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 <linux/smp_lock.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_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         lock_kernel();
  79         dvbdev = dvbdev_find_device (iminor(inode));
  80
  81         if (dvbdev && dvbdev->fops) {
  82                 int err = 0;
  83                 const struct file_operations *old_fops;
  84
  85                 file->private_data = dvbdev;
  86                 old_fops = file->f_op;
  87                 file->f_op = fops_get(dvbdev->fops);
  88                 if(file->f_op->open)
  89                         err = file->f_op->open(inode,file);
  90                 if (err) {
  91                         fops_put(file->f_op);
  92                         file->f_op = fops_get(old_fops);
  93                 }
  94                 fops_put(old_fops);
  95                 unlock_kernel();
  96                 return err;
  97         }
  98         unlock_kernel();
  99         return -ENODEV;
 100 }
 101
 102
 103 static const struct file_operations dvb_device_fops =
 104 {
 105         .owner =        THIS_MODULE,
 106         .open =         dvb_device_open,
 107 };
 108
 109 static struct cdev dvb_device_cdev;
 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", __func__);
 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                        __func__, 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 static int dvbdev_check_free_adapter_num(int num)
 269 {
 270         struct list_head *entry;
 271         list_for_each(entry, &dvb_adapter_list) {
 272                 struct dvb_adapter *adap;
 273                 adap = list_entry(entry, struct dvb_adapter, list_head);
 274                 if (adap->num == num)
 275                         return 0;
 276         }
 277         return 1;
 278 }
 279
 280 static int dvbdev_get_free_adapter_num (void)
 281 {
 282         int num = 0;
 283
 284         while (num < DVB_MAX_ADAPTERS) {
 285                 if (dvbdev_check_free_adapter_num(num))
 286                         return num;
 287                 num++;
 288         }
 289
 290         return -ENFILE;
 291 }
 292
 293
 294 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
 295                          struct module *module, struct device *device,
 296                          short *adapter_nums)
 297 {
 298         int i, num;
 299
 300         mutex_lock(&dvbdev_register_lock);
 301
 302         for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
 303                 num = adapter_nums[i];
 304                 if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
 305                 /* use the one the driver asked for */
 306                         if (dvbdev_check_free_adapter_num(num))
 307                                 break;
 308                 } else {
 309                         num = dvbdev_get_free_adapter_num();
 310                         break;
 311                 }
 312                 num = -1;
 313         }
 314
 315         if (num < 0) {
 316                 mutex_unlock(&dvbdev_register_lock);
 317                 return -ENFILE;
 318         }
 319
 320         memset (adap, 0, sizeof(struct dvb_adapter));
 321         INIT_LIST_HEAD (&adap->device_list);
 322
 323         printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 324
 325         adap->num = num;
 326         adap->name = name;
 327         adap->module = module;
 328         adap->device = device;
 329
 330         list_add_tail (&adap->list_head, &dvb_adapter_list);
 331
 332         mutex_unlock(&dvbdev_register_lock);
 333
 334         return num;
 335 }
 336 EXPORT_SYMBOL(dvb_register_adapter);
 337
 338
 339 int dvb_unregister_adapter(struct dvb_adapter *adap)
 340 {
 341         mutex_lock(&dvbdev_register_lock);
 342         list_del (&adap->list_head);
 343         mutex_unlock(&dvbdev_register_lock);
 344         return 0;
 345 }
 346 EXPORT_SYMBOL(dvb_unregister_adapter);
 347
 348 /* if the miracle happens and "generic_usercopy()" is included into
 349    the kernel, then this can vanish. please don't make the mistake and
 350    define this as video_usercopy(). this will introduce a dependecy
 351    to the v4l "videodev.o" module, which is unnecessary for some
 352    cards (ie. the budget dvb-cards don't need the v4l module...) */
 353 int dvb_usercopy(struct inode *inode, struct file *file,
 354                      unsigned int cmd, unsigned long arg,
 355                      int (*func)(struct inode *inode, struct file *file,
 356                      unsigned int cmd, void *arg))
 357 {
 358         char    sbuf[128];
 359         void    *mbuf = NULL;
 360         void    *parg = NULL;
 361         int     err  = -EINVAL;
 362
 363         /*  Copy arguments into temp kernel buffer  */
 364         switch (_IOC_DIR(cmd)) {
 365         case _IOC_NONE:
 366                 /*
 367                  * For this command, the pointer is actually an integer
 368                  * argument.
 369                  */
 370                 parg = (void *) arg;
 371                 break;
 372         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 373         case _IOC_WRITE:
 374         case (_IOC_WRITE | _IOC_READ):
 375                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 376                         parg = sbuf;
 377                 } else {
 378                         /* too big to allocate from stack */
 379                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 380                         if (NULL == mbuf)
 381                                 return -ENOMEM;
 382                         parg = mbuf;
 383                 }
 384
 385                 err = -EFAULT;
 386                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 387                         goto out;
 388                 break;
 389         }
 390
 391         /* call driver */
 392         if ((err = func(inode, file, cmd, parg)) == -ENOIOCTLCMD)
 393                 err = -EINVAL;
 394
 395         if (err < 0)
 396                 goto out;
 397
 398         /*  Copy results into user buffer  */
 399         switch (_IOC_DIR(cmd))
 400         {
 401         case _IOC_READ:
 402         case (_IOC_WRITE | _IOC_READ):
 403                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 404                         err = -EFAULT;
 405                 break;
 406         }
 407
 408 out:
 409         kfree(mbuf);
 410         return err;
 411 }
 412
 413 static int __init init_dvbdev(void)
 414 {
 415         int retval;
 416         dev_t dev = MKDEV(DVB_MAJOR, 0);
 417
 418         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 419                 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 420                 return retval;
 421         }
 422
 423         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 424         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 425                 printk(KERN_ERR "dvb-core: unable register character device\n");
 426                 goto error;
 427         }
 428
 429         dvb_class = class_create(THIS_MODULE, "dvb");
 430         if (IS_ERR(dvb_class)) {
 431                 retval = PTR_ERR(dvb_class);
 432                 goto error;
 433         }
 434         return 0;
 435
 436 error:
 437         cdev_del(&dvb_device_cdev);
 438         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 439         return retval;
 440 }
 441
 442
 443 static void __exit exit_dvbdev(void)
 444 {
 445         class_destroy(dvb_class);
 446         cdev_del(&dvb_device_cdev);
 447         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 448 }
 449
 450 subsys_initcall(init_dvbdev);
 451 module_exit(exit_dvbdev);
 452
 453 MODULE_DESCRIPTION("DVB Core Driver");
 454 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 455 MODULE_LICENSE("GPL");