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Add code to crawl sysfs to find preexisting classes; now we can

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register multiple devices of the same type for classes other than just
'sound'



git-svn-id: http://svn.xiph.org/trunk/fusd@12352 0101bb08-14d6-0310-b084-bc0e0c8e3800
This commit is contained in:
xiphmont
2007-01-19 17:13:16 +00:00
parent 41185bd56b
commit 0bf42c8088
1 changed files with 147 additions and 75 deletions
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222
kfusd/kfusd.c
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@@ -37,6 +37,7 @@
* Jeremy Elson <jelson@circlemud.org> * Jeremy Elson <jelson@circlemud.org>
* Copyright (c) 2001, Sensoria Corporation * Copyright (c) 2001, Sensoria Corporation
* Copyright (c) 2002-2003, Regents of the University of California * Copyright (c) 2002-2003, Regents of the University of California
* Copyright (c) 2007 Monty and Xiph.Org
* *
* $Id$ * $Id$
*/ */
@@ -127,14 +128,25 @@
#endif #endif
static inline struct kobject * to_kobj(struct dentry * dentry)
{
struct sysfs_dirent * sd = dentry->d_fsdata;
if(sd)
return ((struct kobject *) sd->s_element);
else
return NULL;
}
#define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
/**************************************************************************/ /**************************************************************************/
#include "fusd.h" #include "fusd.h"
#include "fusd_msg.h" #include "fusd_msg.h"
#include "kfusd.h" #include "kfusd.h"
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
# error "***FUSD doesn't work before Linux Kernel v2.6.0" # error "***FUSD doesn't work before Linux Kernel v2.6.13"
#endif #endif
STATIC struct cdev* fusd_control_device; STATIC struct cdev* fusd_control_device;
@@ -1908,6 +1920,11 @@ STATIC int fusd_polldiff_reply(fusd_dev_t *fusd_dev, fusd_msg_t *msg)
return 0; return 0;
} }
STATIC int systest (struct super_block *sb,void *data){
return 1;
}
STATIC int fusd_register_device(fusd_dev_t *fusd_dev, STATIC int fusd_register_device(fusd_dev_t *fusd_dev,
register_msg_t register_msg) register_msg_t register_msg)
{ {
@@ -1921,10 +1938,6 @@ STATIC int fusd_register_device(fusd_dev_t *fusd_dev,
return -EINVAL; return -EINVAL;
} }
/* user can only register one device per instance */
// if (fusd_dev->handle != 0)
// return -EBUSY;
register_msg.name[FUSD_MAX_NAME_LENGTH] = '\0'; register_msg.name[FUSD_MAX_NAME_LENGTH] = '\0';
/* make sure that there isn't already a device by this name */ /* make sure that there isn't already a device by this name */
@@ -1958,83 +1971,143 @@ STATIC int fusd_register_device(fusd_dev_t *fusd_dev,
return -ENOMEM; return -ENOMEM;
} }
strcpy(fusd_dev->class_name, register_msg.clazz); strcpy(fusd_dev->class_name, register_msg.clazz);
/* allocate memory for the class name, and copy */ /* allocate memory for the class name, and copy */
if ((fusd_dev->dev_name = KMALLOC(strlen(register_msg.devname)+1, GFP_KERNEL)) == NULL) { if ((fusd_dev->dev_name = KMALLOC(strlen(register_msg.devname)+1, GFP_KERNEL)) == NULL) {
RDEBUG(1, "yikes! kernel can't allocate memory"); RDEBUG(1, "yikes! kernel can't allocate memory");
return -ENOMEM; return -ENOMEM;
} }
strcpy(fusd_dev->dev_name, register_msg.devname); strcpy(fusd_dev->dev_name, register_msg.devname);
dev_id = 0;
if((error = alloc_chrdev_region(&dev_id, 0, 1, fusd_dev->name)) < 0)
{
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", error);
goto register_failed;
}
fusd_dev->dev_id = dev_id;
fusd_dev->handle = cdev_alloc();
if(fusd_dev->handle == NULL)
{
printk(KERN_ERR "cdev_alloc() failed\n");
error = -ENOMEM;
goto register_failed3;
}
fusd_dev->handle->owner = THIS_MODULE;
fusd_dev->handle->ops = &fusd_client_fops;
kobject_set_name(&fusd_dev->handle->kobj, fusd_dev->name);
if((error = cdev_add(fusd_dev->handle, dev_id, 1)) < 0)
{
printk(KERN_ERR "cdev_add failed status: %d\n", error);
kobject_put(&fusd_dev->handle->kobj);
goto register_failed3;
}
dev_id = 0; /* look up class in sysfs */
if((error = alloc_chrdev_region(&dev_id, 0, 1, fusd_dev->name)) < 0) {
{ struct CLASS *sys_class = NULL;
printk(KERN_ERR "alloc_chrdev_region failed status: %d\n", error); struct file_system_type *sysfs = get_fs_type("sysfs");
goto register_failed; struct dentry *classdir = NULL;
struct dentry *classdir2 = NULL;
struct super_block *sb = NULL;
if(sysfs){
sb = sget (sysfs, systest, NULL,NULL);
/* because put_filesystem isn't exported */
module_put(sysfs->owner);
if(sb){
struct dentry *root = sb->s_root;
if(root){
struct qstr name;
name.name = "class";
name.len = 5;
name.hash = full_name_hash(name.name, name.len);
classdir = d_lookup(root, &name);
if(classdir){
name.name = register_msg.clazz;
name.len = strlen(name.name);
name.hash = full_name_hash(name.name, name.len);
classdir2 = d_lookup(classdir, &name);
if(classdir2){
// jackpot. extract the class.
struct kobject *ko = to_kobj(classdir2);
sys_class = (ko?to_class(ko):NULL);
if(!sys_class)
RDEBUG(2, "WARNING: sysfs entry for %s has no kobject!\n",register_msg.clazz);
}
}else{
RDEBUG(2, "WARNING: sysfs does not list a class directory!\n");
}
}else{
RDEBUG(2, "WARNING: unable to access root firectory in sysfs!\n");
} }
}else{
fusd_dev->dev_id = dev_id; RDEBUG(2, "WARNING: unable to access superblock for sysfs!\n");
}
fusd_dev->handle = cdev_alloc(); }else{
if(fusd_dev->handle == NULL) RDEBUG(2, "WARNING: sysfs not mounted or unavailable!\n");
}
if(sys_class){
RDEBUG(3, "Found entry for class '%s' in sysfs\n",register_msg.clazz);
fusd_dev->clazz = sound_class;
fusd_dev->owns_class = 0;
}else{
RDEBUG(3, "Sysfs has no entry for '%s'; registering new class\n",register_msg.clazz);
fusd_dev->clazz = class_create(THIS_MODULE, fusd_dev->class_name);
if(IS_ERR(fusd_dev->clazz))
{ {
printk(KERN_ERR "cdev_alloc() failed\n"); error = PTR_ERR(fusd_dev->clazz);
error = -ENOMEM; printk(KERN_ERR "class_create failed status: %d\n", error);
goto register_failed3; goto register_failed4;
} }
fusd_dev->owns_class = 1;
}
fusd_dev->handle->owner = THIS_MODULE; if(classdir)
fusd_dev->handle->ops = &fusd_client_fops; dput(classdir);
if(classdir2)
kobject_set_name(&fusd_dev->handle->kobj, fusd_dev->name); dput(classdir2);
if((error = cdev_add(fusd_dev->handle, dev_id, 1)) < 0) if(sb){
{ up_write(&sb->s_umount);
printk(KERN_ERR "cdev_add failed status: %d\n", error); deactivate_super(sb);
kobject_put(&fusd_dev->handle->kobj); }
goto register_failed3; }
}
fusd_dev->class_device = CLASS_DEVICE_CREATE(fusd_dev->clazz, NULL, fusd_dev->dev_id, NULL, fusd_dev->dev_name);
// Hack to add my class to the sound class if(fusd_dev->class_device == NULL)
if(strcmp("sound", register_msg.clazz) == 0) {
{ error = PTR_ERR(fusd_dev->class_device);
fusd_dev->clazz = sound_class; printk(KERN_ERR "class_device_create failed status: %d\n", error);
fusd_dev->owns_class = 0; goto register_failed5;
} }
else
{ /* make sure the registration was successful */
fusd_dev->clazz = class_create(THIS_MODULE, fusd_dev->class_name);
if(IS_ERR(fusd_dev->clazz))
{
error = PTR_ERR(fusd_dev->clazz);
printk(KERN_ERR "class_create failed status: %d\n", error);
goto register_failed4;
}
fusd_dev->owns_class = 1;
}
fusd_dev->class_device = CLASS_DEVICE_CREATE(fusd_dev->clazz, NULL, fusd_dev->dev_id, NULL, fusd_dev->dev_name);
if(fusd_dev->class_device == NULL)
{
error = PTR_ERR(fusd_dev->class_device);
printk(KERN_ERR "class_device_create failed status: %d\n", error);
goto register_failed5;
}
/* make sure the registration was successful */
/*
if (fusd_dev->handle == 0) { if (fusd_dev->handle == 0) {
error = -EIO; error = -EIO;
goto register_failed; goto register_failed;
} }
*/
/* remember the user's private data so we can pass it back later */ /* remember the user's private data so we can pass it back later */
fusd_dev->private_data = register_msg.device_info; fusd_dev->private_data = register_msg.device_info;
/* everything ok */ /* everything ok */
fusd_dev->version = atomic_inc_and_ret(&last_version); fusd_dev->version = atomic_inc_and_ret(&last_version);
RDEBUG(3, "pid %d registered /dev/%s v%ld", fusd_dev->pid, NAME(fusd_dev), RDEBUG(3, "pid %d registered /dev/%s v%ld", fusd_dev->pid, NAME(fusd_dev),
@@ -2133,16 +2206,15 @@ STATIC int fusd_release(struct inode *inode, struct file *file)
} }
#endif #endif
if(fusd_dev->handle) if(fusd_dev->handle){
{ class_device_destroy(fusd_dev->clazz, fusd_dev->dev_id);
class_device_destroy(fusd_dev->clazz, fusd_dev->dev_id); if(fusd_dev->owns_class)
if(fusd_dev->owns_class) {
{ class_destroy(fusd_dev->clazz);
class_destroy(fusd_dev->clazz); }
} cdev_del(fusd_dev->handle);
cdev_del(fusd_dev->handle); unregister_chrdev_region(fusd_dev->dev_id, 1);
unregister_chrdev_region(fusd_dev->dev_id, 1); }
}
/* mark the driver as being gone */ /* mark the driver as being gone */
zombify_dev(fusd_dev); zombify_dev(fusd_dev);