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_IDS             4
  53 #define nums2minor(num,type,id) ((num << 6) | (id << 4) | type)
  54 #define MAX_DVB_MINORS          (DVB_MAX_ADAPTERS*64)
  55
  56 static struct class *dvb_class;
  57
  58 static struct dvb_device* dvbdev_find_device (int minor)
  59 {
  60         struct dvb_adapter *adap;
  61
  62         list_for_each_entry(adap, &dvb_adapter_list, list_head) {
  63                 struct dvb_device *dev;
  64                 list_for_each_entry(dev, &adap->device_list, list_head)
  65                         if (nums2minor(adap->num, dev->type, dev->id) == minor)
  66                                 return dev;
  67         }
  68
  69         return NULL;
  70 }
  71
  72
  73 static int dvb_device_open(struct inode *inode, struct file *file)
  74 {
  75         struct dvb_device *dvbdev;
  76
  77         dvbdev = dvbdev_find_device (iminor(inode));
  78
  79         if (dvbdev && dvbdev->fops) {
  80                 int err = 0;
  81                 const struct file_operations *old_fops;
  82
  83                 file->private_data = dvbdev;
  84                 old_fops = file->f_op;
  85                 file->f_op = fops_get(dvbdev->fops);
  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                 return err;
  94         }
  95         return -ENODEV;
  96 }
  97
  98
  99 static const struct file_operations dvb_device_fops =
 100 {
 101         .owner =        THIS_MODULE,
 102         .open =         dvb_device_open,
 103 };
 104
 105 static struct cdev dvb_device_cdev;
 106
 107 int dvb_generic_open(struct inode *inode, struct file *file)
 108 {
 109         struct dvb_device *dvbdev = file->private_data;
 110
 111         if (!dvbdev)
 112                 return -ENODEV;
 113
 114         if (!dvbdev->users)
 115                 return -EBUSY;
 116
 117         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 118                 if (!dvbdev->readers)
 119                         return -EBUSY;
 120                 dvbdev->readers--;
 121         } else {
 122                 if (!dvbdev->writers)
 123                         return -EBUSY;
 124                 dvbdev->writers--;
 125         }
 126
 127         dvbdev->users--;
 128         return 0;
 129 }
 130 EXPORT_SYMBOL(dvb_generic_open);
 131
 132
 133 int dvb_generic_release(struct inode *inode, struct file *file)
 134 {
 135         struct dvb_device *dvbdev = file->private_data;
 136
 137         if (!dvbdev)
 138                 return -ENODEV;
 139
 140         if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 141                 dvbdev->readers++;
 142         } else {
 143                 dvbdev->writers++;
 144         }
 145
 146         dvbdev->users++;
 147         return 0;
 148 }
 149 EXPORT_SYMBOL(dvb_generic_release);
 150
 151
 152 int dvb_generic_ioctl(struct inode *inode, struct file *file,
 153                       unsigned int cmd, unsigned long arg)
 154 {
 155         struct dvb_device *dvbdev = file->private_data;
 156
 157         if (!dvbdev)
 158                 return -ENODEV;
 159
 160         if (!dvbdev->kernel_ioctl)
 161                 return -EINVAL;
 162
 163         return dvb_usercopy (inode, file, cmd, arg, dvbdev->kernel_ioctl);
 164 }
 165 EXPORT_SYMBOL(dvb_generic_ioctl);
 166
 167
 168 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
 169 {
 170         u32 id = 0;
 171
 172         while (id < DVB_MAX_IDS) {
 173                 struct dvb_device *dev;
 174                 list_for_each_entry(dev, &adap->device_list, list_head)
 175                         if (dev->type == type && dev->id == id)
 176                                 goto skip;
 177                 return id;
 178 skip:
 179                 id++;
 180         }
 181         return -ENFILE;
 182 }
 183
 184
 185 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 186                         const struct dvb_device *template, void *priv, int type)
 187 {
 188         struct dvb_device *dvbdev;
 189         struct file_operations *dvbdevfops;
 190         struct device *clsdev;
 191         int id;
 192
 193         mutex_lock(&dvbdev_register_lock);
 194
 195         if ((id = dvbdev_get_free_id (adap, type)) < 0){
 196                 mutex_unlock(&dvbdev_register_lock);
 197                 *pdvbdev = NULL;
 198                 printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
 199                 return -ENFILE;
 200         }
 201
 202         *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 203
 204         if (!dvbdev){
 205                 mutex_unlock(&dvbdev_register_lock);
 206                 return -ENOMEM;
 207         }
 208
 209         dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
 210
 211         if (!dvbdevfops){
 212                 kfree (dvbdev);
 213                 mutex_unlock(&dvbdev_register_lock);
 214                 return -ENOMEM;
 215         }
 216
 217         memcpy(dvbdev, template, sizeof(struct dvb_device));
 218         dvbdev->type = type;
 219         dvbdev->id = id;
 220         dvbdev->adapter = adap;
 221         dvbdev->priv = priv;
 222         dvbdev->fops = dvbdevfops;
 223         init_waitqueue_head (&dvbdev->wait_queue);
 224
 225         memcpy(dvbdev->fops, template->fops, sizeof(struct file_operations));
 226         dvbdev->fops->owner = adap->module;
 227
 228         list_add_tail (&dvbdev->list_head, &adap->device_list);
 229
 230         mutex_unlock(&dvbdev_register_lock);
 231
 232         clsdev = device_create(dvb_class, adap->device,
 233                                MKDEV(DVB_MAJOR, nums2minor(adap->num, type, id)),
 234                                "dvb%d.%s%d", adap->num, dnames[type], id);
 235         if (IS_ERR(clsdev)) {
 236                 printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
 237                        __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 238                 return PTR_ERR(clsdev);
 239         }
 240
 241         dprintk(KERN_DEBUG "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         device_destroy(dvb_class, MKDEV(DVB_MAJOR, nums2minor(dvbdev->adapter->num,
 256                        dvbdev->type, dvbdev->id)));
 257
 258         list_del (&dvbdev->list_head);
 259         kfree (dvbdev->fops);
 260         kfree (dvbdev);
 261 }
 262 EXPORT_SYMBOL(dvb_unregister_device);
 263
 264 static int dvbdev_check_free_adapter_num(int num)
 265 {
 266         struct list_head *entry;
 267         list_for_each(entry, &dvb_adapter_list) {
 268                 struct dvb_adapter *adap;
 269                 adap = list_entry(entry, struct dvb_adapter, list_head);
 270                 if (adap->num == num)
 271                         return 0;
 272         }
 273         return 1;
 274 }
 275
 276 static int dvbdev_get_free_adapter_num (void)
 277 {
 278         int num = 0;
 279
 280         while (num < DVB_MAX_ADAPTERS) {
 281                 if (dvbdev_check_free_adapter_num(num))
 282                         return num;
 283                 num++;
 284         }
 285
 286         return -ENFILE;
 287 }
 288
 289
 290 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
 291                          struct module *module, struct device *device,
 292                          short *adapter_nums)
 293 {
 294         int i, num;
 295
 296         mutex_lock(&dvbdev_register_lock);
 297
 298         for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
 299                 num = adapter_nums[i];
 300                 if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
 301                 /* use the one the driver asked for */
 302                         if (dvbdev_check_free_adapter_num(num))
 303                                 break;
 304                 } else {
 305                         num = dvbdev_get_free_adapter_num();
 306                         break;
 307                 }
 308                 num = -1;
 309         }
 310
 311         if (num < 0) {
 312                 mutex_unlock(&dvbdev_register_lock);
 313                 return -ENFILE;
 314         }
 315
 316         memset (adap, 0, sizeof(struct dvb_adapter));
 317         INIT_LIST_HEAD (&adap->device_list);
 318
 319         printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 320
 321         adap->num = num;
 322         adap->name = name;
 323         adap->module = module;
 324         adap->device = device;
 325
 326         list_add_tail (&adap->list_head, &dvb_adapter_list);
 327
 328         mutex_unlock(&dvbdev_register_lock);
 329
 330         return num;
 331 }
 332 EXPORT_SYMBOL(dvb_register_adapter);
 333
 334
 335 int dvb_unregister_adapter(struct dvb_adapter *adap)
 336 {
 337         mutex_lock(&dvbdev_register_lock);
 338         list_del (&adap->list_head);
 339         mutex_unlock(&dvbdev_register_lock);
 340         return 0;
 341 }
 342 EXPORT_SYMBOL(dvb_unregister_adapter);
 343
 344 /* if the miracle happens and "generic_usercopy()" is included into
 345    the kernel, then this can vanish. please don't make the mistake and
 346    define this as video_usercopy(). this will introduce a dependecy
 347    to the v4l "videodev.o" module, which is unnecessary for some
 348    cards (ie. the budget dvb-cards don't need the v4l module...) */
 349 int dvb_usercopy(struct inode *inode, struct file *file,
 350                      unsigned int cmd, unsigned long arg,
 351                      int (*func)(struct inode *inode, struct file *file,
 352                      unsigned int cmd, void *arg))
 353 {
 354         char    sbuf[128];
 355         void    *mbuf = NULL;
 356         void    *parg = NULL;
 357         int     err  = -EINVAL;
 358
 359         /*  Copy arguments into temp kernel buffer  */
 360         switch (_IOC_DIR(cmd)) {
 361         case _IOC_NONE:
 362                 /*
 363                  * For this command, the pointer is actually an integer
 364                  * argument.
 365                  */
 366                 parg = (void *) arg;
 367                 break;
 368         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 369         case _IOC_WRITE:
 370         case (_IOC_WRITE | _IOC_READ):
 371                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 372                         parg = sbuf;
 373                 } else {
 374                         /* too big to allocate from stack */
 375                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 376                         if (NULL == mbuf)
 377                                 return -ENOMEM;
 378                         parg = mbuf;
 379                 }
 380
 381                 err = -EFAULT;
 382                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 383                         goto out;
 384                 break;
 385         }
 386
 387         /* call driver */
 388         if ((err = func(inode, file, cmd, parg)) == -ENOIOCTLCMD)
 389                 err = -EINVAL;
 390
 391         if (err < 0)
 392                 goto out;
 393
 394         /*  Copy results into user buffer  */
 395         switch (_IOC_DIR(cmd))
 396         {
 397         case _IOC_READ:
 398         case (_IOC_WRITE | _IOC_READ):
 399                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 400                         err = -EFAULT;
 401                 break;
 402         }
 403
 404 out:
 405         kfree(mbuf);
 406         return err;
 407 }
 408
 409 static int __init init_dvbdev(void)
 410 {
 411         int retval;
 412         dev_t dev = MKDEV(DVB_MAJOR, 0);
 413
 414         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 415                 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 416                 return retval;
 417         }
 418
 419         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 420         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 421                 printk(KERN_ERR "dvb-core: unable register character device\n");
 422                 goto error;
 423         }
 424
 425         dvb_class = class_create(THIS_MODULE, "dvb");
 426         if (IS_ERR(dvb_class)) {
 427                 retval = PTR_ERR(dvb_class);
 428                 goto error;
 429         }
 430         return 0;
 431
 432 error:
 433         cdev_del(&dvb_device_cdev);
 434         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 435         return retval;
 436 }
 437
 438
 439 static void __exit exit_dvbdev(void)
 440 {
 441         class_destroy(dvb_class);
 442         cdev_del(&dvb_device_cdev);
 443         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 444 }
 445
 446 subsys_initcall(init_dvbdev);
 447 module_exit(exit_dvbdev);
 448
 449 MODULE_DESCRIPTION("DVB Core Driver");
 450 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 451 MODULE_LICENSE("GPL");