[adm5120] experimental support for 2.6.27

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@12863 3c298f89-4303-0410-b956-a3cf2f4a3e73

3 files changed, 949 insertions, 0 deletions

diff --git a/target/linux/adm5120/files/drivers/mtd/maps/adm5120-flash.c b/target/linux/adm5120/files/drivers/mtd/maps/adm5120-flash.c
new file mode 100644
index 000000000..8bd7ae1c0
--- /dev/null
+++ b/target/linux/adm5120/files/drivers/mtd/maps/adm5120-flash.c
@@ -0,0 +1,568 @@
+/*
+ *  Platform driver for NOR flash devices on ADM5120 based boards
+ *
+ *  Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This file was derived from: drivers/mtd/map/physmap.c
+ *	Copyright (C) 2003 MontaVista Software Inc.
+ *	Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ *
+ *  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/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/mach-adm5120/adm5120_defs.h>
+#include <asm/mach-adm5120/adm5120_switch.h>
+#include <asm/mach-adm5120/adm5120_mpmc.h>
+#include <asm/mach-adm5120/adm5120_platform.h>
+
+#define DRV_NAME	"adm5120-flash"
+#define DRV_DESC	"ADM5120 flash MAP driver"
+#define MAX_PARSED_PARTS 8
+
+#ifdef ADM5120_FLASH_DEBUG
+#define MAP_DBG(m, f, a...)	printk(KERN_INFO "%s: " f, (m->name) , ## a)
+#else
+#define MAP_DBG(m, f, a...)	do {} while (0)
+#endif
+#define MAP_ERR(m, f, a...)	printk(KERN_ERR "%s: " f, (m->name) , ## a)
+#define MAP_INFO(m, f, a...)	printk(KERN_INFO "%s: " f, (m->name) , ## a)
+
+struct adm5120_map_info {
+	struct map_info	map;
+	void 		(*switch_bank)(unsigned);
+	unsigned long	window_size;
+};
+
+struct adm5120_flash_info {
+	struct mtd_info		*mtd;
+	struct resource		*res;
+	struct platform_device	*dev;
+	struct adm5120_map_info	amap;
+#ifdef CONFIG_MTD_PARTITIONS
+	int			nr_parts;
+	struct mtd_partition	*parts[MAX_PARSED_PARTS];
+#endif
+};
+
+struct flash_desc {
+	u32	phys;
+	u32	srs_shift;
+};
+
+/*
+ * Globals
+ */
+static DEFINE_SPINLOCK(adm5120_flash_spin);
+#define FLASH_LOCK()	spin_lock(&adm5120_flash_spin)
+#define FLASH_UNLOCK()	spin_unlock(&adm5120_flash_spin)
+
+static u32 flash_bankwidths[4] = { 1, 2, 4, 0 };
+
+static u32 flash_sizes[8] = {
+	0, 512*1024, 1024*1024, 2*1024*1024,
+	4*1024*1024, 0, 0, 0
+};
+
+static struct flash_desc flash_descs[2] = {
+	{
+		.phys		= ADM5120_SRAM0_BASE,
+		.srs_shift	= MEMCTRL_SRS0_SHIFT,
+	}, {
+		.phys		= ADM5120_SRAM1_BASE,
+		.srs_shift	= MEMCTRL_SRS1_SHIFT,
+	}
+};
+
+static const char *probe_types[] = {
+	"cfi_probe",
+	"jedec_probe",
+	"map_rom",
+	NULL
+};
+
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *parse_types[] = {
+	"cmdlinepart",
+#ifdef CONFIG_MTD_REDBOOT_PARTS
+	"RedBoot",
+#endif
+#ifdef CONFIG_MTD_MYLOADER_PARTS
+	"MyLoader",
+#endif
+};
+#endif
+
+#define BANK_SIZE	(2<<20)
+#define BANK_SIZE_MAX	(4<<20)
+#define BANK_OFFS_MASK	(BANK_SIZE-1)
+#define BANK_START_MASK	(~BANK_OFFS_MASK)
+
+static inline struct adm5120_map_info *map_to_amap(struct map_info *map)
+{
+	return (struct adm5120_map_info *)map;
+}
+
+static void adm5120_flash_switchbank(struct map_info *map,
+		unsigned long ofs)
+{
+	struct adm5120_map_info *amap = map_to_amap(map);
+	unsigned bank;
+
+	if (amap->switch_bank == NULL)
+		return;
+
+	bank = (ofs & BANK_START_MASK) >> 21;
+	if (bank > 1)
+		BUG();
+
+	MAP_DBG(map, "switching to bank %u, ofs=%lX\n", bank, ofs);
+	amap->switch_bank(bank);
+}
+
+static map_word adm5120_flash_read(struct map_info *map, unsigned long ofs)
+{
+	struct adm5120_map_info *amap = map_to_amap(map);
+	map_word ret;
+
+	MAP_DBG(map, "reading from ofs %lX\n", ofs);
+
+	if (ofs >= amap->window_size)
+		return map_word_ff(map);
+
+	FLASH_LOCK();
+	adm5120_flash_switchbank(map, ofs);
+	ret = inline_map_read(map, (ofs & (amap->window_size-1)));
+	FLASH_UNLOCK();
+
+	return ret;
+}
+
+static void adm5120_flash_write(struct map_info *map, const map_word datum,
+		unsigned long ofs)
+{
+	struct adm5120_map_info *amap = map_to_amap(map);
+
+	MAP_DBG(map, "writing to ofs %lX\n", ofs);
+
+	if (ofs > amap->window_size)
+		return;
+
+	FLASH_LOCK();
+	adm5120_flash_switchbank(map, ofs);
+	inline_map_write(map, datum, (ofs & (amap->window_size-1)));
+	FLASH_UNLOCK();
+}
+
+static void adm5120_flash_copy_from(struct map_info *map, void *to,
+		unsigned long from, ssize_t len)
+{
+	struct adm5120_map_info *amap = map_to_amap(map);
+	char *p;
+	ssize_t t;
+
+	MAP_DBG(map, "copy_from, to=%lX, from=%lX, len=%lX\n",
+		(unsigned long)to, from, (unsigned long)len);
+
+	if (from > amap->window_size)
+		return;
+
+	p = (char *)to;
+	while (len > 0) {
+		t = len;
+		if ((from < BANK_SIZE) && ((from+len) > BANK_SIZE))
+			t = BANK_SIZE-from;
+
+		FLASH_LOCK();
+		MAP_DBG(map, "copying %lu byte(s) from %lX to %lX\n",
+			(unsigned long)t, (from & (amap->window_size-1)),
+			(unsigned long)p);
+		adm5120_flash_switchbank(map, from);
+		inline_map_copy_from(map, p, (from & (amap->window_size-1)), t);
+		FLASH_UNLOCK();
+		p += t;
+		from += t;
+		len -= t;
+	}
+}
+
+static int adm5120_flash_initres(struct adm5120_flash_info *info)
+{
+	struct map_info *map = &info->amap.map;
+	int err = 0;
+
+	info->res = request_mem_region(map->phys, info->amap.window_size,
+			map->name);
+	if (info->res == NULL) {
+		MAP_ERR(map, "could not reserve memory region\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	map->virt = ioremap_nocache(map->phys, info->amap.window_size);
+	if (map->virt == NULL) {
+		MAP_ERR(map, "failed to ioremap flash region\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+out:
+	return err;
+}
+
+static int adm5120_flash_initinfo(struct adm5120_flash_info *info,
+		struct platform_device *dev)
+{
+	struct map_info *map = &info->amap.map;
+	struct adm5120_flash_platform_data *pdata = dev->dev.platform_data;
+	struct flash_desc *fdesc;
+	u32 t = 0;
+
+	map->name = dev->dev.bus_id;
+
+	if (dev->id > 1) {
+		MAP_ERR(map, "invalid flash id\n");
+		goto err_out;
+	}
+
+	fdesc = &flash_descs[dev->id];
+
+	if (pdata)
+		info->amap.window_size = pdata->window_size;
+
+	if (info->amap.window_size == 0) {
+		/* get memory window size */
+		t = SW_READ_REG(SWITCH_REG_MEMCTRL) >> fdesc->srs_shift;
+		t &= MEMCTRL_SRS_MASK;
+		info->amap.window_size = flash_sizes[t];
+	}
+
+	if (info->amap.window_size == 0) {
+		MAP_ERR(map, "unable to determine window size\n");
+		goto err_out;
+	}
+
+	/* get flash bus width */
+	switch (dev->id) {
+	case 0:
+		t = MPMC_READ_REG(SC1) & SC_MW_MASK;
+		break;
+	case 1:
+		t = MPMC_READ_REG(SC0) & SC_MW_MASK;
+		break;
+	}
+	map->bankwidth = flash_bankwidths[t];
+	if (map->bankwidth == 0) {
+		MAP_ERR(map, "invalid bus width detected\n");
+		goto err_out;
+	}
+
+	map->phys = fdesc->phys;
+	map->size = BANK_SIZE_MAX;
+
+	simple_map_init(map);
+	map->read = adm5120_flash_read;
+	map->write = adm5120_flash_write;
+	map->copy_from = adm5120_flash_copy_from;
+
+	if (pdata) {
+		map->set_vpp = pdata->set_vpp;
+		info->amap.switch_bank = pdata->switch_bank;
+	}
+
+	info->dev = dev;
+
+	MAP_INFO(map, "probing at 0x%lX, size:%ldKiB, width:%d bits\n",
+		(unsigned long)map->phys,
+		(unsigned long)info->amap.window_size >> 10,
+		map->bankwidth*8);
+
+	return 0;
+
+err_out:
+	return -ENODEV;
+}
+
+static void adm5120_flash_initbanks(struct adm5120_flash_info *info)
+{
+	struct map_info *map = &info->amap.map;
+
+	if (info->mtd->size <= BANK_SIZE)
+		/* no bank switching needed */
+		return;
+
+	if (info->amap.switch_bank) {
+		info->amap.window_size = info->mtd->size;
+		return;
+	}
+
+	MAP_ERR(map, "reduce visibility from %ldKiB to %ldKiB\n",
+		(unsigned long)map->size >> 10,
+		(unsigned long)info->mtd->size >> 10);
+
+	info->mtd->size = info->amap.window_size;
+}
+
+#ifdef CONFIG_MTD_PARTITIONS
+static int adm5120_flash_initparts(struct adm5120_flash_info *info)
+{
+	struct adm5120_flash_platform_data *pdata;
+	struct map_info *map = &info->amap.map;
+	int num_parsers;
+	const char *parser[2];
+	int err = 0;
+	int nr_parts;
+	int i;
+
+	info->nr_parts = 0;
+
+	pdata = info->dev->dev.platform_data;
+	if (pdata == NULL)
+		goto out;
+
+	if (pdata->nr_parts) {
+		MAP_INFO(map, "adding static partitions\n");
+		err = add_mtd_partitions(info->mtd, pdata->parts,
+			pdata->nr_parts);
+		if (err == 0) {
+			info->nr_parts += pdata->nr_parts;
+			goto out;
+		}
+	}
+
+	num_parsers = ARRAY_SIZE(parse_types);
+	if (num_parsers > MAX_PARSED_PARTS)
+		num_parsers = MAX_PARSED_PARTS;
+
+	parser[1] = NULL;
+	for (i = 0; i < num_parsers; i++) {
+		parser[0] = parse_types[i];
+
+		MAP_INFO(map, "parsing \"%s\" partitions\n",
+			parser[0]);
+		nr_parts = parse_mtd_partitions(info->mtd, parser,
+			&info->parts[i], 0);
+
+		if (nr_parts <= 0)
+			continue;
+
+		MAP_INFO(map, "adding \"%s\" partitions\n",
+			parser[0]);
+
+		err = add_mtd_partitions(info->mtd, info->parts[i], nr_parts);
+		if (err)
+			break;
+
+		info->nr_parts += nr_parts;
+	}
+out:
+	return err;
+}
+#else
+static int adm5120_flash_initparts(struct adm5120_flash_info *info)
+{
+	return 0;
+}
+#endif /* CONFIG_MTD_PARTITIONS */
+
+#ifdef CONFIG_MTD_PARTITIONS
+static void adm5120_flash_remove_mtd(struct adm5120_flash_info *info)
+{
+	int i;
+
+	if (info->nr_parts) {
+		del_mtd_partitions(info->mtd);
+		for (i = 0; i < MAX_PARSED_PARTS; i++)
+			if (info->parts[i] != NULL)
+				kfree(info->parts[i]);
+	} else {
+		del_mtd_device(info->mtd);
+	}
+}
+#else
+static void adm5120_flash_remove_mtd(struct adm5120_flash_info *info)
+{
+	del_mtd_device(info->mtd);
+}
+#endif
+
+static int adm5120_flash_remove(struct platform_device *dev)
+{
+	struct adm5120_flash_info *info;
+
+	info = platform_get_drvdata(dev);
+	if (info == NULL)
+		return 0;
+
+	platform_set_drvdata(dev, NULL);
+
+	if (info->mtd != NULL) {
+		adm5120_flash_remove_mtd(info);
+		map_destroy(info->mtd);
+	}
+
+	if (info->amap.map.virt != NULL)
+		iounmap(info->amap.map.virt);
+
+	if (info->res != NULL) {
+		release_resource(info->res);
+		kfree(info->res);
+	}
+
+	return 0;
+}
+
+static int adm5120_flash_probe(struct platform_device *dev)
+{
+	struct adm5120_flash_info *info;
+	struct map_info *map;
+	const char **probe_type;
+	int err;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (info == NULL) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	platform_set_drvdata(dev, info);
+
+	err = adm5120_flash_initinfo(info, dev);
+	if (err)
+		goto err_out;
+
+	err = adm5120_flash_initres(info);
+	if (err)
+		goto err_out;
+
+	map = &info->amap.map;
+	for (probe_type = probe_types; info->mtd == NULL && *probe_type != NULL;
+		probe_type++)
+		info->mtd = do_map_probe(*probe_type, map);
+
+	if (info->mtd == NULL) {
+		MAP_ERR(map, "map_probe failed\n");
+		err = -ENXIO;
+		goto err_out;
+	}
+
+	adm5120_flash_initbanks(info);
+
+	if (info->mtd->size < info->amap.window_size) {
+		/* readjust resources */
+		iounmap(map->virt);
+		release_resource(info->res);
+		kfree(info->res);
+
+		info->amap.window_size = info->mtd->size;
+		map->size = info->mtd->size;
+		MAP_INFO(map, "reducing map size to %ldKiB\n",
+			(unsigned long)map->size >> 10);
+		err = adm5120_flash_initres(info);
+		if (err)
+			goto err_out;
+	}
+
+	MAP_INFO(map, "found at 0x%lX, size:%ldKiB, width:%d bits\n",
+		(unsigned long)map->phys, (unsigned long)info->mtd->size >> 10,
+		map->bankwidth*8);
+
+	info->mtd->owner = THIS_MODULE;
+
+	err = adm5120_flash_initparts(info);
+	if (err)
+		goto err_out;
+
+	if (info->nr_parts == 0) {
+		MAP_INFO(map, "no partitions available, registering "
+			"whole flash\n");
+		add_mtd_device(info->mtd);
+	}
+
+	return 0;
+
+err_out:
+	adm5120_flash_remove(dev);
+	return err;
+}
+
+#ifdef CONFIG_PM
+static int adm5120_flash_suspend(struct platform_device *dev,
+		pm_message_t state)
+{
+	struct adm5120_flash_info *info = platform_get_drvdata(dev);
+	int ret = 0;
+
+	if (info)
+		ret = info->mtd->suspend(info->mtd);
+
+	return ret;
+}
+
+static int adm5120_flash_resume(struct platform_device *dev)
+{
+	struct adm5120_flash_info *info = platform_get_drvdata(dev);
+
+	if (info)
+		info->mtd->resume(info->mtd);
+
+	return 0;
+}
+
+static void adm5120_flash_shutdown(struct platform_device *dev)
+{
+	struct adm5120_flash_info *info = platform_get_drvdata(dev);
+
+	if (info && info->mtd->suspend(info->mtd) == 0)
+		info->mtd->resume(info->mtd);
+}
+#endif
+
+static struct platform_driver adm5120_flash_driver = {
+	.probe		= adm5120_flash_probe,
+	.remove		= adm5120_flash_remove,
+#ifdef CONFIG_PM
+	.suspend	= adm5120_flash_suspend,
+	.resume		= adm5120_flash_resume,
+	.shutdown	= adm5120_flash_shutdown,
+#endif
+	.driver		= {
+		.name	= DRV_NAME,
+	},
+};
+
+static int __init adm5120_flash_init(void)
+{
+	int err;
+
+	err = platform_driver_register(&adm5120_flash_driver);
+
+	return err;
+}
+
+static void __exit adm5120_flash_exit(void)
+{
+	platform_driver_unregister(&adm5120_flash_driver);
+}
+
+module_init(adm5120_flash_init);
+module_exit(adm5120_flash_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_DESCRIPTION(DRV_DESC);
diff --git a/target/linux/adm5120/files/drivers/mtd/myloader.c b/target/linux/adm5120/files/drivers/mtd/myloader.c
new file mode 100644
index 000000000..22d076b72
--- /dev/null
+++ b/target/linux/adm5120/files/drivers/mtd/myloader.c
@@ -0,0 +1,164 @@
+/*
+ *  Parse MyLoader-style flash partition tables and produce a Linux partition
+ *  array to match.
+ *
+ *  Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This file was based on drivers/mtd/redboot.c
+ *  Author: Red Hat, Inc. - David Woodhouse <dwmw2@cambridge.redhat.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/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/vmalloc.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/byteorder/generic.h>
+
+#include <prom/myloader.h>
+
+#define NAME_LEN_MAX		20
+#define NAME_MYLOADER		"MyLoader"
+#define NAME_PARTITION_TABLE	"Partition Table"
+#define BLOCK_LEN_MIN		0x10000
+
+int parse_myloader_partitions(struct mtd_info *master,
+			struct mtd_partition **pparts,
+			unsigned long origin)
+{
+	struct mylo_partition_table *tab;
+	struct mylo_partition *part;
+	struct mtd_partition *mtd_parts;
+	struct mtd_partition *mtd_part;
+	int num_parts;
+	int ret, i;
+	size_t retlen;
+	char *names;
+	unsigned long offset;
+	unsigned long blocklen;
+
+	tab = vmalloc(sizeof(*tab));
+	if (!tab) {
+		return -ENOMEM;
+		goto out;
+	}
+
+	blocklen = master->erasesize;
+	if (blocklen < BLOCK_LEN_MIN)
+		blocklen = BLOCK_LEN_MIN;
+
+	/* Partition Table is always located on the second erase block */
+	offset = blocklen;
+	printk(KERN_NOTICE "%s: searching for MyLoader partition table at "
+			"offset 0x%lx\n", master->name, offset);
+
+	ret = master->read(master, offset, sizeof(*tab), &retlen, (void *)tab);
+	if (ret)
+		goto out;
+
+	if (retlen != sizeof(*tab)) {
+		ret = -EIO;
+		goto out_free_buf;
+	}
+
+	/* Check for Partition Table magic number */
+	if (tab->magic != le32_to_cpu(MYLO_MAGIC_PARTITIONS)) {
+		printk(KERN_NOTICE "%s: no MyLoader partition table found\n",
+			master->name);
+		ret = 0;
+		goto out_free_buf;
+	}
+
+	/* The MyLoader and the Partition Table is always present */
+	num_parts = 2;
+
+	/* Detect number of used partitions */
+	for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
+		part = &tab->partitions[i];
+
+		if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
+			continue;
+
+		num_parts++;
+	}
+
+	mtd_parts = kzalloc((num_parts * sizeof(*mtd_part) +
+				num_parts * NAME_LEN_MAX), GFP_KERNEL);
+
+	if (!mtd_parts) {
+		ret = -ENOMEM;
+		goto out_free_buf;
+	}
+
+	mtd_part = mtd_parts;
+	names = (char *)&mtd_parts[num_parts];
+
+	strncpy(names, NAME_MYLOADER, NAME_LEN_MAX-1);
+	mtd_part->name = names;
+	mtd_part->offset = 0;
+	mtd_part->size = blocklen;
+	mtd_part->mask_flags = MTD_WRITEABLE;
+	mtd_part++;
+	names += NAME_LEN_MAX;
+
+	strncpy(names, NAME_PARTITION_TABLE, NAME_LEN_MAX-1);
+	mtd_part->name = names;
+	mtd_part->offset = blocklen;
+	mtd_part->size = blocklen;
+	mtd_part->mask_flags = MTD_WRITEABLE;
+	mtd_part++;
+	names += NAME_LEN_MAX;
+
+	for (i = 0; i < MYLO_MAX_PARTITIONS; i++) {
+		part = &tab->partitions[i];
+
+		if (le16_to_cpu(part->type) == PARTITION_TYPE_FREE)
+			continue;
+
+		sprintf(names, "partition%d", i);
+		mtd_part->offset = le32_to_cpu(part->addr);
+		mtd_part->size = le32_to_cpu(part->size);
+		mtd_part->name = names;
+		mtd_part++;
+		names += NAME_LEN_MAX;
+	}
+
+	*pparts = mtd_parts;
+	ret = num_parts;
+
+out_free_buf:
+	vfree(tab);
+out:
+	return ret;
+}
+
+static struct mtd_part_parser mylo_mtd_parser = {
+	.owner = THIS_MODULE,
+	.parse_fn = parse_myloader_partitions,
+	.name = NAME_MYLOADER,
+};
+
+static int __init mylo_mtd_parser_init(void)
+{
+	return register_mtd_parser(&mylo_mtd_parser);
+}
+
+static void __exit mylo_mtd_parser_exit(void)
+{
+	deregister_mtd_parser(&mylo_mtd_parser);
+}
+
+module_init(mylo_mtd_parser_init);
+module_exit(mylo_mtd_parser_exit);
+
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_DESCRIPTION("Parsing code for MyLoader partition tables");
+MODULE_LICENSE("GPL v2");
diff --git a/target/linux/adm5120/files/drivers/mtd/trxsplit.c b/target/linux/adm5120/files/drivers/mtd/trxsplit.c
new file mode 100644
index 000000000..7e4a63b74
--- /dev/null
+++ b/target/linux/adm5120/files/drivers/mtd/trxsplit.c
@@ -0,0 +1,217 @@
+/*
+ *  Copyright (C) Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  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/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/kmod.h>
+#include <linux/root_dev.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/byteorder/generic.h>
+
+#define PFX	"trxsplit: "
+
+#define TRX_MAGIC	0x30524448	/* "HDR0" */
+#define TRX_VERSION	1
+#define TRX_MAX_LEN	0x3A0000
+#define TRX_NO_HEADER	0x1	/* do not write TRX header */
+#define TRX_GZ_FILES	0x2     /* contains individual gzip files */
+#define TRX_MAX_OFFSET	3
+#define TRX_MIN_KERNEL_SIZE	256*1024
+
+struct trx_header {
+	u32 magic;	/* "HDR0" */
+	u32 len;	/* Length of file including header */
+	u32 crc32;	/* 32-bit CRC from flag_version to end of file */
+	u32 flag_version; /* 0:15 flags, 16:31 version */
+	u32 offsets[TRX_MAX_OFFSET]; /* Offsets of partitions */
+};
+
+#define TRX_ALIGN	0x1000
+
+static int trx_nr_parts;
+static unsigned long trx_offset;
+static struct mtd_info *trx_mtd;
+static struct mtd_partition trx_parts[TRX_MAX_OFFSET];
+static struct trx_header trx_hdr;
+
+static int trxsplit_refresh_partitions(struct mtd_info *mtd);
+
+static int trxsplit_checktrx(struct mtd_info *mtd, unsigned long offset)
+{
+	size_t retlen;
+	int err;
+
+	err = mtd->read(mtd, offset, sizeof(trx_hdr), &retlen,
+			(void *)&trx_hdr);
+	if (err) {
+		printk(KERN_ALERT PFX "unable to read from '%s'\n", mtd->name);
+		goto err_out;
+	}
+
+	if (retlen != sizeof(trx_hdr)) {
+		printk(KERN_ALERT PFX "reading failed on '%s'\n", mtd->name);
+		goto err_out;
+	}
+
+	trx_hdr.magic = le32_to_cpu(trx_hdr.magic);
+	trx_hdr.len = le32_to_cpu(trx_hdr.len);
+	trx_hdr.crc32 = le32_to_cpu(trx_hdr.crc32);
+	trx_hdr.flag_version = le32_to_cpu(trx_hdr.flag_version);
+	trx_hdr.offsets[0] = le32_to_cpu(trx_hdr.offsets[0]);
+	trx_hdr.offsets[1] = le32_to_cpu(trx_hdr.offsets[1]);
+	trx_hdr.offsets[2] = le32_to_cpu(trx_hdr.offsets[2]);
+
+	/* sanity checks */
+	if (trx_hdr.magic != TRX_MAGIC)
+		goto err_out;
+
+	if (trx_hdr.len > mtd->size - offset)
+		goto err_out;
+
+	/* TODO: add crc32 checking too? */
+
+	return 0;
+
+err_out:
+	return -1;
+}
+
+static void trxsplit_findtrx(struct mtd_info *mtd)
+{
+	unsigned long offset;
+	int err;
+
+	printk(KERN_INFO PFX "searching TRX header in '%s'\n", mtd->name);
+
+	err = 0;
+	for (offset = 0; offset < mtd->size; offset += TRX_ALIGN) {
+		err = trxsplit_checktrx(mtd, offset);
+		if (err == 0)
+			break;
+	}
+
+	if (err)
+		return;
+
+	printk(KERN_INFO PFX "TRX header found at 0x%lX\n", offset);
+
+	trx_mtd = mtd;
+	trx_offset = offset;
+}
+
+static void trxsplit_create_partitions(struct mtd_info *mtd)
+{
+	struct mtd_partition *part = trx_parts;
+	int err;
+	int i;
+
+	for (i = 0; i < TRX_MAX_OFFSET; i++) {
+		part = &trx_parts[i];
+		if (trx_hdr.offsets[i] == 0)
+			continue;
+		part->offset = trx_offset + trx_hdr.offsets[i];
+		trx_nr_parts++;
+	}
+
+	for (i = 0; i < trx_nr_parts-1; i++)
+		trx_parts[i].size = trx_parts[i+1].offset - trx_parts[i].offset;
+
+	trx_parts[i].size = mtd->size - trx_parts[i].offset;
+
+	i = 0;
+	part = &trx_parts[i];
+	if (part->size < TRX_MIN_KERNEL_SIZE) {
+		part->name = "loader";
+		i++;
+	}
+
+	part = &trx_parts[i];
+	part->name = "kernel";
+	i++;
+
+	part = &trx_parts[i];
+	part->name = "rootfs";
+
+	err = add_mtd_partitions(mtd, trx_parts, trx_nr_parts);
+	if (err) {
+		printk(KERN_ALERT PFX "adding TRX partitions failed\n");
+		return;
+	}
+
+	mtd->refresh_device = trxsplit_refresh_partitions;
+}
+
+static int trxsplit_refresh_partitions(struct mtd_info *mtd)
+{
+	printk(KERN_INFO PFX "refreshing TRX partitions in '%s' (%d,%d)\n",
+		mtd->name, MTD_BLOCK_MAJOR, mtd->index);
+
+	/* remove old partitions */
+	del_mtd_partitions(mtd);
+
+	trxsplit_findtrx(mtd);
+	if (!trx_mtd)
+		goto err;
+
+	trxsplit_create_partitions(trx_mtd);
+	return 1;
+
+err:
+	return 0;
+}
+
+static void __init trxsplit_add_mtd(struct mtd_info *mtd)
+{
+	if (mtd->type != MTD_NORFLASH) {
+		printk(KERN_INFO PFX "'%s' is not a NOR flash, skipped\n",
+				mtd->name);
+		return;
+	}
+
+	if (!trx_mtd)
+		trxsplit_findtrx(mtd);
+}
+
+static void __init trxsplit_remove_mtd(struct mtd_info *mtd)
+{
+	/* nothing to do */
+}
+
+static struct mtd_notifier trxsplit_notifier __initdata = {
+	.add	= trxsplit_add_mtd,
+	.remove	= trxsplit_remove_mtd,
+};
+
+static void __init trxsplit_scan(void)
+{
+	register_mtd_user(&trxsplit_notifier);
+	unregister_mtd_user(&trxsplit_notifier);
+}
+
+static int __init trxsplit_init(void)
+{
+	trxsplit_scan();
+
+	if (trx_mtd) {
+		printk(KERN_INFO PFX "creating TRX partitions in '%s' "
+			"(%d,%d)\n", trx_mtd->name, MTD_BLOCK_MAJOR,
+			trx_mtd->index);
+		trxsplit_create_partitions(trx_mtd);
+	}
+
+	return 0;
+}
+
+late_initcall(trxsplit_init);