/* 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 platform device based RAM map
   *
   * 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
  */
  
  #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/slab.h>
  #include <linux/platform_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 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 platform_device *dev)
  {
  	return platform_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 platform_device *pdev)
  {
  	struct platram_info *info = to_platram_info(pdev);
  
  	dev_dbg(&pdev->dev, "removing device
  ");
  
  	if (info == NULL)
  		return 0;
  
  	if (info->mtd) {
  		mtd_device_unregister(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 platform_device *pdev)
  {
  	struct platdata_mtd_ram	*pdata;
  	struct platram_info *info;
  	struct resource *res;
  	int err = 0;
  
  	dev_dbg(&pdev->dev, "probe entered
  ");
  
  	if (dev_get_platdata(&pdev->dev) == NULL) {
  		dev_err(&pdev->dev, "no platform data supplied
  ");
  		err = -ENOENT;
  		goto exit_error;
  	}
  
  	pdata = dev_get_platdata(&pdev->dev);
  
  	info = kzalloc(sizeof(*info), GFP_KERNEL);
  	if (info == NULL) {
  		dev_err(&pdev->dev, "no memory for flash info
  ");
  		err = -ENOMEM;
  		goto exit_error;
  	}
  
  	platform_set_drvdata(pdev, info);
  
  	info->dev = &pdev->dev;
  	info->pdata = pdata;
  
  	/* get the resource for the memory mapping */
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  
  	if (res == NULL) {
  		dev_err(&pdev->dev, "no memory resource specified
  ");
  		err = -ENOENT;
  		goto exit_free;
  	}
  
  	dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)
  ", res,
  		(unsigned long long)res->start);
  
  	/* setup map parameters */
  
  	info->map.phys = res->start;
  	info->map.size = resource_size(res);
  	info->map.name = pdata->mapname != NULL ?
  			(char *)pdata->mapname : (char *)pdev->name;
  	info->map.bankwidth = pdata->bankwidth;
  
  	/* register our usage of the memory area */
  
  	info->area = request_mem_region(res->start, info->map.size, pdev->name);
  	if (info->area == NULL) {
  		dev_err(&pdev->dev, "failed to request memory region
  ");
  		err = -EIO;
  		goto exit_free;
  	}
  
  	/* remap the memory area */
  
  	info->map.virt = ioremap(res->start, info->map.size);
  	dev_dbg(&pdev->dev, "virt %p, %lu bytes
  ", info->map.virt, info->map.size);
  
  	if (info->map.virt == NULL) {
  		dev_err(&pdev->dev, "failed to ioremap() region
  ");
  		err = -EIO;
  		goto exit_free;
  	}
  
  	simple_map_init(&info->map);
  
  	dev_dbg(&pdev->dev, "initialised map, probing for mtd
  ");
  
  	/* probe for the right mtd map driver
  	 * supplied by the platform_data struct */
  
  	if (pdata->map_probes) {
  		const char * const *map_probes = pdata->map_probes;
  
  		for ( ; !info->mtd && *map_probes; map_probes++)
  			info->mtd = do_map_probe(*map_probes , &info->map);
  	}
  	/* fallback to map_ram */
  	else
  		info->mtd = do_map_probe("map_ram", &info->map);
  
  	if (info->mtd == NULL) {
  		dev_err(&pdev->dev, "failed to probe for map_ram
  ");
  		err = -ENOMEM;
  		goto exit_free;
  	}
  
  	info->mtd->owner = THIS_MODULE;
  	info->mtd->dev.parent = &pdev->dev;
  
  	platram_setrw(info, PLATRAM_RW);
  
  	/* check to see if there are any available partitions, or whether
  	 * to add this device whole */
  
  	err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,
  					pdata->partitions,
  					pdata->nr_partitions);
  	if (!err)
  		dev_info(&pdev->dev, "registered mtd device
  ");
  
  	if (pdata->nr_partitions) {
  		/* add the whole device. */
  		err = mtd_device_register(info->mtd, NULL, 0);
  		if (err) {
  			dev_err(&pdev->dev,
  				"failed to register the entire device
  ");
  		}
  	}
  
  	return err;
  
   exit_free:
  	platram_remove(pdev);
   exit_error:
  	return err;
  }
  
  /* device driver info */
  
  /* work with hotplug and coldplug */
  MODULE_ALIAS("platform:mtd-ram");
  
  static struct platform_driver platram_driver = {
  	.probe		= platram_probe,
  	.remove		= platram_remove,
  	.driver		= {
  		.name	= "mtd-ram",
  		.owner	= THIS_MODULE,
  	},
  };
  
  module_platform_driver(platram_driver);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
  MODULE_DESCRIPTION("MTD platform RAM map driver");