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