drivers/mtd/maps/lantiq-flash.c - linux - Git at Google

 /*
  *  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.
  *
  *  Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
  *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/map.h>
 #include <linux/mtd/partitions.h>
 #include <linux/mtd/cfi.h>
 #include <linux/platform_device.h>
 #include <linux/mtd/physmap.h>

 #include <lantiq_soc.h>
 #include <lantiq_platform.h>

 /*
  * The NOR flash is connected to the same external bus unit (EBU) as PCI.
  * To make PCI work we need to enable the endianness swapping for the address
  * written to the EBU. This endianness swapping works for PCI correctly but
  * fails for attached NOR devices. To workaround this we need to use a complex
  * map. The workaround involves swapping all addresses whilst probing the chip.
  * Once probing is complete we stop swapping the addresses but swizzle the
  * unlock addresses to ensure that access to the NOR device works correctly.
  */

 enum {
 	LTQ_NOR_PROBING,
 	LTQ_NOR_NORMAL
 };

 struct ltq_mtd {
 	struct resource *res;
 	struct mtd_info *mtd;
 	struct map_info *map;
 };

 static char ltq_map_name[] = "ltq_nor";

 static map_word
 ltq_read16(struct map_info *map, unsigned long adr)
 {
 	unsigned long flags;
 	map_word temp;

 	if (map->map_priv_1 == LTQ_NOR_PROBING)
 		adr ^= 2;
 	spin_lock_irqsave(&ebu_lock, flags);
 	temp.x[0] = *(u16 *)(map->virt + adr);
 	spin_unlock_irqrestore(&ebu_lock, flags);
 	return temp;
 }

 static void
 ltq_write16(struct map_info *map, map_word d, unsigned long adr)
 {
 	unsigned long flags;

 	if (map->map_priv_1 == LTQ_NOR_PROBING)
 		adr ^= 2;
 	spin_lock_irqsave(&ebu_lock, flags);
 	*(u16 *)(map->virt + adr) = d.x[0];
 	spin_unlock_irqrestore(&ebu_lock, flags);
 }

 /*
  * The following 2 functions copy data between iomem and a cached memory
  * section. As memcpy() makes use of pre-fetching we cannot use it here.
  * The normal alternative of using memcpy_{to,from}io also makes use of
  * memcpy() on MIPS so it is not applicable either. We are therefore stuck
  * with having to use our own loop.
  */
 static void
 ltq_copy_from(struct map_info *map, void *to,
 	unsigned long from, ssize_t len)
 {
 	unsigned char *f = (unsigned char *)map->virt + from;
 	unsigned char *t = (unsigned char *)to;
 	unsigned long flags;

 	spin_lock_irqsave(&ebu_lock, flags);
 	while (len--)
 		*t++ = *f++;
 	spin_unlock_irqrestore(&ebu_lock, flags);
 }

 static void
 ltq_copy_to(struct map_info *map, unsigned long to,
 	const void *from, ssize_t len)
 {
 	unsigned char *f = (unsigned char *)from;
 	unsigned char *t = (unsigned char *)map->virt + to;
 	unsigned long flags;

 	spin_lock_irqsave(&ebu_lock, flags);
 	while (len--)
 		*t++ = *f++;
 	spin_unlock_irqrestore(&ebu_lock, flags);
 }

 static const char const *part_probe_types[] = { "cmdlinepart", NULL };

 static int __init
 ltq_mtd_probe(struct platform_device *pdev)
 {
 	struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev);
 	struct ltq_mtd *ltq_mtd;
 	struct mtd_partition *parts;
 	struct resource *res;
 	int nr_parts = 0;
 	struct cfi_private *cfi;
 	int err;

 	ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
 	platform_set_drvdata(pdev, ltq_mtd);

 	ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!ltq_mtd->res) {
 		dev_err(&pdev->dev, "failed to get memory resource");
 		err = -ENOENT;
 		goto err_out;
 	}

 	res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start,
 		resource_size(ltq_mtd->res), dev_name(&pdev->dev));
 	if (!ltq_mtd->res) {
 		dev_err(&pdev->dev, "failed to request mem resource");
 		err = -EBUSY;
 		goto err_out;
 	}

 	ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
 	ltq_mtd->map->phys = res->start;
 	ltq_mtd->map->size = resource_size(res);
 	ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev,
 				ltq_mtd->map->phys, ltq_mtd->map->size);
 	if (!ltq_mtd->map->virt) {
 		dev_err(&pdev->dev, "failed to ioremap!\n");
 		err = -ENOMEM;
 		goto err_free;
 	}

 	ltq_mtd->map->name = ltq_map_name;
 	ltq_mtd->map->bankwidth = 2;
 	ltq_mtd->map->read = ltq_read16;
 	ltq_mtd->map->write = ltq_write16;
 	ltq_mtd->map->copy_from = ltq_copy_from;
 	ltq_mtd->map->copy_to = ltq_copy_to;

 	ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
 	ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
 	ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;

 	if (!ltq_mtd->mtd) {
 		dev_err(&pdev->dev, "probing failed\n");
 		err = -ENXIO;
 		goto err_unmap;
 	}

 	ltq_mtd->mtd->owner = THIS_MODULE;

 	cfi = ltq_mtd->map->fldrv_priv;
 	cfi->addr_unlock1 ^= 1;
 	cfi->addr_unlock2 ^= 1;

 	nr_parts = parse_mtd_partitions(ltq_mtd->mtd,
 				part_probe_types, &parts, 0);
 	if (nr_parts > 0) {
 		dev_info(&pdev->dev,
 			"using %d partitions from cmdline", nr_parts);
 	} else {
 		nr_parts = ltq_mtd_data->nr_parts;
 		parts = ltq_mtd_data->parts;
 	}

 	err = add_mtd_partitions(ltq_mtd->mtd, parts, nr_parts);
 	if (err) {
 		dev_err(&pdev->dev, "failed to add partitions\n");
 		goto err_destroy;
 	}

 	return 0;

 err_destroy:
 	map_destroy(ltq_mtd->mtd);
 err_unmap:
 	iounmap(ltq_mtd->map->virt);
 err_free:
 	kfree(ltq_mtd->map);
 err_out:
 	kfree(ltq_mtd);
 	return err;
 }

 static int __devexit
 ltq_mtd_remove(struct platform_device *pdev)
 {
 	struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);

 	if (ltq_mtd) {
 		if (ltq_mtd->mtd) {
 			del_mtd_partitions(ltq_mtd->mtd);
 			map_destroy(ltq_mtd->mtd);
 		}
 		if (ltq_mtd->map->virt)
 			iounmap(ltq_mtd->map->virt);
 		kfree(ltq_mtd->map);
 		kfree(ltq_mtd);
 	}
 	return 0;
 }

 static struct platform_driver ltq_mtd_driver = {
 	.remove = __devexit_p(ltq_mtd_remove),
 	.driver = {
 		.name = "ltq_nor",
 		.owner = THIS_MODULE,
 	},
 };

 static int __init
 init_ltq_mtd(void)
 {
 	int ret = platform_driver_probe(&ltq_mtd_driver, ltq_mtd_probe);

 	if (ret)
 		pr_err("ltq_nor: error registering platform driver");
 	return ret;
 }

 static void __exit
 exit_ltq_mtd(void)
 {
 	platform_driver_unregister(&ltq_mtd_driver);
 }

 module_init(init_ltq_mtd);
 module_exit(exit_ltq_mtd);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
 MODULE_DESCRIPTION("Lantiq SoC NOR");
	/*
	* 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.
	*
	* Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
	* Copyright (C) 2010 John Crispin <blogic@openwrt.org>
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/io.h>
	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/mtd/mtd.h>
	#include <linux/mtd/map.h>
	#include <linux/mtd/partitions.h>
	#include <linux/mtd/cfi.h>
	#include <linux/platform_device.h>
	#include <linux/mtd/physmap.h>

	#include <lantiq_soc.h>
	#include <lantiq_platform.h>

	/*
	* The NOR flash is connected to the same external bus unit (EBU) as PCI.
	* To make PCI work we need to enable the endianness swapping for the address
	* written to the EBU. This endianness swapping works for PCI correctly but
	* fails for attached NOR devices. To workaround this we need to use a complex
	* map. The workaround involves swapping all addresses whilst probing the chip.
	* Once probing is complete we stop swapping the addresses but swizzle the
	* unlock addresses to ensure that access to the NOR device works correctly.
	*/

	enum {
	LTQ_NOR_PROBING,
	LTQ_NOR_NORMAL
	};

	struct ltq_mtd {
	struct resource *res;
	struct mtd_info *mtd;
	struct map_info *map;
	};

	static char ltq_map_name[] = "ltq_nor";

	static map_word
	ltq_read16(struct map_info *map, unsigned long adr)
	{
	unsigned long flags;
	map_word temp;

	if (map->map_priv_1 == LTQ_NOR_PROBING)
	adr ^= 2;
	spin_lock_irqsave(&ebu_lock, flags);
	temp.x[0] = (u16 )(map->virt + adr);
	spin_unlock_irqrestore(&ebu_lock, flags);
	return temp;
	}

	static void
	ltq_write16(struct map_info *map, map_word d, unsigned long adr)
	{
	unsigned long flags;

	if (map->map_priv_1 == LTQ_NOR_PROBING)
	adr ^= 2;
	spin_lock_irqsave(&ebu_lock, flags);
	(u16 )(map->virt + adr) = d.x[0];
	spin_unlock_irqrestore(&ebu_lock, flags);
	}

	/*
	* The following 2 functions copy data between iomem and a cached memory
	* section. As memcpy() makes use of pre-fetching we cannot use it here.
	* The normal alternative of using memcpy_{to,from}io also makes use of
	* memcpy() on MIPS so it is not applicable either. We are therefore stuck
	* with having to use our own loop.
	*/
	static void
	ltq_copy_from(struct map_info map, void to,
	unsigned long from, ssize_t len)
	{
	unsigned char f = (unsigned char )map->virt + from;
	unsigned char t = (unsigned char )to;
	unsigned long flags;

	spin_lock_irqsave(&ebu_lock, flags);
	while (len--)
	t++ = f++;
	spin_unlock_irqrestore(&ebu_lock, flags);
	}

	static void
	ltq_copy_to(struct map_info *map, unsigned long to,
	const void *from, ssize_t len)
	{
	unsigned char f = (unsigned char )from;
	unsigned char t = (unsigned char )map->virt + to;
	unsigned long flags;

	spin_lock_irqsave(&ebu_lock, flags);
	while (len--)
	t++ = f++;
	spin_unlock_irqrestore(&ebu_lock, flags);
	}

	static const char const *part_probe_types[] = { "cmdlinepart", NULL };

	static int __init
	ltq_mtd_probe(struct platform_device *pdev)
	{
	struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev);
	struct ltq_mtd *ltq_mtd;
	struct mtd_partition *parts;
	struct resource *res;
	int nr_parts = 0;
	struct cfi_private *cfi;
	int err;

	ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
	platform_set_drvdata(pdev, ltq_mtd);

	ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!ltq_mtd->res) {
	dev_err(&pdev->dev, "failed to get memory resource");
	err = -ENOENT;
	goto err_out;
	}

	res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start,
	resource_size(ltq_mtd->res), dev_name(&pdev->dev));
	if (!ltq_mtd->res) {
	dev_err(&pdev->dev, "failed to request mem resource");
	err = -EBUSY;
	goto err_out;
	}

	ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
	ltq_mtd->map->phys = res->start;
	ltq_mtd->map->size = resource_size(res);
	ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev,
	ltq_mtd->map->phys, ltq_mtd->map->size);
	if (!ltq_mtd->map->virt) {
	dev_err(&pdev->dev, "failed to ioremap!\n");
	err = -ENOMEM;
	goto err_free;
	}

	ltq_mtd->map->name = ltq_map_name;
	ltq_mtd->map->bankwidth = 2;
	ltq_mtd->map->read = ltq_read16;
	ltq_mtd->map->write = ltq_write16;
	ltq_mtd->map->copy_from = ltq_copy_from;
	ltq_mtd->map->copy_to = ltq_copy_to;

	ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
	ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
	ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;

	if (!ltq_mtd->mtd) {
	dev_err(&pdev->dev, "probing failed\n");
	err = -ENXIO;
	goto err_unmap;
	}

	ltq_mtd->mtd->owner = THIS_MODULE;

	cfi = ltq_mtd->map->fldrv_priv;
	cfi->addr_unlock1 ^= 1;
	cfi->addr_unlock2 ^= 1;

	nr_parts = parse_mtd_partitions(ltq_mtd->mtd,
	part_probe_types, &parts, 0);
	if (nr_parts > 0) {
	dev_info(&pdev->dev,
	"using %d partitions from cmdline", nr_parts);
	} else {
	nr_parts = ltq_mtd_data->nr_parts;
	parts = ltq_mtd_data->parts;
	}

	err = add_mtd_partitions(ltq_mtd->mtd, parts, nr_parts);
	if (err) {
	dev_err(&pdev->dev, "failed to add partitions\n");
	goto err_destroy;
	}

	return 0;

	err_destroy:
	map_destroy(ltq_mtd->mtd);
	err_unmap:
	iounmap(ltq_mtd->map->virt);
	err_free:
	kfree(ltq_mtd->map);
	err_out:
	kfree(ltq_mtd);
	return err;
	}

	static int __devexit
	ltq_mtd_remove(struct platform_device *pdev)
	{
	struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);

	if (ltq_mtd) {
	if (ltq_mtd->mtd) {
	del_mtd_partitions(ltq_mtd->mtd);
	map_destroy(ltq_mtd->mtd);
	}
	if (ltq_mtd->map->virt)
	iounmap(ltq_mtd->map->virt);
	kfree(ltq_mtd->map);
	kfree(ltq_mtd);
	}
	return 0;
	}

	static struct platform_driver ltq_mtd_driver = {
	.remove = __devexit_p(ltq_mtd_remove),
	.driver = {
	.name = "ltq_nor",
	.owner = THIS_MODULE,
	},
	};

	static int __init
	init_ltq_mtd(void)
	{
	int ret = platform_driver_probe(&ltq_mtd_driver, ltq_mtd_probe);

	if (ret)
	pr_err("ltq_nor: error registering platform driver");
	return ret;
	}

	static void __exit
	exit_ltq_mtd(void)
	{
	platform_driver_unregister(&ltq_mtd_driver);
	}

	module_init(init_ltq_mtd);
	module_exit(exit_ltq_mtd);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
	MODULE_DESCRIPTION("Lantiq SoC NOR");