From 7799308f34d3c3371a319559687c78c0f2506fcf Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Wed, 11 Oct 2006 14:52:44 +0300 Subject: [PATCH] [MTD] add get_mtd_device_nm() function This patch adds one more function to the MTD interface to make it possible to open MTD devices by their names, not only numbers. This is very handy in many situations. Also, MTD device number depend on load order and may vary, while names are fixed. Signed-off-by: Artem Bityutskiy --- drivers/mtd/mtdcore.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/mtd/mtd.h | 1 + 2 files changed, 39 insertions(+) diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index c4d26de743..06ec9f836a 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -223,6 +224,42 @@ struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) return ret; } +/** + * get_mtd_device_nm - obtain a validated handle for an MTD device by + * device name + * @name: MTD device name to open + * + * This function returns MTD device description structure in case of + * success and an error code in case of failure. + */ + +struct mtd_info *get_mtd_device_nm(const char *name) +{ + int i; + struct mtd_info *mtd = ERR_PTR(-ENODEV); + + mutex_lock(&mtd_table_mutex); + + for (i = 0; i < MAX_MTD_DEVICES; i++) { + if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) { + mtd = mtd_table[i]; + break; + } + } + + if (i == MAX_MTD_DEVICES) + goto out_unlock; + + if (!try_module_get(mtd->owner)) + goto out_unlock; + + mtd->usecount++; + +out_unlock: + mutex_unlock(&mtd_table_mutex); + return mtd; +} + void put_mtd_device(struct mtd_info *mtd) { int c; @@ -267,6 +304,7 @@ int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, EXPORT_SYMBOL(add_mtd_device); EXPORT_SYMBOL(del_mtd_device); EXPORT_SYMBOL(get_mtd_device); +EXPORT_SYMBOL(get_mtd_device_nm); EXPORT_SYMBOL(put_mtd_device); EXPORT_SYMBOL(register_mtd_user); EXPORT_SYMBOL(unregister_mtd_user); diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 18acb6d003..89e937dfef 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -216,6 +216,7 @@ extern int add_mtd_device(struct mtd_info *mtd); extern int del_mtd_device (struct mtd_info *mtd); extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num); +extern struct mtd_info *get_mtd_device_nm(const char *name); extern void put_mtd_device(struct mtd_info *mtd); -- 2.39.5