diff options
Diffstat (limited to 'drivers/mtd/mtdcore.c')
| -rw-r--r-- | drivers/mtd/mtdcore.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c new file mode 100644 index 000000000000..9c0315d1b1c4 --- /dev/null +++ b/drivers/mtd/mtdcore.c @@ -0,0 +1,419 @@ +/* + * $Id: mtdcore.c,v 1.44 2004/11/16 18:28:59 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 <linux/init.h> +#include <linux/mtd/compatmac.h> +#ifdef CONFIG_PROC_FS +#include <linux/proc_fs.h> +#endif + +#include <linux/mtd/mtd.h> + +/* These are exported solely for the purpose of mtd_blkdevs.c. You + should not use them for _anything_ else */ +DECLARE_MUTEX(mtd_table_mutex); +struct mtd_info *mtd_table[MAX_MTD_DEVICES]; + +EXPORT_SYMBOL_GPL(mtd_table_mutex); +EXPORT_SYMBOL_GPL(mtd_table); + +static LIST_HEAD(mtd_notifiers); + +/** + * 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 list_head *this; + + mtd_table[i] = mtd; + mtd->index = i; + mtd->usecount = 0; + + DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name); + /* No need to get a refcount on the module containing + the notifier, since we hold the mtd_table_mutex */ + list_for_each(this, &mtd_notifiers) { + struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list); + not->add(mtd); + } + + up(&mtd_table_mutex); + /* We _know_ we aren't being removed, because + our caller is still holding us here. So none + of this try_ nonsense, and no bitching about it + either. :) */ + __module_get(THIS_MODULE); + 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) +{ + int ret; + + down(&mtd_table_mutex); + + if (mtd_table[mtd->index] != mtd) { + ret = -ENODEV; + } else if (mtd->usecount) { + printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", + mtd->index, mtd->name, mtd->usecount); + ret = -EBUSY; + } else { + struct list_head *this; + + /* No need to get a refcount on the module containing + the notifier, since we hold the mtd_table_mutex */ + list_for_each(this, &mtd_notifiers) { + struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list); + not->remove(mtd); + } + + mtd_table[mtd->index] = NULL; + + module_put(THIS_MODULE); + ret = 0; + } + + up(&mtd_table_mutex); + return ret; +} + +/** + * 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); + + list_add(&new->list, &mtd_notifiers); + + __module_get(THIS_MODULE); + + 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) +{ + int i; + + down(&mtd_table_mutex); + + module_put(THIS_MODULE); + + for (i=0; i< MAX_MTD_DEVICES; i++) + if (mtd_table[i]) + old->remove(mtd_table[i]); + + list_del(&old->list); + up(&mtd_table_mutex); + return 0; +} + + +/** + * 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. + */ + +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; + } + + if (ret && !try_module_get(ret->owner)) + ret = NULL; + + if (ret) + ret->usecount++; + + up(&mtd_table_mutex); + return ret; +} + +void put_mtd_device(struct mtd_info *mtd) +{ + int c; + + down(&mtd_table_mutex); + c = --mtd->usecount; + up(&mtd_table_mutex); + BUG_ON(c < 0); + + module_put(mtd->owner); +} + +/* default_mtd_writev - default mtd writev method for MTD devices that + * dont implement their own + */ + +int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, + unsigned long count, loff_t to, size_t *retlen) +{ + unsigned long i; + size_t totlen = 0, thislen; + int ret = 0; + + if(!mtd->write) { + ret = -EROFS; + } else { + for (i=0; i<count; i++) { + if (!vecs[i].iov_len) + continue; + ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base); + totlen += thislen; + if (ret || thislen != vecs[i].iov_len) + break; + to += vecs[i].iov_len; + } + } + if (retlen) + *retlen = totlen; + return ret; +} + + +/* default_mtd_readv - default mtd readv method for MTD devices that dont + * implement their own + */ + +int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs, + unsigned long count, loff_t from, size_t *retlen) +{ + unsigned long i; + size_t totlen = 0, thislen; + int ret = 0; + + if(!mtd->read) { + ret = -EIO; + } else { + for (i=0; i<count; i++) { + if (!vecs[i].iov_len) + continue; + ret = mtd->read(mtd, from, vecs[i].iov_len, &thislen, vecs[i].iov_base); + totlen += thislen; + if (ret || thislen != vecs[i].iov_len) + break; + from += vecs[i].iov_len; + } + } + if (retlen) + *retlen = totlen; + return ret; +} + + +EXPORT_SYMBOL(add_mtd_device); +EXPORT_SYMBOL(del_mtd_device); +EXPORT_SYMBOL(get_mtd_device); +EXPORT_SYMBOL(put_mtd_device); +EXPORT_SYMBOL(register_mtd_user); +EXPORT_SYMBOL(unregister_mtd_user); +EXPORT_SYMBOL(default_mtd_writev); +EXPORT_SYMBOL(default_mtd_readv); + +/*====================================================================*/ +/* 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 +static struct proc_dir_entry *proc_mtd; + +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, + int *eof, void *data_unused) +{ + 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; + } + } + + *eof = 1; + +done: + up(&mtd_table_mutex); + if (off >= len+begin) + return 0; + *start = page + (off-begin); + return ((count < begin+len-off) ? count : begin+len-off); +} + +#endif /* CONFIG_PROC_FS */ + +/*====================================================================*/ +/* Init code */ + +static int __init init_mtd(void) +{ +#ifdef CONFIG_PROC_FS + if ((proc_mtd = create_proc_entry( "mtd", 0, NULL ))) + proc_mtd->read_proc = mtd_read_proc; +#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 (proc_mtd) + remove_proc_entry( "mtd", NULL); +#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"); |