1/* 2 * $Id: chipreg.c,v 1.1.1.1 2008/10/15 03:26:35 james26_jang Exp $ 3 * 4 * Registration for chip drivers 5 * 6 */ 7 8#include <linux/kernel.h> 9#include <linux/config.h> 10#include <linux/kmod.h> 11#include <linux/spinlock.h> 12#include <linux/mtd/compatmac.h> 13#include <linux/mtd/map.h> 14 15spinlock_t chip_drvs_lock = SPIN_LOCK_UNLOCKED; 16static LIST_HEAD(chip_drvs_list); 17 18void register_mtd_chip_driver(struct mtd_chip_driver *drv) 19{ 20 spin_lock(&chip_drvs_lock); 21 list_add(&drv->list, &chip_drvs_list); 22 spin_unlock(&chip_drvs_lock); 23} 24 25void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) 26{ 27 spin_lock(&chip_drvs_lock); 28 list_del(&drv->list); 29 spin_unlock(&chip_drvs_lock); 30} 31 32static struct mtd_chip_driver *get_mtd_chip_driver (char *name) 33{ 34 struct list_head *pos; 35 struct mtd_chip_driver *ret = NULL, *this; 36 37 spin_lock(&chip_drvs_lock); 38 39 list_for_each(pos, &chip_drvs_list) { 40 this = list_entry(pos, typeof(*this), list); 41 42 if (!strcmp(this->name, name)) { 43 ret = this; 44 break; 45 } 46 } 47 if (ret && !try_inc_mod_count(ret->module)) { 48 /* Eep. Failed. */ 49 ret = NULL; 50 } 51 52 spin_unlock(&chip_drvs_lock); 53 54 return ret; 55} 56 57 /* Hide all the horrid details, like some silly person taking 58 get_module_symbol() away from us, from the caller. */ 59 60struct mtd_info *do_map_probe(char *name, struct map_info *map) 61{ 62 struct mtd_chip_driver *drv; 63 struct mtd_info *ret; 64 65 drv = get_mtd_chip_driver(name); 66 67 if (!drv && !request_module(name)) 68 drv = get_mtd_chip_driver(name); 69 70 if (!drv) 71 return NULL; 72 73 ret = drv->probe(map); 74#ifdef CONFIG_MODULES 75 /* We decrease the use count here. It may have been a 76 probe-only module, which is no longer required from this 77 point, having given us a handle on (and increased the use 78 count of) the actual driver code. 79 */ 80 if(drv->module) 81 __MOD_DEC_USE_COUNT(drv->module); 82#endif 83 84 if (ret) 85 return ret; 86 87 return NULL; 88} 89 90EXPORT_SYMBOL(register_mtd_chip_driver); 91EXPORT_SYMBOL(unregister_mtd_chip_driver); 92EXPORT_SYMBOL(do_map_probe); 93 94MODULE_LICENSE("GPL"); 95MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 96MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); 97