Commit 99f2a8ae authored by Ben Dooks's avatar Ben Dooks Committed by Thomas Gleixner
Browse files

[MTD] Platform RAM Driver 



Driver for generic RAM blocks which are exported by an platform_device
from the device driver system.

Signed-off-by: default avatarBen Dooks <ben@simtec.co.uk>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent a4ab4c5d

drivers/mtd/maps/Kconfig

+11 −1
Original line number Diff line number Diff line 
# drivers/mtd/maps/Kconfig

# $Id: Kconfig,v 1.42 2005/01/05 16:59:50 dwmw2 Exp $

# $Id: Kconfig,v 1.43 2005/01/24 00:35:21 bjd Exp $



menu "Mapping drivers for chip access"

	depends on MTD!=n
@@ -659,5 +659,15 @@ config MTD_SHARP_SL 
	help

	  This enables access to the flash chip on the Sharp SL Series of PDAs.



config MTD_PLATRAM

	tristate "Map driver for platfrom device RAM (mtd-ram)"

	depends on MTD

	select MTD_RAM

	help

	  Map driver for RAM areas described via the platform device

	  system.



	  This selection automatically selects the map_ram driver.



endmenu

drivers/mtd/maps/Makefile

+2 −1
Original line number Diff line number Diff line 
#

# linux/drivers/maps/Makefile

#

# $Id: Makefile.common,v 1.23 2005/01/05 17:06:36 dwmw2 Exp $

# $Id: Makefile.common,v 1.24 2005/01/24 00:35:21 bjd Exp $



ifeq ($(CONFIG_MTD_COMPLEX_MAPPINGS),y)

obj-$(CONFIG_MTD)		+= map_funcs.o
@@ -71,3 +71,4 @@ obj-$(CONFIG_MTD_IXP2000) += ixp2000.o 
obj-$(CONFIG_MTD_WRSBC8260)	+= wr_sbc82xx_flash.o

obj-$(CONFIG_MTD_DMV182)	+= dmv182.o

obj-$(CONFIG_MTD_SHARP_SL)	+= sharpsl-flash.o

obj-$(CONFIG_MTD_PLATRAM)	+= plat-ram.o

drivers/mtd/maps/plat-ram.c

0 → 100644
+286 −0
Original line number Diff line number Diff line 
/* drivers/mtd/maps/plat-ram.c

 *

 * (c) 2004-2005 Simtec Electronics

 *	http://www.simtec.co.uk/products/SWLINUX/

 *	Ben Dooks <ben@simtec.co.uk>

 *

 * Generic platfrom device based RAM map

 *

 * $Id: plat-ram.c,v 1.1 2005/01/24 00:37:02 bjd Exp $

 *

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/



#define DEBUG



#include <linux/module.h>

#include <linux/types.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/string.h>

#include <linux/ioport.h>

#include <linux/device.h>



#include <linux/mtd/mtd.h>

#include <linux/mtd/map.h>

#include <linux/mtd/partitions.h>

#include <linux/mtd/plat-ram.h>



#include <asm/io.h>



/* private structure for each mtd platform ram device created */



struct platram_info {

	struct device		*dev;

	struct mtd_info		*mtd;

	struct map_info		 map;

	struct mtd_partition	*partitions;

	struct resource		*area;

	struct platdata_mtd_ram	*pdata;

};



/* to_platram_info()

 *

 * device private data to struct platram_info conversion

*/



static inline struct platram_info *to_platram_info(struct device *dev)

{

	return (struct platram_info *)dev_get_drvdata(dev);

}



/* platram_setrw

 *

 * call the platform device's set rw/ro control

 *

 * to = 0 => read-only

 *    = 1 => read-write

*/



static inline void platram_setrw(struct platram_info *info, int to)

{

	if (info->pdata == NULL)

		return;



	if (info->pdata->set_rw != NULL)

		(info->pdata->set_rw)(info->dev, to);

}



/* platram_remove

 *

 * called to remove the device from the driver's control

*/



static int platram_remove(struct device *dev)

{

	struct platram_info *info = to_platram_info(dev);



	dev_set_drvdata(dev, NULL);



	dev_dbg(dev, "removing device\n");



	if (info == NULL) 

		return 0;



	if (info->mtd) {

#ifdef CONFIG_MTD_PARTITIONS

		if (info->partitions) {

			del_mtd_partitions(info->mtd);

			kfree(info->partitions);

		}

#endif

		del_mtd_device(info->mtd);

		map_destroy(info->mtd);

	}



	/* ensure ram is left read-only */



	platram_setrw(info, PLATRAM_RO);



	/* release resources */



	if (info->area) {

		release_resource(info->area);

		kfree(info->area);

	}



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

		iounmap(info->map.virt);

	

	kfree(info);



	return 0;

}



/* platram_probe

 *

 * called from device drive system when a device matching our

 * driver is found.

*/



static int platram_probe(struct device *dev)

{

	struct platform_device *pd = to_platform_device(dev);

	struct platdata_mtd_ram	*pdata;

	struct platram_info *info;

	struct resource *res;

	int err = 0;



	dev_dbg(dev, "probe entered\n");

	

	if (dev->platform_data == NULL) {

		dev_err(dev, "no platform data supplied\n");

		err = -ENOENT;

		goto exit_error;

	}



	pdata = dev->platform_data;



	info = kmalloc(sizeof(*info), GFP_KERNEL);

	if (info == NULL) {

		dev_err(dev, "no memory for flash info\n");

		err = -ENOMEM;

		goto exit_error;

	}



	memzero(info, sizeof(*info));

	dev_set_drvdata(dev, info);



	info->dev = dev;

	info->pdata = pdata;



	/* get the resource for the memory mapping */



	res = platform_get_resource(pd, IORESOURCE_MEM, 0);



	if (res == NULL) {

		dev_err(dev, "no memory resource specified\n");

		err = -ENOENT;

		goto exit_free;

	}



	dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start);



	/* setup map parameters */



	info->map.phys = res->start;

	info->map.size = (res->end - res->start) + 1;

	info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->name;

	info->map.bankwidth = pdata->bankwidth;



	/* register our usage of the memory area */



	info->area = request_mem_region(res->start, info->map.size, pd->name);

	if (info->area == NULL) {

		dev_err(dev, "failed to request memory region\n");

		err = -EIO;

		goto exit_free;

	}



	/* remap the memory area */



	info->map.virt = ioremap(res->start, info->map.size);

	dev_dbg(dev, "virt %p, %d bytes\n", info->map.virt, info->map.size);



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

		dev_err(dev, "failed to ioremap() region\n");

		err = -EIO;

		goto exit_free;

	}



	{

		unsigned int *p = (unsigned int *)info->map.virt;

		printk("%08x %08x %08x %08x\n",

		       readl(p), readl(p+1), readl(p+2), readl(p+3));

	}



	simple_map_init(&info->map);



	dev_dbg(dev, "initialised map, probing for mtd\n");



	/* probe for the right mtd map driver */



	info->mtd = do_map_probe("map_ram" , &info->map);

	if (info->mtd == NULL) {

		dev_err(dev, "failed to probe for map_ram\n");

		err = -ENOMEM;

		goto exit_free;

	}



	info->mtd->owner = THIS_MODULE;



	platram_setrw(info, PLATRAM_RW);



	/* check to see if there are any available partitions, or wether

	 * to add this device whole */



#ifdef CONFIG_MTD_PARTITIONS

	if (pdata->nr_partitions > 0) {

		const char **probes = { NULL };



		if (pdata->probes)

			probes = (const char **)pdata->probes;



		err = parse_mtd_partitions(info->mtd, probes,

					   &info->partitions, 0);

		if (err > 0) {

			err = add_mtd_partitions(info->mtd, info->partitions,

						 err);

		}

	}

#endif /* CONFIG_MTD_PARTITIONS */



	if (add_mtd_device(info->mtd)) {

		dev_err(dev, "add_mtd_device() failed\n");

		err = -ENOMEM;

	}

	

	dev_info(dev, "registered mtd device\n");

	return err;



 exit_free:

	platram_remove(dev);

 exit_error:

	return err;

}



/* device driver info */



static struct device_driver platram_driver = {

	.name		= "mtd-ram",

	.bus		= &platform_bus_type,

	.probe		= platram_probe,

	.remove		= platram_remove,

};



/* module init/exit */



static int __init platram_init(void)

{

	printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");

	return driver_register(&platram_driver);

}



static void __exit platram_exit(void)

{

	driver_unregister(&platram_driver);

}



module_init(platram_init);

module_exit(platram_exit);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");

MODULE_DESCRIPTION("MTD platform RAM map driver");

include/linux/mtd/plat-ram.h

0 → 100644
+35 −0
Original line number Diff line number Diff line 
/* linux/include/mtd/plat-ram.h

 *

 * (c) 2004 Simtec Electronics

 *	http://www.simtec.co.uk/products/SWLINUX/

 *	Ben Dooks <ben@simtec.co.uk>

 *

 * Generic platform device based RAM map

 *

 * $Id: plat-ram.h,v 1.2 2005/01/24 00:37:40 bjd Exp $

 *

 * 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.

 *

 */



#ifndef __LINUX_MTD_PLATRAM_H

#define __LINUX_MTD_PLATRAM_H __FILE__



#define PLATRAM_RO (0)

#define PLATRAM_RW (1)



struct platdata_mtd_ram {

	char			*mapname;

	char		       **probes;

	struct mtd_partition	*partitions;

	int			 nr_partitions;

	int			 bankwidth;



	/* control callbacks */



	void	(*set_rw)(struct device *dev, int to);

};



#endif /* __LINUX_MTD_PLATRAM_H */

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