1 /* 2 * $Id: chipreg.c,v 1.17 2004/11/16 18:29:00 dwmw2 Exp $ 3 * 4 * Registration for chip drivers 5 * 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/config.h> 10 #include <linux/module.h> 11 #include <linux/kmod.h> 12 #include <linux/spinlock.h> 13 #include <linux/slab.h> 14 #include <linux/mtd/map.h> 15 #include <linux/mtd/mtd.h> 16 #include <linux/mtd/compatmac.h> 17 18 static DEFINE_SPINLOCK(chip_drvs_lock); 19 static LIST_HEAD(chip_drvs_list); 20 21 void register_mtd_chip_driver(struct mtd_chip_driver *drv) 22 { 23 spin_lock(&chip_drvs_lock); 24 list_add(&drv->list, &chip_drvs_list); 25 spin_unlock(&chip_drvs_lock); 26 } 27 28 void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) 29 { 30 spin_lock(&chip_drvs_lock); 31 list_del(&drv->list); 32 spin_unlock(&chip_drvs_lock); 33 } 34 35 static struct mtd_chip_driver *get_mtd_chip_driver (const char *name) 36 { 37 struct list_head *pos; 38 struct mtd_chip_driver *ret = NULL, *this; 39 40 spin_lock(&chip_drvs_lock); 41 42 list_for_each(pos, &chip_drvs_list) { 43 this = list_entry(pos, typeof(*this), list); 44 45 if (!strcmp(this->name, name)) { 46 ret = this; 47 break; 48 } 49 } 50 if (ret && !try_module_get(ret->module)) 51 ret = NULL; 52 53 spin_unlock(&chip_drvs_lock); 54 55 return ret; 56 } 57 58 /* Hide all the horrid details, like some silly person taking 59 get_module_symbol() away from us, from the caller. */ 60 61 struct mtd_info *do_map_probe(const char *name, struct map_info *map) 62 { 63 struct mtd_chip_driver *drv; 64 struct mtd_info *ret; 65 66 drv = get_mtd_chip_driver(name); 67 68 if (!drv && !request_module("%s", name)) 69 drv = get_mtd_chip_driver(name); 70 71 if (!drv) 72 return NULL; 73 74 ret = drv->probe(map); 75 76 /* We decrease the use count here. It may have been a 77 probe-only module, which is no longer required from this 78 point, having given us a handle on (and increased the use 79 count of) the actual driver code. 80 */ 81 module_put(drv->module); 82 83 if (ret) 84 return ret; 85 86 return NULL; 87 } 88 /* 89 * Destroy an MTD device which was created for a map device. 90 * Make sure the MTD device is already unregistered before calling this 91 */ 92 void map_destroy(struct mtd_info *mtd) 93 { 94 struct map_info *map = mtd->priv; 95 96 if (map->fldrv->destroy) 97 map->fldrv->destroy(mtd); 98 99 module_put(map->fldrv->module); 100 101 kfree(mtd); 102 } 103 104 EXPORT_SYMBOL(register_mtd_chip_driver); 105 EXPORT_SYMBOL(unregister_mtd_chip_driver); 106 EXPORT_SYMBOL(do_map_probe); 107 EXPORT_SYMBOL(map_destroy); 108 109 MODULE_LICENSE("GPL"); 110 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 111 MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); 112