130 lines
3.4 KiB
C
130 lines
3.4 KiB
C
/*
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* NV-RAM memory access on autcpu12
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* (C) 2002 Thomas Gleixner (gleixner@autronix.de)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/err.h>
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#include <linux/sizes.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/map.h>
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struct autcpu12_nvram_priv {
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struct mtd_info *mtd;
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struct map_info map;
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};
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static int autcpu12_nvram_probe(struct platform_device *pdev)
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{
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map_word tmp, save0, save1;
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struct resource *res;
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struct autcpu12_nvram_priv *priv;
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priv = devm_kzalloc(&pdev->dev,
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sizeof(struct autcpu12_nvram_priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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platform_set_drvdata(pdev, priv);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(&pdev->dev, "failed to get memory resource\n");
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return -ENOENT;
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}
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priv->map.bankwidth = 4;
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priv->map.phys = res->start;
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priv->map.size = resource_size(res);
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priv->map.virt = devm_ioremap_resource(&pdev->dev, res);
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strcpy((char *)priv->map.name, res->name);
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if (IS_ERR(priv->map.virt))
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return PTR_ERR(priv->map.virt);
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simple_map_init(&priv->map);
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/*
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* Check for 32K/128K
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* read ofs 0
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* read ofs 0x10000
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* Write complement to ofs 0x100000
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* Read and check result on ofs 0x0
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* Restore contents
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*/
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save0 = map_read(&priv->map, 0);
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save1 = map_read(&priv->map, 0x10000);
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tmp.x[0] = ~save0.x[0];
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map_write(&priv->map, tmp, 0x10000);
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tmp = map_read(&priv->map, 0);
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/* if we find this pattern on 0x0, we have 32K size */
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if (!map_word_equal(&priv->map, tmp, save0)) {
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map_write(&priv->map, save0, 0x0);
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priv->map.size = SZ_32K;
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} else
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map_write(&priv->map, save1, 0x10000);
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priv->mtd = do_map_probe("map_ram", &priv->map);
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if (!priv->mtd) {
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dev_err(&pdev->dev, "probing failed\n");
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return -ENXIO;
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}
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priv->mtd->owner = THIS_MODULE;
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priv->mtd->erasesize = 16;
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priv->mtd->dev.parent = &pdev->dev;
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if (!mtd_device_register(priv->mtd, NULL, 0)) {
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dev_info(&pdev->dev,
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"NV-RAM device size %ldKiB registered on AUTCPU12\n",
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priv->map.size / SZ_1K);
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return 0;
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}
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map_destroy(priv->mtd);
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dev_err(&pdev->dev, "NV-RAM device addition failed\n");
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return -ENOMEM;
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}
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static int autcpu12_nvram_remove(struct platform_device *pdev)
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{
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struct autcpu12_nvram_priv *priv = platform_get_drvdata(pdev);
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mtd_device_unregister(priv->mtd);
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map_destroy(priv->mtd);
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return 0;
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}
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static struct platform_driver autcpu12_nvram_driver = {
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.driver = {
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.name = "autcpu12_nvram",
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.owner = THIS_MODULE,
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},
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.probe = autcpu12_nvram_probe,
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.remove = autcpu12_nvram_remove,
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};
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module_platform_driver(autcpu12_nvram_driver);
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MODULE_AUTHOR("Thomas Gleixner");
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MODULE_DESCRIPTION("autcpu12 NVRAM map driver");
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MODULE_LICENSE("GPL");
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