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 *new_fops;
  78
  79                 new_fops = fops_get(dvbdev->fops);
  80                 if (!new_fops)
  81                         goto fail;
  82                 file->private_data = dvbdev;
  83                 replace_fops(file, new_fops);
  84                 if (file->f_op->open)
  85                         err = file->f_op->open(inode,file);
  86                 up_read(&minor_rwsem);
  87                 mutex_unlock(&dvbdev_mutex);
  88                 return err;
  89         }
  90 fail:
  91         up_read(&minor_rwsem);
  92         mutex_unlock(&dvbdev_mutex);
  93         return -ENODEV;
  94 }
  95
  96
  97 static const struct file_operations dvb_device_fops =
  98 {
  99         .owner =        THIS_MODULE,
 100         .open =         dvb_device_open,
 101         .llseek =       noop_llseek,
 102 };
 103
 104 static struct cdev dvb_device_cdev;
 105
 106 int dvb_generic_open(struct inode *inode, struct file *file)
 107 {
 108         struct dvb_device *dvbdev = file->private_data;
 109
 110         if (!dvbdev)
 111                 return -ENODEV;
 112
 113         if (!dvbdev->users)
 114                 return -EBUSY;
 115
 116         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 117                 if (!dvbdev->readers)
 118                         return -EBUSY;
 119                 dvbdev->readers--;
 120         } else {
 121                 if (!dvbdev->writers)
 122                         return -EBUSY;
 123                 dvbdev->writers--;
 124         }
 125
 126         dvbdev->users--;
 127         return 0;
 128 }
 129 EXPORT_SYMBOL(dvb_generic_open);
 130
 131
 132 int dvb_generic_release(struct inode *inode, struct file *file)
 133 {
 134         struct dvb_device *dvbdev = file->private_data;
 135
 136         if (!dvbdev)
 137                 return -ENODEV;
 138
 139         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 140                 dvbdev->readers++;
 141         } else {
 142                 dvbdev->writers++;
 143         }
 144
 145         dvbdev->users++;
 146         return 0;
 147 }
 148 EXPORT_SYMBOL(dvb_generic_release);
 149
 150
 151 long dvb_generic_ioctl(struct file *file,
 152                        unsigned int cmd, unsigned long arg)
 153 {
 154         struct dvb_device *dvbdev = file->private_data;
 155
 156         if (!dvbdev)
 157                 return -ENODEV;
 158
 159         if (!dvbdev->kernel_ioctl)
 160                 return -EINVAL;
 161
 162         return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
 163 }
 164 EXPORT_SYMBOL(dvb_generic_ioctl);
 165
 166
 167 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
 168 {
 169         u32 id = 0;
 170
 171         while (id < DVB_MAX_IDS) {
 172                 struct dvb_device *dev;
 173                 list_for_each_entry(dev, &adap->device_list, list_head)
 174                         if (dev->type == type && dev->id == id)
 175                                 goto skip;
 176                 return id;
 177 skip:
 178                 id++;
 179         }
 180         return -ENFILE;
 181 }
 182
 183
 184 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 185                         const struct dvb_device *template, void *priv, int type)
 186 {
 187         struct dvb_device *dvbdev;
 188         struct file_operations *dvbdevfops;
 189         struct device *clsdev;
 190         int minor;
 191         int id;
 192
 193         mutex_lock(&dvbdev_register_lock);
 194
 195         if ((id = dvbdev_get_free_id (adap, type)) < 0){
 196                 mutex_unlock(&dvbdev_register_lock);
 197                 *pdvbdev = NULL;
 198                 printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
 199                 return -ENFILE;
 200         }
 201
 202         *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 203
 204         if (!dvbdev){
 205                 mutex_unlock(&dvbdev_register_lock);
 206                 return -ENOMEM;
 207         }
 208
 209         dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
 210
 211         if (!dvbdevfops){
 212                 kfree (dvbdev);
 213                 mutex_unlock(&dvbdev_register_lock);
 214                 return -ENOMEM;
 215         }
 216
 217         memcpy(dvbdev, template, sizeof(struct dvb_device));
 218         dvbdev->type = type;
 219         dvbdev->id = id;
 220         dvbdev->adapter = adap;
 221         dvbdev->priv = priv;
 222         dvbdev->fops = dvbdevfops;
 223         init_waitqueue_head (&dvbdev->wait_queue);
 224
 225         memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
 226         dvbdevfops->owner = adap->module;
 227
 228         list_add_tail (&dvbdev->list_head, &adap->device_list);
 229
 230         down_write(&minor_rwsem);
 231 #ifdef CONFIG_DVB_DYNAMIC_MINORS
 232         for (minor = 0; minor < MAX_DVB_MINORS; minor++)
 233                 if (dvb_minors[minor] == NULL)
 234                         break;
 235
 236         if (minor == MAX_DVB_MINORS) {
 237                 kfree(dvbdevfops);
 238                 kfree(dvbdev);
 239                 up_write(&minor_rwsem);
 240                 mutex_unlock(&dvbdev_register_lock);
 241                 return -EINVAL;
 242         }
 243 #else
 244         minor = nums2minor(adap->num, type, id);
 245 #endif
 246
 247         dvbdev->minor = minor;
 248         dvb_minors[minor] = dvbdev;
 249         up_write(&minor_rwsem);
 250
 251         mutex_unlock(&dvbdev_register_lock);
 252
 253         clsdev = device_create(dvb_class, adap->device,
 254                                MKDEV(DVB_MAJOR, minor),
 255                                dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
 256         if (IS_ERR(clsdev)) {
 257                 printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
 258                        __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 259                 return PTR_ERR(clsdev);
 260         }
 261
 262         dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 263                 adap->num, dnames[type], id, minor, minor);
 264
 265         return 0;
 266 }
 267 EXPORT_SYMBOL(dvb_register_device);
 268
 269
 270 void dvb_unregister_device(struct dvb_device *dvbdev)
 271 {
 272         if (!dvbdev)
 273                 return;
 274
 275         down_write(&minor_rwsem);
 276         dvb_minors[dvbdev->minor] = NULL;
 277         up_write(&minor_rwsem);
 278
 279         device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
 280
 281         list_del (&dvbdev->list_head);
 282         kfree (dvbdev->fops);
 283         kfree (dvbdev);
 284 }
 285 EXPORT_SYMBOL(dvb_unregister_device);
 286
 287 static int dvbdev_check_free_adapter_num(int num)
 288 {
 289         struct list_head *entry;
 290         list_for_each(entry, &dvb_adapter_list) {
 291                 struct dvb_adapter *adap;
 292                 adap = list_entry(entry, struct dvb_adapter, list_head);
 293                 if (adap->num == num)
 294                         return 0;
 295         }
 296         return 1;
 297 }
 298
 299 static int dvbdev_get_free_adapter_num (void)
 300 {
 301         int num = 0;
 302
 303         while (num < DVB_MAX_ADAPTERS) {
 304                 if (dvbdev_check_free_adapter_num(num))
 305                         return num;
 306                 num++;
 307         }
 308
 309         return -ENFILE;
 310 }
 311
 312
 313 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
 314                          struct module *module, struct device *device,
 315                          short *adapter_nums)
 316 {
 317         int i, num;
 318
 319         mutex_lock(&dvbdev_register_lock);
 320
 321         for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
 322                 num = adapter_nums[i];
 323                 if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
 324                 /* use the one the driver asked for */
 325                         if (dvbdev_check_free_adapter_num(num))
 326                                 break;
 327                 } else {
 328                         num = dvbdev_get_free_adapter_num();
 329                         break;
 330                 }
 331                 num = -1;
 332         }
 333
 334         if (num < 0) {
 335                 mutex_unlock(&dvbdev_register_lock);
 336                 return -ENFILE;
 337         }
 338
 339         memset (adap, 0, sizeof(struct dvb_adapter));
 340         INIT_LIST_HEAD (&adap->device_list);
 341
 342         printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 343
 344         adap->num = num;
 345         adap->name = name;
 346         adap->module = module;
 347         adap->device = device;
 348         adap->mfe_shared = 0;
 349         adap->mfe_dvbdev = NULL;
 350         mutex_init (&adap->mfe_lock);
 351
 352         list_add_tail (&adap->list_head, &dvb_adapter_list);
 353
 354         mutex_unlock(&dvbdev_register_lock);
 355
 356         return num;
 357 }
 358 EXPORT_SYMBOL(dvb_register_adapter);
 359
 360
 361 int dvb_unregister_adapter(struct dvb_adapter *adap)
 362 {
 363         mutex_lock(&dvbdev_register_lock);
 364         list_del (&adap->list_head);
 365         mutex_unlock(&dvbdev_register_lock);
 366         return 0;
 367 }
 368 EXPORT_SYMBOL(dvb_unregister_adapter);
 369
 370 /* if the miracle happens and "generic_usercopy()" is included into
 371    the kernel, then this can vanish. please don't make the mistake and
 372    define this as video_usercopy(). this will introduce a dependecy
 373    to the v4l "videodev.o" module, which is unnecessary for some
 374    cards (ie. the budget dvb-cards don't need the v4l module...) */
 375 int dvb_usercopy(struct file *file,
 376                      unsigned int cmd, unsigned long arg,
 377                      int (*func)(struct file *file,
 378                      unsigned int cmd, void *arg))
 379 {
 380         char    sbuf[128];
 381         void    *mbuf = NULL;
 382         void    *parg = NULL;
 383         int     err  = -EINVAL;
 384
 385         /*  Copy arguments into temp kernel buffer  */
 386         switch (_IOC_DIR(cmd)) {
 387         case _IOC_NONE:
 388                 /*
 389                  * For this command, the pointer is actually an integer
 390                  * argument.
 391                  */
 392                 parg = (void *) arg;
 393                 break;
 394         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 395         case _IOC_WRITE:
 396         case (_IOC_WRITE | _IOC_READ):
 397                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 398                         parg = sbuf;
 399                 } else {
 400                         /* too big to allocate from stack */
 401                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 402                         if (NULL == mbuf)
 403                                 return -ENOMEM;
 404                         parg = mbuf;
 405                 }
 406
 407                 err = -EFAULT;
 408                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 409                         goto out;
 410                 break;
 411         }
 412
 413         /* call driver */
 414         if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
 415                 err = -ENOTTY;
 416
 417         if (err < 0)
 418                 goto out;
 419
 420         /*  Copy results into user buffer  */
 421         switch (_IOC_DIR(cmd))
 422         {
 423         case _IOC_READ:
 424         case (_IOC_WRITE | _IOC_READ):
 425                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 426                         err = -EFAULT;
 427                 break;
 428         }
 429
 430 out:
 431         kfree(mbuf);
 432         return err;
 433 }
 434
 435 static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
 436 {
 437         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 438
 439         add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
 440         add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
 441         add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
 442         return 0;
 443 }
 444
 445 static char *dvb_devnode(struct device *dev, umode_t *mode)
 446 {
 447         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 448
 449         return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
 450                 dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
 451 }
 452
 453
 454 static int __init init_dvbdev(void)
 455 {
 456         int retval;
 457         dev_t dev = MKDEV(DVB_MAJOR, 0);
 458
 459         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 460                 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 461                 return retval;
 462         }
 463
 464         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 465         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 466                 printk(KERN_ERR "dvb-core: unable register character device\n");
 467                 goto error;
 468         }
 469
 470         dvb_class = class_create(THIS_MODULE, "dvb");
 471         if (IS_ERR(dvb_class)) {
 472                 retval = PTR_ERR(dvb_class);
 473                 goto error;
 474         }
 475         dvb_class->dev_uevent = dvb_uevent;
 476         dvb_class->devnode = dvb_devnode;
 477         return 0;
 478
 479 error:
 480         cdev_del(&dvb_device_cdev);
 481         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 482         return retval;
 483 }
 484
 485
 486 static void __exit exit_dvbdev(void)
 487 {
 488         class_destroy(dvb_class);
 489         cdev_del(&dvb_device_cdev);
 490         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 491 }
 492
 493 subsys_initcall(init_dvbdev);
 494 module_exit(exit_dvbdev);
 495
 496 MODULE_DESCRIPTION("DVB Core Driver");
 497 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 498 MODULE_LICENSE("GPL");