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Commit dcfb81d6 authored by David Griego's avatar David Griego Committed by David Woodhouse
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mtd: NOR flash driver for OMAP-L137/AM17x 



OMAP-L137/AM17x has limited number of dedicated EMIFA
address pins, enough to interface directly to an SDRAM.
If a device such as an asynchronous flash needs to be
attached to the EMIFA, then either GPIO pins or a chip
select may be used to control the flash device's upper
address lines.

This patch adds support for the NOR flash on the OMAP-L137/
AM17x user interface daughter board using the latch-addr-flash
MTD mapping driver which allows flashes to be partially
physically addressed. The upper address lines are set by
a board specific code which is a separate patch.

Signed-off-by: default avatarDavid Griego <dgriego@mvista.com>
Signed-off-by: default avatarAleksey Makarov <amakarov@ru.mvista.com>
Signed-off-by: default avatarSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: default avatarSavinay Dharmappa <savinay.dharmappa@ti.com>
Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent a3215902

drivers/mtd/maps/Kconfig

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Original line number Diff line number Diff line
@@ -552,4 +552,13 @@ config MTD_PISMO 


	  When built as a module, it will be called pismo.ko



config MTD_LATCH_ADDR

        tristate "Latch-assisted Flash Chip Support"

        depends on MTD_COMPLEX_MAPPINGS

        help

          Map driver which allows flashes to be partially physically addressed

          and have the upper address lines set by a board specific code.



          If compiled as a module, it will be called latch-addr-flash.



endmenu

drivers/mtd/maps/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -59,3 +59,4 @@ obj-$(CONFIG_MTD_RBTX4939) += rbtx4939-flash.o 
obj-$(CONFIG_MTD_VMU)		+= vmu-flash.o

obj-$(CONFIG_MTD_GPIO_ADDR)	+= gpio-addr-flash.o

obj-$(CONFIG_MTD_BCM963XX)	+= bcm963xx-flash.o

obj-$(CONFIG_MTD_LATCH_ADDR)	+= latch-addr-flash.o

drivers/mtd/maps/latch-addr-flash.c

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Original line number Diff line number Diff line 
/*

 * Interface for NOR flash driver whose high address lines are latched

 *

 * Copyright © 2000 Nicolas Pitre <nico@cam.org>

 * Copyright © 2005-2008 Analog Devices Inc.

 * Copyright © 2008 MontaVista Software, Inc. <source@mvista.com>

 *

 * This file is licensed under the terms of the GNU General Public License

 * version 2. This program is licensed "as is" without any warranty of any

 * kind, whether express or implied.

 */



#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/map.h>

#include <linux/mtd/partitions.h>

#include <linux/platform_device.h>

#include <linux/mtd/latch-addr-flash.h>

#include <linux/slab.h>



#define DRIVER_NAME "latch-addr-flash"



struct latch_addr_flash_info {

	struct mtd_info		*mtd;

	struct map_info		map;

	struct resource		*res;



	void			(*set_window)(unsigned long offset, void *data);

	void			*data;



	/* cache; could be found out of res */

	unsigned long		win_mask;



	int			nr_parts;

	struct mtd_partition	*parts;



	spinlock_t		lock;

};



static map_word lf_read(struct map_info *map, unsigned long ofs)

{

	struct latch_addr_flash_info *info;

	map_word datum;



	info = (struct latch_addr_flash_info *)map->map_priv_1;



	spin_lock(&info->lock);



	info->set_window(ofs, info->data);

	datum = inline_map_read(map, info->win_mask & ofs);



	spin_unlock(&info->lock);



	return datum;

}



static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)

{

	struct latch_addr_flash_info *info;



	info = (struct latch_addr_flash_info *)map->map_priv_1;



	spin_lock(&info->lock);



	info->set_window(ofs, info->data);

	inline_map_write(map, datum, info->win_mask & ofs);



	spin_unlock(&info->lock);

}



static void lf_copy_from(struct map_info *map, void *to,

		unsigned long from, ssize_t len)

{

	struct latch_addr_flash_info *info =

		(struct latch_addr_flash_info *) map->map_priv_1;

	unsigned n;



	while (len > 0) {

		n = info->win_mask + 1 - (from & info->win_mask);

		if (n > len)

			n = len;



		spin_lock(&info->lock);



		info->set_window(from, info->data);

		memcpy_fromio(to, map->virt + (from & info->win_mask), n);



		spin_unlock(&info->lock);



		to += n;

		from += n;

		len -= n;

	}

}



static char *rom_probe_types[] = { "cfi_probe", NULL };



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



static int latch_addr_flash_remove(struct platform_device *dev)

{

	struct latch_addr_flash_info *info;

	struct latch_addr_flash_data *latch_addr_data;



	info = platform_get_drvdata(dev);

	if (info == NULL)

		return 0;

	platform_set_drvdata(dev, NULL);



	latch_addr_data = dev->dev.platform_data;



	if (info->mtd != NULL) {

		if (mtd_has_partitions()) {

			if (info->nr_parts) {

				del_mtd_partitions(info->mtd);

				kfree(info->parts);

			} else if (latch_addr_data->nr_parts) {

				del_mtd_partitions(info->mtd);

			} else {

				del_mtd_device(info->mtd);

			}

		} else {

			del_mtd_device(info->mtd);

		}

		map_destroy(info->mtd);

	}



	if (info->map.virt != NULL)

		iounmap(info->map.virt);



	if (info->res != NULL)

		release_mem_region(info->res->start, resource_size(info->res));



	kfree(info);



	if (latch_addr_data->done)

		latch_addr_data->done(latch_addr_data->data);



	return 0;

}



static int __devinit latch_addr_flash_probe(struct platform_device *dev)

{

	struct latch_addr_flash_data *latch_addr_data;

	struct latch_addr_flash_info *info;

	resource_size_t win_base = dev->resource->start;

	resource_size_t win_size = resource_size(dev->resource);

	char **probe_type;

	int chipsel;

	int err;



	latch_addr_data = dev->dev.platform_data;

	if (latch_addr_data == NULL)

		return -ENODEV;



	pr_notice("latch-addr platform flash device: %#llx byte "

		  "window at %#.8llx\n",

		  (unsigned long long)win_size, (unsigned long long)win_base);



	chipsel = dev->id;



	if (latch_addr_data->init) {

		err = latch_addr_data->init(latch_addr_data->data, chipsel);

		if (err != 0)

			return err;

	}



	info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);

	if (info == NULL) {

		err = -ENOMEM;

		goto done;

	}



	platform_set_drvdata(dev, info);



	info->res = request_mem_region(win_base, win_size, DRIVER_NAME);

	if (info->res == NULL) {

		dev_err(&dev->dev, "Could not reserve memory region\n");

		err = -EBUSY;

		goto free_info;

	}



	info->map.name		= DRIVER_NAME;

	info->map.size		= latch_addr_data->size;

	info->map.bankwidth	= latch_addr_data->width;



	info->map.phys		= NO_XIP;

	info->map.virt		= ioremap(win_base, win_size);

	if (!info->map.virt) {

		err = -ENOMEM;

		goto free_res;

	}



	info->map.map_priv_1	= (unsigned long)info;



	info->map.read		= lf_read;

	info->map.copy_from	= lf_copy_from;

	info->map.write		= lf_write;

	info->set_window	= latch_addr_data->set_window;

	info->data		= latch_addr_data->data;

	info->win_mask		= win_size - 1;



	spin_lock_init(&info->lock);



	for (probe_type = rom_probe_types; !info->mtd && *probe_type;

		probe_type++)

		info->mtd = do_map_probe(*probe_type, &info->map);



	if (info->mtd == NULL) {

		dev_err(&dev->dev, "map_probe failed\n");

		err = -ENODEV;

		goto iounmap;

	}

	info->mtd->owner = THIS_MODULE;



	if (mtd_has_partitions()) {



		err = parse_mtd_partitions(info->mtd,

					   (const char **)part_probe_types,

					   &info->parts, 0);

		if (err > 0) {

			add_mtd_partitions(info->mtd, info->parts, err);

			return 0;

		}

		if (latch_addr_data->nr_parts) {

			pr_notice("Using latch-addr-flash partition information\n");

			add_mtd_partitions(info->mtd, latch_addr_data->parts,

					latch_addr_data->nr_parts);

			return 0;

		}

	}

	add_mtd_device(info->mtd);

	return 0;



iounmap:

	iounmap(info->map.virt);

free_res:

	release_mem_region(info->res->start, resource_size(info->res));

free_info:

	kfree(info);

done:

	if (latch_addr_data->done)

		latch_addr_data->done(latch_addr_data->data);

	return err;

}



static struct platform_driver latch_addr_flash_driver = {

	.probe		= latch_addr_flash_probe,

	.remove		= __devexit_p(latch_addr_flash_remove),

	.driver		= {

		.name	= DRIVER_NAME,

	},

};



static int __init latch_addr_flash_init(void)

{

	return platform_driver_register(&latch_addr_flash_driver);

}

module_init(latch_addr_flash_init);



static void __exit latch_addr_flash_exit(void)

{

	platform_driver_unregister(&latch_addr_flash_driver);

}

module_exit(latch_addr_flash_exit);



MODULE_AUTHOR("David Griego <dgriego@mvista.com>");

MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "

		"address lines being set board specifically");

MODULE_LICENSE("GPL v2");

include/linux/mtd/latch-addr-flash.h

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/*

 * Interface for NOR flash driver whose high address lines are latched

 *

 * Copyright © 2008 MontaVista Software, Inc. <source@mvista.com>

 *

 * This file is licensed under the terms of the GNU General Public License

 * version 2. This program is licensed "as is" without any warranty of any

 * kind, whether express or implied.

 */

#ifndef __LATCH_ADDR_FLASH__

#define __LATCH_ADDR_FLASH__



struct map_info;

struct mtd_partition;



struct latch_addr_flash_data {

	unsigned int		width;

	unsigned int		size;



	int			(*init)(void *data, int cs);

	void			(*done)(void *data);

	void			(*set_window)(unsigned long offset, void *data);

	void			*data;



	unsigned int		nr_parts;

	struct mtd_partition	*parts;

};



#endif