Viewing file:  mtdcore.c (8.4 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* $Id: mtdcore.c,v 1.31 2001/10/02 15:05:11 dwmw2 Exp $
*
* Core registration and callback routines for MTD
* drivers and users.
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <stdarg.h>
#include <linux/mtd/compatmac.h>
#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
#endif
#include <linux/mtd/mtd.h>
static DECLARE_MUTEX(mtd_table_mutex);
static struct mtd_info *mtd_table[MAX_MTD_DEVICES];
static struct mtd_notifier *mtd_notifiers = NULL;
/**
* add_mtd_device - register an MTD device
* @mtd: pointer to new MTD device info structure
*
* Add a device to the list of MTD devices present in the system, and
* notify each currently active MTD 'user' of its arrival. Returns
* zero on success or 1 on failure, which currently will only happen
* if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
*/
int add_mtd_device(struct mtd_info *mtd)
{
int i;
down(&mtd_table_mutex);
for (i=0; i< MAX_MTD_DEVICES; i++)
if (!mtd_table[i])
{
struct mtd_notifier *not=mtd_notifiers;
mtd_table[i] = mtd;
mtd->index = i;
DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
while (not)
{
(*(not->add))(mtd);
not = not->next;
}
up(&mtd_table_mutex);
MOD_INC_USE_COUNT;
return 0;
}
up(&mtd_table_mutex);
return 1;
}
/**
* del_mtd_device - unregister an MTD device
* @mtd: pointer to MTD device info structure
*
* Remove a device from the list of MTD devices present in the system,
* and notify each currently active MTD 'user' of its departure.
* Returns zero on success or 1 on failure, which currently will happen
* if the requested device does not appear to be present in the list.
*/
int del_mtd_device (struct mtd_info *mtd)
{
struct mtd_notifier *not=mtd_notifiers;
int i;
down(&mtd_table_mutex);
for (i=0; i < MAX_MTD_DEVICES; i++)
{
if (mtd_table[i] == mtd)
{
while (not)
{
(*(not->remove))(mtd);
not = not->next;
}
mtd_table[i] = NULL;
up (&mtd_table_mutex);
MOD_DEC_USE_COUNT;
return 0;
}
}
up(&mtd_table_mutex);
return 1;
}
/**
* register_mtd_user - register a 'user' of MTD devices.
* @new: pointer to notifier info structure
*
* Registers a pair of callbacks function to be called upon addition
* or removal of MTD devices. Causes the 'add' callback to be immediately
* invoked for each MTD device currently present in the system.
*/
void register_mtd_user (struct mtd_notifier *new)
{
int i;
down(&mtd_table_mutex);
new->next = mtd_notifiers;
mtd_notifiers = new;
MOD_INC_USE_COUNT;
for (i=0; i< MAX_MTD_DEVICES; i++)
if (mtd_table[i])
new->add(mtd_table[i]);
up(&mtd_table_mutex);
}
/**
* register_mtd_user - unregister a 'user' of MTD devices.
* @new: pointer to notifier info structure
*
* Removes a callback function pair from the list of 'users' to be
* notified upon addition or removal of MTD devices. Causes the
* 'remove' callback to be immediately invoked for each MTD device
* currently present in the system.
*/
int unregister_mtd_user (struct mtd_notifier *old)
{
struct mtd_notifier **prev = &mtd_notifiers;
struct mtd_notifier *cur;
int i;
down(&mtd_table_mutex);
while ((cur = *prev)) {
if (cur == old) {
*prev = cur->next;
MOD_DEC_USE_COUNT;
for (i=0; i< MAX_MTD_DEVICES; i++)
if (mtd_table[i])
old->remove(mtd_table[i]);
up(&mtd_table_mutex);
return 0;
}
prev = &cur->next;
}
up(&mtd_table_mutex);
return 1;
}
/**
* __get_mtd_device - obtain a validated handle for an MTD device
* @mtd: last known address of the required MTD device
* @num: internal device number of the required MTD device
*
* Given a number and NULL address, return the num'th entry in the device
* table, if any. Given an address and num == -1, search the device table
* for a device with that address and return if it's still present. Given
* both, return the num'th driver only if its address matches. Return NULL
* if not. get_mtd_device() increases the use count, but
* __get_mtd_device() doesn't - you should generally use get_mtd_device().
*/
struct mtd_info *__get_mtd_device(struct mtd_info *mtd, int num)
{
struct mtd_info *ret = NULL;
int i;
down(&mtd_table_mutex);
if (num == -1) {
for (i=0; i< MAX_MTD_DEVICES; i++)
if (mtd_table[i] == mtd)
ret = mtd_table[i];
} else if (num < MAX_MTD_DEVICES) {
ret = mtd_table[num];
if (mtd && mtd != ret)
ret = NULL;
}
up(&mtd_table_mutex);
return ret;
}
EXPORT_SYMBOL(add_mtd_device);
EXPORT_SYMBOL(del_mtd_device);
EXPORT_SYMBOL(__get_mtd_device);
EXPORT_SYMBOL(register_mtd_user);
EXPORT_SYMBOL(unregister_mtd_user);
/*====================================================================*/
/* Power management code */
#ifdef CONFIG_PM
#include <linux/pm.h>
static struct pm_dev *mtd_pm_dev = NULL;
static int mtd_pm_callback(struct pm_dev *dev, pm_request_t rqst, void *data)
{
int ret = 0, i;
if (down_trylock(&mtd_table_mutex))
return -EAGAIN;
if (rqst == PM_SUSPEND) {
for (i = 0; ret == 0 && i < MAX_MTD_DEVICES; i++) {
if (mtd_table[i] && mtd_table[i]->suspend)
ret = mtd_table[i]->suspend(mtd_table[i]);
}
} else i = MAX_MTD_DEVICES-1;
if (rqst == PM_RESUME || ret) {
for ( ; i >= 0; i--) {
if (mtd_table[i] && mtd_table[i]->resume)
mtd_table[i]->resume(mtd_table[i]);
}
}
up(&mtd_table_mutex);
return ret;
}
#endif
/*====================================================================*/
/* Support for /proc/mtd */
#ifdef CONFIG_PROC_FS
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
static struct proc_dir_entry *proc_mtd;
#endif
static inline int mtd_proc_info (char *buf, int i)
{
struct mtd_info *this = mtd_table[i];
if (!this)
return 0;
return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
this->erasesize, this->name);
}
static int mtd_read_proc ( char *page, char **start, off_t off,int count
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
,int *eof, void *data_unused
#else
,int unused
#endif
)
{
int len, l, i;
off_t begin = 0;
down(&mtd_table_mutex);
len = sprintf(page, "dev: size erasesize name\n");
for (i=0; i< MAX_MTD_DEVICES; i++) {
l = mtd_proc_info(page + len, i);
len += l;
if (len+begin > off+count)
goto done;
if (len+begin < off) {
begin += len;
len = 0;
}
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
*eof = 1;
#endif
done:
up(&mtd_table_mutex);
if (off >= len+begin)
return 0;
*start = page + (begin-off);
return ((count < begin+len-off) ? count : begin+len-off);
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,2,0)
struct proc_dir_entry mtd_proc_entry = {
0, /* low_ino: the inode -- dynamic */
3, "mtd", /* len of name and name */
S_IFREG | S_IRUGO, /* mode */
1, 0, 0, /* nlinks, owner, group */
0, NULL, /* size - unused; operations -- use default */
&mtd_read_proc, /* function used to read data */
/* nothing more */
};
#endif
#endif /* CONFIG_PROC_FS */
/*====================================================================*/
/* Init code */
int __init init_mtd(void)
{
#ifdef CONFIG_PROC_FS
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
if ((proc_mtd = create_proc_entry( "mtd", 0, 0 )))
proc_mtd->read_proc = mtd_read_proc;
#else
proc_register_dynamic(&proc_root,&mtd_proc_entry);
#endif
#endif
#if LINUX_VERSION_CODE < 0x20212
init_mtd_devices();
#endif
#ifdef CONFIG_PM
mtd_pm_dev = pm_register(PM_UNKNOWN_DEV, 0, mtd_pm_callback);
#endif
return 0;
}
static void __exit cleanup_mtd(void)
{
#ifdef CONFIG_PM
if (mtd_pm_dev) {
pm_unregister(mtd_pm_dev);
mtd_pm_dev = NULL;
}
#endif
#ifdef CONFIG_PROC_FS
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
if (proc_mtd)
remove_proc_entry( "mtd", 0);
#else
proc_unregister(&proc_root,mtd_proc_entry.low_ino);
#endif
#endif
}
module_init(init_mtd);
module_exit(cleanup_mtd);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Core MTD registration and access routines");
|