mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-01 06:33:07 +00:00
87194abaa5
Some of the files in mtd/chips do not have a SPDX license header, presumably because the text string "GPL'd" didn't parse with Thomas rulesets for magic license tagging. Fix this, the code is initially from RedHat which clearly targeted the Linux kernel and intended it to be GPLv2. In any case the original author appears to be David Woodhouse who can then confirm this. Cc: David Woodhouse <dwmw2@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20230603185200.3571174-1-linus.walleij@linaro.org
159 lines
3.7 KiB
C
159 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Common code to handle map devices which are simple RAM
|
|
* (C) 2000 Red Hat.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <asm/io.h>
|
|
#include <asm/byteorder.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/init.h>
|
|
#include <linux/mtd/mtd.h>
|
|
#include <linux/mtd/map.h>
|
|
|
|
|
|
static int mapram_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
|
|
static int mapram_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
|
|
static int mapram_erase (struct mtd_info *, struct erase_info *);
|
|
static void mapram_nop (struct mtd_info *);
|
|
static struct mtd_info *map_ram_probe(struct map_info *map);
|
|
static int mapram_point (struct mtd_info *mtd, loff_t from, size_t len,
|
|
size_t *retlen, void **virt, resource_size_t *phys);
|
|
static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
|
|
|
|
|
|
static struct mtd_chip_driver mapram_chipdrv = {
|
|
.probe = map_ram_probe,
|
|
.name = "map_ram",
|
|
.module = THIS_MODULE
|
|
};
|
|
|
|
static struct mtd_info *map_ram_probe(struct map_info *map)
|
|
{
|
|
struct mtd_info *mtd;
|
|
|
|
/* Check the first byte is RAM */
|
|
#if 0
|
|
map_write8(map, 0x55, 0);
|
|
if (map_read8(map, 0) != 0x55)
|
|
return NULL;
|
|
|
|
map_write8(map, 0xAA, 0);
|
|
if (map_read8(map, 0) != 0xAA)
|
|
return NULL;
|
|
|
|
/* Check the last byte is RAM */
|
|
map_write8(map, 0x55, map->size-1);
|
|
if (map_read8(map, map->size-1) != 0x55)
|
|
return NULL;
|
|
|
|
map_write8(map, 0xAA, map->size-1);
|
|
if (map_read8(map, map->size-1) != 0xAA)
|
|
return NULL;
|
|
#endif
|
|
/* OK. It seems to be RAM. */
|
|
|
|
mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
|
|
if (!mtd)
|
|
return NULL;
|
|
|
|
map->fldrv = &mapram_chipdrv;
|
|
mtd->priv = map;
|
|
mtd->name = map->name;
|
|
mtd->type = MTD_RAM;
|
|
mtd->size = map->size;
|
|
mtd->_erase = mapram_erase;
|
|
mtd->_read = mapram_read;
|
|
mtd->_write = mapram_write;
|
|
mtd->_panic_write = mapram_write;
|
|
mtd->_point = mapram_point;
|
|
mtd->_sync = mapram_nop;
|
|
mtd->_unpoint = mapram_unpoint;
|
|
mtd->flags = MTD_CAP_RAM;
|
|
mtd->writesize = 1;
|
|
|
|
mtd->erasesize = PAGE_SIZE;
|
|
while(mtd->size & (mtd->erasesize - 1))
|
|
mtd->erasesize >>= 1;
|
|
|
|
__module_get(THIS_MODULE);
|
|
return mtd;
|
|
}
|
|
|
|
static int mapram_point(struct mtd_info *mtd, loff_t from, size_t len,
|
|
size_t *retlen, void **virt, resource_size_t *phys)
|
|
{
|
|
struct map_info *map = mtd->priv;
|
|
|
|
if (!map->virt)
|
|
return -EINVAL;
|
|
*virt = map->virt + from;
|
|
if (phys)
|
|
*phys = map->phys + from;
|
|
*retlen = len;
|
|
return 0;
|
|
}
|
|
|
|
static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int mapram_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
|
|
{
|
|
struct map_info *map = mtd->priv;
|
|
|
|
map_copy_from(map, buf, from, len);
|
|
*retlen = len;
|
|
return 0;
|
|
}
|
|
|
|
static int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
|
|
{
|
|
struct map_info *map = mtd->priv;
|
|
|
|
map_copy_to(map, to, buf, len);
|
|
*retlen = len;
|
|
return 0;
|
|
}
|
|
|
|
static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr)
|
|
{
|
|
/* Yeah, it's inefficient. Who cares? It's faster than a _real_
|
|
flash erase. */
|
|
struct map_info *map = mtd->priv;
|
|
map_word allff;
|
|
unsigned long i;
|
|
|
|
allff = map_word_ff(map);
|
|
for (i=0; i<instr->len; i += map_bankwidth(map))
|
|
map_write(map, allff, instr->addr + i);
|
|
return 0;
|
|
}
|
|
|
|
static void mapram_nop(struct mtd_info *mtd)
|
|
{
|
|
/* Nothing to see here */
|
|
}
|
|
|
|
static int __init map_ram_init(void)
|
|
{
|
|
register_mtd_chip_driver(&mapram_chipdrv);
|
|
return 0;
|
|
}
|
|
|
|
static void __exit map_ram_exit(void)
|
|
{
|
|
unregister_mtd_chip_driver(&mapram_chipdrv);
|
|
}
|
|
|
|
module_init(map_ram_init);
|
|
module_exit(map_ram_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
|
|
MODULE_DESCRIPTION("MTD chip driver for RAM chips");
|