179 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			179 lines
		
	
	
		
			3.9 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/compatmac.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 ram_erase(struct mtd_info *mtd, struct erase_info *instr)
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{
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	if (instr->addr + instr->len > mtd->size)
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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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	if (from + len > mtd->size)
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		return -EINVAL;
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	/* can we return a physical address with this driver? */
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	if (phys)
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		return -EINVAL;
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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 void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
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{
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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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	if (from + len > mtd->size)
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		return -EINVAL;
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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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	if (to + len > mtd->size)
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		return -EINVAL;
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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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		del_mtd_device(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, 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->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 (add_mtd_device(mtd)) {
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		return -EIO;
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	}
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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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