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/*
* linux/drivers/char/misc.c
*
* Generic misc open routine by Johan Myreen
*
* Based on code from Linus
*
* Teemu Rantanen's Microsoft Busmouse support and Derrick Cole's
* changes incorporated into 0.97pl4
* by Peter Cervasio (pete%q106fm.uucp@wupost.wustl.edu) (08SEP92)
* See busmouse.c for particulars.
*
* Made things a lot mode modular - easy to compile in just one or two
* of the misc drivers, as they are now completely independent. Linus.
*
* Support for loadable modules. 8-Sep-95 Philip Blundell <pjb27@cam.ac.uk>
*
* Fixed a failing symbol register to free the device registration
* Alan Cox <alan@lxorguk.ukuu.org.uk> 21-Jan-96
*
* Dynamic minors and /proc/mice by Alessandro Rubini. 26-Mar-96
*
* Renamed to misc and miscdevice to be more accurate. Alan Cox 26-Mar-96
*
* Handling of mouse minor numbers for kerneld:
* Idea by Jacques Gelinas <jack@solucorp.qc.ca>,
* adapted by Bjorn Ekwall <bj0rn@blox.se>
* corrected by Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* Changes for kmod (from kerneld):
* Cyrus Durgin <cider@speakeasy.org>
*
* Added devfs support. Richard Gooch <rgooch@atnf.csiro.au> 10-Jan-1998
*/
#include <linux/module.h>
#include <linux/config.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/selection.h>
#include <linux/kmod.h>
#include "busmouse.h"
/*
* Head entry for the doubly linked miscdevice list
*/
static struct miscdevice misc_list = { 0, "head", NULL, &misc_list, &misc_list };
static DECLARE_MUTEX(misc_sem);
/*
* Assigned numbers, used for dynamic minors
*/
#define DYNAMIC_MINORS 64 /* like dynamic majors */
static unsigned char misc_minors[DYNAMIC_MINORS / 8];
extern int psaux_init(void);
#ifdef CONFIG_SGI_NEWPORT_GFX
extern void gfx_register(void);
#endif
extern void streamable_init(void);
extern int rtc_DP8570A_init(void);
extern int rtc_MK48T08_init(void);
extern int ds1286_init(void);
extern int pmu_device_init(void);
extern int tosh_init(void);
extern int i8k_init(void);
static int misc_read_proc(char *buf, char **start, off_t offset,
int len, int *eof, void *private)
{
struct miscdevice *p;
int written;
written=0;
for (p = misc_list.next; p != &misc_list && written < len; p = p->next) {
written += sprintf(buf+written, "%3i %s\n",p->minor, p->name ?: "");
if (written < offset) {
offset -= written;
written = 0;
}
}
*start = buf + offset;
written -= offset;
if(written > len) {
*eof = 0;
return len;
}
*eof = 1;
return (written<0) ? 0 : written;
}
static int misc_open(struct inode * inode, struct file * file)
{
int minor = MINOR(inode->i_rdev);
struct miscdevice *c;
int err = -ENODEV;
struct file_operations *old_fops, *new_fops = NULL;
down(&misc_sem);
c = misc_list.next;
while ((c != &misc_list) && (c->minor != minor))
c = c->next;
if (c != &misc_list)
new_fops = fops_get(c->fops);
if (!new_fops) {
char modname[20];
up(&misc_sem);
sprintf(modname, "char-major-%d-%d", MISC_MAJOR, minor);
request_module(modname);
down(&misc_sem);
c = misc_list.next;
while ((c != &misc_list) && (c->minor != minor))
c = c->next;
if (c == &misc_list || (new_fops = fops_get(c->fops)) == NULL)
goto fail;
}
err = 0;
old_fops = file->f_op;
file->f_op = new_fops;
if (file->f_op->open) {
err=file->f_op->open(inode,file);
if (err) {
fops_put(file->f_op);
file->f_op = fops_get(old_fops);
}
}
fops_put(old_fops);
fail:
up(&misc_sem);
return err;
}
static struct file_operations misc_fops = {
owner: THIS_MODULE,
open: misc_open,
};
/**
* misc_register - register a miscellaneous device
* @misc: device structure
*
* Register a miscellaneous device with the kernel. If the minor
* number is set to %MISC_DYNAMIC_MINOR a minor number is assigned
* and placed in the minor field of the structure. For other cases
* the minor number requested is used.
*
* The structure passed is linked into the kernel and may not be
* destroyed until it has been unregistered.
*
* A zero is returned on success and a negative errno code for
* failure.
*/
int misc_register(struct miscdevice * misc)
{
static devfs_handle_t devfs_handle;
struct miscdevice *c;
if (misc->next || misc->prev)
return -EBUSY;
down(&misc_sem);
c = misc_list.next;
while ((c != &misc_list) && (c->minor != misc->minor))
c = c->next;
if (c != &misc_list) {
up(&misc_sem);
return -EBUSY;
}
if (misc->minor == MISC_DYNAMIC_MINOR) {
int i = DYNAMIC_MINORS;
while (--i >= 0)
if ( (misc_minors[i>>3] & (1 << (i&7))) == 0)
break;
if (i<0)
{
up(&misc_sem);
return -EBUSY;
}
misc->minor = i;
}
if (misc->minor < DYNAMIC_MINORS)
misc_minors[misc->minor >> 3] |= 1 << (misc->minor & 7);
if (!devfs_handle)
devfs_handle = devfs_mk_dir (NULL, "misc", NULL);
misc->devfs_handle =
devfs_register (devfs_handle, misc->name, DEVFS_FL_NONE,
MISC_MAJOR, misc->minor,
S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP,
misc->fops, NULL);
/*
* Add it to the front, so that later devices can "override"
* earlier defaults
*/
misc->prev = &misc_list;
misc->next = misc_list.next;
misc->prev->next = misc;
misc->next->prev = misc;
up(&misc_sem);
return 0;
}
/**
* misc_deregister - unregister a miscellaneous device
* @misc: device to unregister
*
* Unregister a miscellaneous device that was previously
* successfully registered with misc_register(). Success
* is indicated by a zero return, a negative errno code
* indicates an error.
*/
int misc_deregister(struct miscdevice * misc)
{
int i = misc->minor;
if (!misc->next || !misc->prev)
return -EINVAL;
down(&misc_sem);
misc->prev->next = misc->next;
misc->next->prev = misc->prev;
misc->next = NULL;
misc->prev = NULL;
devfs_unregister (misc->devfs_handle);
if (i < DYNAMIC_MINORS && i>0) {
misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
}
up(&misc_sem);
return 0;
}
EXPORT_SYMBOL(misc_register);
EXPORT_SYMBOL(misc_deregister);
int __init misc_init(void)
{
create_proc_read_entry("misc", 0, 0, misc_read_proc, NULL);
#ifdef CONFIG_MVME16x
rtc_MK48T08_init();
#endif
#ifdef CONFIG_BVME6000
rtc_DP8570A_init();
#endif
#ifdef CONFIG_SGI_DS1286
ds1286_init();
#endif
#ifdef CONFIG_PMAC_PBOOK
pmu_device_init();
#endif
#ifdef CONFIG_SGI_NEWPORT_GFX
gfx_register ();
#endif
#ifdef CONFIG_SGI_IP22
streamable_init ();
#endif
#ifdef CONFIG_SGI_NEWPORT_GFX
gfx_register ();
#endif
#ifdef CONFIG_TOSHIBA
tosh_init();
#endif
#ifdef CONFIG_I8K
i8k_init();
#endif
if (devfs_register_chrdev(MISC_MAJOR,"misc",&misc_fops)) {
printk("unable to get major %d for misc devices\n",
MISC_MAJOR);
return -EIO;
}
return 0;
}
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