OpenWrt – Rev 1
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/*
* NAND flash driver for the MikroTik RouterBOARD 750
*
* Copyright (C) 2010-2012 Gabor Juhos <juhosg@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/version.h>
#include <linux/kernel.h>
#include <linux/module.h>
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,14,0)
#include <linux/mtd/nand.h>
#else
#include <linux/mtd/rawnand.h>
#endif
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/mach-rb750.h>
#define DRV_NAME "rb750-nand"
#define DRV_VERSION "0.1.0"
#define DRV_DESC "NAND flash driver for the RouterBOARD 750"
#define RB750_NAND_IO0 BIT(RB750_GPIO_NAND_IO0)
#define RB750_NAND_ALE BIT(RB750_GPIO_NAND_ALE)
#define RB750_NAND_CLE BIT(RB750_GPIO_NAND_CLE)
#define RB750_NAND_NRE BIT(RB750_GPIO_NAND_NRE)
#define RB750_NAND_NWE BIT(RB750_GPIO_NAND_NWE)
#define RB750_NAND_RDY BIT(RB750_GPIO_NAND_RDY)
#define RB750_NAND_DATA_SHIFT 1
#define RB750_NAND_DATA_BITS (0xff << RB750_NAND_DATA_SHIFT)
#define RB750_NAND_INPUT_BITS (RB750_NAND_DATA_BITS | RB750_NAND_RDY)
#define RB750_NAND_OUTPUT_BITS (RB750_NAND_ALE | RB750_NAND_CLE | \
RB750_NAND_NRE | RB750_NAND_NWE)
struct rb750_nand_info {
struct nand_chip chip;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
struct mtd_info mtd;
#endif
struct rb7xx_nand_platform_data *pdata;
};
static inline struct rb750_nand_info *mtd_to_rbinfo(struct mtd_info *mtd)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
return container_of(mtd, struct rb750_nand_info, mtd);
#else
struct nand_chip *chip = mtd_to_nand(mtd);
return container_of(chip, struct rb750_nand_info, chip);
#endif
}
static struct mtd_info *rbinfo_to_mtd(struct rb750_nand_info *nfc)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
return &nfc->mtd;
#else
return nand_to_mtd(&nfc->chip);
#endif
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
/*
* We need to use the OLD Yaffs-1 OOB layout, otherwise the RB bootloader
* will not be able to find the kernel that we load.
*/
static struct nand_ecclayout rb750_nand_ecclayout = {
.eccbytes = 6,
.eccpos = { 8, 9, 10, 13, 14, 15 },
.oobavail = 9,
.oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
};
#else
static int rb750_ooblayout_ecc(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
switch (section) {
case 0:
oobregion->offset = 8;
oobregion->length = 3;
return 0;
case 1:
oobregion->offset = 13;
oobregion->length = 3;
return 0;
default:
return -ERANGE;
}
}
static int rb750_ooblayout_free(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
switch (section) {
case 0:
oobregion->offset = 0;
oobregion->length = 4;
return 0;
case 1:
oobregion->offset = 4;
oobregion->length = 1;
return 0;
case 2:
oobregion->offset = 6;
oobregion->length = 2;
return 0;
case 3:
oobregion->offset = 11;
oobregion->length = 2;
return 0;
default:
return -ERANGE;
}
}
static const struct mtd_ooblayout_ops rb750_nand_ecclayout_ops = {
.ecc = rb750_ooblayout_ecc,
.free = rb750_ooblayout_free,
};
#endif /* < 4.6 */
static struct mtd_partition rb750_nand_partitions[] = {
{
.name = "booter",
.offset = 0,
.size = (256 * 1024),
.mask_flags = MTD_WRITEABLE,
}, {
.name = "kernel",
.offset = (256 * 1024),
.size = (4 * 1024 * 1024) - (256 * 1024),
}, {
.name = "ubi",
.offset = MTDPART_OFS_NXTBLK,
.size = MTDPART_SIZ_FULL,
},
};
static void rb750_nand_write(const u8 *buf, unsigned len)
{
void __iomem *base = ath79_gpio_base;
u32 out;
u32 t;
unsigned i;
/* set data lines to output mode */
t = __raw_readl(base + AR71XX_GPIO_REG_OE);
__raw_writel(t | RB750_NAND_DATA_BITS, base + AR71XX_GPIO_REG_OE);
out = __raw_readl(base + AR71XX_GPIO_REG_OUT);
out &= ~(RB750_NAND_DATA_BITS | RB750_NAND_NWE);
for (i = 0; i != len; i++) {
u32 data;
data = buf[i];
data <<= RB750_NAND_DATA_SHIFT;
data |= out;
__raw_writel(data, base + AR71XX_GPIO_REG_OUT);
__raw_writel(data | RB750_NAND_NWE, base + AR71XX_GPIO_REG_OUT);
/* flush write */
__raw_readl(base + AR71XX_GPIO_REG_OUT);
}
/* set data lines to input mode */
t = __raw_readl(base + AR71XX_GPIO_REG_OE);
__raw_writel(t & ~RB750_NAND_DATA_BITS, base + AR71XX_GPIO_REG_OE);
/* flush write */
__raw_readl(base + AR71XX_GPIO_REG_OE);
}
static void rb750_nand_read(u8 *read_buf, unsigned len)
{
void __iomem *base = ath79_gpio_base;
unsigned i;
for (i = 0; i < len; i++) {
u8 data;
/* activate RE line */
__raw_writel(RB750_NAND_NRE, base + AR71XX_GPIO_REG_CLEAR);
/* flush write */
__raw_readl(base + AR71XX_GPIO_REG_CLEAR);
/* read input lines */
data = __raw_readl(base + AR71XX_GPIO_REG_IN) >>
RB750_NAND_DATA_SHIFT;
/* deactivate RE line */
__raw_writel(RB750_NAND_NRE, base + AR71XX_GPIO_REG_SET);
read_buf[i] = data;
}
}
static void rb750_nand_select_chip(struct mtd_info *mtd, int chip)
{
struct rb750_nand_info *rbinfo = mtd_to_rbinfo(mtd);
void __iomem *base = ath79_gpio_base;
u32 t;
if (chip >= 0) {
rbinfo->pdata->enable_pins();
/* set input mode for data lines */
t = __raw_readl(base + AR71XX_GPIO_REG_OE);
__raw_writel(t & ~RB750_NAND_INPUT_BITS,
base + AR71XX_GPIO_REG_OE);
/* deactivate RE and WE lines */
__raw_writel(RB750_NAND_NRE | RB750_NAND_NWE,
base + AR71XX_GPIO_REG_SET);
/* flush write */
(void) __raw_readl(base + AR71XX_GPIO_REG_SET);
/* activate CE line */
__raw_writel(rbinfo->pdata->nce_line,
base + AR71XX_GPIO_REG_CLEAR);
} else {
/* deactivate CE line */
__raw_writel(rbinfo->pdata->nce_line,
base + AR71XX_GPIO_REG_SET);
/* flush write */
(void) __raw_readl(base + AR71XX_GPIO_REG_SET);
t = __raw_readl(base + AR71XX_GPIO_REG_OE);
__raw_writel(t | RB750_NAND_IO0 | RB750_NAND_RDY,
base + AR71XX_GPIO_REG_OE);
rbinfo->pdata->disable_pins();
}
}
static int rb750_nand_dev_ready(struct mtd_info *mtd)
{
void __iomem *base = ath79_gpio_base;
return !!(__raw_readl(base + AR71XX_GPIO_REG_IN) & RB750_NAND_RDY);
}
static void rb750_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
unsigned int ctrl)
{
if (ctrl & NAND_CTRL_CHANGE) {
void __iomem *base = ath79_gpio_base;
u32 t;
t = __raw_readl(base + AR71XX_GPIO_REG_OUT);
t &= ~(RB750_NAND_CLE | RB750_NAND_ALE);
t |= (ctrl & NAND_CLE) ? RB750_NAND_CLE : 0;
t |= (ctrl & NAND_ALE) ? RB750_NAND_ALE : 0;
__raw_writel(t, base + AR71XX_GPIO_REG_OUT);
/* flush write */
__raw_readl(base + AR71XX_GPIO_REG_OUT);
}
if (cmd != NAND_CMD_NONE) {
u8 t = cmd;
rb750_nand_write(&t, 1);
}
}
static u8 rb750_nand_read_byte(struct mtd_info *mtd)
{
u8 data = 0;
rb750_nand_read(&data, 1);
return data;
}
static void rb750_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len)
{
rb750_nand_read(buf, len);
}
static void rb750_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
{
rb750_nand_write(buf, len);
}
static void __init rb750_nand_gpio_init(struct rb750_nand_info *info)
{
void __iomem *base = ath79_gpio_base;
u32 out;
u32 t;
out = __raw_readl(base + AR71XX_GPIO_REG_OUT);
/* setup output levels */
__raw_writel(RB750_NAND_NCE | RB750_NAND_NRE | RB750_NAND_NWE,
base + AR71XX_GPIO_REG_SET);
__raw_writel(RB750_NAND_ALE | RB750_NAND_CLE,
base + AR71XX_GPIO_REG_CLEAR);
/* setup input lines */
t = __raw_readl(base + AR71XX_GPIO_REG_OE);
__raw_writel(t & ~(RB750_NAND_INPUT_BITS), base + AR71XX_GPIO_REG_OE);
/* setup output lines */
t = __raw_readl(base + AR71XX_GPIO_REG_OE);
t |= RB750_NAND_OUTPUT_BITS;
t |= info->pdata->nce_line;
__raw_writel(t, base + AR71XX_GPIO_REG_OE);
info->pdata->latch_change(~out & RB750_NAND_IO0, out & RB750_NAND_IO0);
}
static int rb750_nand_probe(struct platform_device *pdev)
{
struct rb750_nand_info *info;
struct rb7xx_nand_platform_data *pdata;
struct mtd_info *mtd;
int ret;
printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
pdata = pdev->dev.platform_data;
if (!pdata)
return -EINVAL;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->chip.priv = &info;
mtd = rbinfo_to_mtd(info);
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
mtd->priv = &info->chip;
#endif
mtd->owner = THIS_MODULE;
info->chip.select_chip = rb750_nand_select_chip;
info->chip.cmd_ctrl = rb750_nand_cmd_ctrl;
info->chip.dev_ready = rb750_nand_dev_ready;
info->chip.read_byte = rb750_nand_read_byte;
info->chip.write_buf = rb750_nand_write_buf;
info->chip.read_buf = rb750_nand_read_buf;
info->chip.chip_delay = 25;
info->chip.ecc.mode = NAND_ECC_SOFT;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0)
info->chip.ecc.algo = NAND_ECC_HAMMING;
#endif
info->chip.options = NAND_NO_SUBPAGE_WRITE;
info->pdata = pdata;
platform_set_drvdata(pdev, info);
rb750_nand_gpio_init(info);
ret = nand_scan_ident(mtd, 1, NULL);
if (ret) {
ret = -ENXIO;
goto err_free_info;
}
if (mtd->writesize == 512)
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,6,0)
info->chip.ecc.layout = &rb750_nand_ecclayout;
#else
mtd_set_ooblayout(mtd, &rb750_nand_ecclayout_ops);
#endif
ret = nand_scan_tail(mtd);
if (ret) {
return -ENXIO;
goto err_set_drvdata;
}
ret = mtd_device_register(mtd, rb750_nand_partitions,
ARRAY_SIZE(rb750_nand_partitions));
if (ret)
goto err_release_nand;
return 0;
err_release_nand:
nand_release(mtd);
err_set_drvdata:
platform_set_drvdata(pdev, NULL);
err_free_info:
kfree(info);
return ret;
}
static int rb750_nand_remove(struct platform_device *pdev)
{
struct rb750_nand_info *info = platform_get_drvdata(pdev);
nand_release(rbinfo_to_mtd(info));
platform_set_drvdata(pdev, NULL);
kfree(info);
return 0;
}
static struct platform_driver rb750_nand_driver = {
.probe = rb750_nand_probe,
.remove = rb750_nand_remove,
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
};
static int __init rb750_nand_init(void)
{
return platform_driver_register(&rb750_nand_driver);
}
static void __exit rb750_nand_exit(void)
{
platform_driver_unregister(&rb750_nand_driver);
}
module_init(rb750_nand_init);
module_exit(rb750_nand_exit);
MODULE_DESCRIPTION(DRV_DESC);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_LICENSE("GPL v2");