237 lines
		
	
	
		
			6.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			237 lines
		
	
	
		
			6.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* sbc_gxx.c -- MTD map driver for Arcom Control Systems SBC-MediaGX,
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                SBC-GXm and SBC-GX1 series boards.
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   Copyright (C) 2001 Arcom Control System Ltd
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   This program is free software; you can redistribute it and/or modify
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   it under the terms of the GNU General Public License as published by
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   the Free Software Foundation; either version 2 of the License, or
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   (at your option) any later version.
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   This program is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   GNU General Public License for more details.
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   You should have received a copy of the GNU General Public License
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   along with this program; if not, write to the Free Software
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   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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The SBC-MediaGX / SBC-GXx has up to 16 MiB of
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Intel StrataFlash (28F320/28F640) in x8 mode.
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This driver uses the CFI probe and Intel Extended Command Set drivers.
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The flash is accessed as follows:
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   16 KiB memory window at 0xdc000-0xdffff
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   Two IO address locations for paging
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   0x258
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       bit 0-7: address bit 14-21
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   0x259
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       bit 0-1: address bit 22-23
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       bit 7:   0 - reset/powered down
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                1 - device enabled
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The single flash device is divided into 3 partition which appear as
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separate MTD devices.
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25/04/2001 AJL (Arcom)  Modified signon strings and partition sizes
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                        (to support bzImages up to 638KiB-ish)
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*/
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// Includes
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/init.h>
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#include <asm/io.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/map.h>
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#include <linux/mtd/partitions.h>
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// Defines
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// - Hardware specific
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#define WINDOW_START 0xdc000
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/* Number of bits in offset. */
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#define WINDOW_SHIFT 14
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#define WINDOW_LENGTH (1 << WINDOW_SHIFT)
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/* The bits for the offset into the window. */
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#define WINDOW_MASK (WINDOW_LENGTH-1)
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#define PAGE_IO 0x258
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#define PAGE_IO_SIZE 2
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/* bit 7 of 0x259 must be 1 to enable device. */
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#define DEVICE_ENABLE 0x8000
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// - Flash / Partition sizing
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#define MAX_SIZE_KiB             16384
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#define BOOT_PARTITION_SIZE_KiB  768
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#define DATA_PARTITION_SIZE_KiB  1280
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#define APP_PARTITION_SIZE_KiB   6144
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// Globals
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static volatile int page_in_window = -1; // Current page in window.
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static void __iomem *iomapadr;
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static DEFINE_SPINLOCK(sbc_gxx_spin);
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/* partition_info gives details on the logical partitions that the split the
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 * single flash device into. If the size if zero we use up to the end of the
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 * device. */
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static const struct mtd_partition partition_info[] = {
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    { .name = "SBC-GXx flash boot partition",
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      .offset = 0,
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      .size =   BOOT_PARTITION_SIZE_KiB*1024 },
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    { .name = "SBC-GXx flash data partition",
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      .offset = BOOT_PARTITION_SIZE_KiB*1024,
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      .size = (DATA_PARTITION_SIZE_KiB)*1024 },
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    { .name = "SBC-GXx flash application partition",
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      .offset = (BOOT_PARTITION_SIZE_KiB+DATA_PARTITION_SIZE_KiB)*1024 }
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};
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#define NUM_PARTITIONS 3
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static inline void sbc_gxx_page(struct map_info *map, unsigned long ofs)
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{
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	unsigned long page = ofs >> WINDOW_SHIFT;
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	if( page!=page_in_window ) {
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		outw( page | DEVICE_ENABLE, PAGE_IO );
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		page_in_window = page;
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	}
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}
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static map_word sbc_gxx_read8(struct map_info *map, unsigned long ofs)
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{
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	map_word ret;
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	spin_lock(&sbc_gxx_spin);
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	sbc_gxx_page(map, ofs);
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	ret.x[0] = readb(iomapadr + (ofs & WINDOW_MASK));
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	spin_unlock(&sbc_gxx_spin);
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	return ret;
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}
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static void sbc_gxx_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
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{
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	while(len) {
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		unsigned long thislen = len;
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		if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
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			thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
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		spin_lock(&sbc_gxx_spin);
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		sbc_gxx_page(map, from);
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		memcpy_fromio(to, iomapadr + (from & WINDOW_MASK), thislen);
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		spin_unlock(&sbc_gxx_spin);
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		to += thislen;
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		from += thislen;
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		len -= thislen;
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	}
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}
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static void sbc_gxx_write8(struct map_info *map, map_word d, unsigned long adr)
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{
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	spin_lock(&sbc_gxx_spin);
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	sbc_gxx_page(map, adr);
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	writeb(d.x[0], iomapadr + (adr & WINDOW_MASK));
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	spin_unlock(&sbc_gxx_spin);
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}
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static void sbc_gxx_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
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{
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	while(len) {
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		unsigned long thislen = len;
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		if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
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			thislen = WINDOW_LENGTH-(to & WINDOW_MASK);
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		spin_lock(&sbc_gxx_spin);
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		sbc_gxx_page(map, to);
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		memcpy_toio(iomapadr + (to & WINDOW_MASK), from, thislen);
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		spin_unlock(&sbc_gxx_spin);
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		to += thislen;
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		from += thislen;
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		len -= thislen;
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	}
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}
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static struct map_info sbc_gxx_map = {
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	.name = "SBC-GXx flash",
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	.phys = NO_XIP,
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	.size = MAX_SIZE_KiB*1024, /* this must be set to a maximum possible amount
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			 of flash so the cfi probe routines find all
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			 the chips */
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	.bankwidth = 1,
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	.read = sbc_gxx_read8,
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	.copy_from = sbc_gxx_copy_from,
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	.write = sbc_gxx_write8,
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	.copy_to = sbc_gxx_copy_to
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};
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/* MTD device for all of the flash. */
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static struct mtd_info *all_mtd;
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static void cleanup_sbc_gxx(void)
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{
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	if( all_mtd ) {
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		mtd_device_unregister(all_mtd);
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		map_destroy( all_mtd );
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	}
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	iounmap(iomapadr);
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	release_region(PAGE_IO,PAGE_IO_SIZE);
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}
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static int __init init_sbc_gxx(void)
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{
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  	iomapadr = ioremap(WINDOW_START, WINDOW_LENGTH);
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	if (!iomapadr) {
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		printk( KERN_ERR"%s: failed to ioremap memory region\n",
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			sbc_gxx_map.name );
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		return -EIO;
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	}
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	if (!request_region( PAGE_IO, PAGE_IO_SIZE, "SBC-GXx flash")) {
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		printk( KERN_ERR"%s: IO ports 0x%x-0x%x in use\n",
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			sbc_gxx_map.name,
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			PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1 );
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		iounmap(iomapadr);
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		return -EAGAIN;
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	}
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	printk( KERN_INFO"%s: IO:0x%x-0x%x MEM:0x%x-0x%x\n",
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		sbc_gxx_map.name,
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		PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1,
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		WINDOW_START, WINDOW_START+WINDOW_LENGTH-1 );
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	/* Probe for chip. */
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	all_mtd = do_map_probe( "cfi_probe", &sbc_gxx_map );
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	if( !all_mtd ) {
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		cleanup_sbc_gxx();
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		return -ENXIO;
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	}
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	all_mtd->owner = THIS_MODULE;
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	/* Create MTD devices for each partition. */
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	mtd_device_register(all_mtd, partition_info, NUM_PARTITIONS);
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	return 0;
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}
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module_init(init_sbc_gxx);
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module_exit(cleanup_sbc_gxx);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Arcom Control Systems Ltd.");
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MODULE_DESCRIPTION("MTD map driver for SBC-GXm and SBC-GX1 series boards");
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