Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | /*
* 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_hw_control base;
void __iomem *io_base;
struct clk *clk;
struct nand_chip *chips[OXNAS_NAND_MAX_CHIPS];
};
static uint8_t oxnas_nand_read_byte(struct mtd_info *mtd)
{
struct nand_chip *chip = mtd_to_nand(mtd);
struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
return readb(oxnas->io_base);
}
static void oxnas_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *chip = mtd_to_nand(mtd);
struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
ioread8_rep(oxnas->io_base, buf, len);
}
static void oxnas_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
{
struct nand_chip *chip = mtd_to_nand(mtd);
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 mtd_info *mtd, int cmd,
unsigned int ctrl)
{
struct nand_chip *chip = mtd_to_nand(mtd);
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_hw_control_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(mtd, 1);
if (err)
goto err_clk_unprepare;
err = mtd_device_register(mtd, NULL, 0);
if (err) {
nand_release(mtd);
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(nand_to_mtd(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");
|