180 lines
4.1 KiB
C
180 lines
4.1 KiB
C
/*
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* mtdram - a test mtd device
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* Author: Alexander Larsson <alex@cendio.se>
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*
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* Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
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* Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
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*
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* This code is GPL
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*
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/ioport.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/mtdram.h>
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static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
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static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
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#define MTDRAM_TOTAL_SIZE (total_size * 1024)
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#define MTDRAM_ERASE_SIZE (erase_size * 1024)
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#ifdef MODULE
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module_param(total_size, ulong, 0);
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MODULE_PARM_DESC(total_size, "Total device size in KiB");
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module_param(erase_size, ulong, 0);
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MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
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#endif
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// We could store these in the mtd structure, but we only support 1 device..
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static struct mtd_info *mtd_info;
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static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
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{
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int ret = 0;
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/* Start address must align on block boundary */
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if (mtd_mod_by_eb(ofs, mtd)) {
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pr_debug("%s: unaligned address\n", __func__);
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ret = -EINVAL;
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}
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/* Length must align on block boundary */
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if (mtd_mod_by_eb(len, mtd)) {
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pr_debug("%s: length not block aligned\n", __func__);
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ret = -EINVAL;
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}
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return ret;
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}
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static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
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{
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if (check_offs_len(mtd, instr->addr, instr->len))
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return -EINVAL;
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memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
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instr->state = MTD_ERASE_DONE;
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mtd_erase_callback(instr);
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return 0;
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}
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static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
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size_t *retlen, void **virt, resource_size_t *phys)
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{
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*virt = mtd->priv + from;
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*retlen = len;
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return 0;
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}
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static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
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{
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return 0;
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}
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/*
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* Allow NOMMU mmap() to directly map the device (if not NULL)
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* - return the address to which the offset maps
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* - return -ENOSYS to indicate refusal to do the mapping
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*/
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static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
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unsigned long len,
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unsigned long offset,
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unsigned long flags)
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{
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return (unsigned long) mtd->priv + offset;
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}
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static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
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size_t *retlen, u_char *buf)
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{
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memcpy(buf, mtd->priv + from, len);
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*retlen = len;
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return 0;
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}
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static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
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size_t *retlen, const u_char *buf)
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{
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memcpy((char *)mtd->priv + to, buf, len);
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*retlen = len;
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return 0;
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}
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static void __exit cleanup_mtdram(void)
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{
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if (mtd_info) {
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mtd_device_unregister(mtd_info);
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vfree(mtd_info->priv);
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kfree(mtd_info);
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}
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}
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int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
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unsigned long size, const char *name)
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{
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memset(mtd, 0, sizeof(*mtd));
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/* Setup the MTD structure */
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mtd->name = name;
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mtd->type = MTD_RAM;
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mtd->flags = MTD_CAP_RAM;
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mtd->size = size;
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mtd->writesize = 1;
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mtd->writebufsize = 64; /* Mimic CFI NOR flashes */
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mtd->erasesize = MTDRAM_ERASE_SIZE;
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mtd->priv = mapped_address;
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mtd->owner = THIS_MODULE;
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mtd->_erase = ram_erase;
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mtd->_point = ram_point;
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mtd->_unpoint = ram_unpoint;
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mtd->_get_unmapped_area = ram_get_unmapped_area;
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mtd->_read = ram_read;
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mtd->_write = ram_write;
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if (mtd_device_register(mtd, NULL, 0))
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return -EIO;
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return 0;
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}
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static int __init init_mtdram(void)
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{
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void *addr;
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int err;
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if (!total_size)
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return -EINVAL;
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/* Allocate some memory */
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mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
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if (!mtd_info)
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return -ENOMEM;
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addr = vmalloc(MTDRAM_TOTAL_SIZE);
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if (!addr) {
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kfree(mtd_info);
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mtd_info = NULL;
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return -ENOMEM;
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}
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err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
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if (err) {
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vfree(addr);
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kfree(mtd_info);
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mtd_info = NULL;
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return err;
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}
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memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
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return err;
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}
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module_init(init_mtdram);
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module_exit(cleanup_mtdram);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
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MODULE_DESCRIPTION("Simulated MTD driver for testing");
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