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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 | // SPDX-License-Identifier: GPL-2.0-only /* * Registration for chip drivers * */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/kmod.h> #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/mtd/map.h> #include <linux/mtd/mtd.h> static DEFINE_SPINLOCK(chip_drvs_lock); static LIST_HEAD(chip_drvs_list); void register_mtd_chip_driver(struct mtd_chip_driver *drv) { spin_lock(&chip_drvs_lock); list_add(&drv->list, &chip_drvs_list); spin_unlock(&chip_drvs_lock); } void unregister_mtd_chip_driver(struct mtd_chip_driver *drv) { spin_lock(&chip_drvs_lock); list_del(&drv->list); spin_unlock(&chip_drvs_lock); } static struct mtd_chip_driver *get_mtd_chip_driver (const char *name) { struct list_head *pos; struct mtd_chip_driver *ret = NULL, *this; spin_lock(&chip_drvs_lock); list_for_each(pos, &chip_drvs_list) { this = list_entry(pos, typeof(*this), list); if (!strcmp(this->name, name)) { ret = this; break; } } if (ret && !try_module_get(ret->module)) ret = NULL; spin_unlock(&chip_drvs_lock); return ret; } /* Hide all the horrid details, like some silly person taking get_module_symbol() away from us, from the caller. */ struct mtd_info *do_map_probe(const char *name, struct map_info *map) { struct mtd_chip_driver *drv; struct mtd_info *ret; drv = get_mtd_chip_driver(name); if (!drv && !request_module("%s", name)) drv = get_mtd_chip_driver(name); if (!drv) return NULL; ret = drv->probe(map); /* We decrease the use count here. It may have been a probe-only module, which is no longer required from this point, having given us a handle on (and increased the use count of) the actual driver code. */ module_put(drv->module); return ret; } /* * Destroy an MTD device which was created for a map device. * Make sure the MTD device is already unregistered before calling this */ void map_destroy(struct mtd_info *mtd) { struct map_info *map = mtd->priv; if (map->fldrv->destroy) map->fldrv->destroy(mtd); module_put(map->fldrv->module); kfree(mtd); } EXPORT_SYMBOL(register_mtd_chip_driver); EXPORT_SYMBOL(unregister_mtd_chip_driver); EXPORT_SYMBOL(do_map_probe); EXPORT_SYMBOL(map_destroy); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); MODULE_DESCRIPTION("Core routines for registering and invoking MTD chip drivers"); |