drivers/media/dvb/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/moduleparam.h>
  29 #include <linux/kernel.h>
  30 #include <linux/sched.h>
  31 #include <linux/init.h>
  32 #include <linux/slab.h>
  33 #include <linux/device.h>
  34 #include <linux/fs.h>
  35 #include <linux/cdev.h>
  36
  37 #include "dvbdev.h"
  38
  39 static int dvbdev_debug;
  40
  41 module_param(dvbdev_debug, int, 0644);
  42 MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");
  43
  44 #define dprintk if (dvbdev_debug) printk
  45
  46 static LIST_HEAD(dvb_adapter_list);
  47 static DECLARE_MUTEX(dvbdev_register_lock);
  48
  49 static const char * const dnames[] = {
  50         "video", "audio", "sec", "frontend", "demux", "dvr", "ca",
  51         "net", "osd"
  52 };
  53
  54 #define DVB_MAX_ADAPTERS        8
  55 #define DVB_MAX_IDS             4
  56 #define nums2minor(num,type,id) ((num << 6) | (id << 4) | type)
  57 #define MAX_DVB_MINORS          (DVB_MAX_ADAPTERS*64)
  58
  59 struct class_simple *dvb_class;
  60 EXPORT_SYMBOL(dvb_class);
  61
  62 static struct dvb_device* dvbdev_find_device (int minor)
  63 {
  64         struct list_head *entry;
  65
  66         list_for_each (entry, &dvb_adapter_list) {
  67                 struct list_head *entry0;
  68                 struct dvb_adapter *adap;
  69                 adap = list_entry (entry, struct dvb_adapter, list_head);
  70                 list_for_each (entry0, &adap->device_list) {
  71                         struct dvb_device *dev;
  72                         dev = list_entry (entry0, struct dvb_device, list_head);
  73                         if (nums2minor(adap->num, dev->type, dev->id) == minor)
  74                                 return dev;
  75                 }
  76         }
  77
  78         return NULL;
  79 }
  80
  81
  82 static int dvb_device_open(struct inode *inode, struct file *file)
  83 {
  84         struct dvb_device *dvbdev;
  85
  86         dvbdev = dvbdev_find_device (iminor(inode));
  87
  88         if (dvbdev && dvbdev->fops) {
  89                 int err = 0;
  90                 struct file_operations *old_fops;
  91
  92                 file->private_data = dvbdev;
  93                 old_fops = file->f_op;
  94                 file->f_op = fops_get(dvbdev->fops);
  95                 if(file->f_op->open)
  96                         err = file->f_op->open(inode,file);
  97                 if (err) {
  98                         fops_put(file->f_op);
  99                         file->f_op = fops_get(old_fops);
 100                 }
 101                 fops_put(old_fops);
 102                 return err;
 103         }
 104         return -ENODEV;
 105 }
 106
 107
 108 static struct file_operations dvb_device_fops =
 109 {
 110         .owner =        THIS_MODULE,
 111         .open =         dvb_device_open,
 112 };
 113
 114 static struct cdev dvb_device_cdev = {
 115         .kobj   = {.name = "dvb", },
 116         .owner  =       THIS_MODULE,
 117 };
 118
 119 int dvb_generic_open(struct inode *inode, struct file *file)
 120 {
 121         struct dvb_device *dvbdev = file->private_data;
 122
 123         if (!dvbdev)
 124                 return -ENODEV;
 125
 126         if (!dvbdev->users)
 127                 return -EBUSY;
 128
 129         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 130                 if (!dvbdev->readers)
 131                         return -EBUSY;
 132                 dvbdev->readers--;
 133         } else {
 134                 if (!dvbdev->writers)
 135                         return -EBUSY;
 136                 dvbdev->writers--;
 137         }
 138
 139         dvbdev->users--;
 140         return 0;
 141 }
 142 EXPORT_SYMBOL(dvb_generic_open);
 143
 144
 145 int dvb_generic_release(struct inode *inode, struct file *file)
 146 {
 147         struct dvb_device *dvbdev = file->private_data;
 148
 149         if (!dvbdev)
 150                 return -ENODEV;
 151
 152         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 153                 dvbdev->readers++;
 154         } else {
 155                 dvbdev->writers++;
 156         }
 157
 158         dvbdev->users++;
 159         return 0;
 160 }
 161 EXPORT_SYMBOL(dvb_generic_release);
 162
 163
 164 int dvb_generic_ioctl(struct inode *inode, struct file *file,
 165                       unsigned int cmd, unsigned long arg)
 166 {
 167         struct dvb_device *dvbdev = file->private_data;
 168
 169         if (!dvbdev)
 170                 return -ENODEV;
 171
 172         if (!dvbdev->kernel_ioctl)
 173                 return -EINVAL;
 174
 175         return dvb_usercopy (inode, file, cmd, arg, dvbdev->kernel_ioctl);
 176 }
 177 EXPORT_SYMBOL(dvb_generic_ioctl);
 178
 179
 180 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
 181 {
 182         u32 id = 0;
 183
 184         while (id < DVB_MAX_IDS) {
 185                 struct list_head *entry;
 186                 list_for_each (entry, &adap->device_list) {
 187                         struct dvb_device *dev;
 188                         dev = list_entry (entry, struct dvb_device, list_head);
 189                         if (dev->type == type && dev->id == id)
 190                                 goto skip;
 191                 }
 192                 return id;
 193 skip:
 194                 id++;
 195         }
 196         return -ENFILE;
 197 }
 198
 199
 200 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 201                         const struct dvb_device *template, void *priv, int type)
 202 {
 203         struct dvb_device *dvbdev;
 204         int id;
 205
 206         if (down_interruptible (&dvbdev_register_lock))
 207                 return -ERESTARTSYS;
 208
 209         if ((id = dvbdev_get_free_id (adap, type)) < 0) {
 210                 up (&dvbdev_register_lock);
 211                 *pdvbdev = NULL;
 212                 printk ("%s: could get find free device id...\n", __FUNCTION__);
 213                 return -ENFILE;
 214         }
 215
 216         *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 217
 218         if (!dvbdev) {
 219                 up(&dvbdev_register_lock);
 220                 return -ENOMEM;
 221         }
 222
 223         up (&dvbdev_register_lock);
 224
 225         memcpy(dvbdev, template, sizeof(struct dvb_device));
 226         dvbdev->type = type;
 227         dvbdev->id = id;
 228         dvbdev->adapter = adap;
 229         dvbdev->priv = priv;
 230
 231         dvbdev->fops->owner = adap->module;
 232
 233         list_add_tail (&dvbdev->list_head, &adap->device_list);
 234
 235         devfs_mk_cdev(MKDEV(DVB_MAJOR, nums2minor(adap->num, type, id)),
 236                         S_IFCHR | S_IRUSR | S_IWUSR,
 237                         "dvb/adapter%d/%s%d", adap->num, dnames[type], id);
 238
 239         class_simple_device_add(dvb_class, MKDEV(DVB_MAJOR, nums2minor(adap->num, type, id)),
 240                                 NULL, "dvb%d.%s%d", adap->num, dnames[type], id);
 241
 242         dprintk("DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 243                 adap->num, dnames[type], id, nums2minor(adap->num, type, id),
 244                 nums2minor(adap->num, type, id));
 245
 246         return 0;
 247 }
 248 EXPORT_SYMBOL(dvb_register_device);
 249
 250
 251 void dvb_unregister_device(struct dvb_device *dvbdev)
 252 {
 253         if (!dvbdev)
 254                 return;
 255
 256         devfs_remove("dvb/adapter%d/%s%d", dvbdev->adapter->num,
 257                         dnames[dvbdev->type], dvbdev->id);
 258
 259         class_simple_device_remove(MKDEV(DVB_MAJOR, nums2minor(dvbdev->adapter->num,
 260                                         dvbdev->type, dvbdev->id)));
 261
 262         list_del (&dvbdev->list_head);
 263         kfree (dvbdev);
 264 }
 265 EXPORT_SYMBOL(dvb_unregister_device);
 266
 267
 268 static int dvbdev_get_free_adapter_num (void)
 269 {
 270         int num = 0;
 271
 272         while (num < DVB_MAX_ADAPTERS) {
 273                 struct list_head *entry;
 274                 list_for_each (entry, &dvb_adapter_list) {
 275                         struct dvb_adapter *adap;
 276                         adap = list_entry (entry, struct dvb_adapter, list_head);
 277                         if (adap->num == num)
 278                                 goto skip;
 279                 }
 280                 return num;
 281 skip:
 282                 num++;
 283         }
 284
 285         return -ENFILE;
 286 }
 287
 288
 289 int dvb_register_adapter(struct dvb_adapter *adap, const char *name, struct module *module)
 290 {
 291         int num;
 292
 293         if (down_interruptible (&dvbdev_register_lock))
 294                 return -ERESTARTSYS;
 295
 296         if ((num = dvbdev_get_free_adapter_num ()) < 0) {
 297                 up (&dvbdev_register_lock);
 298                 return -ENFILE;
 299         }
 300
 301         memset (adap, 0, sizeof(struct dvb_adapter));
 302         INIT_LIST_HEAD (&adap->device_list);
 303
 304         printk ("DVB: registering new adapter (%s).\n", name);
 305
 306         devfs_mk_dir("dvb/adapter%d", num);
 307         adap->num = num;
 308         adap->name = name;
 309         adap->module = module;
 310
 311         list_add_tail (&adap->list_head, &dvb_adapter_list);
 312
 313         up (&dvbdev_register_lock);
 314
 315         return num;
 316 }
 317 EXPORT_SYMBOL(dvb_register_adapter);
 318
 319
 320 int dvb_unregister_adapter(struct dvb_adapter *adap)
 321 {
 322         devfs_remove("dvb/adapter%d", adap->num);
 323
 324         if (down_interruptible (&dvbdev_register_lock))
 325                 return -ERESTARTSYS;
 326         list_del (&adap->list_head);
 327         up (&dvbdev_register_lock);
 328         return 0;
 329 }
 330 EXPORT_SYMBOL(dvb_unregister_adapter);
 331
 332 /* if the miracle happens and "generic_usercopy()" is included into
 333    the kernel, then this can vanish. please don't make the mistake and
 334    define this as video_usercopy(). this will introduce a dependecy
 335    to the v4l "videodev.o" module, which is unnecessary for some
 336    cards (ie. the budget dvb-cards don't need the v4l module...) */
 337 int dvb_usercopy(struct inode *inode, struct file *file,
 338                      unsigned int cmd, unsigned long arg,
 339                      int (*func)(struct inode *inode, struct file *file,
 340                      unsigned int cmd, void *arg))
 341 {
 342         char    sbuf[128];
 343         void    *mbuf = NULL;
 344         void    *parg = NULL;
 345         int     err  = -EINVAL;
 346
 347         /*  Copy arguments into temp kernel buffer  */
 348         switch (_IOC_DIR(cmd)) {
 349         case _IOC_NONE:
 350                 /*
 351                  * For this command, the pointer is actually an integer
 352                  * argument.
 353                  */
 354                 parg = (void *) arg;
 355                 break;
 356         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 357         case _IOC_WRITE:
 358         case (_IOC_WRITE | _IOC_READ):
 359                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 360                         parg = sbuf;
 361                 } else {
 362                         /* too big to allocate from stack */
 363                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 364                         if (NULL == mbuf)
 365                                 return -ENOMEM;
 366                         parg = mbuf;
 367                 }
 368
 369                 err = -EFAULT;
 370                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 371                         goto out;
 372                 break;
 373         }
 374
 375         /* call driver */
 376         if ((err = func(inode, file, cmd, parg)) == -ENOIOCTLCMD)
 377                 err = -EINVAL;
 378
 379         if (err < 0)
 380                 goto out;
 381
 382         /*  Copy results into user buffer  */
 383         switch (_IOC_DIR(cmd))
 384         {
 385         case _IOC_READ:
 386         case (_IOC_WRITE | _IOC_READ):
 387                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 388                         err = -EFAULT;
 389                 break;
 390         }
 391
 392 out:
 393         kfree(mbuf);
 394         return err;
 395 }
 396
 397 static int __init init_dvbdev(void)
 398 {
 399         int retval;
 400         dev_t dev = MKDEV(DVB_MAJOR, 0);
 401
 402         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 403                 printk("dvb-core: unable to get major %d\n", DVB_MAJOR);
 404                 return retval;
 405         }
 406
 407         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 408         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 409                 printk("dvb-core: unable to get major %d\n", DVB_MAJOR);
 410                 goto error;
 411         }
 412
 413         devfs_mk_dir("dvb");
 414
 415         dvb_class = class_simple_create(THIS_MODULE, "dvb");
 416         if (IS_ERR(dvb_class)) {
 417                 retval = PTR_ERR(dvb_class);
 418                 goto error;
 419         }
 420         return 0;
 421
 422 error:
 423         cdev_del(&dvb_device_cdev);
 424         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 425         return retval;
 426 }
 427
 428
 429 static void __exit exit_dvbdev(void)
 430 {
 431         devfs_remove("dvb");
 432         class_simple_destroy(dvb_class);
 433         cdev_del(&dvb_device_cdev);
 434         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 435 }
 436
 437 module_init(init_dvbdev);
 438 module_exit(exit_dvbdev);
 439
 440 MODULE_DESCRIPTION("DVB Core Driver");
 441 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 442 MODULE_LICENSE("GPL");