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/module.h> 10 #include <linux/kmod.h> 11 #include <linux/spinlock.h> 12 #include <linux/slab.h> 13 #include <linux/mtd/map.h> 14 #include <linux/mtd/mtd.h> 15 #include <linux/mtd/compatmac.h> 16 17 static DEFINE_SPINLOCK(chip_drvs_lock); 18 static LIST_HEAD(chip_drvs_list); 19 20 void register_mtd_chip_driver(struct mtd_chip_driver *drv) 21 { 22 spin_lock(&chip_drvs_lock); 23 list_add(&drv->list, &chip_drvs_list); 24 spin_unlock(&chip_drvs_lock); 25 } 26 27 void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) 28 { 29 spin_lock(&chip_drvs_lock); 30 list_del(&drv->list); 31 spin_unlock(&chip_drvs_lock); 32 } 33 34 static struct mtd_chip_driver *get_mtd_chip_driver (const char *name) 35 { 36 struct list_head *pos; 37 struct mtd_chip_driver *ret = NULL, *this; 38 39 spin_lock(&chip_drvs_lock); 40 41 list_for_each(pos, &chip_drvs_list) { 42 this = list_entry(pos, typeof(*this), list); 43 44 if (!strcmp(this->name, name)) { 45 ret = this; 46 break; 47 } 48 } 49 if (ret && !try_module_get(ret->module)) 50 ret = NULL; 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 60 struct mtd_info *do_map_probe(const 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("%s", name)) 68 drv = get_mtd_chip_driver(name); 69 70 if (!drv) 71 return NULL; 72 73 ret = drv->probe(map); 74 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 module_put(drv->module); 81 82 if (ret) 83 return ret; 84 85 return NULL; 86 } 87 /* 88 * Destroy an MTD device which was created for a map device. 89 * Make sure the MTD device is already unregistered before calling this 90 */ 91 void map_destroy(struct mtd_info *mtd) 92 { 93 struct map_info *map = mtd->priv; 94 95 if (map->fldrv->destroy) 96 map->fldrv->destroy(mtd); 97 98 module_put(map->fldrv->module); 99 100 kfree(mtd); 101 } 102 103 EXPORT_SYMBOL(register_mtd_chip_driver); 104 EXPORT_SYMBOL(unregister_mtd_chip_driver); 105 EXPORT_SYMBOL(do_map_probe); 106 EXPORT_SYMBOL(map_destroy); 107 108 MODULE_LICENSE("GPL"); 109 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 110 MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); 111