1 // SPDX-License-Identifier: GPL-2.0-only
6  * This map driver is used to allocate "placeholder" MTD
9  * registration of MTD device nodes regardless of probe outcome.
17  * Any device 'probed' with this driver will return -ENODEV
27 #include <linux/mtd/mtd.h>
28 #include <linux/mtd/map.h>
41 	.name		= "map_absent",
47 	struct mtd_info *mtd;  in map_absent_probe()  local
49 	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);  in map_absent_probe()
50 	if (!mtd) {  in map_absent_probe()
54 	map->fldrv 	= &map_absent_chipdrv;  in map_absent_probe()
55 	mtd->priv 	= map;  in map_absent_probe()
56 	mtd->name 	= map->name;  in map_absent_probe()
57 	mtd->type 	= MTD_ABSENT;  in map_absent_probe()
58 	mtd->size 	= map->size;  in map_absent_probe()
59 	mtd->_erase 	= map_absent_erase;  in map_absent_probe()
60 	mtd->_read 	= map_absent_read;  in map_absent_probe()
61 	mtd->_write 	= map_absent_write;  in map_absent_probe()
62 	mtd->_sync 	= map_absent_sync;  in map_absent_probe()
63 	mtd->flags 	= 0;  in map_absent_probe()
64 	mtd->erasesize  = PAGE_SIZE;  in map_absent_probe()
65 	mtd->writesize  = 1;  in map_absent_probe()
68 	return mtd;  in map_absent_probe()
72 static int map_absent_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *b…  in map_absent_read()  argument
74 	return -ENODEV;  in map_absent_read()
77 static int map_absent_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_ch…  in map_absent_write()  argument
79 	return -ENODEV;  in map_absent_write()
82 static int map_absent_erase(struct mtd_info *mtd, struct erase_info *instr)  in map_absent_erase()  argument
84 	return -ENODEV;  in map_absent_erase()
87 static void map_absent_sync(struct mtd_info *mtd)  in map_absent_sync()  argument
92 static void map_absent_destroy(struct mtd_info *mtd)  in map_absent_destroy()  argument
112 MODULE_AUTHOR("Resilience Corporation - Eric Brower <ebrower@resilience.com>");
113 MODULE_DESCRIPTION("Placeholder MTD chip driver for 'absent' chips");