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 int dvb_generic_ioctl(struct inode *inode, struct file *file,
 158                       unsigned int cmd, unsigned long arg)
 159 {
 160         struct dvb_device *dvbdev = file->private_data;
 161
 162         if (!dvbdev)
 163                 return -ENODEV;
 164
 165         if (!dvbdev->kernel_ioctl)
 166                 return -EINVAL;
 167
 168         return dvb_usercopy (inode, file, cmd, arg, dvbdev->kernel_ioctl);
 169 }
 170 EXPORT_SYMBOL(dvb_generic_ioctl);
 171
 172
 173 static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
 174 {
 175         u32 id = 0;
 176
 177         while (id < DVB_MAX_IDS) {
 178                 struct dvb_device *dev;
 179                 list_for_each_entry(dev, &adap->device_list, list_head)
 180                         if (dev->type == type && dev->id == id)
 181                                 goto skip;
 182                 return id;
 183 skip:
 184                 id++;
 185         }
 186         return -ENFILE;
 187 }
 188
 189
 190 int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 191                         const struct dvb_device *template, void *priv, int type)
 192 {
 193         struct dvb_device *dvbdev;
 194         struct file_operations *dvbdevfops;
 195         struct device *clsdev;
 196         int minor;
 197         int id;
 198
 199         mutex_lock(&dvbdev_register_lock);
 200
 201         if ((id = dvbdev_get_free_id (adap, type)) < 0){
 202                 mutex_unlock(&dvbdev_register_lock);
 203                 *pdvbdev = NULL;
 204                 printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
 205                 return -ENFILE;
 206         }
 207
 208         *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 209
 210         if (!dvbdev){
 211                 mutex_unlock(&dvbdev_register_lock);
 212                 return -ENOMEM;
 213         }
 214
 215         dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
 216
 217         if (!dvbdevfops){
 218                 kfree (dvbdev);
 219                 mutex_unlock(&dvbdev_register_lock);
 220                 return -ENOMEM;
 221         }
 222
 223         memcpy(dvbdev, template, sizeof(struct dvb_device));
 224         dvbdev->type = type;
 225         dvbdev->id = id;
 226         dvbdev->adapter = adap;
 227         dvbdev->priv = priv;
 228         dvbdev->fops = dvbdevfops;
 229         init_waitqueue_head (&dvbdev->wait_queue);
 230
 231         memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
 232         dvbdevfops->owner = adap->module;
 233
 234         list_add_tail (&dvbdev->list_head, &adap->device_list);
 235
 236         down_write(&minor_rwsem);
 237 #ifdef CONFIG_DVB_DYNAMIC_MINORS
 238         for (minor = 0; minor < MAX_DVB_MINORS; minor++)
 239                 if (dvb_minors[minor] == NULL)
 240                         break;
 241
 242         if (minor == MAX_DVB_MINORS) {
 243                 kfree(dvbdevfops);
 244                 kfree(dvbdev);
 245                 mutex_unlock(&dvbdev_register_lock);
 246                 return -EINVAL;
 247         }
 248 #else
 249         minor = nums2minor(adap->num, type, id);
 250 #endif
 251
 252         dvbdev->minor = minor;
 253         dvb_minors[minor] = dvbdev;
 254         up_write(&minor_rwsem);
 255
 256         mutex_unlock(&dvbdev_register_lock);
 257
 258         clsdev = device_create(dvb_class, adap->device,
 259                                MKDEV(DVB_MAJOR, minor),
 260                                dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
 261         if (IS_ERR(clsdev)) {
 262                 printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
 263                        __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 264                 return PTR_ERR(clsdev);
 265         }
 266
 267         dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 268                 adap->num, dnames[type], id, minor, minor);
 269
 270         return 0;
 271 }
 272 EXPORT_SYMBOL(dvb_register_device);
 273
 274
 275 void dvb_unregister_device(struct dvb_device *dvbdev)
 276 {
 277         if (!dvbdev)
 278                 return;
 279
 280         down_write(&minor_rwsem);
 281         dvb_minors[dvbdev->minor] = NULL;
 282         up_write(&minor_rwsem);
 283
 284         device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
 285
 286         list_del (&dvbdev->list_head);
 287         kfree (dvbdev->fops);
 288         kfree (dvbdev);
 289 }
 290 EXPORT_SYMBOL(dvb_unregister_device);
 291
 292 static int dvbdev_check_free_adapter_num(int num)
 293 {
 294         struct list_head *entry;
 295         list_for_each(entry, &dvb_adapter_list) {
 296                 struct dvb_adapter *adap;
 297                 adap = list_entry(entry, struct dvb_adapter, list_head);
 298                 if (adap->num == num)
 299                         return 0;
 300         }
 301         return 1;
 302 }
 303
 304 static int dvbdev_get_free_adapter_num (void)
 305 {
 306         int num = 0;
 307
 308         while (num < DVB_MAX_ADAPTERS) {
 309                 if (dvbdev_check_free_adapter_num(num))
 310                         return num;
 311                 num++;
 312         }
 313
 314         return -ENFILE;
 315 }
 316
 317
 318 int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
 319                          struct module *module, struct device *device,
 320                          short *adapter_nums)
 321 {
 322         int i, num;
 323
 324         mutex_lock(&dvbdev_register_lock);
 325
 326         for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
 327                 num = adapter_nums[i];
 328                 if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
 329                 /* use the one the driver asked for */
 330                         if (dvbdev_check_free_adapter_num(num))
 331                                 break;
 332                 } else {
 333                         num = dvbdev_get_free_adapter_num();
 334                         break;
 335                 }
 336                 num = -1;
 337         }
 338
 339         if (num < 0) {
 340                 mutex_unlock(&dvbdev_register_lock);
 341                 return -ENFILE;
 342         }
 343
 344         memset (adap, 0, sizeof(struct dvb_adapter));
 345         INIT_LIST_HEAD (&adap->device_list);
 346
 347         printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 348
 349         adap->num = num;
 350         adap->name = name;
 351         adap->module = module;
 352         adap->device = device;
 353         adap->mfe_shared = 0;
 354         adap->mfe_dvbdev = NULL;
 355         mutex_init (&adap->mfe_lock);
 356
 357         list_add_tail (&adap->list_head, &dvb_adapter_list);
 358
 359         mutex_unlock(&dvbdev_register_lock);
 360
 361         return num;
 362 }
 363 EXPORT_SYMBOL(dvb_register_adapter);
 364
 365
 366 int dvb_unregister_adapter(struct dvb_adapter *adap)
 367 {
 368         mutex_lock(&dvbdev_register_lock);
 369         list_del (&adap->list_head);
 370         mutex_unlock(&dvbdev_register_lock);
 371         return 0;
 372 }
 373 EXPORT_SYMBOL(dvb_unregister_adapter);
 374
 375 /* if the miracle happens and "generic_usercopy()" is included into
 376    the kernel, then this can vanish. please don't make the mistake and
 377    define this as video_usercopy(). this will introduce a dependecy
 378    to the v4l "videodev.o" module, which is unnecessary for some
 379    cards (ie. the budget dvb-cards don't need the v4l module...) */
 380 int dvb_usercopy(struct inode *inode, struct file *file,
 381                      unsigned int cmd, unsigned long arg,
 382                      int (*func)(struct inode *inode, struct file *file,
 383                      unsigned int cmd, void *arg))
 384 {
 385         char    sbuf[128];
 386         void    *mbuf = NULL;
 387         void    *parg = NULL;
 388         int     err  = -EINVAL;
 389
 390         /*  Copy arguments into temp kernel buffer  */
 391         switch (_IOC_DIR(cmd)) {
 392         case _IOC_NONE:
 393                 /*
 394                  * For this command, the pointer is actually an integer
 395                  * argument.
 396                  */
 397                 parg = (void *) arg;
 398                 break;
 399         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 400         case _IOC_WRITE:
 401         case (_IOC_WRITE | _IOC_READ):
 402                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 403                         parg = sbuf;
 404                 } else {
 405                         /* too big to allocate from stack */
 406                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 407                         if (NULL == mbuf)
 408                                 return -ENOMEM;
 409                         parg = mbuf;
 410                 }
 411
 412                 err = -EFAULT;
 413                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 414                         goto out;
 415                 break;
 416         }
 417
 418         /* call driver */
 419         if ((err = func(inode, file, cmd, parg)) == -ENOIOCTLCMD)
 420                 err = -EINVAL;
 421
 422         if (err < 0)
 423                 goto out;
 424
 425         /*  Copy results into user buffer  */
 426         switch (_IOC_DIR(cmd))
 427         {
 428         case _IOC_READ:
 429         case (_IOC_WRITE | _IOC_READ):
 430                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 431                         err = -EFAULT;
 432                 break;
 433         }
 434
 435 out:
 436         kfree(mbuf);
 437         return err;
 438 }
 439
 440 static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
 441 {
 442         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 443
 444         add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
 445         add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
 446         add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
 447         return 0;
 448 }
 449
 450 static char *dvb_devnode(struct device *dev, mode_t *mode)
 451 {
 452         struct dvb_device *dvbdev = dev_get_drvdata(dev);
 453
 454         return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
 455                 dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
 456 }
 457
 458
 459 static int __init init_dvbdev(void)
 460 {
 461         int retval;
 462         dev_t dev = MKDEV(DVB_MAJOR, 0);
 463
 464         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 465                 printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 466                 return retval;
 467         }
 468
 469         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 470         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 471                 printk(KERN_ERR "dvb-core: unable register character device\n");
 472                 goto error;
 473         }
 474
 475         dvb_class = class_create(THIS_MODULE, "dvb");
 476         if (IS_ERR(dvb_class)) {
 477                 retval = PTR_ERR(dvb_class);
 478                 goto error;
 479         }
 480         dvb_class->dev_uevent = dvb_uevent;
 481         dvb_class->devnode = dvb_devnode;
 482         return 0;
 483
 484 error:
 485         cdev_del(&dvb_device_cdev);
 486         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 487         return retval;
 488 }
 489
 490
 491 static void __exit exit_dvbdev(void)
 492 {
 493         class_destroy(dvb_class);
 494         cdev_del(&dvb_device_cdev);
 495         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 496 }
 497
 498 subsys_initcall(init_dvbdev);
 499 module_exit(exit_dvbdev);
 500
 501 MODULE_DESCRIPTION("DVB Core Driver");
 502 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 503 MODULE_LICENSE("GPL");