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