[deliverable/linux.git] / arch / cris / arch-v10 / drivers / axisflashmap.c

/*
 * 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.
 *
 */

#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 <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",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part2",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part3",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part4",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part5",
		.size = 0,
		.offset = 0
	},
	{
		.name = "part6",
		.size = 0,
		.offset = 0
	},
};

#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
/* Main flash device */
static struct mtd_partition main_partition = {
	.name = "main",
	.size = 0,
	.offset = 0
};
#endif

/*
 * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
 * chips in that order (because the amd_flash-driver is faster).
 */
static struct mtd_info *probe_cs(struct map_info *map_cs)
{
	struct mtd_info *mtd_cs = NULL;

	printk(KERN_INFO
               "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
	       map_cs->name, map_cs->size, map_cs->map_priv_1);

#ifdef CONFIG_MTD_CFI
	mtd_cs = do_map_probe("cfi_probe", map_cs);
#endif
#ifdef CONFIG_MTD_JEDECPROBE
	if (!mtd_cs)
		mtd_cs = do_map_probe("jedec_probe", map_cs);
#endif

	return mtd_cs;
}

/*
 * Probe each chip select individually for flash chips. If there are chips on
 * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
 * so that MTD partitions can cross chip boundaries.
 *
 * The only known restriction to how you can mount your chips is that each
 * chip select must hold similar flash chips. But you need external hardware
 * to do that anyway and you can put totally different chips on cse0 and cse1
 * so it isn't really much of a restriction.
 */
static struct mtd_info *flash_probe(void)
{
	struct mtd_info *mtd_cse0;
	struct mtd_info *mtd_cse1;
	struct mtd_info *mtd_cse;

	mtd_cse0 = probe_cs(&map_cse0);
	mtd_cse1 = probe_cs(&map_cse1);

	if (!mtd_cse0 && !mtd_cse1) {
		/* No chip found. */
		return NULL;
	}

	if (mtd_cse0 && mtd_cse1) {
		struct mtd_info *mtds[] = { mtd_cse0, mtd_cse1 };

		/* Since the concatenation layer adds a small overhead we
		 * could try to figure out if the chips in cse0 and cse1 are
		 * identical and reprobe the whole cse0+cse1 window. But since
		 * flash chips are slow, the overhead is relatively small.
		 * So we use the MTD concatenation layer instead of further
		 * complicating the probing procedure.
		 */
		mtd_cse = mtd_concat_create(mtds, ARRAY_SIZE(mtds),
					    "cse0+cse1");
		if (!mtd_cse) {
			printk(KERN_ERR "%s and %s: Concatenation failed!\n",
			       map_cse0.name, map_cse1.name);

			/* The best we can do now is to only use what we found
			 * at cse0.
			 */
			mtd_cse = mtd_cse0;
			map_destroy(mtd_cse1);
		}
	} else {
		mtd_cse = mtd_cse0? mtd_cse0 : mtd_cse1;
	}

	return mtd_cse;
}

/*
 * Probe the flash chip(s) and, if it succeeds, read the partition-table
 * and register the partitions with MTD.
 */
static int __init init_axis_flash(void)
{
	struct mtd_info *mymtd;
	int err = 0;
	int pidx = 0;
	struct partitiontable_head *ptable_head = NULL;
	struct partitiontable_entry *ptable;
	int use_default_ptable = 1; /* Until proven otherwise. */
	const char pmsg[] = "  /dev/flash%d at 0x%08x, size 0x%08x\n";

	if (!(mymtd = flash_probe())) {
		/* There's no reason to use this module if no flash chip can
		 * be identified. Make sure that's understood.
		 */
		printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
	} else {
		printk(KERN_INFO "%s: 0x%08x bytes of flash memory.\n",
		       mymtd->name, mymtd->size);
		axisflash_mtd = mymtd;
	}

	if (mymtd) {
		mymtd->owner = THIS_MODULE;
		ptable_head = (struct partitiontable_head *)(FLASH_CACHED_ADDR +
			      CONFIG_ETRAX_PTABLE_SECTOR +
			      PARTITION_TABLE_OFFSET);
	}
	pidx++;  /* First partition is always set to the default. */

	if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
	    && (ptable_head->size <
		(MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
		PARTITIONTABLE_END_MARKER_SIZE))
	    && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
				  ptable_head->size -
				  PARTITIONTABLE_END_MARKER_SIZE)
		== PARTITIONTABLE_END_MARKER)) {
		/* Looks like a start, sane length and end of a
		 * partition table, lets check csum etc.
		 */
		int ptable_ok = 0;
		struct partitiontable_entry *max_addr =
			(struct partitiontable_entry *)
			((unsigned long)ptable_head + sizeof(*ptable_head) +
			 ptable_head->size);
		unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
		unsigned char *p;
		unsigned long csum = 0;

		ptable = (struct partitiontable_entry *)
			((unsigned long)ptable_head + sizeof(*ptable_head));

		/* Lets be PARANOID, and check the checksum. */
		p = (unsigned char*) ptable;

		while (p <= (unsigned char*)max_addr) {
			csum += *p++;
			csum += *p++;
			csum += *p++;
			csum += *p++;
		}
		ptable_ok = (csum == ptable_head->checksum);

		/* Read the entries and use/show the info.  */
		printk(KERN_INFO " Found a%s partition table at 0x%p-0x%p.\n",
		       (ptable_ok ? " valid" : "n invalid"), ptable_head,
		       max_addr);

		/* We have found a working bootblock.  Now read the
		 * partition table.  Scan the table.  It ends when
		 * there is 0xffffffff, that is, empty flash.
		 */
		while (ptable_ok
		       && ptable->offset != 0xffffffff
		       && ptable < max_addr
		       && pidx < MAX_PARTITIONS) {

			axis_partitions[pidx].offset = offset + ptable->offset;
			axis_partitions[pidx].size = ptable->size;

			printk(pmsg, pidx, axis_partitions[pidx].offset,
			       axis_partitions[pidx].size);
			pidx++;
			ptable++;
		}
		use_default_ptable = !ptable_ok;
	}

	if (romfs_in_flash) {
		/* Add an overlapping device for the root partition (romfs). */

		axis_partitions[pidx].name = "romfs";
		axis_partitions[pidx].size = romfs_length;
		axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
		axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;

		printk(KERN_INFO
                       " Adding readonly flash partition for romfs image:\n");
		printk(pmsg, pidx, axis_partitions[pidx].offset,
		       axis_partitions[pidx].size);
		pidx++;
	}

#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
	if (mymtd) {
		main_partition.size = mymtd->size;
		err = mtd_device_register(mymtd, &main_partition, 1);
		if (err)
			panic("axisflashmap: Could not initialize "
			      "partition for whole main mtd device!\n");
	}
#endif

        if (mymtd) {
		if (use_default_ptable) {
			printk(KERN_INFO " Using default partition table.\n");
			err = mtd_device_register(mymtd,
						  axis_default_partitions,
						  NUM_DEFAULT_PARTITIONS);
		} else {
			err = mtd_device_register(mymtd, axis_partitions,
						  pidx);
		}

		if (err)
			panic("axisflashmap could not add MTD partitions!\n");
	}

	if (!romfs_in_flash) {
		/* Create an RAM device for the root partition (romfs). */

#if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0)
		/* No use trying to boot this kernel from RAM. Panic! */
		printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
		       "device due to kernel (mis)configuration!\n");
		panic("This kernel cannot boot from RAM!\n");
#else
		struct mtd_info *mtd_ram;

		mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
		if (!mtd_ram)
			panic("axisflashmap couldn't allocate memory for "
			      "mtd_info!\n");

		printk(KERN_INFO " Adding RAM partition for romfs image:\n");
		printk(pmsg, pidx, (unsigned)romfs_start,
			(unsigned)romfs_length);

		err = mtdram_init_device(mtd_ram,
			(void *)romfs_start,
			romfs_length,
			"romfs");
		if (err)
			panic("axisflashmap could not initialize MTD RAM "
			      "device!\n");
#endif
	}
	return err;
}

/* This adds the above to the kernels init-call chain. */
module_init(init_axis_flash);

EXPORT_SYMBOL(axisflash_mtd);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Physical mapping layer for MTD using the Axis partitiontable format
	3	*
	4	* Copyright (c) 2001, 2002 Axis Communications AB
	5	*
	6	* This file is under the GPL.
	7	*
	8	* First partition is always sector 0 regardless of if we find a partitiontable
	9	* or not. In the start of the next sector, there can be a partitiontable that
	10	* tells us what other partitions to define. If there isn't, we use a default
	11	* partition split defined below.
	12	*
1da177e4 LT	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/types.h>
	17	#include <linux/kernel.h>
1da177e4	18	#include <linux/init.h>
4e57b681	19	#include <linux/slab.h>
1da177e4 LT	20
	21	#include <linux/mtd/concat.h>
	22	#include <linux/mtd/map.h>
	23	#include <linux/mtd/mtd.h>
	24	#include <linux/mtd/mtdram.h>
	25	#include <linux/mtd/partitions.h>
	26
	27	#include <asm/axisflashmap.h>
	28	#include <asm/mmu.h>
556dcee7	29	#include <arch/sv_addr_ag.h>
1da177e4 LT	30
	31	#ifdef CONFIG_CRIS_LOW_MAP
	32	#define FLASH_UNCACHED_ADDR KSEG_8
	33	#define FLASH_CACHED_ADDR KSEG_5
	34	#else
	35	#define FLASH_UNCACHED_ADDR KSEG_E
	36	#define FLASH_CACHED_ADDR KSEG_F
	37	#endif
	38
	39	#if CONFIG_ETRAX_FLASH_BUSWIDTH==1
	40	#define flash_data __u8
	41	#elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
	42	#define flash_data __u16
	43	#elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
7e920426	44	#define flash_data __u32
1da177e4 LT	45	#endif
	46
	47	/* From head.S */
	48	extern unsigned long romfs_start, romfs_length, romfs_in_flash;
	49
	50	/* The master mtd for the entire flash. */
	51	struct mtd_info* axisflash_mtd = NULL;
	52
	53	/* Map driver functions. */
	54
	55	static map_word flash_read(struct map_info *map, unsigned long ofs)
	56	{
	57	map_word tmp;
	58	tmp.x[0] = (flash_data )(map->map_priv_1 + ofs);
	59	return tmp;
	60	}
	61
	62	static void flash_copy_from(struct map_info map, void to,
	63	unsigned long from, ssize_t len)
	64	{
	65	memcpy(to, (void *)(map->map_priv_1 + from), len);
	66	}
	67
	68	static void flash_write(struct map_info *map, map_word d, unsigned long adr)
	69	{
	70	(flash_data )(map->map_priv_1 + adr) = (flash_data)d.x[0];
	71	}
	72
	73	/*
	74	* The map for chip select e0.
	75	*
	76	* We run into tricky coherence situations if we mix cached with uncached
	77	* accesses to we only use the uncached version here.
	78	*
	79	* The size field is the total size where the flash chips may be mapped on the
	80	* chip select. MTD probes should find all devices there and it does not matter
	81	* if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
	82	* probes will ignore them.
	83	*
	84	* The start address in map_priv_1 is in virtual memory so we cannot use
	85	* MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
	86	* address of cse0.
	87	*/
	88	static struct map_info map_cse0 = {
	89	.name = "cse0",
	90	.size = MEM_CSE0_SIZE,
	91	.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
	92	.read = flash_read,
	93	.copy_from = flash_copy_from,
	94	.write = flash_write,
	95	.map_priv_1 = FLASH_UNCACHED_ADDR
	96	};
	97
	98	/*
	99	* The map for chip select e1.
	100	*
	101	* If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
	102	* address, but there isn't.
	103	*/
	104	static struct map_info map_cse1 = {
	105	.name = "cse1",
	106	.size = MEM_CSE1_SIZE,
	107	.bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
	108	.read = flash_read,
109	.copy_from = flash_copy_from,
110	.write = flash_write,
111	.map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
112	};
113
114	/* If no partition-table was found, we use this default-set. */
32872b20	115	#define MAX_PARTITIONS 7
1da177e4 LT	116	#define NUM_DEFAULT_PARTITIONS 3
	117
	118	/*
	119	* Default flash size is 2MB. CONFIG_ETRAX_PTABLE_SECTOR is most likely the
	120	* size of one flash block and "filesystem"-partition needs 5 blocks to be able
	121	* to use JFFS.
	122	*/
	123	static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
	124	{
	125	.name = "boot firmware",
	126	.size = CONFIG_ETRAX_PTABLE_SECTOR,
	127	.offset = 0
	128	},
	129	{
	130	.name = "kernel",
	131	.size = 0x200000 - (6 * CONFIG_ETRAX_PTABLE_SECTOR),
	132	.offset = CONFIG_ETRAX_PTABLE_SECTOR
	133	},
	134	{
	135	.name = "filesystem",
	136	.size = 5 * CONFIG_ETRAX_PTABLE_SECTOR,
	137	.offset = 0x200000 - (5 * CONFIG_ETRAX_PTABLE_SECTOR)
	138	}
	139	};
	140
	141	/* Initialize the ones normally used. */
	142	static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
	143	{
	144	.name = "part0",
	145	.size = CONFIG_ETRAX_PTABLE_SECTOR,
	146	.offset = 0
	147	},
	148	{
	149	.name = "part1",
	150	.size = 0,
	151	.offset = 0
	152	},
	153	{
	154	.name = "part2",
	155	.size = 0,
	156	.offset = 0
	157	},
	158	{
	159	.name = "part3",
	160	.size = 0,
	161	.offset = 0
	162	},
	163	{
	164	.name = "part4",
	165	.size = 0,
	166	.offset = 0
	167	},
	168	{
	169	.name = "part5",
	170	.size = 0,
	171	.offset = 0
	172	},
	173	{
	174	.name = "part6",
	175	.size = 0,
	176	.offset = 0
	177	},
	178	};
	179
32872b20 JN	180	#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
	181	/* Main flash device */
	182	static struct mtd_partition main_partition = {
	183	.name = "main",
	184	.size = 0,
	185	.offset = 0
	186	};
	187	#endif
	188
1da177e4 LT	189	/*
	190	* Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
	191	* chips in that order (because the amd_flash-driver is faster).
	192	*/
	193	static struct mtd_info probe_cs(struct map_info map_cs)
	194	{
	195	struct mtd_info *mtd_cs = NULL;
	196
	197	printk(KERN_INFO
	198	"%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
	199	map_cs->name, map_cs->size, map_cs->map_priv_1);
	200
1da177e4	201	#ifdef CONFIG_MTD_CFI
1b8be1d8 JN	202	mtd_cs = do_map_probe("cfi_probe", map_cs);
	203	#endif
	204	#ifdef CONFIG_MTD_JEDECPROBE
32872b20	205	if (!mtd_cs)
1b8be1d8	206	mtd_cs = do_map_probe("jedec_probe", map_cs);
1da177e4 LT	207	#endif
	208
	209	return mtd_cs;
	210	}
	211
32872b20	212	/*
1da177e4 LT	213	* Probe each chip select individually for flash chips. If there are chips on
1da177e4 LT	214	* both cse0 and cse1, the mtd_info structs will be concatenated to one struct
014b38ec	215	* so that MTD partitions can cross chip boundaries.
1da177e4 LT	216	*
	217	* The only known restriction to how you can mount your chips is that each
	218	* chip select must hold similar flash chips. But you need external hardware
	219	* to do that anyway and you can put totally different chips on cse0 and cse1
	220	* so it isn't really much of a restriction.
	221	*/
	222	static struct mtd_info *flash_probe(void)
	223	{
	224	struct mtd_info *mtd_cse0;
	225	struct mtd_info *mtd_cse1;
	226	struct mtd_info *mtd_cse;
	227
	228	mtd_cse0 = probe_cs(&map_cse0);
	229	mtd_cse1 = probe_cs(&map_cse1);
	230
	231	if (!mtd_cse0 && !mtd_cse1) {
	232	/* No chip found. */
	233	return NULL;
	234	}
	235
	236	if (mtd_cse0 && mtd_cse1) {
1da177e4	237	struct mtd_info *mtds[] = { mtd_cse0, mtd_cse1 };
32872b20	238
1da177e4 LT	239	/* Since the concatenation layer adds a small overhead we
	240	* could try to figure out if the chips in cse0 and cse1 are
	241	* identical and reprobe the whole cse0+cse1 window. But since
	242	* flash chips are slow, the overhead is relatively small.
	243	* So we use the MTD concatenation layer instead of further
	244	* complicating the probing procedure.
	245	*/
8447157a	246	mtd_cse = mtd_concat_create(mtds, ARRAY_SIZE(mtds),
1da177e4	247	"cse0+cse1");
1da177e4 LT	248	if (!mtd_cse) {
	249	printk(KERN_ERR "%s and %s: Concatenation failed!\n",
	250	map_cse0.name, map_cse1.name);
	251
	252	/* The best we can do now is to only use what we found
	253	* at cse0.
32872b20	254	*/
1da177e4 LT	255	mtd_cse = mtd_cse0;
	256	map_destroy(mtd_cse1);
	257	}
	258	} else {
	259	mtd_cse = mtd_cse0? mtd_cse0 : mtd_cse1;
	260	}
	261
	262	return mtd_cse;
	263	}
	264
	265	/*
	266	* Probe the flash chip(s) and, if it succeeds, read the partition-table
	267	* and register the partitions with MTD.
	268	*/
	269	static int __init init_axis_flash(void)
	270	{
	271	struct mtd_info *mymtd;
	272	int err = 0;
	273	int pidx = 0;
	274	struct partitiontable_head *ptable_head = NULL;
	275	struct partitiontable_entry *ptable;
	276	int use_default_ptable = 1; /* Until proven otherwise. */
32872b20	277	const char pmsg[] = " /dev/flash%d at 0x%08x, size 0x%08x\n";
1da177e4 LT	278
	279	if (!(mymtd = flash_probe())) {
	280	/* There's no reason to use this module if no flash chip can
	281	* be identified. Make sure that's understood.
	282	*/
	283	printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
	284	} else {
	285	printk(KERN_INFO "%s: 0x%08x bytes of flash memory.\n",
	286	mymtd->name, mymtd->size);
	287	axisflash_mtd = mymtd;
	288	}
	289
	290	if (mymtd) {
	291	mymtd->owner = THIS_MODULE;
	292	ptable_head = (struct partitiontable_head *)(FLASH_CACHED_ADDR +
	293	CONFIG_ETRAX_PTABLE_SECTOR +
	294	PARTITION_TABLE_OFFSET);
	295	}
	296	pidx++; /* First partition is always set to the default. */
	297
	298	if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
	299	&& (ptable_head->size <
	300	(MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
	301	PARTITIONTABLE_END_MARKER_SIZE))
	302	&& ((unsigned long)((void)ptable_head + sizeof(ptable_head) +
	303	ptable_head->size -
	304	PARTITIONTABLE_END_MARKER_SIZE)
	305	== PARTITIONTABLE_END_MARKER)) {
	306	/* Looks like a start, sane length and end of a
	307	* partition table, lets check csum etc.
	308	*/
	309	int ptable_ok = 0;
	310	struct partitiontable_entry *max_addr =
	311	(struct partitiontable_entry *)
	312	((unsigned long)ptable_head + sizeof(*ptable_head) +
	313	ptable_head->size);
	314	unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
	315	unsigned char *p;
	316	unsigned long csum = 0;
32872b20	317
1da177e4 LT	318	ptable = (struct partitiontable_entry *)
	319	((unsigned long)ptable_head + sizeof(*ptable_head));
	320
	321	/* Lets be PARANOID, and check the checksum. */
	322	p = (unsigned char*) ptable;
	323
	324	while (p <= (unsigned char*)max_addr) {
	325	csum += *p++;
	326	csum += *p++;
	327	csum += *p++;
	328	csum += *p++;
	329	}
	330	ptable_ok = (csum == ptable_head->checksum);
	331
	332	/* Read the entries and use/show the info. */
	333	printk(KERN_INFO " Found a%s partition table at 0x%p-0x%p.\n",
	334	(ptable_ok ? " valid" : "n invalid"), ptable_head,
	335	max_addr);
	336
	337	/* We have found a working bootblock. Now read the
	338	* partition table. Scan the table. It ends when
	339	* there is 0xffffffff, that is, empty flash.
	340	*/
	341	while (ptable_ok
	342	&& ptable->offset != 0xffffffff
	343	&& ptable < max_addr
	344	&& pidx < MAX_PARTITIONS) {
	345
	346	axis_partitions[pidx].offset = offset + ptable->offset;
	347	axis_partitions[pidx].size = ptable->size;
	348
	349	printk(pmsg, pidx, axis_partitions[pidx].offset,
	350	axis_partitions[pidx].size);
	351	pidx++;
	352	ptable++;
	353	}
	354	use_default_ptable = !ptable_ok;
	355	}
	356
	357	if (romfs_in_flash) {
	358	/* Add an overlapping device for the root partition (romfs). */
	359
	360	axis_partitions[pidx].name = "romfs";
	361	axis_partitions[pidx].size = romfs_length;
	362	axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
	363	axis_partitions[pidx].mask_flags \|= MTD_WRITEABLE;
	364
	365	printk(KERN_INFO
	366	" Adding readonly flash partition for romfs image:\n");
	367	printk(pmsg, pidx, axis_partitions[pidx].offset,
	368	axis_partitions[pidx].size);
	369	pidx++;
	370	}
	371
32872b20 JN	372	#ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
	373	if (mymtd) {
	374	main_partition.size = mymtd->size;
36cda05b	375	err = mtd_device_register(mymtd, &main_partition, 1);
32872b20 JN	376	if (err)
	377	panic("axisflashmap: Could not initialize "
	378	"partition for whole main mtd device!\n");
	379	}
	380	#endif
	381
1da177e4 LT	382	if (mymtd) {
	383	if (use_default_ptable) {
	384	printk(KERN_INFO " Using default partition table.\n");
36cda05b JI	385	err = mtd_device_register(mymtd,
	386	axis_default_partitions,
	387	NUM_DEFAULT_PARTITIONS);
1da177e4	388	} else {
36cda05b JI	389	err = mtd_device_register(mymtd, axis_partitions,
36cda05b JI	390	pidx);
1da177e4 LT	391	}
1da177e4 LT	392
32872b20	393	if (err)
1da177e4	394	panic("axisflashmap could not add MTD partitions!\n");
1da177e4 LT	395	}
	396
	397	if (!romfs_in_flash) {
	398	/* Create an RAM device for the root partition (romfs). */
	399
ef158bdf	400	#if !defined(CONFIG_MTD_MTDRAM) \|\| (CONFIG_MTDRAM_TOTAL_SIZE != 0)
1da177e4 LT	401	/* No use trying to boot this kernel from RAM. Panic! */
	402	printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
	403	"device due to kernel (mis)configuration!\n");
	404	panic("This kernel cannot boot from RAM!\n");
	405	#else
	406	struct mtd_info *mtd_ram;
	407
32872b20 JN	408	mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
32872b20 JN	409	if (!mtd_ram)
1da177e4 LT	410	panic("axisflashmap couldn't allocate memory for "
1da177e4 LT	411	"mtd_info!\n");
1da177e4 LT	412
1da177e4 LT	413	printk(KERN_INFO " Adding RAM partition for romfs image:\n");
32872b20 JN	414	printk(pmsg, pidx, (unsigned)romfs_start,
	415	(unsigned)romfs_length);
	416
	417	err = mtdram_init_device(mtd_ram,
	418	(void *)romfs_start,
	419	romfs_length,
	420	"romfs");
	421	if (err)
1da177e4 LT	422	panic("axisflashmap could not initialize MTD RAM "
1da177e4 LT	423	"device!\n");
1da177e4 LT	424	#endif
1da177e4 LT	425	}
1da177e4 LT	426	return err;
	427	}
	428
	429	/* This adds the above to the kernels init-call chain. */
	430	module_init(init_axis_flash);
	431
	432	EXPORT_SYMBOL(axisflash_mtd);