axisflashmap.c

linux内核源码

/*
 * Physical mapping layer for MTD using the Axis partitiontable format
 *
 * Copyright (c) 2001, 2002 Axis Communications AB
 *
 * This file is under the GPL.
 *
 * First partition is always sector 0 regardless of if we find a partitiontable
 * or not. In the start of the next sector, there can be a partitiontable that
 * tells us what other partitions to define. If there isn't, we use a default
 * partition split defined below.
 *
 * $Log: axisflashmap.c,v $
 * Revision 1.11  2004/11/15 10:27:14  starvik
 * Corrected typo (Thanks to Milton Miller <[e-mail]>).
 *
 * Revision 1.10  2004/08/16 12:37:22  starvik
 * Merge of Linux 2.6.8
 *
 * Revision 1.8  2004/05/14 07:58:03  starvik
 * Merge of changes from 2.4
 *
 * Revision 1.6  2003/07/04 08:27:37  starvik
 * Merge of Linux 2.5.74
 *
 * Revision 1.5  2002/12/11 13:13:57  starvik
 * Added arch/ to v10 specific includes
 * Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
 *
 * Revision 1.4  2002/11/20 11:56:10  starvik
 * Merge of Linux 2.5.48
 *
 * Revision 1.3  2002/11/13 14:54:13  starvik
 * Copied from linux 2.4
 *
 * Revision 1.28  2002/10/01 08:08:43  jonashg
 * The first partition ends at the start of the partition table.
 *
 * Revision 1.27  2002/08/21 09:23:13  jonashg
 * Speling.
 *
 * Revision 1.26  2002/08/21 08:35:20  jonashg
 * Cosmetic change to printouts.
 *
 * Revision 1.25  2002/08/21 08:15:42  jonashg
 * Made it compile even without CONFIG_MTD_CONCAT defined.
 *
 * Revision 1.24  2002/08/20 13:12:35  jonashg
 * * New approach to probing. Probe cse0 and cse1 separately and (mtd)concat
 *   the results.
 * * Removed compile time tests concerning how the mtdram driver has been
 *   configured. The user will know about the misconfiguration at runtime
 *   instead. (The old approach made it impossible to use mtdram for anything
 *   else than RAM boot).
 *
 * Revision 1.23  2002/05/13 12:12:28  johana
 * Allow compile without CONFIG_MTD_MTDRAM but warn at compiletime and
 * be informative at runtime.
 *
 * Revision 1.22  2002/05/13 10:24:44  johana
 * Added #if checks on MTDRAM CONFIG
 *
 * Revision 1.21  2002/05/06 16:05:20  johana
 * Removed debug printout.
 *
 * Revision 1.20  2002/05/06 16:03:00  johana
 * No more cramfs as root hack in generic code.
 * It's handled by axisflashmap using mtdram.
 *
 * Revision 1.19  2002/03/15 17:10:28  bjornw
 * Changed comment about cached access since we changed this before
 *
 * Revision 1.18  2002/03/05 17:06:15  jonashg
 * Try amd_flash probe before cfi_probe since amd_flash driver can handle two
 * (or more) flash chips of different model and the cfi driver cannot.
 *
 * Revision 1.17  2001/11/12 19:42:38  pkj
 * Fixed compiler warnings.
 *
 * Revision 1.16  2001/11/08 11:18:58  jonashg
 * Always read from uncached address to avoid problems with flushing
 * cachelines after write and MTD-erase. No performance loss have been
 * seen yet.
 *
 * Revision 1.15  2001/10/19 12:41:04  jonashg
 * Name of probe has changed in MTD.
 *
 * Revision 1.14  2001/09/21 07:14:10  jonashg
 * Made root filesystem (cramfs) use mtdblock driver when booting from flash.
 *
 * Revision 1.13  2001/08/15 13:57:35  jonashg
 * Entire MTD updated to the linux 2.4.7 version.
 *
 * Revision 1.12  2001/06/11 09:50:30  jonashg
 * Oops, 2MB is 0x200000 bytes.
 *
 * Revision 1.11  2001/06/08 11:39:44  jonashg
 * Changed sizes and offsets in axis_default_partitions to use
 * CONFIG_ETRAX_PTABLE_SECTOR.
 *
 * Revision 1.10  2001/05/29 09:42:03  jonashg
 * Use macro for end marker length instead of sizeof.
 *
 * Revision 1.9  2001/05/29 08:52:52  jonashg
 * Gave names to the magic fours (size of the ptable end marker).
 *
 * Revision 1.8  2001/05/28 15:36:20  jonashg
 * * Removed old comment about ptable location in flash (it's a CONFIG_ option).
 * * Variable ptable was initialized twice to the same value.
 *
 * Revision 1.7  2001/04/05 13:41:46  markusl
 * Updated according to review remarks
 *
 * Revision 1.6  2001/03/07 09:21:21  bjornw
 * No need to waste .data
 *
 * Revision 1.5  2001/03/06 16:27:01  jonashg
 * Probe the entire flash area for flash devices.
 *
 * Revision 1.4  2001/02/23 12:47:15  bjornw
 * Uncached flash in LOW_MAP moved from 0xe to 0x8
 *
 * Revision 1.3  2001/02/16 12:11:45  jonashg
 * MTD driver amd_flash is now included in MTD CVS repository.
 * (It's now in drivers/mtd).
 *
 * Revision 1.2  2001/02/09 11:12:22  jonashg
 * Support for AMD compatible non-CFI flash chips.
 * Only tested with Toshiba TC58FVT160 so far.
 *
 * Revision 1.1  2001/01/12 17:01:18  bjornw
 * * Added axisflashmap.c, a physical mapping for MTD that reads and understands
 *   Axis partition-table format.
 *
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>

#include <linux/mtd/concat.h>
#include <linux/mtd/map.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/mtdram.h>
#include <linux/mtd/partitions.h>

#include <asm/axisflashmap.h>
#include <asm/mmu.h>
#include <asm/arch/sv_addr_ag.h>

#ifdef CONFIG_CRIS_LOW_MAP
#define FLASH_UNCACHED_ADDR  KSEG_8
#define FLASH_CACHED_ADDR    KSEG_5
#else
#define FLASH_UNCACHED_ADDR  KSEG_E
#define FLASH_CACHED_ADDR    KSEG_F
#endif

#if CONFIG_ETRAX_FLASH_BUSWIDTH==1
#define flash_data __u8
#elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
#define flash_data __u16
#elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
#define flash_data __u32
#endif

/* From head.S */
extern unsigned long romfs_start, romfs_length, romfs_in_flash;

/* The master mtd for the entire flash. */
struct mtd_info* axisflash_mtd = NULL;

/* Map driver functions. */

static map_word flash_read(struct map_info *map, unsigned long ofs)
{
	map_word tmp;
	tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
	return tmp;
}

static void flash_copy_from(struct map_info *map, void *to,
			    unsigned long from, ssize_t len)
{
	memcpy(to, (void *)(map->map_priv_1 + from), len);
}

static void flash_write(struct map_info *map, map_word d, unsigned long adr)
{
	*(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
}

/*
 * The map for chip select e0.
 *
 * We run into tricky coherence situations if we mix cached with uncached
 * accesses to we only use the uncached version here.
 *
 * The size field is the total size where the flash chips may be mapped on the
 * chip select. MTD probes should find all devices there and it does not matter
 * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
 * probes will ignore them.
 *
 * The start address in map_priv_1 is in virtual memory so we cannot use
 * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
 * address of cse0.
 */
static struct map_info map_cse0 = {
	.name = "cse0",
	.size = MEM_CSE0_SIZE,
	.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
	.read = flash_read,
	.copy_from = flash_copy_from,
	.write = flash_write,
	.map_priv_1 = FLASH_UNCACHED_ADDR
};

/*
 * The map for chip select e1.
 *
 * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
 * address, but there isn't.
 */
static struct map_info map_cse1 = {
	.name = "cse1",
	.size = MEM_CSE1_SIZE,
	.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
	.read = flash_read,
	.copy_from = flash_copy_from,
	.write = flash_write,
	.map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
};

/* If no partition-table was found, we use this default-set. */
#define MAX_PARTITIONS         7  
#define NUM_DEFAULT_PARTITIONS 3

/*
 * Default flash size is 2MB. CONFIG_ETRAX_PTABLE_SECTOR is most likely the
 * size of one flash block and "filesystem"-partition needs 5 blocks to be able
 * to use JFFS.
 */
static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
	{
		.name = "boot firmware",
		.size = CONFIG_ETRAX_PTABLE_SECTOR,
		.offset = 0
	},
	{
		.name = "kernel",
		.size = 0x200000 - (6 * CONFIG_ETRAX_PTABLE_SECTOR),
		.offset = CONFIG_ETRAX_PTABLE_SECTOR
	},
	{
		.name = "filesystem",
		.size = 5 * CONFIG_ETRAX_PTABLE_SECTOR,
		.offset = 0x200000 - (5 * CONFIG_ETRAX_PTABLE_SECTOR)
	}
};

/* Initialize the ones normally used. */
static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
	{
		.name = "part0",
		.size = CONFIG_ETRAX_PTABLE_SECTOR,
		.offset = 0
	},
	{
		.name = "part1",