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95 lines
2.3 KiB
C
95 lines
2.3 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation.
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*
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* based on xway_nand.c
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* Copyright © 2012 John Crispin <blogic@openwrt.org>
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* and oxnas_nand.c "NAND glue for Oxnas platforms"
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* written by Ma Haijun <mahaijuns@gmail.com>
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*/
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#include <linux/mtd/nand.h>
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#include <linux/of_gpio.h>
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#include <linux/of_platform.h>
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#include <linux/clk.h>
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#include <linux/reset.h>
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/* nand commands */
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#define NAND_CMD_ALE BIT(18)
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#define NAND_CMD_CLE BIT(19)
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#define NAND_CMD_CS 0
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#define NAND_CMD_RESET 0xff
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#define NAND_CMD (NAND_CMD_CS | NAND_CMD_CLE)
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#define NAND_ADDR (NAND_CMD_CS | NAND_CMD_ALE)
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#define NAND_DATA (NAND_CMD_CS)
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static void oxnas_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
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{
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struct nand_chip *this = mtd->priv;
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unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
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if (ctrl & NAND_CTRL_CHANGE) {
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nandaddr &= ~(NAND_CMD | NAND_ADDR);
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if (ctrl & NAND_CLE)
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nandaddr |= NAND_CMD;
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else if (ctrl & NAND_ALE)
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nandaddr |= NAND_ADDR;
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this->IO_ADDR_W = (void __iomem *) nandaddr;
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}
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if (cmd != NAND_CMD_NONE)
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writeb(cmd, (void __iomem *) nandaddr);
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}
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static int oxnas_nand_probe(struct platform_device *pdev)
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{
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/* enable clock and release static block reset */
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struct clk *clk = of_clk_get(pdev->dev.of_node, 0);
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if (IS_ERR(clk))
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return PTR_ERR(clk);
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clk_prepare_enable(clk);
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device_reset(&pdev->dev);
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return 0;
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}
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/* allow users to override the partition in DT using the cmdline */
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static const char * part_probes[] = { "cmdlinepart", "ofpart", NULL };
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static struct platform_nand_data oxnas_nand_data = {
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.chip = {
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.nr_chips = 1,
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.chip_delay = 30,
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.part_probe_types = part_probes,
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},
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.ctrl = {
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.probe = oxnas_nand_probe,
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.cmd_ctrl = oxnas_cmd_ctrl,
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}
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};
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/*
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* Try to find the node inside the DT. If it is available attach out
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* platform_nand_data
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*/
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static int __init oxnas_register_nand(void)
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{
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struct device_node *node;
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struct platform_device *pdev;
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node = of_find_compatible_node(NULL, NULL, "plxtech,nand-nas782x");
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if (!node)
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return -ENOENT;
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pdev = of_find_device_by_node(node);
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if (!pdev)
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return -EINVAL;
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pdev->dev.platform_data = &oxnas_nand_data;
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of_node_put(node);
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return 0;
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}
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subsys_initcall(oxnas_register_nand);
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