- 根目录:
- drivers
- mtd
- nand
- jz4740_nand.c
/*
* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 SoC NAND controller driver
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/gpio.h>
#include <asm/mach-jz4740/jz4740_nand.h>
#define JZ_REG_NAND_CTRL 0x50
#define JZ_REG_NAND_ECC_CTRL 0x100
#define JZ_REG_NAND_DATA 0x104
#define JZ_REG_NAND_PAR0 0x108
#define JZ_REG_NAND_PAR1 0x10C
#define JZ_REG_NAND_PAR2 0x110
#define JZ_REG_NAND_IRQ_STAT 0x114
#define JZ_REG_NAND_IRQ_CTRL 0x118
#define JZ_REG_NAND_ERR(x) (0x11C + ((x) << 2))
#define JZ_NAND_ECC_CTRL_PAR_READY BIT(4)
#define JZ_NAND_ECC_CTRL_ENCODING BIT(3)
#define JZ_NAND_ECC_CTRL_RS BIT(2)
#define JZ_NAND_ECC_CTRL_RESET BIT(1)
#define JZ_NAND_ECC_CTRL_ENABLE BIT(0)
#define JZ_NAND_STATUS_ERR_COUNT (BIT(31) | BIT(30) | BIT(29))
#define JZ_NAND_STATUS_PAD_FINISH BIT(4)
#define JZ_NAND_STATUS_DEC_FINISH BIT(3)
#define JZ_NAND_STATUS_ENC_FINISH BIT(2)
#define JZ_NAND_STATUS_UNCOR_ERROR BIT(1)
#define JZ_NAND_STATUS_ERROR BIT(0)
#define JZ_NAND_CTRL_ENABLE_CHIP(x) BIT((x) << 1)
#define JZ_NAND_CTRL_ASSERT_CHIP(x) BIT(((x) << 1) + 1)
#define JZ_NAND_MEM_ADDR_OFFSET 0x10000
#define JZ_NAND_MEM_CMD_OFFSET 0x08000
struct jz_nand {
struct mtd_info mtd;
struct nand_chip chip;
void __iomem *base;
struct resource *mem;
void __iomem *bank_base;
struct resource *bank_mem;
struct jz_nand_platform_data *pdata;
bool is_reading;
};
static inline struct jz_nand *mtd_to_jz_nand(struct mtd_info *mtd)
{
return container_of(mtd, struct jz_nand, mtd);
}
static void jz_nand_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
{
struct jz_nand *nand = mtd_to_jz_nand(mtd);
struct nand_chip *chip = mtd->priv;
uint32_t reg;
if (ctrl & NAND_CTRL_CHANGE) {
BUG_ON((ctrl & NAND_ALE) && (ctrl & NAND_CLE));
if (ctrl & NAND_ALE)
chip->IO_ADDR_W = nand->bank_base + JZ_NAND_MEM_ADDR_OFFSET;
else if (ctrl & NAND_CLE)
chip->IO_ADDR_W = nand->bank_base + JZ_NAND_MEM_CMD_OFFSET;
else
chip->IO_ADDR_W = nand->bank_base;
reg = readl(nand->base + JZ_REG_NAND_CTRL);
if (ctrl & NAND_NCE)
reg |= JZ_NAND_CTRL_ASSERT_CHIP(0);
else
reg &= ~JZ_NAND_CTRL_ASSERT_CHIP(0);
writel(reg, nand->base + JZ_REG_NAND_CTRL);
}
if (dat != NAND_CMD_NONE)
writeb(dat, chip->IO_ADDR_W);
}
static int jz_nand_dev_ready(struct mtd_info *mtd)
{
struct jz_nand *nand = mtd_to_jz_nand(mtd);
return gpio_get_value_cansleep(nand->pdata->busy_gpio);
}
static void jz_nand_hwctl(struct mtd_info *mtd, int mode)
{
struct jz_nand *nand = mtd_to_jz_nand(mtd);
uint32_t reg;
writel(0, nand->base + JZ_REG_NAND_IRQ_STAT);
reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
reg |= JZ_NAND_ECC_CTRL_RESET;
reg |= JZ_NAND_ECC_CTRL_ENABLE;
reg |= JZ_NAND_ECC_CTRL_RS;
switch (mode) {
case NAND_ECC_READ:
reg &= ~JZ_NAND_ECC_CTRL_ENCODING;
nand->is_reading = true;
break;
case NAND_ECC_WRITE:
reg |= JZ_NAND_ECC_CTRL_ENCODING;
nand->is_reading = false;
break;
default:
break;
}
writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
}
static int jz_nand_calculate_ecc_rs(struct mtd_info *mtd, const uint8_t *dat,
uint8_t *ecc_code)
{
struct jz_nand *nand = mtd_to_jz_nand(mtd);
uint32_t reg, status;
int i;
unsigned int timeout = 1000;
static uint8_t empty_block_ecc[] = {0xcd, 0x9d, 0x90, 0x58, 0xf4,
0x8b, 0xff, 0xb7, 0x6f};
if (nand->is_reading)
return 0;
do {
status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
} while (!(status & JZ_NAND_STATUS_ENC_FINISH) && --timeout);
if (timeout == 0)
return -1;
reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
for (i = 0; i < 9; ++i)
ecc_code[i] = readb(nand->base + JZ_REG_NAND_PAR0 + i);
/* If the written data is completly 0xff, we also want to write 0xff as
* ecc, otherwise we will get in trouble when doing subpage writes. */
if (memcmp(ecc_code, empty_block_ecc, 9) == 0)
memset(ecc_code, 0xff, 9);
return 0;
}
static void jz_nand_correct_data(uint8_t *dat, int index, int mask)
{
int offset = index & 0x7;
uint16_t data;
index += (index >> 3);
data = dat[index];
data |= dat[index+1] << 8;
mask ^= (data >> offset) & 0x1ff;
data &= ~(0x1ff << offset);
data |= (mask << offset);
dat[index] = data & 0xff;
dat[index+1] = (data >> 8) & 0xff;
}
static int jz_nand_correct_ecc_rs(struct mtd_info *mtd, uint8_t *dat,
uint8_t *read_ecc, uint8_t *calc_ecc)
{
struct jz_nand *nand = mtd_to_jz_nand(mtd);
int i, error_count, index;
uint32_t reg, status, error;
uint32_t t;
unsigned int timeout = 1000;
t = read_ecc[0];
if (t == 0xff) {
for (i = 1; i < 9; ++i)
t &= read_ecc[i];
t &= dat[0];
t &= dat[nand->chip.ecc.size / 2];
t &= dat[nand->chip.ecc.size - 1];
if (t == 0xff) {
for (i = 1; i < nand->chip.ecc.size - 1; ++i)
t &= dat[i];
if (t == 0xff)
return 0;
}
}
for (i = 0; i < 9; ++i)
writeb(read_ecc[i], nand->base + JZ_REG_NAND_PAR0 + i);
reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
reg |= JZ_NAND_ECC_CTRL_PAR_READY;
writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
do {
status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
} while (!(status & JZ_NAND_STATUS_DEC_FINISH) && --timeout);
if (timeout == 0)
return -1;
reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
if (status & JZ_NAND_STATUS_ERROR) {
if (status & JZ_NAND_STATUS_UNCOR_ERROR)
return -1;
error_count = (status & JZ_NAND_STATUS_ERR_COUNT) >> 29;
for (i = 0; i < error_count; ++i) {
error = readl(nand->base + JZ_REG_NAND_ERR(i));
index = ((error >> 16) & 0x1ff) - 1;
if (index >= 0 && index < 512)
jz_nand_correct_data(dat, index, error & 0x1ff);
}
return error_count;
}
return 0;
}
static int jz_nand_ioremap_resource(struct platform_device *pdev,
const char *name, struct resource **res, void __iomem **base)
{
int ret;
*res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
if (!*res) {
dev_err(&pdev->dev, "Failed to get platform %s memory\n", name);
ret = -ENXIO;
goto err;
}
*res = request_mem_region((*res)->start, resource_size(*res),
pdev->name);
if (!*res) {
dev_err(&pdev->dev, "Failed to request %s memory region\n", name);
ret = -EBUSY;
goto err;
}
*base = ioremap((*res)->start, resource_size(*res));
if (!*base) {
dev_err(&pdev->dev, "Failed to ioremap %s memory region\n", name);
ret = -EBUSY;
goto err_release_mem;
}
return 0;
err_release_mem:
release_mem_region((*res)->start, resource_size(*res));
err:
*res = NULL;
*base = NULL;
return ret;
}
static int __devinit jz_nand_probe(struct platform_device *pdev)
{
int ret;
struct jz_nand *nand;
struct nand_chip *chip;
struct mtd_info *mtd;
struct jz_nand_platform_data *pdata = pdev->dev.platform_data;
nand = kzalloc(sizeof(*nand), GFP_KERNEL);
if (!nand) {
dev_err(&pdev->dev, "Failed to allocate device structure.\n");
return -ENOMEM;
}
ret = jz_nand_ioremap_resource(pdev, "mmio", &nand->mem, &nand->base);
if (ret)
goto err_free;
ret = jz_nand_ioremap_resource(pdev, "bank", &nand->bank_mem,
&nand->bank_base);
if (ret)
goto err_iounmap_mmio;
if (pdata && gpio_is_valid(pdata->busy_gpio)) {
ret = gpio_request(pdata->busy_gpio, "NAND busy pin");
if (ret) {
dev_err(&pdev->dev,
"Failed to request busy gpio %d: %d\n",
pdata->busy_gpio, ret);
goto err_iounmap_mem;
}
}
mtd = &nand->mtd;
chip = &nand->chip;
mtd->priv = chip;
mtd->owner = THIS_MODULE;
mtd->name = "jz4740-nand";
chip->ecc.hwctl = jz_nand_hwctl;
chip->ecc.calculate = jz_nand_calculate_ecc_rs;
chip->ecc.correct = jz_nand_correct_ecc_rs;
chip->ecc.mode = NAND_ECC_HW_OOB_FIRST;
chip->ecc.size = 512;
chip->ecc.bytes = 9;
chip->ecc.strength = 2;
/*
* FIXME: ecc_strength value of 2 bits per 512 bytes of data is a
* conservative guess, given 9 ecc bytes and reed-solomon alg.
*/
if (pdata)
chip->ecc.layout = pdata->ecc_layout;
chip->chip_delay = 50;
chip->cmd_ctrl = jz_nand_cmd_ctrl;
if (pdata && gpio_is_valid(pdata->busy_gpio))
chip->dev_ready = jz_nand_dev_ready;
chip->IO_ADDR_R = nand->bank_base;
chip->IO_ADDR_W = nand->bank_base;
nand->pdata = pdata;
platform_set_drvdata(pdev, nand);
writel(JZ_NAND_CTRL_ENABLE_CHIP(0), nand->base + JZ_REG_NAND_CTRL);
ret = nand_scan_ident(mtd, 1, NULL);
if (ret) {
dev_err(&pdev->dev, "Failed to scan nand\n");
goto err_gpio_free;
}
if (pdata && pdata->ident_callback) {
pdata->ident_callback(pdev, chip, &pdata->partitions,
&pdata->num_partitions);
}
ret = nand_scan_tail(mtd);
if (ret) {
dev_err(&pdev->dev, "Failed to scan nand\n");
goto err_gpio_free;
}
ret = mtd_device_parse_register(mtd, NULL, NULL,
pdata ? pdata->partitions : NULL,
pdata ? pdata->num_partitions : 0);
if (ret) {
dev_err(&pdev->dev, "Failed to add mtd device\n");
goto err_nand_release;
}
dev_info(&pdev->dev, "Successfully registered JZ4740 NAND driver\n");
return 0;
err_nand_release:
nand_release(&nand->mtd);
err_gpio_free:
platform_set_drvdata(pdev, NULL);
gpio_free(pdata->busy_gpio);
err_iounmap_mem:
iounmap(nand->bank_base);
err_iounmap_mmio:
iounmap(nand->base);
err_free:
kfree(nand);
return ret;
}
static int __devexit jz_nand_remove(struct platform_device *pdev)
{
struct jz_nand *nand = platform_get_drvdata(pdev);
nand_release(&nand->mtd);
/* Deassert and disable all chips */
writel(0, nand->base + JZ_REG_NAND_CTRL);
iounmap(nand->bank_base);
release_mem_region(nand->bank_mem->start, resource_size(nand->bank_mem));
iounmap(nand->base);
release_mem_region(nand->mem->start, resource_size(nand->mem));
platform_set_drvdata(pdev, NULL);
kfree(nand);
return 0;
}
static struct platform_driver jz_nand_driver = {
.probe = jz_nand_probe,
.remove = __devexit_p(jz_nand_remove),
.driver = {
.name = "jz4740-nand",
.owner = THIS_MODULE,
},
};
module_platform_driver(jz_nand_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("NAND controller driver for JZ4740 SoC");
MODULE_ALIAS("platform:jz4740-nand");