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/*
* Oxford Semiconductor OXNAS NAND driver
* Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
* Heavily based on plat_nand.c :
* Author: Vitaly Wool <vitalywool@gmail.com>
* Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
* Copyright (C) 2012 John Crispin <blogic@openwrt.org>
*
* 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.
*
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/reset.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/partitions.h>
#include <linux/of.h>
/* Nand commands */
#define OXNAS_NAND_CMD_ALE BIT(18)
#define OXNAS_NAND_CMD_CLE BIT(19)
#define OXNAS_NAND_MAX_CHIPS 1
struct oxnas_nand_ctrl {
struct nand_controller base;
void __iomem *io_base;
struct clk *clk;
struct nand_chip *chips[OXNAS_NAND_MAX_CHIPS];
};
static uint8_t oxnas_nand_read_byte(struct nand_chip *chip)
{
struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
return readb(oxnas->io_base);
}
static void oxnas_nand_read_buf(struct nand_chip *chip, u8 *buf, int len)
{
struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
ioread8_rep(oxnas->io_base, buf, len);
}
static void oxnas_nand_write_buf(struct nand_chip *chip, const u8 *buf,
int len)
{
struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
iowrite8_rep(oxnas->io_base, buf, len);
}
/* Single CS command control */
static void oxnas_nand_cmd_ctrl(struct nand_chip *chip, int cmd,
unsigned int ctrl)
{
struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
if (ctrl & NAND_CLE)
writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_CLE);
else if (ctrl & NAND_ALE)
writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_ALE);
}
/*
* Probe for the NAND device.
*/
static int oxnas_nand_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct device_node *nand_np;
struct oxnas_nand_ctrl *oxnas;
struct nand_chip *chip;
struct mtd_info *mtd;
struct resource *res;
int nchips = 0;
int count = 0;
int err = 0;
/* Allocate memory for the device structure (and zero it) */
oxnas = devm_kzalloc(&pdev->dev, sizeof(*oxnas),
GFP_KERNEL);
if (!oxnas)
return -ENOMEM;
nand_controller_init(&oxnas->base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
oxnas->io_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(oxnas->io_base))
return PTR_ERR(oxnas->io_base);
oxnas->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(oxnas->clk))
oxnas->clk = NULL;
/* Only a single chip node is supported */
count = of_get_child_count(np);
if (count > 1)
return -EINVAL;
err = clk_prepare_enable(oxnas->clk);
if (err)
return err;
device_reset_optional(&pdev->dev);
for_each_child_of_node(np, nand_np) {
chip = devm_kzalloc(&pdev->dev, sizeof(struct nand_chip),
GFP_KERNEL);
if (!chip) {
err = -ENOMEM;
goto err_clk_unprepare;
}
chip->controller = &oxnas->base;
nand_set_flash_node(chip, nand_np);
nand_set_controller_data(chip, oxnas);
mtd = nand_to_mtd(chip);
mtd->dev.parent = &pdev->dev;
mtd->priv = chip;
chip->cmd_ctrl = oxnas_nand_cmd_ctrl;
chip->read_buf = oxnas_nand_read_buf;
chip->read_byte = oxnas_nand_read_byte;
chip->write_buf = oxnas_nand_write_buf;
chip->chip_delay = 30;
/* Scan to find existence of the device */
err = nand_scan(chip, 1);
if (err)
goto err_clk_unprepare;
err = mtd_device_register(mtd, NULL, 0);
if (err) {
nand_release(chip);
goto err_clk_unprepare;
}
oxnas->chips[nchips] = chip;
++nchips;
}
/* Exit if no chips found */
if (!nchips) {
err = -ENODEV;
goto err_clk_unprepare;
}
platform_set_drvdata(pdev, oxnas);
return 0;
err_clk_unprepare:
clk_disable_unprepare(oxnas->clk);
return err;
}
static int oxnas_nand_remove(struct platform_device *pdev)
{
struct oxnas_nand_ctrl *oxnas = platform_get_drvdata(pdev);
if (oxnas->chips[0])
nand_release(oxnas->chips[0]);
clk_disable_unprepare(oxnas->clk);
return 0;
}
static const struct of_device_id oxnas_nand_match[] = {
{ .compatible = "oxsemi,ox820-nand" },
{},
};
MODULE_DEVICE_TABLE(of, oxnas_nand_match);
static struct platform_driver oxnas_nand_driver = {
.probe = oxnas_nand_probe,
.remove = oxnas_nand_remove,
.driver = {
.name = "oxnas_nand",
.of_match_table = oxnas_nand_match,
},
};
module_platform_driver(oxnas_nand_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_DESCRIPTION("Oxnas NAND driver");
MODULE_ALIAS("platform:oxnas_nand");
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