTEX(dvbdev_mutex);
  38 static int dvbdev_debug;
  39
  40 module_param(dvbdev_debug, int, 0644);
  41 MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");
  42
  43 #define dprintk if (dvbdev_debug) printk
  44
  45 static LIST_HEAD(dvb_adapter_list);
  46 static DEFINE_MUTEX(dvbdev_register_lock);
  47
  48 static const char * const dnames[] = {
  49         "video", "audio", "sec", "frontend", "demux", "dvr", "ca",
  50         "net", "osd"
  51 };
  52
  53 #ifdef CONFIG_DVB_DYNAMIC_MINORS
  54 #define MAX_DVB_MINORS          256
  55 #define DVB_MAX_IDS             MAX_DVB_MINORS
  56 #else
  57 #define DVB_MAX_IDS             4
  58 #define nums2minor(num,type,id) ((num << 6) | (id << 4) | type)
  59 #define MAX_DVB_MINORS          (DVB_MAX_ADAPTERS*64)
  60 #endif
  61
  62 static struct class *dvb_class;
  63
  64 static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
  65 static DECLARE_RWSEM(minor_rwsem);
  66
  67 static int dvb_device_open(struct inode *inode, struct file *file)
  68 {
  69         struct dvb_device *dvbdev;
  70
  71         mutex_lock(&dvbdev_mutex);
  72         down_read(&minor_rwsem);
  73         dvbdev = dvb_minors[iminor(inode)];
  74
  75         if (dvbdev && dvbdev->fops) {
  76                 int err = 0;
  77                 const struct file_operations *old_fops;
  78
  79                 file->private_data = dvbdev;
  80                 old_fops = file->f_op;
  81                 file->f_op = fops_get(dvbdev->fops);
  82                 if (file->f_op == NULL) {
  83                         file->f_op = old_fops;
  84                         goto fail;
  85                 }
  86                 if(file->f_op->open)
  87                         err = file->f_op->open(inode,file);
  88                 if (err) {
  89                         fops_put(file->f_op);
  90                         file->f_op = fops_get(old_fops);
  91                 }
  92                 fops_put(old_fops);
  93                 up_read(&minor_rwsem);
  94                 mutex_unlock(&dvbdev_mutex);
  95                 return err;
  96         }
  97 fail:
  98         up_read(&minor_rwsem);
  99         mutex_unlock(&dvbdev_mutex);
 100         return -ENODEV;
 101 }
 102
 103
 104 static const struct file_operations dvb_device_fops =
 105 {
 106         .owner =        THIS_MODULE,
 107         .open =         dvb_device_open,
 108         .llseek =       noop_llseek,
 109 };
 110
 111 static struct cdev dvb_device_cdev;
 112
 113 int dvb_generic_open(struct inode *inode, struct file *file)
 114 {
 115         struct dvb_device *dvbdev = file->private_data;
 116
 117         if (!dvbdev)
 118                 return -ENODEV;
 119
 120         if (!dvbdev->users)
 121                 return -EBUSY;
 122
 123         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 124                 if (!dvbdev->readers)
 125                         return -EBUSY;
 126                 dvbdev->readers--;
 127         } else {
 128                 if (!dvbdev->writers)
 129                         return -EBUSY;
 130                 dvbdev->writers--;
 131         }
 132
 133         dvbdev->users--;
 134         return 0;
 135 }
 136 EXPORT_SYMBOL(dvb_generic_open);
 137
 138
 139 int dvb_generic_release(struct inode *inode, struct file *file)
 140 {
 141         struct dvb_device *dvbdev = file->private_data;
 142
 143         if (!dvbdev)
 144                 return -ENODEV;
 145
 146         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 147                 dvbdev->readers++;
 148         } else {
 149                 dvbdev->writers++;
 150         }
 151
 152         dvbdev->users++;
 153         return 0;
 154 }
 155 EXPORT_SYMBOL(dvb_generic_release);
 156
 157
 158 long dvb_generic_ioctl(struct file *file,
 159                        unsigned int cmd, unsigned long arg)
 160 {
 161         struct dvb_device *dvbdev = file->private_data;
 162
 163         if (!dvbdev)
 164                 return -ENODEV;
 165
 166         if (!dvbdev->kernel_ioctl)
 167                 return -EINVAL;
 168
 169         return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
 170 }
 171 EXPORT_SYMBOL(dvb_generic_ioctl);
 172
 173
 174 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
 175 {
 176         u32 id = 0;
 177
 178         while (id < DVB_MAX_IDS) {
 179                 struct dvb_device *dev;
 180                 list_for_each_entry(dev, &adap->device_list, list_head)
 181                         if (dev->type == type && dev->id == id)
 182                                 goto skip;
 183                 return id;
 184 skip:
 185                 id++;
 186         }
 187         return -ENFILE;
 188 }
 189
 190
 191 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 192                         const struct dvb_device *template, void *priv, int type)
 193 {
 194         struct dvb_device *dvbdev;
 195         struct file_operations *dvbdevfops;
 196         struct device *clsdev;
 197         int minor;
 198         int id;
 199
 200         mutex_lock(&dvbdev_register_lock);
 201
 202         if ((id = dvbdev_get_free_id (adap, type)) < 0){
 203                 mutex_unlock(&dvbdev_register_lock);
 204                 *pdvbdev = NULL;
 205                 printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
 206                 return -ENFILE;
 207         }
 208
 209         *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 210
 211         if (!dvbdev){
 212                 mutex_unlock(&dvbdev_register_lock);
 213                 return -ENOMEM;
 214         }
 215
 216         dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
 217
 218         if (!dvbdevfops){
 219                 kfree (dvbdev);
 220                 mutex_unlock(&dvbdev_register_lock);
 221                 return -ENOMEM;
 222         }
 223
 224         memcpy(dvbdev, template, sizeof(struct dvb_device));
 225         dvbdev->type = type;
 226         dvbdev->id = id;
 227         dvbdev->adapter = adap;
 228         dvbdev->priv = priv;
 229         dvbdev->fops = dvbdevfops;
 230         init_waitqueue_head (&dvbdev->wait_queue);
 231
 232         memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
 233         dvbdevfops->owner = adap->module;
 234
 235         list_add_tail (&dvbdev->list_head, &adap->device_list);
 236
 237         down_write(&minor_rwsem);
 238 #ifdef CONFIG_DVB_DYNAMIC_MINORS
 239         for (minor = 0; minor < MAX_DVB_MINORS; minor++)
 240                 if (dvb_minors[minor] == NULL)
 241                         break;
 242
 243         if (minor == MAX_DVB_MINORS) {
 244                 kfree(dvbdevfops);
 245                 kfree(dvbdev);
 246                 up_write(&minor_rwsem);
 247                 mutex_unlock(&dvbdev_register_lock);
 248                 return -EINVAL;
 249         }
 250 #else
 251         minor = nums2minor(adap->num, type, id);
 252 #endif
 253
 254         dvbdev->minor = minor;
 255         dvb_minors[minor] = dvbdev;
 256         up_write(&minor_rwsem);
 257
 258         mutex_unlock(&dvbdev_register_lock);
 259
 260         clsdev = device_create(dvb_class, adap->device,
 261                                MKDEV(DVB_MAJOR, minor),
 262                                dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
 263         if (IS_ERR(clsdev)) {
 264                 printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
 265                        __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 266                 return PTR_ERR(clsdev);
 267         }
 268
 269         dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 270                 adap->num, dnames[type], id, minor, minor);
 271
 272         return 0;
 273 }
 274 EXPORT_SYMBOL(dvb_register_device);
 275
 276
 277 void dvb_unregister_device(struct dvb_device *dvbdev)
 278 {
 279         if (!dvbdev)
 280                 return;
 281
 282         down_write(&minor_rwsem);
 283         dvb_minors[dvbdev->minor] = NULL;
 284         up_write(&minor_rwsem);
 285
 286         device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
 287
 288         list_del (&dvbdev->list_head);
 289         kfree (dvbdev->fops);
 290         kfree (dvbdev);
 291 }
 292 EXPORT_SYMBOL(dvb_unregister_device);
 293
 294 static int dvbdev_check_free_adapter_num(int num)
 295 {
 296         struct list_head *entry;
 297         list_for_each(entry, &dvb_adapter_list) {
 298                 struct dvb_adapter *adap;
 299                 adap = list_entry(entry, struct dvb_adapter, list_head);
 300                 if (adap->num == num)
 301                         return 0;
 302         }
 303         return 1;
 304 }
 305
 306 static int dvbdev_get_free_adapter_num (void)
 307 {
 308         int num = 0;
 309
 310         while (num < DVB_MAX_ADAPTERS) {
 311                 if (dvbdev_check_free_adapter_num(num))
 312                         return num;
 313                 num++;
 314         }
 315
 316         return -ENFILE;
 317 }
 318
 319
 320 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
 321                          struct module *module, struct device *device,
 322                          short *adapter_nums)
 323 {
 324         int i, num;
 325
 326         mutex_lock(&dvbdev_register_lock);
 327
 328         for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
 329                 num = adapter_nums[i];
 330                 if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
 331                 /* use the one the driver asked for */
 332                         if (dvbdev_check_free_adapter_num(num))
 333                                 break;
 334                 } else {
 335                         num = dvbdev_get_free_adapter_num();
 336                         break;
 337                 }
 338                 num = -1;
 339         }
 340
 341         if (num < 0) {
 342                 mutex_unlock(&dvbdev_register_lock);
 343                 return -ENFILE;
 344         }
 345
 346         memset (adap, 0, sizeof(struct dvb_adapter));
 347         INIT_LIST_HEAD (&adap->device_list);
 348
 349         printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 350
 351         adap->num = num;
 352         adap->name = name;
 353         adap->module = module;
 354         adap->device = device;
 355         adap->mfe_shared = 0;
 356         adap->mfe_dvbdev = NULL;
 357         mutex_init (&adap->mfe_lock);
 358
 359         list_add_tail (&adap->list_head, &dvb_adapter_list);
 360
 361         mutex_unlock(&dvbdev_register_lock);
 362
 363         return num;
 364 }
 365 EXPORT_SYMBOL(dvb_register_adapter);
 366
 367
 368 int dvb_unregister_adapter(struct dvb_adapter *adap)
 369 {
 370         mutex_lock(&dvbdev_register_lock);
 371         list_del (&adap->list_head);
 372         mutex_unlock(&dvbdev_register_lock);
 373         return 0;
 374 }
 375 EXPORT_SYMBOL(dvb_unregister_adapter);
 376
 377 /* if the miracle happens and "generic_usercopy()" is included into
 378    the kernel, then this can vanish. please don't make the mistake and
 379    define this as video_usercopy(). this will introduce a dependecy
 380    to the v4l "videodev.o" module, which is unnecessary for some
 381    cards (ie. the budget dvb-cards don't need the v4l module...) */
 382 int dvb_usercopy(struct file *file,
 383                      unsigned int cmd, unsigned long arg,
 384                      int (*func)(struct file *file,
 385                      unsigned int cmd, void *arg))
 386 {
 387         char    sbuf[128];
 388         void    *mbuf = NULL;
 389         void    *parg = NULL;
 390         int     err  = -EINVAL;
 391
 392         /*  Copy arguments into temp kernel buffer  */
 393         switch (_IOC_DIR(cmd)) {
 394         case _IOC_NONE:
 395                 /*
 396                  * For this command, the pointer is actually an integer
 397                  * argument.
 398                  */
 399                 parg = (void *) arg;
 400                 break;
 401         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 402         case _IOC_WRITE:
 403         case (_IOC_WRITE | _IOC_READ):
 404                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 405                         parg = sbuf;
 406                 } else {
 407                         /* too big to allocate from stack */
 408                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 409                         if (NULL == mbuf)
 410                                 return -ENOMEM;
 411                         parg = mbuf;
 412                 }
 413
 414                 err = -EFAULT;
 415                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 416                         goto out;
 417                 break;
 418         }
 419
 420         /* call driver */
 421         if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
 422                 err = -ENOTTY;
 423
 424         if (err < 0)
 425                 goto out;
 426
 427         /*  Copy results into user buffer  */
 428         switch (_IOC_DIR(cmd))
 429         {
 430         case _IOC_READ:
 431         case (_IOC_WRITE | _IOC_READ):
 432                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 433                         err = -EFAULT;
 434                 break;
 435         }
 436
 437 out:
 438         kfree(mbuf);
 439         return err;
 440 }
 441
 442 static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
 443 {
 444         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 445
 446         add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
 447         add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
 448         add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
 449         return 0;
 450 }
 451
 452 static char *dvb_devnode(struct device *dev, umode_t *mode)
 453 {
 454         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 455
 456         return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
 457                 dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
 458 }
 459
 460
 461 static int __init init_dvbdev(void)
 462 {
 463         int retval;
 464         dev_t dev = MKDEV(DVB_MAJOR, 0);
 465
 466         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 467                 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 468                 return retval;
 469         }
 470
 471         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 472         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 473                 printk(KERN_ERR "dvb-core: unable register character device\n");
 474                 goto error;
 475         }
 476
 477         dvb_class = class_create(THIS_MODULE, "dvb");
 478         if (IS_ERR(dvb_class)) {
 479                 retval = PTR_ERR(dvb_class);
 480                 goto error;
 481         }
 482         dvb_class->dev_uevent = dvb_uevent;
 483         dvb_class->devnode = dvb_devnode;
 484         return 0;
 485
 486 error:
 487         cdev_del(&dvb_device_cdev);
 488         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 489         return retval;
 490 }
 491
 492
 493 static void __exit exit_dvbdev(void)
 494 {
 495         class_destroy(dvb_class);
 496         cdev_del(&dvb_device_cdev);
 497         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 498 }
 499
 500 subsys_initcall(init_dvbdev);
 501 module_exit(exit_dvbdev);
 502
 503 MODULE_DESCRIPTION("DVB Core Driver");
 504 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 505 MODULE_LICENSE("GPL");