1/* 2 * Registration for chip drivers 3 * 4 */ 5 6#include <linux/kernel.h> 7#include <linux/module.h> 8#include <linux/kmod.h> 9#include <linux/spinlock.h> 10#include <linux/slab.h> 11#include <linux/mtd/map.h> 12#include <linux/mtd/mtd.h> 13 14static DEFINE_SPINLOCK(chip_drvs_lock); 15static LIST_HEAD(chip_drvs_list); 16 17void register_mtd_chip_driver(struct mtd_chip_driver *drv) 18{ 19 spin_lock(&chip_drvs_lock); 20 list_add(&drv->list, &chip_drvs_list); 21 spin_unlock(&chip_drvs_lock); 22} 23 24void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) 25{ 26 spin_lock(&chip_drvs_lock); 27 list_del(&drv->list); 28 spin_unlock(&chip_drvs_lock); 29} 30 31static struct mtd_chip_driver *get_mtd_chip_driver (const char *name) 32{ 33 struct list_head *pos; 34 struct mtd_chip_driver *ret = NULL, *this; 35 36 spin_lock(&chip_drvs_lock); 37 38 list_for_each(pos, &chip_drvs_list) { 39 this = list_entry(pos, typeof(*this), list); 40 41 if (!strcmp(this->name, name)) { 42 ret = this; 43 break; 44 } 45 } 46 if (ret && !try_module_get(ret->module)) 47 ret = NULL; 48 49 spin_unlock(&chip_drvs_lock); 50 51 return ret; 52} 53 54 /* Hide all the horrid details, like some silly person taking 55 get_module_symbol() away from us, from the caller. */ 56 57struct mtd_info *do_map_probe(const char *name, struct map_info *map) 58{ 59 struct mtd_chip_driver *drv; 60 struct mtd_info *ret; 61 62 drv = get_mtd_chip_driver(name); 63 64 if (!drv && !request_module("%s", name)) 65 drv = get_mtd_chip_driver(name); 66 67 if (!drv) 68 return NULL; 69 70 ret = drv->probe(map); 71 72 /* We decrease the use count here. It may have been a 73 probe-only module, which is no longer required from this 74 point, having given us a handle on (and increased the use 75 count of) the actual driver code. 76 */ 77 module_put(drv->module); 78 79 if (ret) 80 return ret; 81 82 return NULL; 83} 84/* 85 * Destroy an MTD device which was created for a map device. 86 * Make sure the MTD device is already unregistered before calling this 87 */ 88void map_destroy(struct mtd_info *mtd) 89{ 90 struct map_info *map = mtd->priv; 91 92 if (map->fldrv->destroy) 93 map->fldrv->destroy(mtd); 94 95 module_put(map->fldrv->module); 96 97 kfree(mtd); 98} 99 100EXPORT_SYMBOL(register_mtd_chip_driver); 101EXPORT_SYMBOL(unregister_mtd_chip_driver); 102EXPORT_SYMBOL(do_map_probe); 103EXPORT_SYMBOL(map_destroy); 104 105MODULE_LICENSE("GPL"); 106MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 107MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); 108