Orange Pi5 kernel

/*
 * Common code to handle map devices which are simple RAM
 * (C) 2000 Red Hat. GPL'd.
 */
 
#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");