openwrt-owl/target/linux/oxnas/files/drivers/mtd/nand/oxnas_nand.c

91 lines
2.1 KiB
C

/*
* 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.
*
* based on xway_nand.c
* Copyright © 2012 John Crispin <blogic@openwrt.org>
* and oxnas_nand.c "NAND glue for Oxnas platforms"
* written by Ma Haijun <mahaijuns@gmail.com>
*/
#include <linux/mtd/nand.h>
#include <linux/of_gpio.h>
#include <linux/of_platform.h>
#include <linux/clk.h>
#include <linux/reset.h>
/* nand commands */
#define NAND_CMD_ALE BIT(18)
#define NAND_CMD_CLE BIT(19)
#define NAND_CMD_CS 0
#define NAND_CMD_RESET 0xff
#define NAND_CMD (NAND_CMD_CS | NAND_CMD_CLE)
#define NAND_ADDR (NAND_CMD_CS | NAND_CMD_ALE)
#define NAND_DATA (NAND_CMD_CS)
static void oxnas_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct nand_chip *this = mtd->priv;
unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
if (ctrl & NAND_CTRL_CHANGE) {
nandaddr &= ~(NAND_CMD | NAND_ADDR);
if (ctrl & NAND_CLE)
nandaddr |= NAND_CMD;
else if (ctrl & NAND_ALE)
nandaddr |= NAND_ADDR;
this->IO_ADDR_W = (void __iomem *) nandaddr;
}
if (cmd != NAND_CMD_NONE)
writeb(cmd, (void __iomem *) nandaddr);
}
static int oxnas_nand_probe(struct platform_device *pdev)
{
/* enable clock and release static block reset */
struct clk *clk = of_clk_get(pdev->dev.of_node, 0);
if (IS_ERR(clk))
return PTR_ERR(clk);
clk_prepare_enable(clk);
device_reset(&pdev->dev);
return 0;
}
static struct platform_nand_data oxnas_nand_data = {
.chip = {
.nr_chips = 1,
.chip_delay = 30,
},
.ctrl = {
.probe = oxnas_nand_probe,
.cmd_ctrl = oxnas_cmd_ctrl,
}
};
/*
* Try to find the node inside the DT. If it is available attach out
* platform_nand_data
*/
static int __init oxnas_register_nand(void)
{
struct device_node *node;
struct platform_device *pdev;
node = of_find_compatible_node(NULL, NULL, "plxtech,nand-nas782x");
if (!node)
return -ENOENT;
pdev = of_find_device_by_node(node);
if (!pdev)
return -EINVAL;
pdev->dev.platform_data = &oxnas_nand_data;
of_node_put(node);
return 0;
}
subsys_initcall(oxnas_register_nand);