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/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/device.h>
  33 #include <linux/fs.h>
  34 #include <linux/cdev.h>
  35 #include <linux/mutex.h>
  36 #include "dvbdev.h"
  37
  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 #define DVB_MAX_ADAPTERS        8
  54 #define DVB_MAX_IDS             4
  55 #define nums2minor(num,type,id) ((num << 6) | (id << 4) | type)
  56 #define MAX_DVB_MINORS          (DVB_MAX_ADAPTERS*64)
  57
  58 static struct class *dvb_class;
  59
  60 static struct dvb_device* dvbdev_find_device (int minor)
  61 {
  62         struct list_head *entry;
  63
  64         list_for_each (entry, &dvb_adapter_list) {
  65                 struct list_head *entry0;
  66                 struct dvb_adapter *adap;
  67                 adap = list_entry (entry, struct dvb_adapter, list_head);
  68                 list_for_each (entry0, &adap->device_list) {
  69                         struct dvb_device *dev;
  70                         dev = list_entry (entry0, struct dvb_device, list_head);
  71                         if (nums2minor(adap->num, dev->type, dev->id) == minor)
  72                                 return dev;
  73                 }
  74         }
  75
  76         return NULL;
  77 }
  78
  79
  80 static int dvb_device_open(struct inode *inode, struct file *file)
  81 {
  82         struct dvb_device *dvbdev;
  83
  84         dvbdev = dvbdev_find_device (iminor(inode));
  85
  86         if (dvbdev && dvbdev->fops) {
  87                 int err = 0;
  88                 const struct file_operations *old_fops;
  89
  90                 file->private_data = dvbdev;
  91                 old_fops = file->f_op;
  92                 file->f_op = fops_get(dvbdev->fops);
  93                 if(file->f_op->open)
  94                         err = file->f_op->open(inode,file);
  95                 if (err) {
  96                         fops_put(file->f_op);
  97                         file->f_op = fops_get(old_fops);
  98                 }
  99                 fops_put(old_fops);
 100                 return err;
 101         }
 102         return -ENODEV;
 103 }
 104
 105
 106 static struct file_operations dvb_device_fops =
 107 {
 108         .owner =        THIS_MODULE,
 109         .open =         dvb_device_open,
 110 };
 111
 112 static struct cdev dvb_device_cdev = {
 113         .kobj   = {.name = "dvb", },
 114         .owner  =       THIS_MODULE,
 115 };
 116
 117 int dvb_generic_open(struct inode *inode, struct file *file)
 118 {
 119         struct dvb_device *dvbdev = file->private_data;
 120
 121         if (!dvbdev)
 122                 return -ENODEV;
 123
 124         if (!dvbdev->users)
 125                 return -EBUSY;
 126
 127         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 128                 if (!dvbdev->readers)
 129                         return -EBUSY;
 130                 dvbdev->readers--;
 131         } else {
 132                 if (!dvbdev->writers)
 133                         return -EBUSY;
 134                 dvbdev->writers--;
 135         }
 136
 137         dvbdev->users--;
 138         return 0;
 139 }
 140 EXPORT_SYMBOL(dvb_generic_open);
 141
 142
 143 int dvb_generic_release(struct inode *inode, struct file *file)
 144 {
 145         struct dvb_device *dvbdev = file->private_data;
 146
 147         if (!dvbdev)
 148                 return -ENODEV;
 149
 150         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 151                 dvbdev->readers++;
 152         } else {
 153                 dvbdev->writers++;
 154         }
 155
 156         dvbdev->users++;
 157         return 0;
 158 }
 159 EXPORT_SYMBOL(dvb_generic_release);
 160
 161
 162 int dvb_generic_ioctl(struct inode *inode, struct file *file,
 163                       unsigned int cmd, unsigned long arg)
 164 {
 165         struct dvb_device *dvbdev = file->private_data;
 166
 167         if (!dvbdev)
 168                 return -ENODEV;
 169
 170         if (!dvbdev->kernel_ioctl)
 171                 return -EINVAL;
 172
 173         return dvb_usercopy (inode, file, cmd, arg, dvbdev->kernel_ioctl);
 174 }
 175 EXPORT_SYMBOL(dvb_generic_ioctl);
 176
 177
 178 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
 179 {
 180         u32 id = 0;
 181
 182         while (id < DVB_MAX_IDS) {
 183                 struct list_head *entry;
 184                 list_for_each (entry, &adap->device_list) {
 185                         struct dvb_device *dev;
 186                         dev = list_entry (entry, struct dvb_device, list_head);
 187                         if (dev->type == type && dev->id == id)
 188                                 goto skip;
 189                 }
 190                 return id;
 191 skip:
 192                 id++;
 193         }
 194         return -ENFILE;
 195 }
 196
 197
 198 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 199                         const struct dvb_device *template, void *priv, int type)
 200 {
 201         struct dvb_device *dvbdev;
 202         struct file_operations *dvbdevfops;
 203         struct class_device *clsdev;
 204         int id;
 205
 206         mutex_lock(&dvbdev_register_lock);
 207
 208         if ((id = dvbdev_get_free_id (adap, type)) < 0){
 209                 mutex_unlock(&dvbdev_register_lock);
 210                 *pdvbdev = NULL;
 211                 printk(KERN_ERR "%s: couldn't find free device id\n", __FUNCTION__);
 212                 return -ENFILE;
 213         }
 214
 215         *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 216
 217         if (!dvbdev){
 218                 mutex_unlock(&dvbdev_register_lock);
 219                 return -ENOMEM;
 220         }
 221
 222         dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
 223
 224         if (!dvbdevfops){
 225                 kfree (dvbdev);
 226                 mutex_unlock(&dvbdev_register_lock);
 227                 return -ENOMEM;
 228         }
 229
 230         memcpy(dvbdev, template, sizeof(struct dvb_device));
 231         dvbdev->type = type;
 232         dvbdev->id = id;
 233         dvbdev->adapter = adap;
 234         dvbdev->priv = priv;
 235         dvbdev->fops = dvbdevfops;
 236         init_waitqueue_head (&dvbdev->wait_queue);
 237
 238         memcpy(dvbdev->fops, template->fops, sizeof(struct file_operations));
 239         dvbdev->fops->owner = adap->module;
 240
 241         list_add_tail (&dvbdev->list_head, &adap->device_list);
 242
 243         mutex_unlock(&dvbdev_register_lock);
 244
 245         clsdev = class_device_create(dvb_class, NULL, MKDEV(DVB_MAJOR,
 246                                      nums2minor(adap->num, type, id)),
 247                                      adap->device, "dvb%d.%s%d", adap->num,
 248                                      dnames[type], id);
 249         if (IS_ERR(clsdev)) {
 250                 printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
 251                        __FUNCTION__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 252                 return PTR_ERR(clsdev);
 253         }
 254
 255         dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 256                 adap->num, dnames[type], id, nums2minor(adap->num, type, id),
 257                 nums2minor(adap->num, type, id));
 258
 259         return 0;
 260 }
 261 EXPORT_SYMBOL(dvb_register_device);
 262
 263
 264 void dvb_unregister_device(struct dvb_device *dvbdev)
 265 {
 266         if (!dvbdev)
 267                 return;
 268
 269         class_device_destroy(dvb_class, MKDEV(DVB_MAJOR, nums2minor(dvbdev->adapter->num,
 270                                         dvbdev->type, dvbdev->id)));
 271
 272         list_del (&dvbdev->list_head);
 273         kfree (dvbdev->fops);
 274         kfree (dvbdev);
 275 }
 276 EXPORT_SYMBOL(dvb_unregister_device);
 277
 278
 279 static int dvbdev_get_free_adapter_num (void)
 280 {
 281         int num = 0;
 282
 283         while (num < DVB_MAX_ADAPTERS) {
 284                 struct list_head *entry;
 285                 list_for_each (entry, &dvb_adapter_list) {
 286                         struct dvb_adapter *adap;
 287                         adap = list_entry (entry, struct dvb_adapter, list_head);
 288                         if (adap->num == num)
 289                                 goto skip;
 290                 }
 291                 return num;
 292 skip:
 293                 num++;
 294         }
 295
 296         return -ENFILE;
 297 }
 298
 299
 300 int dvb_register_adapter(struct dvb_adapter *adap, const char *name, struct module *module, struct device *device)
 301 {
 302         int num;
 303
 304         mutex_lock(&dvbdev_register_lock);
 305
 306         if ((num = dvbdev_get_free_adapter_num ()) < 0) {
 307                 mutex_unlock(&dvbdev_register_lock);
 308                 return -ENFILE;
 309         }
 310
 311         memset (adap, 0, sizeof(struct dvb_adapter));
 312         INIT_LIST_HEAD (&adap->device_list);
 313
 314         printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 315
 316         adap->num = num;
 317         adap->name = name;
 318         adap->module = module;
 319         adap->device = device;
 320
 321         list_add_tail (&adap->list_head, &dvb_adapter_list);
 322
 323         mutex_unlock(&dvbdev_register_lock);
 324
 325         return num;
 326 }
 327 EXPORT_SYMBOL(dvb_register_adapter);
 328
 329
 330 int dvb_unregister_adapter(struct dvb_adapter *adap)
 331 {
 332         mutex_lock(&dvbdev_register_lock);
 333         list_del (&adap->list_head);
 334         mutex_unlock(&dvbdev_register_lock);
 335         return 0;
 336 }
 337 EXPORT_SYMBOL(dvb_unregister_adapter);
 338
 339 /* if the miracle happens and "generic_usercopy()" is included into
 340    the kernel, then this can vanish. please don't make the mistake and
 341    define this as video_usercopy(). this will introduce a dependecy
 342    to the v4l "videodev.o" module, which is unnecessary for some
 343    cards (ie. the budget dvb-cards don't need the v4l module...) */
 344 int dvb_usercopy(struct inode *inode, struct file *file,
 345                      unsigned int cmd, unsigned long arg,
 346                      int (*func)(struct inode *inode, struct file *file,
 347                      unsigned int cmd, void *arg))
 348 {
 349         char    sbuf[128];
 350         void    *mbuf = NULL;
 351         void    *parg = NULL;
 352         int     err  = -EINVAL;
 353
 354         /*  Copy arguments into temp kernel buffer  */
 355         switch (_IOC_DIR(cmd)) {
 356         case _IOC_NONE:
 357                 /*
 358                  * For this command, the pointer is actually an integer
 359                  * argument.
 360                  */
 361                 parg = (void *) arg;
 362                 break;
 363         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 364         case _IOC_WRITE:
 365         case (_IOC_WRITE | _IOC_READ):
 366                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 367                         parg = sbuf;
 368                 } else {
 369                         /* too big to allocate from stack */
 370                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 371                         if (NULL == mbuf)
 372                                 return -ENOMEM;
 373                         parg = mbuf;
 374                 }
 375
 376                 err = -EFAULT;
 377                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 378                         goto out;
 379                 break;
 380         }
 381
 382         /* call driver */
 383         if ((err = func(inode, file, cmd, parg)) == -ENOIOCTLCMD)
 384                 err = -EINVAL;
 385
 386         if (err < 0)
 387                 goto out;
 388
 389         /*  Copy results into user buffer  */
 390         switch (_IOC_DIR(cmd))
 391         {
 392         case _IOC_READ:
 393         case (_IOC_WRITE | _IOC_READ):
 394                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 395                         err = -EFAULT;
 396                 break;
 397         }
 398
 399 out:
 400         kfree(mbuf);
 401         return err;
 402 }
 403
 404 static int __init init_dvbdev(void)
 405 {
 406         int retval;
 407         dev_t dev = MKDEV(DVB_MAJOR, 0);
 408
 409         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 410                 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 411                 return retval;
 412         }
 413
 414         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 415         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 416                 printk(KERN_ERR "dvb-core: unable register character device\n");
 417                 goto error;
 418         }
 419
 420         dvb_class = class_create(THIS_MODULE, "dvb");
 421         if (IS_ERR(dvb_class)) {
 422                 retval = PTR_ERR(dvb_class);
 423                 goto error;
 424         }
 425         return 0;
 426
 427 error:
 428         cdev_del(&dvb_device_cdev);
 429         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 430         return retval;
 431 }
 432
 433
 434 static void __exit exit_dvbdev(void)
 435 {
 436         class_destroy(dvb_class);
 437         cdev_del(&dvb_device_cdev);
 438         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 439 }
 440
 441 subsys_initcall(init_dvbdev);
 442 module_exit(exit_dvbdev);
 443
 444 MODULE_DESCRIPTION("DVB Core Driver");
 445 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 446 MODULE_LICENSE("GPL");