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/*
* NV-RAM memory access on autcpu12
* (C) 2002 Thomas Gleixner (gleixner@autronix.de)
*
* 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/sizes.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
struct autcpu12_nvram_priv {
struct mtd_info *mtd;
struct map_info map;
};
static int autcpu12_nvram_probe(struct platform_device *pdev)
{
map_word tmp, save0, save1;
struct resource *res;
struct autcpu12_nvram_priv *priv;
priv = devm_kzalloc(&pdev->dev,
sizeof(struct autcpu12_nvram_priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
platform_set_drvdata(pdev, priv);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "failed to get memory resource\n");
return -ENOENT;
}
priv->map.bankwidth = 4;
priv->map.phys = res->start;
priv->map.size = resource_size(res);
priv->map.virt = devm_request_and_ioremap(&pdev->dev, res);
strcpy((char *)priv->map.name, res->name);
if (!priv->map.virt) {
dev_err(&pdev->dev, "failed to remap mem resource\n");
return -EBUSY;
}
simple_map_init(&priv->map);
/*
* Check for 32K/128K
* read ofs 0
* read ofs 0x10000
* Write complement to ofs 0x100000
* Read and check result on ofs 0x0
* Restore contents
*/
save0 = map_read(&priv->map, 0);
save1 = map_read(&priv->map, 0x10000);
tmp.x[0] = ~save0.x[0];
map_write(&priv->map, tmp, 0x10000);
tmp = map_read(&priv->map, 0);
/* if we find this pattern on 0x0, we have 32K size */
if (!map_word_equal(&priv->map, tmp, save0)) {
map_write(&priv->map, save0, 0x0);
priv->map.size = SZ_32K;
} else
map_write(&priv->map, save1, 0x10000);
priv->mtd = do_map_probe("map_ram", &priv->map);
if (!priv->mtd) {
dev_err(&pdev->dev, "probing failed\n");
return -ENXIO;
}
priv->mtd->owner = THIS_MODULE;
priv->mtd->erasesize = 16;
priv->mtd->dev.parent = &pdev->dev;
if (!mtd_device_register(priv->mtd, NULL, 0)) {
dev_info(&pdev->dev,
"NV-RAM device size %ldKiB registered on AUTCPU12\n",
priv->map.size / SZ_1K);
return 0;
}
map_destroy(priv->mtd);
dev_err(&pdev->dev, "NV-RAM device addition failed\n");
return -ENOMEM;
}
static int autcpu12_nvram_remove(struct platform_device *pdev)
{
struct autcpu12_nvram_priv *priv = platform_get_drvdata(pdev);
mtd_device_unregister(priv->mtd);
map_destroy(priv->mtd);
return 0;
}
static struct platform_driver autcpu12_nvram_driver = {
.driver = {
.name = "autcpu12_nvram",
.owner = THIS_MODULE,
},
.probe = autcpu12_nvram_probe,
.remove = autcpu12_nvram_remove,
};
module_platform_driver(autcpu12_nvram_driver);
MODULE_AUTHOR("Thomas Gleixner");
MODULE_DESCRIPTION("autcpu12 NVRAM map driver");
MODULE_LICENSE("GPL");
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