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 #include <linux/mutex.h>
  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 DEFINE_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                 const 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 (mutex_lock_interruptible(&dvbdev_register_lock))
 206                 return -ERESTARTSYS;
 207
 208         if ((id = dvbdev_get_free_id (adap, type)) < 0) {
 209                 mutex_unlock(&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                 mutex_unlock(&dvbdev_register_lock);
 219                 return -ENOMEM;
 220         }
 221
 222         memcpy(dvbdev, template, sizeof(struct dvb_device));
 223         dvbdev->type = type;
 224         dvbdev->id = id;
 225         dvbdev->adapter = adap;
 226         dvbdev->priv = priv;
 227
 228         dvbdev->fops->owner = adap->module;
 229
 230         list_add_tail (&dvbdev->list_head, &adap->device_list);
 231
 232         mutex_unlock(&dvbdev_register_lock);
 233
 234         class_device_create(dvb_class, NULL, MKDEV(DVB_MAJOR, nums2minor(adap->num, type, id)),
 235                             adap->device, "dvb%d.%s%d", adap->num, dnames[type], id);
 236
 237         dprintk("DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 238                 adap->num, dnames[type], id, nums2minor(adap->num, type, id),
 239                 nums2minor(adap->num, type, id));
 240
 241         return 0;
 242 }
 243 EXPORT_SYMBOL(dvb_register_device);
 244
 245
 246 void dvb_unregister_device(struct dvb_device *dvbdev)
 247 {
 248         if (!dvbdev)
 249                 return;
 250
 251         class_device_destroy(dvb_class, MKDEV(DVB_MAJOR, nums2minor(dvbdev->adapter->num,
 252                                         dvbdev->type, dvbdev->id)));
 253
 254         list_del (&dvbdev->list_head);
 255         kfree (dvbdev);
 256 }
 257 EXPORT_SYMBOL(dvb_unregister_device);
 258
 259
 260 static int dvbdev_get_free_adapter_num (void)
 261 {
 262         int num = 0;
 263
 264         while (num < DVB_MAX_ADAPTERS) {
 265                 struct list_head *entry;
 266                 list_for_each (entry, &dvb_adapter_list) {
 267                         struct dvb_adapter *adap;
 268                         adap = list_entry (entry, struct dvb_adapter, list_head);
 269                         if (adap->num == num)
 270                                 goto skip;
 271                 }
 272                 return num;
 273 skip:
 274                 num++;
 275         }
 276
 277         return -ENFILE;
 278 }
 279
 280
 281 int dvb_register_adapter(struct dvb_adapter *adap, const char *name, struct module *module, struct device *device)
 282 {
 283         int num;
 284
 285         if (mutex_lock_interruptible(&dvbdev_register_lock))
 286                 return -ERESTARTSYS;
 287
 288         if ((num = dvbdev_get_free_adapter_num ()) < 0) {
 289                 mutex_unlock(&dvbdev_register_lock);
 290                 return -ENFILE;
 291         }
 292
 293         memset (adap, 0, sizeof(struct dvb_adapter));
 294         INIT_LIST_HEAD (&adap->device_list);
 295
 296         printk ("DVB: registering new adapter (%s).\n", name);
 297
 298         adap->num = num;
 299         adap->name = name;
 300         adap->module = module;
 301         adap->device = device;
 302
 303         list_add_tail (&adap->list_head, &dvb_adapter_list);
 304
 305         mutex_unlock(&dvbdev_register_lock);
 306
 307         return num;
 308 }
 309 EXPORT_SYMBOL(dvb_register_adapter);
 310
 311
 312 int dvb_unregister_adapter(struct dvb_adapter *adap)
 313 {
 314         if (mutex_lock_interruptible(&dvbdev_register_lock))
 315                 return -ERESTARTSYS;
 316         list_del (&adap->list_head);
 317         mutex_unlock(&dvbdev_register_lock);
 318         return 0;
 319 }
 320 EXPORT_SYMBOL(dvb_unregister_adapter);
 321
 322 /* if the miracle happens and "generic_usercopy()" is included into
 323    the kernel, then this can vanish. please don't make the mistake and
 324    define this as video_usercopy(). this will introduce a dependecy
 325    to the v4l "videodev.o" module, which is unnecessary for some
 326    cards (ie. the budget dvb-cards don't need the v4l module...) */
 327 int dvb_usercopy(struct inode *inode, struct file *file,
 328                      unsigned int cmd, unsigned long arg,
 329                      int (*func)(struct inode *inode, struct file *file,
 330                      unsigned int cmd, void *arg))
 331 {
 332         char    sbuf[128];
 333         void    *mbuf = NULL;
 334         void    *parg = NULL;
 335         int     err  = -EINVAL;
 336
 337         /*  Copy arguments into temp kernel buffer  */
 338         switch (_IOC_DIR(cmd)) {
 339         case _IOC_NONE:
 340                 /*
 341                  * For this command, the pointer is actually an integer
 342                  * argument.
 343                  */
 344                 parg = (void *) arg;
 345                 break;
 346         case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 347         case _IOC_WRITE:
 348         case (_IOC_WRITE | _IOC_READ):
 349                 if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 350                         parg = sbuf;
 351                 } else {
 352                         /* too big to allocate from stack */
 353                         mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 354                         if (NULL == mbuf)
 355                                 return -ENOMEM;
 356                         parg = mbuf;
 357                 }
 358
 359                 err = -EFAULT;
 360                 if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 361                         goto out;
 362                 break;
 363         }
 364
 365         /* call driver */
 366         if ((err = func(inode, file, cmd, parg)) == -ENOIOCTLCMD)
 367                 err = -EINVAL;
 368
 369         if (err < 0)
 370                 goto out;
 371
 372         /*  Copy results into user buffer  */
 373         switch (_IOC_DIR(cmd))
 374         {
 375         case _IOC_READ:
 376         case (_IOC_WRITE | _IOC_READ):
 377                 if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 378                         err = -EFAULT;
 379                 break;
 380         }
 381
 382 out:
 383         kfree(mbuf);
 384         return err;
 385 }
 386
 387 static int __init init_dvbdev(void)
 388 {
 389         int retval;
 390         dev_t dev = MKDEV(DVB_MAJOR, 0);
 391
 392         if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 393                 printk("dvb-core: unable to get major %d\n", DVB_MAJOR);
 394                 return retval;
 395         }
 396
 397         cdev_init(&dvb_device_cdev, &dvb_device_fops);
 398         if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 399                 printk("dvb-core: unable to get major %d\n", DVB_MAJOR);
 400                 goto error;
 401         }
 402
 403         dvb_class = class_create(THIS_MODULE, "dvb");
 404         if (IS_ERR(dvb_class)) {
 405                 retval = PTR_ERR(dvb_class);
 406                 goto error;
 407         }
 408         return 0;
 409
 410 error:
 411         cdev_del(&dvb_device_cdev);
 412         unregister_chrdev_region(dev, MAX_DVB_MINORS);
 413         return retval;
 414 }
 415
 416
 417 static void __exit exit_dvbdev(void)
 418 {
 419         class_destroy(dvb_class);
 420         cdev_del(&dvb_device_cdev);
 421         unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 422 }
 423
 424 module_init(init_dvbdev);
 425 module_exit(exit_dvbdev);
 426
 427 MODULE_DESCRIPTION("DVB Core Driver");
 428 MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 429 MODULE_LICENSE("GPL");