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 #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         lock_kernel();
  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 *old_fops;
  78
  79                 file->private_data = dvbdev;
  80                 old_fops = file->f_op;
  81                 file->f_op = fops_get(dvbdev->fops);
  82                 if (file->f_op == NULL) {
  83                         file->f_op = old_fops;
  84                         goto fail;
  85                 }
  86                 if(file->f_op->open)
  87                         err = file->f_op->open(inode,file);
  88                 if (err) {
  89                         fops_put(file->f_op);
  90                         file->f_op = fops_get(old_fops);
  91                 }
  92                 fops_put(old_fops);
  93                 up_read(&minor_rwsem);
  94                 unlock_kernel();
  95                 return err;
  96         }
  97 fail:
  98         up_read(&minor_rwsem);
  99         unlock_kernel();
 100         return -ENODEV;
 101 }
 102
 103
 104 static const struct file_operations dvb_device_fops =
 105 {
 106         .owner =        THIS_MODULE,
 107         .open =         dvb_device_open,
 108 };
 109
 110 static struct cdev dvb_device_cdev;
 111
 112 int dvb_generic_open(struct inode *inode, struct file *file)
 113 {
 114         struct dvb_device *dvbdev = file->private_data;
 115
 116         if (!dvbdev)
 117                 return -ENODEV;
 118
 119         if (!dvbdev->users)
 120                 return -EBUSY;
 121
 122         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 123                 if (!dvbdev->readers)
 124                         return -EBUSY;
 125                 dvbdev->readers--;
 126         } else {
 127                 if (!dvbdev->writers)
 128                         return -EBUSY;
 129                 dvbdev->writers--;
 130         }
 131
 132         dvbdev->users--;
 133         return 0;
 134 }
 135 EXPORT_SYMBOL(dvb_generic_open);
 136
 137
 138 int dvb_generic_release(struct inode *inode, struct file *file)
 139 {
 140         struct dvb_device *dvbdev = file->private_data;
 141
 142         if (!dvbdev)
 143                 return -ENODEV;
 144
 145         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 146                 dvbdev->readers++;
 147         } else {
 148                 dvbdev->writers++;
 149         }
 150
 151         dvbdev->users++;
 152         return 0;
 153 }
 154 EXPORT_SYMBOL(dvb_generic_release);
 155
 156
 157 long dvb_generic_ioctl(struct file *file,
 158                        unsigned int cmd, unsigned long arg)
 159 {
 160         struct dvb_device *dvbdev = file->private_data;
 161         int ret;
 162
 163         if (!dvbdev)
 164                 return -ENODEV;
 165
 166         if (!dvbdev->kernel_ioctl)
 167                 return -EINVAL;
 168
 169         lock_kernel();
 170         ret = dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
 171         unlock_kernel();
 172
 173         return ret;
 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 dvb_device *dev;
 184                 list_for_each_entry(dev, &adap->device_list, list_head)
 185                         if (dev->type == type && dev->id == id)
 186                                 goto skip;
 187                 return id;
 188 skip:
 189                 id++;
 190         }
 191         return -ENFILE;
 192 }
 193
 194
 195 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 196                         const struct dvb_device *template, void *priv, int type)
 197 {
 198         struct dvb_device *dvbdev;
 199         struct file_operations *dvbdevfops;
 200         struct device *clsdev;
 201         int minor;
 202         int id;
 203
 204         mutex_lock(&dvbdev_register_lock);
 205
 206         if ((id = dvbdev_get_free_id (adap, type)) < 0){
 207                 mutex_unlock(&dvbdev_register_lock);
 208                 *pdvbdev = NULL;
 209                 printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
 210                 return -ENFILE;
 211         }
 212
 213         *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 214
 215         if (!dvbdev){
 216                 mutex_unlock(&dvbdev_register_lock);
 217                 return -ENOMEM;
 218         }
 219
 220         dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
 221
 222         if (!dvbdevfops){
 223                 kfree (dvbdev);
 224                 mutex_unlock(&dvbdev_register_lock);
 225                 return -ENOMEM;
 226         }
 227
 228         memcpy(dvbdev, template, sizeof(struct dvb_device));
 229         dvbdev->type = type;
 230         dvbdev->id = id;
 231         dvbdev->adapter = adap;
 232         dvbdev->priv = priv;
 233         dvbdev->fops = dvbdevfops;
 234         init_waitqueue_head (&dvbdev->wait_queue);
 235
 236         memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
 237         dvbdevfops->owner = adap->module;
 238
 239         list_add_tail (&dvbdev->list_head, &adap->device_list);
 240
 241         down_write(&minor_rwsem);
 242 #ifdef CONFIG_DVB_DYNAMIC_MINORS
 243         for (minor = 0; minor < MAX_DVB_MINORS; minor++)
 244                 if (dvb_minors[minor] == NULL)
 245                         break;
 246
 247         if (minor == MAX_DVB_MINORS) {
 248                 kfree(dvbdevfops);
 249                 kfree(dvbdev);
 250                 mutex_unlock(&dvbdev_register_lock);
 251                 return -EINVAL;
 252         }
 253 #else
 254         minor = nums2minor(adap->num, type, id);
 255 #endif
 256
 257         dvbdev->minor = minor;
 258         dvb_minors[minor] = dvbdev;
 259         up_write(&minor_rwsem);
 260
 261         mutex_unlock(&dvbdev_register_lock);
 262
 263         clsdev = device_create(dvb_class, adap->device,
 264                                MKDEV(DVB_MAJOR, minor),
 265                                dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
 266         if (IS_ERR(clsdev)) {
 267                 printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
 268                        __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 269                 return PTR_ERR(clsdev);
 270         }
 271
 272         dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 273                 adap->num, dnames[type], id, minor, minor);
 274
 275         return 0;
 276 }
 277 EXPORT_SYMBOL(dvb_register_device);
 278
 279
 280 void dvb_unregister_device(struct dvb_device *dvbdev)
 281 {
 282         if (!dvbdev)
 283                 return;
 284
 285         down_write(&minor_rwsem);
 286         dvb_minors[dvbdev->minor] = NULL;
 287         up_write(&minor_rwsem);
 288
 289         device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
 290
 291         list_del (&dvbdev->list_head);
 292         kfree (dvbdev->fops);
 293         kfree (dvbdev);
 294 }
 295 EXPORT_SYMBOL(dvb_unregister_device);
 296
 297 static int dvbdev_check_free_adapter_num(int num)
 298 {
 299         struct list_head *entry;
 300         list_for_each(entry, &dvb_adapter_list) {
 301                 struct dvb_adapter *adap;
 302                 adap = list_entry(entry, struct dvb_adapter, list_head);
 303                 if (adap->num == num)
 304                         return 0;
 305         }
 306         return 1;
 307 }
 308
 309 static int dvbdev_get_free_adapter_num (void)
 310 {
 311         int num = 0;
 312
 313         while (num < DVB_MAX_ADAPTERS) {
 314                 if (dvbdev_check_free_adapter_num(num))
 315                         return num;
 316                 num++;
 317         }
 318
 319         return -ENFILE;
 320 }
 321
 322
 323 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
 324                          struct module *module, struct device *device,
 325                          short *adapter_nums)
 326 {
 327         int i, num;
 328
 329         mutex_lock(&dvbdev_register_lock);
 330
 331         for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
 332                 num = adapter_nums[i];
 333                 if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
 334                 /* use the one the driver asked for */
 335                         if (dvbdev_check_free_adapter_num(num))
 336                                 break;
 337                 } else {
 338                         num = dvbdev_get_free_adapter_num();
 339                         break;
 340                 }
 341                 num = -1;
 342         }
 343
 344         if (num < 0) {
 345                 mutex_unlock(&dvbdev_register_lock);
 346                 return -ENFILE;
 347         }
 348
 349         memset (adap, 0, sizeof(struct dvb_adapter));
 350         INIT_LIST_HEAD (&adap->device_list);
 351
 352         printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 353
 354         adap->num = num;
 355         adap->name = name;
 356         adap->module = module;
 357         adap->device = device;
 358         adap->mfe_shared = 0;
 359         adap->mfe_dvbdev = NULL;
 360         mutex_init (&adap->mfe_lock);
 361
 362         list_add_tail (&adap->list_head, &dvb_adapter_list);
 363
 364         mutex_unlock(&dvbdev_register_lock);
 365
 366         return num;
 367 }
 368 EXPORT_SYMBOL(dvb_register_adapter);
 369
 370
 371 int dvb_unregister_adapter(struct dvb_adapter *adap)
 372 {
 373         mutex_lock(&dvbdev_register_lock);
 374         list_del (&adap->list_head);
 375         mutex_unlock(&dvbdev_register_lock);
 376         return 0;
 377 }
 378 EXPORT_SYMBOL(dvb_unregister_adapter);
 379
 380 /* if the miracle happens and "generic_usercopy()" is included into
 381    the kernel, then this can vanish. please don't make the mistake and
 382    define this as video_usercopy(). this will introduce a dependecy
 383    to the v4l "videodev.o" module, which is unnecessary for some
 384    cards (ie. the budget dvb-cards don't need the v4l module...) */
 385 int dvb_usercopy(struct file *file,
 386                      unsigned int cmd, unsigned long arg,
 387                      int (*func)(struct file *file,
 388                      unsigned int cmd, void *arg))
 389 {
 390         char    sbuf[128];
 391         void    *mbuf = NULL;
 392         void    *parg = NULL;
 393         int     err  = -EINVAL;
 394
 395         /*  Copy arguments into temp kernel buffer  */
 396         switch (_IOC_DIR(cmd)) {
 397         case _IOC_NONE:
 398                 /*
 399                  * For this command, the pointer is actually an integer
 400                  * argument.
 401                  */
 402                 parg = (void *) arg;
 403                 break;
 404         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 405         case _IOC_WRITE:
 406         case (_IOC_WRITE | _IOC_READ):
 407                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 408                         parg = sbuf;
 409                 } else {
 410                         /* too big to allocate from stack */
 411                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 412                         if (NULL == mbuf)
 413                                 return -ENOMEM;
 414                         parg = mbuf;
 415                 }
 416
 417                 err = -EFAULT;
 418                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 419                         goto out;
 420                 break;
 421         }
 422
 423         /* call driver */
 424         if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
 425                 err = -EINVAL;
 426
 427         if (err < 0)
 428                 goto out;
 429
 430         /*  Copy results into user buffer  */
 431         switch (_IOC_DIR(cmd))
 432         {
 433         case _IOC_READ:
 434         case (_IOC_WRITE | _IOC_READ):
 435                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 436                         err = -EFAULT;
 437                 break;
 438         }
 439
 440 out:
 441         kfree(mbuf);
 442         return err;
 443 }
 444
 445 static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
 446 {
 447         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 448
 449         add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
 450         add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
 451         add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
 452         return 0;
 453 }
 454
 455 static char *dvb_devnode(struct device *dev, mode_t *mode)
 456 {
 457         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 458
 459         return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
 460                 dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
 461 }
 462
 463
 464 static int __init init_dvbdev(void)
 465 {
 466         int retval;
 467         dev_t dev = MKDEV(DVB_MAJOR, 0);
 468
 469         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 470                 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 471                 return retval;
 472         }
 473
 474         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 475         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 476                 printk(KERN_ERR "dvb-core: unable register character device\n");
 477                 goto error;
 478         }
 479
 480         dvb_class = class_create(THIS_MODULE, "dvb");
 481         if (IS_ERR(dvb_class)) {
 482                 retval = PTR_ERR(dvb_class);
 483                 goto error;
 484         }
 485         dvb_class->dev_uevent = dvb_uevent;
 486         dvb_class->devnode = dvb_devnode;
 487         return 0;
 488
 489 error:
 490         cdev_del(&dvb_device_cdev);
 491         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 492         return retval;
 493 }
 494
 495
 496 static void __exit exit_dvbdev(void)
 497 {
 498         class_destroy(dvb_class);
 499         cdev_del(&dvb_device_cdev);
 500         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 501 }
 502
 503 subsys_initcall(init_dvbdev);
 504 module_exit(exit_dvbdev);
 505
 506 MODULE_DESCRIPTION("DVB Core Driver");
 507 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 508 MODULE_LICENSE("GPL");