From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/mtd/chips/map_absent.c | 113 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 drivers/mtd/chips/map_absent.c (limited to 'drivers/mtd/chips/map_absent.c') diff --git a/drivers/mtd/chips/map_absent.c b/drivers/mtd/chips/map_absent.c new file mode 100644 index 0000000000..fc68557f49 --- /dev/null +++ b/drivers/mtd/chips/map_absent.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Common code to handle absent "placeholder" devices + * Copyright 2001 Resilience Corporation + * + * This map driver is used to allocate "placeholder" MTD + * devices on systems that have socketed/removable media. + * Use of this driver as a fallback preserves the expected + * registration of MTD device nodes regardless of probe outcome. + * A usage example is as follows: + * + * my_dev[i] = do_map_probe("cfi", &my_map[i]); + * if(NULL == my_dev[i]) { + * my_dev[i] = do_map_probe("map_absent", &my_map[i]); + * } + * + * Any device 'probed' with this driver will return -ENODEV + * upon open. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +static int map_absent_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *); +static int map_absent_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *); +static int map_absent_erase (struct mtd_info *, struct erase_info *); +static void map_absent_sync (struct mtd_info *); +static struct mtd_info *map_absent_probe(struct map_info *map); +static void map_absent_destroy (struct mtd_info *); + + +static struct mtd_chip_driver map_absent_chipdrv = { + .probe = map_absent_probe, + .destroy = map_absent_destroy, + .name = "map_absent", + .module = THIS_MODULE +}; + +static struct mtd_info *map_absent_probe(struct map_info *map) +{ + struct mtd_info *mtd; + + mtd = kzalloc(sizeof(*mtd), GFP_KERNEL); + if (!mtd) { + return NULL; + } + + map->fldrv = &map_absent_chipdrv; + mtd->priv = map; + mtd->name = map->name; + mtd->type = MTD_ABSENT; + mtd->size = map->size; + mtd->_erase = map_absent_erase; + mtd->_read = map_absent_read; + mtd->_write = map_absent_write; + mtd->_sync = map_absent_sync; + mtd->flags = 0; + mtd->erasesize = PAGE_SIZE; + mtd->writesize = 1; + + __module_get(THIS_MODULE); + return mtd; +} + + +static int map_absent_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + return -ENODEV; +} + +static int map_absent_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) +{ + return -ENODEV; +} + +static int map_absent_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + return -ENODEV; +} + +static void map_absent_sync(struct mtd_info *mtd) +{ + /* nop */ +} + +static void map_absent_destroy(struct mtd_info *mtd) +{ + /* nop */ +} + +static int __init map_absent_init(void) +{ + register_mtd_chip_driver(&map_absent_chipdrv); + return 0; +} + +static void __exit map_absent_exit(void) +{ + unregister_mtd_chip_driver(&map_absent_chipdrv); +} + +module_init(map_absent_init); +module_exit(map_absent_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Resilience Corporation - Eric Brower "); +MODULE_DESCRIPTION("Placeholder MTD chip driver for 'absent' chips"); -- cgit v1.2.3