247 lines
7.3 KiB
C
247 lines
7.3 KiB
C
/**
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* \file drm_stub.h
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* Stub support
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*
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* \author Rickard E. (Rik) Faith <faith@valinux.com>
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*/
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/*
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* Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
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*
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* Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
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* All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*/
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#define __NO_VERSION__
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#include "drmP.h"
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#define DRM_STUB_MAXCARDS 16 /* Enough for one machine */
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/** Stub list. One for each minor. */
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static struct drm_stub_list {
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const char *name;
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struct file_operations *fops; /**< file operations */
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struct proc_dir_entry *dev_root; /**< proc directory entry */
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} *DRM(stub_list);
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static struct proc_dir_entry *DRM(stub_root);
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/**
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* File \c open operation.
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*
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* \param inode device inode.
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* \param filp file pointer.
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*
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* Puts the drm_stub_list::fops corresponding to the device minor number into
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* \p filp, call the \c open method, and restore the file operations.
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*/
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static int DRM(stub_open)(struct inode *inode, struct file *filp)
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{
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int minor = iminor(inode);
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int err = -ENODEV;
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struct file_operations *old_fops;
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if (!DRM(stub_list) || !DRM(stub_list)[minor].fops) return -ENODEV;
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old_fops = filp->f_op;
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filp->f_op = fops_get(DRM(stub_list)[minor].fops);
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if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
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fops_put(filp->f_op);
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filp->f_op = fops_get(old_fops);
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}
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fops_put(old_fops);
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return err;
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}
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/** File operations structure */
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static struct file_operations DRM(stub_fops) = {
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.owner = THIS_MODULE,
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.open = DRM(stub_open)
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};
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/**
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* Get a device minor number.
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*
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* \param name driver name.
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* \param fops file operations.
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* \param dev DRM device.
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* \return minor number on success, or a negative number on failure.
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*
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* Allocate and initialize ::stub_list if one doesn't exist already. Search an
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* empty entry and initialize it to the given parameters, and create the proc
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* init entry via proc_init().
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*/
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static int DRM(stub_getminor)(const char *name, struct file_operations *fops,
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drm_device_t *dev)
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{
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int i;
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if (!DRM(stub_list)) {
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DRM(stub_list) = DRM(alloc)(sizeof(*DRM(stub_list))
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* DRM_STUB_MAXCARDS, DRM_MEM_STUB);
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if(!DRM(stub_list)) return -1;
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for (i = 0; i < DRM_STUB_MAXCARDS; i++) {
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DRM(stub_list)[i].name = NULL;
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DRM(stub_list)[i].fops = NULL;
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}
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}
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for (i = 0; i < DRM_STUB_MAXCARDS; i++) {
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if (!DRM(stub_list)[i].fops) {
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DRM(stub_list)[i].name = name;
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DRM(stub_list)[i].fops = fops;
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DRM(stub_root) = DRM(proc_init)(dev, i, DRM(stub_root),
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&DRM(stub_list)[i]
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.dev_root);
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(*DRM(stub_info).info_count)++;
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DRM_DEBUG("info count increased %d\n", *DRM(stub_info).info_count);
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return i;
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}
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}
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return -1;
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}
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/**
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* Put a device minor number.
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*
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* \param minor minor number.
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* \return always zero.
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*
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* Cleans up the proc resources. If a minor is zero then release the foreign
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* "drm" data, otherwise unregisters the "drm" data, frees the stub list and
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* unregisters the character device.
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*/
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static int DRM(stub_putminor)(int minor)
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{
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if (minor < 0 || minor >= DRM_STUB_MAXCARDS) return -1;
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DRM(stub_list)[minor].name = NULL;
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DRM(stub_list)[minor].fops = NULL;
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DRM(proc_cleanup)(minor, DRM(stub_root),
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DRM(stub_list)[minor].dev_root);
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(*DRM(stub_info).info_count)--;
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if ((*DRM(stub_info).info_count)!=0) {
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DRM_DEBUG("inter_module_put called %d\n", *DRM(stub_info).info_count);
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inter_module_put("drm");
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} else {
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DRM_DEBUG("unregistering inter_module \n");
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inter_module_unregister("drm");
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DRM(free)(DRM(stub_list),
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sizeof(*DRM(stub_list)) * DRM_STUB_MAXCARDS,
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DRM_MEM_STUB);
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class_simple_destroy(DRM(stub_info).drm_class);
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unregister_chrdev(DRM_MAJOR, "drm");
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}
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return 0;
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}
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/**
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* Register.
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*
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* \param name driver name.
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* \param fops file operations
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* \param dev DRM device.
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* \return zero on success or a negative number on failure.
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*
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* Attempt to gets inter module "drm" information. If we are first
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* then register the character device and inter module information.
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* Try and register, if we fail to register, backout previous work.
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*
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* Finally calls stub_info::info_register.
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*/
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int DRM(stub_register)(const char *name, struct file_operations *fops,
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drm_device_t *dev)
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{
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struct drm_stub_info *i = NULL;
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int ret1;
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int ret2;
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DRM_DEBUG("\n");
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/* use the inter_module_get to check - as if the same module
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registers chrdev twice it succeeds */
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i = (struct drm_stub_info *)inter_module_get("drm");
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if (i) {
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/* Already registered */
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DRM(stub_info).info_register = i->info_register;
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DRM(stub_info).info_unregister = i->info_unregister;
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DRM(stub_info).drm_class = i->drm_class;
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DRM(stub_info).info_count = i->info_count;
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DRM_DEBUG("already registered %d\n", *i->info_count);
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} else if (*DRM(stub_info).info_count == 0) {
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ret1 = register_chrdev(DRM_MAJOR, "drm", &DRM(stub_fops));
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if (ret1 < 0) {
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printk (KERN_ERR "Error registering drm major number.\n");
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return ret1;
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}
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DRM(stub_info).drm_class = class_simple_create(THIS_MODULE, "drm");
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if (IS_ERR(DRM(stub_info).drm_class)) {
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printk (KERN_ERR "Error creating drm class.\n");
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unregister_chrdev(DRM_MAJOR, "drm");
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return PTR_ERR(DRM(stub_info).drm_class);
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}
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DRM_DEBUG("calling inter_module_register\n");
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inter_module_register("drm", THIS_MODULE, &DRM(stub_info));
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}
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if (DRM(stub_info).info_register) {
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ret2 = DRM(stub_info).info_register(name, fops, dev);
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if (ret2 < 0) {
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if (!i) {
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inter_module_unregister("drm");
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unregister_chrdev(DRM_MAJOR, "drm");
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class_simple_destroy(DRM(stub_info).drm_class);
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DRM_DEBUG("info_register failed deregistered everything\n");
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}
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DRM_DEBUG("info_register failed\n");
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}
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return ret2;
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}
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return -1;
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}
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/**
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* Unregister.
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*
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* \param minor
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*
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* Calls drm_stub_info::unregister.
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*/
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int DRM(stub_unregister)(int minor)
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{
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DRM_DEBUG("%d\n", minor);
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if (DRM(stub_info).info_unregister)
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return DRM(stub_info).info_unregister(minor);
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return -1;
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}
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int DRM(stub_count);
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/** Stub information */
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struct drm_stub_info DRM(stub_info) = {
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.info_register = DRM(stub_getminor),
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.info_unregister = DRM(stub_putminor),
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.drm_class = NULL,
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.info_count = &DRM(stub_count),
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};
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