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