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