linux/drivers/media/dvb/dvb-core/dvbdev.c
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   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
  37static DEFINE_MUTEX(dvbdev_mutex);
  38static int dvbdev_debug;
  39
  40module_param(dvbdev_debug, int, 0644);
  41MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");
  42
  43#define dprintk if (dvbdev_debug) printk
  44
  45static LIST_HEAD(dvb_adapter_list);
  46static DEFINE_MUTEX(dvbdev_register_lock);
  47
  48static 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
  62static struct class *dvb_class;
  63
  64static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
  65static DECLARE_RWSEM(minor_rwsem);
  66
  67static int dvb_device_open(struct inode *inode, struct file *file)
  68{
  69        struct dvb_device *dvbdev;
  70
  71        mutex_lock(&dvbdev_mutex);
  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                mutex_unlock(&dvbdev_mutex);
  95                return err;
  96        }
  97fail:
  98        up_read(&minor_rwsem);
  99        mutex_unlock(&dvbdev_mutex);
 100        return -ENODEV;
 101}
 102
 103
 104static const struct file_operations dvb_device_fops =
 105{
 106        .owner =        THIS_MODULE,
 107        .open =         dvb_device_open,
 108        .llseek =       noop_llseek,
 109};
 110
 111static struct cdev dvb_device_cdev;
 112
 113int dvb_generic_open(struct inode *inode, struct file *file)
 114{
 115        struct dvb_device *dvbdev = file->private_data;
 116
 117        if (!dvbdev)
 118                return -ENODEV;
 119
 120        if (!dvbdev->users)
 121                return -EBUSY;
 122
 123        if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 124                if (!dvbdev->readers)
 125                        return -EBUSY;
 126                dvbdev->readers--;
 127        } else {
 128                if (!dvbdev->writers)
 129                        return -EBUSY;
 130                dvbdev->writers--;
 131        }
 132
 133        dvbdev->users--;
 134        return 0;
 135}
 136EXPORT_SYMBOL(dvb_generic_open);
 137
 138
 139int dvb_generic_release(struct inode *inode, struct file *file)
 140{
 141        struct dvb_device *dvbdev = file->private_data;
 142
 143        if (!dvbdev)
 144                return -ENODEV;
 145
 146        if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
 147                dvbdev->readers++;
 148        } else {
 149                dvbdev->writers++;
 150        }
 151
 152        dvbdev->users++;
 153        return 0;
 154}
 155EXPORT_SYMBOL(dvb_generic_release);
 156
 157
 158long dvb_generic_ioctl(struct file *file,
 159                       unsigned int cmd, unsigned long arg)
 160{
 161        struct dvb_device *dvbdev = file->private_data;
 162
 163        if (!dvbdev)
 164                return -ENODEV;
 165
 166        if (!dvbdev->kernel_ioctl)
 167                return -EINVAL;
 168
 169        return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
 170}
 171EXPORT_SYMBOL(dvb_generic_ioctl);
 172
 173
 174static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
 175{
 176        u32 id = 0;
 177
 178        while (id < DVB_MAX_IDS) {
 179                struct dvb_device *dev;
 180                list_for_each_entry(dev, &adap->device_list, list_head)
 181                        if (dev->type == type && dev->id == id)
 182                                goto skip;
 183                return id;
 184skip:
 185                id++;
 186        }
 187        return -ENFILE;
 188}
 189
 190
 191int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
 192                        const struct dvb_device *template, void *priv, int type)
 193{
 194        struct dvb_device *dvbdev;
 195        struct file_operations *dvbdevfops;
 196        struct device *clsdev;
 197        int minor;
 198        int id;
 199
 200        mutex_lock(&dvbdev_register_lock);
 201
 202        if ((id = dvbdev_get_free_id (adap, type)) < 0){
 203                mutex_unlock(&dvbdev_register_lock);
 204                *pdvbdev = NULL;
 205                printk(KERN_ERR "%s: couldn't find free device id\n", __func__);
 206                return -ENFILE;
 207        }
 208
 209        *pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 210
 211        if (!dvbdev){
 212                mutex_unlock(&dvbdev_register_lock);
 213                return -ENOMEM;
 214        }
 215
 216        dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
 217
 218        if (!dvbdevfops){
 219                kfree (dvbdev);
 220                mutex_unlock(&dvbdev_register_lock);
 221                return -ENOMEM;
 222        }
 223
 224        memcpy(dvbdev, template, sizeof(struct dvb_device));
 225        dvbdev->type = type;
 226        dvbdev->id = id;
 227        dvbdev->adapter = adap;
 228        dvbdev->priv = priv;
 229        dvbdev->fops = dvbdevfops;
 230        init_waitqueue_head (&dvbdev->wait_queue);
 231
 232        memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
 233        dvbdevfops->owner = adap->module;
 234
 235        list_add_tail (&dvbdev->list_head, &adap->device_list);
 236
 237        down_write(&minor_rwsem);
 238#ifdef CONFIG_DVB_DYNAMIC_MINORS
 239        for (minor = 0; minor < MAX_DVB_MINORS; minor++)
 240                if (dvb_minors[minor] == NULL)
 241                        break;
 242
 243        if (minor == MAX_DVB_MINORS) {
 244                kfree(dvbdevfops);
 245                kfree(dvbdev);
 246                mutex_unlock(&dvbdev_register_lock);
 247                return -EINVAL;
 248        }
 249#else
 250        minor = nums2minor(adap->num, type, id);
 251#endif
 252
 253        dvbdev->minor = minor;
 254        dvb_minors[minor] = dvbdev;
 255        up_write(&minor_rwsem);
 256
 257        mutex_unlock(&dvbdev_register_lock);
 258
 259        clsdev = device_create(dvb_class, adap->device,
 260                               MKDEV(DVB_MAJOR, minor),
 261                               dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
 262        if (IS_ERR(clsdev)) {
 263                printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)\n",
 264                       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
 265                return PTR_ERR(clsdev);
 266        }
 267
 268        dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
 269                adap->num, dnames[type], id, minor, minor);
 270
 271        return 0;
 272}
 273EXPORT_SYMBOL(dvb_register_device);
 274
 275
 276void dvb_unregister_device(struct dvb_device *dvbdev)
 277{
 278        if (!dvbdev)
 279                return;
 280
 281        down_write(&minor_rwsem);
 282        dvb_minors[dvbdev->minor] = NULL;
 283        up_write(&minor_rwsem);
 284
 285        device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
 286
 287        list_del (&dvbdev->list_head);
 288        kfree (dvbdev->fops);
 289        kfree (dvbdev);
 290}
 291EXPORT_SYMBOL(dvb_unregister_device);
 292
 293static int dvbdev_check_free_adapter_num(int num)
 294{
 295        struct list_head *entry;
 296        list_for_each(entry, &dvb_adapter_list) {
 297                struct dvb_adapter *adap;
 298                adap = list_entry(entry, struct dvb_adapter, list_head);
 299                if (adap->num == num)
 300                        return 0;
 301        }
 302        return 1;
 303}
 304
 305static int dvbdev_get_free_adapter_num (void)
 306{
 307        int num = 0;
 308
 309        while (num < DVB_MAX_ADAPTERS) {
 310                if (dvbdev_check_free_adapter_num(num))
 311                        return num;
 312                num++;
 313        }
 314
 315        return -ENFILE;
 316}
 317
 318
 319int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
 320                         struct module *module, struct device *device,
 321                         short *adapter_nums)
 322{
 323        int i, num;
 324
 325        mutex_lock(&dvbdev_register_lock);
 326
 327        for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
 328                num = adapter_nums[i];
 329                if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
 330                /* use the one the driver asked for */
 331                        if (dvbdev_check_free_adapter_num(num))
 332                                break;
 333                } else {
 334                        num = dvbdev_get_free_adapter_num();
 335                        break;
 336                }
 337                num = -1;
 338        }
 339
 340        if (num < 0) {
 341                mutex_unlock(&dvbdev_register_lock);
 342                return -ENFILE;
 343        }
 344
 345        memset (adap, 0, sizeof(struct dvb_adapter));
 346        INIT_LIST_HEAD (&adap->device_list);
 347
 348        printk(KERN_INFO "DVB: registering new adapter (%s)\n", name);
 349
 350        adap->num = num;
 351        adap->name = name;
 352        adap->module = module;
 353        adap->device = device;
 354        adap->mfe_shared = 0;
 355        adap->mfe_dvbdev = NULL;
 356        mutex_init (&adap->mfe_lock);
 357
 358        list_add_tail (&adap->list_head, &dvb_adapter_list);
 359
 360        mutex_unlock(&dvbdev_register_lock);
 361
 362        return num;
 363}
 364EXPORT_SYMBOL(dvb_register_adapter);
 365
 366
 367int dvb_unregister_adapter(struct dvb_adapter *adap)
 368{
 369        mutex_lock(&dvbdev_register_lock);
 370        list_del (&adap->list_head);
 371        mutex_unlock(&dvbdev_register_lock);
 372        return 0;
 373}
 374EXPORT_SYMBOL(dvb_unregister_adapter);
 375
 376/* if the miracle happens and "generic_usercopy()" is included into
 377   the kernel, then this can vanish. please don't make the mistake and
 378   define this as video_usercopy(). this will introduce a dependecy
 379   to the v4l "videodev.o" module, which is unnecessary for some
 380   cards (ie. the budget dvb-cards don't need the v4l module...) */
 381int dvb_usercopy(struct file *file,
 382                     unsigned int cmd, unsigned long arg,
 383                     int (*func)(struct file *file,
 384                     unsigned int cmd, void *arg))
 385{
 386        char    sbuf[128];
 387        void    *mbuf = NULL;
 388        void    *parg = NULL;
 389        int     err  = -EINVAL;
 390
 391        /*  Copy arguments into temp kernel buffer  */
 392        switch (_IOC_DIR(cmd)) {
 393        case _IOC_NONE:
 394                /*
 395                 * For this command, the pointer is actually an integer
 396                 * argument.
 397                 */
 398                parg = (void *) arg;
 399                break;
 400        case _IOC_READ: /* some v4l ioctls are marked wrong ... */
 401        case _IOC_WRITE:
 402        case (_IOC_WRITE | _IOC_READ):
 403                if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
 404                        parg = sbuf;
 405                } else {
 406                        /* too big to allocate from stack */
 407                        mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
 408                        if (NULL == mbuf)
 409                                return -ENOMEM;
 410                        parg = mbuf;
 411                }
 412
 413                err = -EFAULT;
 414                if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
 415                        goto out;
 416                break;
 417        }
 418
 419        /* call driver */
 420        mutex_lock(&dvbdev_mutex);
 421        if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
 422                err = -EINVAL;
 423        mutex_unlock(&dvbdev_mutex);
 424
 425        if (err < 0)
 426                goto out;
 427
 428        /*  Copy results into user buffer  */
 429        switch (_IOC_DIR(cmd))
 430        {
 431        case _IOC_READ:
 432        case (_IOC_WRITE | _IOC_READ):
 433                if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
 434                        err = -EFAULT;
 435                break;
 436        }
 437
 438out:
 439        kfree(mbuf);
 440        return err;
 441}
 442
 443static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
 444{
 445        struct dvb_device *dvbdev = dev_get_drvdata(dev);
 446
 447        add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
 448        add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
 449        add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
 450        return 0;
 451}
 452
 453static char *dvb_devnode(struct device *dev, mode_t *mode)
 454{
 455        struct dvb_device *dvbdev = dev_get_drvdata(dev);
 456
 457        return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
 458                dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
 459}
 460
 461
 462static int __init init_dvbdev(void)
 463{
 464        int retval;
 465        dev_t dev = MKDEV(DVB_MAJOR, 0);
 466
 467        if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
 468                printk(KERN_ERR "dvb-core: unable to get major %d\n", DVB_MAJOR);
 469                return retval;
 470        }
 471
 472        cdev_init(&dvb_device_cdev, &dvb_device_fops);
 473        if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
 474                printk(KERN_ERR "dvb-core: unable register character device\n");
 475                goto error;
 476        }
 477
 478        dvb_class = class_create(THIS_MODULE, "dvb");
 479        if (IS_ERR(dvb_class)) {
 480                retval = PTR_ERR(dvb_class);
 481                goto error;
 482        }
 483        dvb_class->dev_uevent = dvb_uevent;
 484        dvb_class->devnode = dvb_devnode;
 485        return 0;
 486
 487error:
 488        cdev_del(&dvb_device_cdev);
 489        unregister_chrdev_region(dev, MAX_DVB_MINORS);
 490        return retval;
 491}
 492
 493
 494static void __exit exit_dvbdev(void)
 495{
 496        class_destroy(dvb_class);
 497        cdev_del(&dvb_device_cdev);
 498        unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
 499}
 500
 501subsys_initcall(init_dvbdev);
 502module_exit(exit_dvbdev);
 503
 504MODULE_DESCRIPTION("DVB Core Driver");
 505MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
 506MODULE_LICENSE("GPL");
 507