[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / mtd / bcm47xxpart.c

/*
 * BCM47XX MTD partitioning
 *
 * Copyright © 2012 Rafał Miłecki <zajec5@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <bcm47xx_nvram.h>

/* 10 parts were found on sflash on Netgear WNDR4500 */
#define BCM47XXPART_MAX_PARTS		12

/* Magics */
#define BOARD_DATA_MAGIC		0x5246504D	/* MPFR */
#define POT_MAGIC1			0x54544f50	/* POTT */
#define POT_MAGIC2			0x504f		/* OP */
#define ML_MAGIC1			0x39685a42
#define ML_MAGIC2			0x26594131
#define TRX_MAGIC			0x30524448

struct trx_header {
	uint32_t magic;
	uint32_t length;
	uint32_t crc32;
	uint16_t flags;
	uint16_t version;
	uint32_t offset[3];
} __packed;

static void bcm47xxpart_add_part(struct mtd_partition *part, char *name,
				 u64 offset, uint32_t mask_flags)
{
	part->name = name;
	part->offset = offset;
	part->mask_flags = mask_flags;
}

static int bcm47xxpart_parse(struct mtd_info *master,
			     struct mtd_partition **pparts,
			     struct mtd_part_parser_data *data)
{
	struct mtd_partition *parts;
	uint8_t i, curr_part = 0;
	uint32_t *buf;
	size_t bytes_read;
	uint32_t offset;
	uint32_t blocksize = master->erasesize;
	struct trx_header *trx;
	int trx_part = -1;
	int last_trx_part = -1;
	int max_bytes_to_read = 0x8004;

	if (blocksize <= 0x10000)
		blocksize = 0x10000;
	if (blocksize == 0x20000)
		max_bytes_to_read = 0x18004;

	/* Alloc */
	parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
			GFP_KERNEL);
	buf = kzalloc(max_bytes_to_read, GFP_KERNEL);

	/* Parse block by block looking for magics */
	for (offset = 0; offset <= master->size - blocksize;
	     offset += blocksize) {
		/* Nothing more in higher memory */
		if (offset >= 0x2000000)
			break;

		if (curr_part > BCM47XXPART_MAX_PARTS) {
			pr_warn("Reached maximum number of partitions, scanning stopped!\n");
			break;
		}

		/* Read beginning of the block */
		if (mtd_read(master, offset, max_bytes_to_read,
			     &bytes_read, (uint8_t *)buf) < 0) {
			pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
			       offset);
			continue;
		}

		/* CFE has small NVRAM at 0x400 */
		if (buf[0x400 / 4] == NVRAM_HEADER) {
			bcm47xxpart_add_part(&parts[curr_part++], "boot",
					     offset, MTD_WRITEABLE);
			continue;
		}

		/* Standard NVRAM */
		if (buf[0x000 / 4] == NVRAM_HEADER ||
		    buf[0x1000 / 4] == NVRAM_HEADER ||
		    buf[0x8000 / 4] == NVRAM_HEADER ||
		    (blocksize == 0x20000 && (
		      buf[0x10000 / 4] == NVRAM_HEADER ||
		      buf[0x11000 / 4] == NVRAM_HEADER ||
		      buf[0x18000 / 4] == NVRAM_HEADER))) {
			bcm47xxpart_add_part(&parts[curr_part++], "nvram",
					     offset, 0);
			offset = rounddown(offset, blocksize);
			continue;
		}

		/*
		 * board_data starts with board_id which differs across boards,
		 * but we can use 'MPFR' (hopefully) magic at 0x100
		 */
		if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {
			bcm47xxpart_add_part(&parts[curr_part++], "board_data",
					     offset, MTD_WRITEABLE);
			continue;
		}

		/* POT(TOP) */
		if (buf[0x000 / 4] == POT_MAGIC1 &&
		    (buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {
			bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,
					     MTD_WRITEABLE);
			continue;
		}

		/* ML */
		if (buf[0x010 / 4] == ML_MAGIC1 &&
		    buf[0x014 / 4] == ML_MAGIC2) {
			bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,
					     MTD_WRITEABLE);
			continue;
		}

		/* TRX */
		if (buf[0x000 / 4] == TRX_MAGIC) {
			trx = (struct trx_header *)buf;

			trx_part = curr_part;
			bcm47xxpart_add_part(&parts[curr_part++], "firmware",
					     offset, 0);

			i = 0;
			/* We have LZMA loader if offset[2] points to sth */
			if (trx->offset[2]) {
				bcm47xxpart_add_part(&parts[curr_part++],
						     "loader",
						     offset + trx->offset[i],
						     0);
				i++;
			}

			bcm47xxpart_add_part(&parts[curr_part++], "linux",
					     offset + trx->offset[i], 0);
			i++;

			/*
			 * Pure rootfs size is known and can be calculated as:
			 * trx->length - trx->offset[i]. We don't fill it as
			 * we want to have jffs2 (overlay) in the same mtd.
			 */
			bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
					     offset + trx->offset[i], 0);
			i++;

			last_trx_part = curr_part - 1;

			/*
			 * We have whole TRX scanned, skip to the next part. Use
			 * roundown (not roundup), as the loop will increase
			 * offset in next step.
			 */
			offset = rounddown(offset + trx->length, blocksize);
			continue;
		}
	}
	kfree(buf);

	/*
	 * Assume that partitions end at the beginning of the one they are
	 * followed by.
	 */
	for (i = 0; i < curr_part; i++) {
		u64 next_part_offset = (i < curr_part - 1) ?
				       parts[i + 1].offset : master->size;

		parts[i].size = next_part_offset - parts[i].offset;
		if (i == last_trx_part && trx_part >= 0)
			parts[trx_part].size = next_part_offset -
					       parts[trx_part].offset;
	}

	*pparts = parts;
	return curr_part;
};

static struct mtd_part_parser bcm47xxpart_mtd_parser = {
	.owner = THIS_MODULE,
	.parse_fn = bcm47xxpart_parse,
	.name = "bcm47xxpart",
};

static int __init bcm47xxpart_init(void)
{
	return register_mtd_parser(&bcm47xxpart_mtd_parser);
}

static void __exit bcm47xxpart_exit(void)
{
	deregister_mtd_parser(&bcm47xxpart_mtd_parser);
}

module_init(bcm47xxpart_init);
module_exit(bcm47xxpart_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");
Commit	Line	Data
3cf7f131 RM	1	/*
	2	* BCM47XX MTD partitioning
	3	*
	4	* Copyright © 2012 Rafał Miłecki <zajec5@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/kernel.h>
	14	#include <linux/slab.h>
	15	#include <linux/mtd/mtd.h>
	16	#include <linux/mtd/partitions.h>
111bd981	17	#include <bcm47xx_nvram.h>
3cf7f131 RM	18
	19	/* 10 parts were found on sflash on Netgear WNDR4500 */
	20	#define BCM47XXPART_MAX_PARTS 12
	21
3cf7f131 RM	22	/* Magics */
	23	#define BOARD_DATA_MAGIC 0x5246504D /* MPFR */
	24	#define POT_MAGIC1 0x54544f50 /* POTT */
	25	#define POT_MAGIC2 0x504f /* OP */
	26	#define ML_MAGIC1 0x39685a42
	27	#define ML_MAGIC2 0x26594131
	28	#define TRX_MAGIC 0x30524448
	29
	30	struct trx_header {
	31	uint32_t magic;
	32	uint32_t length;
	33	uint32_t crc32;
	34	uint16_t flags;
	35	uint16_t version;
	36	uint32_t offset[3];
	37	} __packed;
	38
	39	static void bcm47xxpart_add_part(struct mtd_partition part, char name,
	40	u64 offset, uint32_t mask_flags)
	41	{
	42	part->name = name;
	43	part->offset = offset;
	44	part->mask_flags = mask_flags;
	45	}
	46
	47	static int bcm47xxpart_parse(struct mtd_info *master,
	48	struct mtd_partition **pparts,
	49	struct mtd_part_parser_data *data)
	50	{
	51	struct mtd_partition *parts;
	52	uint8_t i, curr_part = 0;
	53	uint32_t *buf;
	54	size_t bytes_read;
	55	uint32_t offset;
25bad1d3	56	uint32_t blocksize = master->erasesize;
3cf7f131	57	struct trx_header *trx;
396afe55 RM	58	int trx_part = -1;
396afe55 RM	59	int last_trx_part = -1;
be3781b7	60	int max_bytes_to_read = 0x8004;
3cf7f131	61
25bad1d3 HM	62	if (blocksize <= 0x10000)
25bad1d3 HM	63	blocksize = 0x10000;
be3781b7 HM	64	if (blocksize == 0x20000)
be3781b7 HM	65	max_bytes_to_read = 0x18004;
3cf7f131 RM	66
	67	/* Alloc */
	68	parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
	69	GFP_KERNEL);
be3781b7	70	buf = kzalloc(max_bytes_to_read, GFP_KERNEL);
3cf7f131 RM	71
	72	/* Parse block by block looking for magics */
	73	for (offset = 0; offset <= master->size - blocksize;
	74	offset += blocksize) {
	75	/* Nothing more in higher memory */
	76	if (offset >= 0x2000000)
	77	break;
	78
	79	if (curr_part > BCM47XXPART_MAX_PARTS) {
	80	pr_warn("Reached maximum number of partitions, scanning stopped!\n");
	81	break;
	82	}
	83
	84	/* Read beginning of the block */
be3781b7	85	if (mtd_read(master, offset, max_bytes_to_read,
3cf7f131 RM	86	&bytes_read, (uint8_t *)buf) < 0) {
	87	pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
	88	offset);
	89	continue;
	90	}
	91
	92	/* CFE has small NVRAM at 0x400 */
	93	if (buf[0x400 / 4] == NVRAM_HEADER) {
	94	bcm47xxpart_add_part(&parts[curr_part++], "boot",
	95	offset, MTD_WRITEABLE);
	96	continue;
	97	}
	98
	99	/* Standard NVRAM */
be3781b7 HM	100	if (buf[0x000 / 4] == NVRAM_HEADER \|\|
	101	buf[0x1000 / 4] == NVRAM_HEADER \|\|
	102	buf[0x8000 / 4] == NVRAM_HEADER \|\|
	103	(blocksize == 0x20000 && (
	104	buf[0x10000 / 4] == NVRAM_HEADER \|\|
	105	buf[0x11000 / 4] == NVRAM_HEADER \|\|
	106	buf[0x18000 / 4] == NVRAM_HEADER))) {
3cf7f131 RM	107	bcm47xxpart_add_part(&parts[curr_part++], "nvram",
3cf7f131 RM	108	offset, 0);
be3781b7	109	offset = rounddown(offset, blocksize);
3cf7f131 RM	110	continue;
	111	}
	112
	113	/*
	114	* board_data starts with board_id which differs across boards,
	115	* but we can use 'MPFR' (hopefully) magic at 0x100
	116	*/
	117	if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {
	118	bcm47xxpart_add_part(&parts[curr_part++], "board_data",
	119	offset, MTD_WRITEABLE);
	120	continue;
	121	}
	122
	123	/* POT(TOP) */
	124	if (buf[0x000 / 4] == POT_MAGIC1 &&
	125	(buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {
	126	bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,
	127	MTD_WRITEABLE);
	128	continue;
	129	}
	130
	131	/* ML */
	132	if (buf[0x010 / 4] == ML_MAGIC1 &&
	133	buf[0x014 / 4] == ML_MAGIC2) {
	134	bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,
	135	MTD_WRITEABLE);
	136	continue;
	137	}
	138
	139	/* TRX */
	140	if (buf[0x000 / 4] == TRX_MAGIC) {
	141	trx = (struct trx_header *)buf;
	142
396afe55 RM	143	trx_part = curr_part;
	144	bcm47xxpart_add_part(&parts[curr_part++], "firmware",
	145	offset, 0);
	146
3cf7f131 RM	147	i = 0;
	148	/* We have LZMA loader if offset[2] points to sth */
	149	if (trx->offset[2]) {
	150	bcm47xxpart_add_part(&parts[curr_part++],
	151	"loader",
	152	offset + trx->offset[i],
	153	0);
	154	i++;
	155	}
	156
	157	bcm47xxpart_add_part(&parts[curr_part++], "linux",
	158	offset + trx->offset[i], 0);
	159	i++;
	160
	161	/*
	162	* Pure rootfs size is known and can be calculated as:
	163	* trx->length - trx->offset[i]. We don't fill it as
	164	* we want to have jffs2 (overlay) in the same mtd.
	165	*/
	166	bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
	167	offset + trx->offset[i], 0);
	168	i++;
	169
396afe55 RM	170	last_trx_part = curr_part - 1;
396afe55 RM	171
3cf7f131 RM	172	/*
	173	* We have whole TRX scanned, skip to the next part. Use
	174	* roundown (not roundup), as the loop will increase
	175	* offset in next step.
	176	*/
	177	offset = rounddown(offset + trx->length, blocksize);
	178	continue;
	179	}
	180	}
	181	kfree(buf);
	182
	183	/*
	184	* Assume that partitions end at the beginning of the one they are
	185	* followed by.
	186	*/
648bdbee RM	187	for (i = 0; i < curr_part; i++) {
	188	u64 next_part_offset = (i < curr_part - 1) ?
	189	parts[i + 1].offset : master->size;
	190
	191	parts[i].size = next_part_offset - parts[i].offset;
396afe55 RM	192	if (i == last_trx_part && trx_part >= 0)
	193	parts[trx_part].size = next_part_offset -
	194	parts[trx_part].offset;
648bdbee	195	}
3cf7f131 RM	196
	197	*pparts = parts;
	198	return curr_part;
	199	};
	200
	201	static struct mtd_part_parser bcm47xxpart_mtd_parser = {
	202	.owner = THIS_MODULE,
	203	.parse_fn = bcm47xxpart_parse,
	204	.name = "bcm47xxpart",
	205	};
	206
	207	static int __init bcm47xxpart_init(void)
	208	{
	209	return register_mtd_parser(&bcm47xxpart_mtd_parser);
	210	}
	211
	212	static void __exit bcm47xxpart_exit(void)
	213	{
	214	deregister_mtd_parser(&bcm47xxpart_mtd_parser);
	215	}
	216
	217	module_init(bcm47xxpart_init);
	218	module_exit(bcm47xxpart_exit);
	219
	220	MODULE_LICENSE("GPL");
	221	MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");