drivers/mtd/maps/physmap_of.c - arm/linux - Git at Google

 /*
  * Flash mappings described by the OF (or flattened) device tree
  *
  * Copyright (C) 2006 MontaVista Software Inc.
  * Author: Vitaly Wool <vwool@ru.mvista.com>
  *
  * Revised to handle newer style flash binding by:
  *   Copyright (C) 2007 David Gibson, IBM Corporation.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
  * Free Software Foundation;  either version 2 of the  License, or (at your
  * option) any later version.
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/partitions.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>

 struct of_flash {
 	struct mtd_info		*mtd;
 	struct map_info		map;
 	struct resource		*res;
 #ifdef CONFIG_MTD_PARTITIONS
 	struct mtd_partition	*parts;
 #endif
 };

 #ifdef CONFIG_MTD_PARTITIONS
 #define OF_FLASH_PARTS(info)	((info)->parts)

 static int parse_obsolete_partitions(struct of_device *dev,
 				     struct of_flash *info,
 				     struct device_node *dp)
 {
 	int i, plen, nr_parts;
 	const struct {
 		u32 offset, len;
 	} *part;
 	const char *names;

 	part = of_get_property(dp, "partitions", &plen);
 	if (!part)
 		return 0; /* No partitions found */

 	dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");

 	nr_parts = plen / sizeof(part[0]);

 	info->parts = kzalloc(nr_parts * sizeof(*info->parts), GFP_KERNEL);
 	if (!info->parts)
 		return -ENOMEM;

 	names = of_get_property(dp, "partition-names", &plen);

 	for (i = 0; i < nr_parts; i++) {
 		info->parts[i].offset = part->offset;
 		info->parts[i].size   = part->len & ~1;
 		if (part->len & 1) /* bit 0 set signifies read only partition */
 			info->parts[i].mask_flags = MTD_WRITEABLE;

 		if (names && (plen > 0)) {
 			int len = strlen(names) + 1;

 			info->parts[i].name = (char *)names;
 			plen -= len;
 			names += len;
 		} else {
 			info->parts[i].name = "unnamed";
 		}

 		part++;
 	}

 	return nr_parts;
 }
 #else /* MTD_PARTITIONS */
 #define	OF_FLASH_PARTS(info)		(0)
 #define parse_partitions(info, dev)	(0)
 #endif /* MTD_PARTITIONS */

 static int of_flash_remove(struct of_device *dev)
 {
 	struct of_flash *info;

 	info = dev_get_drvdata(&dev->dev);
 	if (!info)
 		return 0;
 	dev_set_drvdata(&dev->dev, NULL);

 	if (info->mtd) {
 		if (OF_FLASH_PARTS(info)) {
 			del_mtd_partitions(info->mtd);
 			kfree(OF_FLASH_PARTS(info));
 		} else {
 			del_mtd_device(info->mtd);
 		}
 		map_destroy(info->mtd);
 	}

 	if (info->map.virt)
 		iounmap(info->map.virt);

 	if (info->res) {
 		release_resource(info->res);
 		kfree(info->res);
 	}

 	return 0;
 }

 /* Helper function to handle probing of the obsolete "direct-mapped"
  * compatible binding, which has an extra "probe-type" property
  * describing the type of flash probe necessary. */
 static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
 						  struct map_info *map)
 {
 	struct device_node *dp = dev->node;
 	const char *of_probe;
 	struct mtd_info *mtd;
 	static const char *rom_probe_types[]
 		= { "cfi_probe", "jedec_probe", "map_rom"};
 	int i;

 	dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
 		 "flash binding\n");

 	of_probe = of_get_property(dp, "probe-type", NULL);
 	if (!of_probe) {
 		for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
 			mtd = do_map_probe(rom_probe_types[i], map);
 			if (mtd)
 				return mtd;
 		}
 		return NULL;
 	} else if (strcmp(of_probe, "CFI") == 0) {
 		return do_map_probe("cfi_probe", map);
 	} else if (strcmp(of_probe, "JEDEC") == 0) {
 		return do_map_probe("jedec_probe", map);
 	} else {
 		if (strcmp(of_probe, "ROM") != 0)
 			dev_warn(&dev->dev, "obsolete_probe: don't know probe "
 				 "type '%s', mapping as rom\n", of_probe);
 		return do_map_probe("mtd_rom", map);
 	}
 }

 static int __devinit of_flash_probe(struct of_device *dev,
 				    const struct of_device_id *match)
 {
 #ifdef CONFIG_MTD_PARTITIONS
 	static const char *part_probe_types[]
 		= { "cmdlinepart", "RedBoot", NULL };
 #endif
 	struct device_node *dp = dev->node;
 	struct resource res;
 	struct of_flash *info;
 	const char *probe_type = match->data;
 	const u32 *width;
 	int err;

 	err = -ENXIO;
 	if (of_address_to_resource(dp, 0, &res)) {
 		dev_err(&dev->dev, "Can't get IO address from device tree\n");
 		goto err_out;
 	}

        	dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
 		(unsigned long long)res.start, (unsigned long long)res.end);

 	err = -ENOMEM;
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info)
 		goto err_out;

 	dev_set_drvdata(&dev->dev, info);

 	err = -EBUSY;
 	info->res = request_mem_region(res.start, res.end - res.start + 1,
 				       dev_name(&dev->dev));
 	if (!info->res)
 		goto err_out;

 	err = -ENXIO;
 	width = of_get_property(dp, "bank-width", NULL);
 	if (!width) {
 		dev_err(&dev->dev, "Can't get bank width from device tree\n");
 		goto err_out;
 	}

 	info->map.name = dev_name(&dev->dev);
 	info->map.phys = res.start;
 	info->map.size = res.end - res.start + 1;
 	info->map.bankwidth = *width;

 	err = -ENOMEM;
 	info->map.virt = ioremap(info->map.phys, info->map.size);
 	if (!info->map.virt) {
 		dev_err(&dev->dev, "Failed to ioremap() flash region\n");
 		goto err_out;
 	}

 	simple_map_init(&info->map);

 	if (probe_type)
 		info->mtd = do_map_probe(probe_type, &info->map);
 	else
 		info->mtd = obsolete_probe(dev, &info->map);

 	err = -ENXIO;
 	if (!info->mtd) {
 		dev_err(&dev->dev, "do_map_probe() failed\n");
 		goto err_out;
 	}
 	info->mtd->owner = THIS_MODULE;
 	info->mtd->dev.parent = &dev->dev;

 #ifdef CONFIG_MTD_PARTITIONS
 	/* First look for RedBoot table or partitions on the command
 	 * line, these take precedence over device tree information */
 	err = parse_mtd_partitions(info->mtd, part_probe_types,
 	                           &info->parts, 0);
 	if (err < 0)
 		return err;

 #ifdef CONFIG_MTD_OF_PARTS
 	if (err == 0) {
 		err = of_mtd_parse_partitions(&dev->dev, dp, &info->parts);
 		if (err < 0)
 			return err;
 	}
 #endif

 	if (err == 0) {
 		err = parse_obsolete_partitions(dev, info, dp);
 		if (err < 0)
 			return err;
 	}

 	if (err > 0)
 		add_mtd_partitions(info->mtd, info->parts, err);
 	else
 #endif
 		add_mtd_device(info->mtd);

 	return 0;

 err_out:
 	of_flash_remove(dev);
 	return err;
 }

 static struct of_device_id of_flash_match[] = {
 	{
 		.compatible	= "cfi-flash",
 		.data		= (void *)"cfi_probe",
 	},
 	{
 		/* FIXME: JEDEC chips can't be safely and reliably
 		 * probed, although the mtd code gets it right in
 		 * practice most of the time.  We should use the
 		 * vendor and device ids specified by the binding to
 		 * bypass the heuristic probe code, but the mtd layer
 		 * provides, at present, no interface for doing so
 		 * :(. */
 		.compatible	= "jedec-flash",
 		.data		= (void *)"jedec_probe",
 	},
 	{
 		.type		= "rom",
 		.compatible	= "direct-mapped"
 	},
 	{ },
 };
 MODULE_DEVICE_TABLE(of, of_flash_match);

 static struct of_platform_driver of_flash_driver = {
 	.name		= "of-flash",
 	.match_table	= of_flash_match,
 	.probe		= of_flash_probe,
 	.remove		= of_flash_remove,
 };

 static int __init of_flash_init(void)
 {
 	return of_register_platform_driver(&of_flash_driver);
 }

 static void __exit of_flash_exit(void)
 {
 	of_unregister_platform_driver(&of_flash_driver);
 }

 module_init(of_flash_init);
 module_exit(of_flash_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
 MODULE_DESCRIPTION("Device tree based MTD map driver");
	/*
	* Flash mappings described by the OF (or flattened) device tree
	*
	* Copyright (C) 2006 MontaVista Software Inc.
	* Author: Vitaly Wool <vwool@ru.mvista.com>
	*
	* Revised to handle newer style flash binding by:
	* Copyright (C) 2007 David Gibson, IBM Corporation.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/init.h>
	#include <linux/device.h>
	#include <linux/mtd/mtd.h>
	#include <linux/mtd/map.h>
	#include <linux/mtd/partitions.h>
	#include <linux/of.h>
	#include <linux/of_platform.h>

	struct of_flash {
	struct mtd_info *mtd;
	struct map_info map;
	struct resource *res;
	#ifdef CONFIG_MTD_PARTITIONS
	struct mtd_partition *parts;
	#endif
	};

	#ifdef CONFIG_MTD_PARTITIONS
	#define OF_FLASH_PARTS(info) ((info)->parts)

	static int parse_obsolete_partitions(struct of_device *dev,
	struct of_flash *info,
	struct device_node *dp)
	{
	int i, plen, nr_parts;
	const struct {
	u32 offset, len;
	} *part;
	const char *names;

	part = of_get_property(dp, "partitions", &plen);
	if (!part)
	return 0; /* No partitions found */

	dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");

	nr_parts = plen / sizeof(part[0]);

	info->parts = kzalloc(nr_parts * sizeof(*info->parts), GFP_KERNEL);
	if (!info->parts)
	return -ENOMEM;

	names = of_get_property(dp, "partition-names", &plen);

	for (i = 0; i < nr_parts; i++) {
	info->parts[i].offset = part->offset;
	info->parts[i].size = part->len & ~1;
	if (part->len & 1) /* bit 0 set signifies read only partition */
	info->parts[i].mask_flags = MTD_WRITEABLE;

	if (names && (plen > 0)) {
	int len = strlen(names) + 1;

	info->parts[i].name = (char *)names;
	plen -= len;
	names += len;
	} else {
	info->parts[i].name = "unnamed";
	}

	part++;
	}

	return nr_parts;
	}
	#else /* MTD_PARTITIONS */
	#define OF_FLASH_PARTS(info) (0)
	#define parse_partitions(info, dev) (0)
	#endif /* MTD_PARTITIONS */

	static int of_flash_remove(struct of_device *dev)
	{
	struct of_flash *info;

	info = dev_get_drvdata(&dev->dev);
	if (!info)
	return 0;
	dev_set_drvdata(&dev->dev, NULL);

	if (info->mtd) {
	if (OF_FLASH_PARTS(info)) {
	del_mtd_partitions(info->mtd);
	kfree(OF_FLASH_PARTS(info));
	} else {
	del_mtd_device(info->mtd);
	}
	map_destroy(info->mtd);
	}

	if (info->map.virt)
	iounmap(info->map.virt);

	if (info->res) {
	release_resource(info->res);
	kfree(info->res);
	}

	return 0;
	}

	/* Helper function to handle probing of the obsolete "direct-mapped"
	* compatible binding, which has an extra "probe-type" property
	* describing the type of flash probe necessary. */
	static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
	struct map_info *map)
	{
	struct device_node *dp = dev->node;
	const char *of_probe;
	struct mtd_info *mtd;
	static const char *rom_probe_types[]
	= { "cfi_probe", "jedec_probe", "map_rom"};
	int i;

	dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
	"flash binding\n");

	of_probe = of_get_property(dp, "probe-type", NULL);
	if (!of_probe) {
	for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
	mtd = do_map_probe(rom_probe_types[i], map);
	if (mtd)
	return mtd;
	}
	return NULL;
	} else if (strcmp(of_probe, "CFI") == 0) {
	return do_map_probe("cfi_probe", map);
	} else if (strcmp(of_probe, "JEDEC") == 0) {
	return do_map_probe("jedec_probe", map);
	} else {
	if (strcmp(of_probe, "ROM") != 0)
	dev_warn(&dev->dev, "obsolete_probe: don't know probe "
	"type '%s', mapping as rom\n", of_probe);
	return do_map_probe("mtd_rom", map);
	}
	}

	static int __devinit of_flash_probe(struct of_device *dev,
	const struct of_device_id *match)
	{
	#ifdef CONFIG_MTD_PARTITIONS
	static const char *part_probe_types[]
	= { "cmdlinepart", "RedBoot", NULL };
	#endif
	struct device_node *dp = dev->node;
	struct resource res;
	struct of_flash *info;
	const char *probe_type = match->data;
	const u32 *width;
	int err;

	err = -ENXIO;
	if (of_address_to_resource(dp, 0, &res)) {
	dev_err(&dev->dev, "Can't get IO address from device tree\n");
	goto err_out;
	}

	dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
	(unsigned long long)res.start, (unsigned long long)res.end);

	err = -ENOMEM;
	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
	goto err_out;

	dev_set_drvdata(&dev->dev, info);

	err = -EBUSY;
	info->res = request_mem_region(res.start, res.end - res.start + 1,
	dev_name(&dev->dev));
	if (!info->res)
	goto err_out;

	err = -ENXIO;
	width = of_get_property(dp, "bank-width", NULL);
	if (!width) {
	dev_err(&dev->dev, "Can't get bank width from device tree\n");
	goto err_out;
	}

	info->map.name = dev_name(&dev->dev);
	info->map.phys = res.start;
	info->map.size = res.end - res.start + 1;
	info->map.bankwidth = *width;

	err = -ENOMEM;
	info->map.virt = ioremap(info->map.phys, info->map.size);
	if (!info->map.virt) {
	dev_err(&dev->dev, "Failed to ioremap() flash region\n");
	goto err_out;
	}

	simple_map_init(&info->map);

	if (probe_type)
	info->mtd = do_map_probe(probe_type, &info->map);
	else
	info->mtd = obsolete_probe(dev, &info->map);

	err = -ENXIO;
	if (!info->mtd) {
	dev_err(&dev->dev, "do_map_probe() failed\n");
	goto err_out;
	}
	info->mtd->owner = THIS_MODULE;
	info->mtd->dev.parent = &dev->dev;

	#ifdef CONFIG_MTD_PARTITIONS
	/* First look for RedBoot table or partitions on the command
	* line, these take precedence over device tree information */
	err = parse_mtd_partitions(info->mtd, part_probe_types,
	&info->parts, 0);
	if (err < 0)
	return err;

	#ifdef CONFIG_MTD_OF_PARTS
	if (err == 0) {
	err = of_mtd_parse_partitions(&dev->dev, dp, &info->parts);
	if (err < 0)
	return err;
	}
	#endif

	if (err == 0) {
	err = parse_obsolete_partitions(dev, info, dp);
	if (err < 0)
	return err;
	}

	if (err > 0)
	add_mtd_partitions(info->mtd, info->parts, err);
	else
	#endif
	add_mtd_device(info->mtd);

	return 0;

	err_out:
	of_flash_remove(dev);
	return err;
	}

	static struct of_device_id of_flash_match[] = {
	{
	.compatible = "cfi-flash",
	.data = (void *)"cfi_probe",
	},
	{
	/* FIXME: JEDEC chips can't be safely and reliably
	* probed, although the mtd code gets it right in
	* practice most of the time. We should use the
	* vendor and device ids specified by the binding to
	* bypass the heuristic probe code, but the mtd layer
	* provides, at present, no interface for doing so
	* :(. */
	.compatible = "jedec-flash",
	.data = (void *)"jedec_probe",
	},
	{
	.type = "rom",
	.compatible = "direct-mapped"
	},
	{ },
	};
	MODULE_DEVICE_TABLE(of, of_flash_match);

	static struct of_platform_driver of_flash_driver = {
	.name = "of-flash",
	.match_table = of_flash_match,
	.probe = of_flash_probe,
	.remove = of_flash_remove,
	};

	static int __init of_flash_init(void)
	{
	return of_register_platform_driver(&of_flash_driver);
	}

	static void __exit of_flash_exit(void)
	{
	of_unregister_platform_driver(&of_flash_driver);
	}

	module_init(of_flash_init);
	module_exit(of_flash_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
	MODULE_DESCRIPTION("Device tree based MTD map driver");