linux/drivers/mtd/nand/atmel_nand.c
Artem Bityutskiy 500823195d Revert "mtd: atmel_nand: optimize read/write buffer functions"
This reverts commit fb5427508a.

The reason is that it breaks 16 bits NAND flash as it was reported by
Nikolaus Voss and confirmed by Eric Bénard.

Nicolas Ferre <nicolas.ferre@atmel.com> alco confirmed:
"After double checking with designers, I must admit that I misunderstood
the way of optimizing accesses to SMC. 16 bit nand is not so common
those days..."

Reported-by: Nikolaus Voss <n.voss@weinmann.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [3.1+]
2012-02-04 08:04:57 +00:00

725 lines
17 KiB
C

/*
* Copyright (C) 2003 Rick Bronson
*
* Derived from drivers/mtd/nand/autcpu12.c
* Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
*
* Derived from drivers/mtd/spia.c
* Copyright (C) 2000 Steven J. Hill (sjhill@cotw.com)
*
*
* Add Hardware ECC support for AT91SAM9260 / AT91SAM9263
* Richard Genoud (richard.genoud@gmail.com), Adeneo Copyright (C) 2007
*
* Derived from Das U-Boot source code
* (u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c)
* (C) Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
*
*
* 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/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/dmaengine.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <mach/board.h>
#include <mach/cpu.h>
#ifdef CONFIG_MTD_NAND_ATMEL_ECC_HW
#define hard_ecc 1
#else
#define hard_ecc 0
#endif
#ifdef CONFIG_MTD_NAND_ATMEL_ECC_NONE
#define no_ecc 1
#else
#define no_ecc 0
#endif
static int use_dma = 1;
module_param(use_dma, int, 0);
static int on_flash_bbt = 0;
module_param(on_flash_bbt, int, 0);
/* Register access macros */
#define ecc_readl(add, reg) \
__raw_readl(add + ATMEL_ECC_##reg)
#define ecc_writel(add, reg, value) \
__raw_writel((value), add + ATMEL_ECC_##reg)
#include "atmel_nand_ecc.h" /* Hardware ECC registers */
/* oob layout for large page size
* bad block info is on bytes 0 and 1
* the bytes have to be consecutives to avoid
* several NAND_CMD_RNDOUT during read
*/
static struct nand_ecclayout atmel_oobinfo_large = {
.eccbytes = 4,
.eccpos = {60, 61, 62, 63},
.oobfree = {
{2, 58}
},
};
/* oob layout for small page size
* bad block info is on bytes 4 and 5
* the bytes have to be consecutives to avoid
* several NAND_CMD_RNDOUT during read
*/
static struct nand_ecclayout atmel_oobinfo_small = {
.eccbytes = 4,
.eccpos = {0, 1, 2, 3},
.oobfree = {
{6, 10}
},
};
struct atmel_nand_host {
struct nand_chip nand_chip;
struct mtd_info mtd;
void __iomem *io_base;
dma_addr_t io_phys;
struct atmel_nand_data *board;
struct device *dev;
void __iomem *ecc;
struct completion comp;
struct dma_chan *dma_chan;
};
static int cpu_has_dma(void)
{
return cpu_is_at91sam9rl() || cpu_is_at91sam9g45();
}
/*
* Enable NAND.
*/
static void atmel_nand_enable(struct atmel_nand_host *host)
{
if (gpio_is_valid(host->board->enable_pin))
gpio_set_value(host->board->enable_pin, 0);
}
/*
* Disable NAND.
*/
static void atmel_nand_disable(struct atmel_nand_host *host)
{
if (gpio_is_valid(host->board->enable_pin))
gpio_set_value(host->board->enable_pin, 1);
}
/*
* Hardware specific access to control-lines
*/
static void atmel_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
if (ctrl & NAND_CTRL_CHANGE) {
if (ctrl & NAND_NCE)
atmel_nand_enable(host);
else
atmel_nand_disable(host);
}
if (cmd == NAND_CMD_NONE)
return;
if (ctrl & NAND_CLE)
writeb(cmd, host->io_base + (1 << host->board->cle));
else
writeb(cmd, host->io_base + (1 << host->board->ale));
}
/*
* Read the Device Ready pin.
*/
static int atmel_nand_device_ready(struct mtd_info *mtd)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
return gpio_get_value(host->board->rdy_pin) ^
!!host->board->rdy_pin_active_low;
}
/*
* Minimal-overhead PIO for data access.
*/
static void atmel_read_buf8(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_readsb(nand_chip->IO_ADDR_R, buf, len);
}
static void atmel_read_buf16(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_readsw(nand_chip->IO_ADDR_R, buf, len / 2);
}
static void atmel_write_buf8(struct mtd_info *mtd, const u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_writesb(nand_chip->IO_ADDR_W, buf, len);
}
static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len)
{
struct nand_chip *nand_chip = mtd->priv;
__raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2);
}
static void dma_complete_func(void *completion)
{
complete(completion);
}
static int atmel_nand_dma_op(struct mtd_info *mtd, void *buf, int len,
int is_read)
{
struct dma_device *dma_dev;
enum dma_ctrl_flags flags;
dma_addr_t dma_src_addr, dma_dst_addr, phys_addr;
struct dma_async_tx_descriptor *tx = NULL;
dma_cookie_t cookie;
struct nand_chip *chip = mtd->priv;
struct atmel_nand_host *host = chip->priv;
void *p = buf;
int err = -EIO;
enum dma_data_direction dir = is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
if (buf >= high_memory)
goto err_buf;
dma_dev = host->dma_chan->device;
flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP |
DMA_COMPL_SKIP_DEST_UNMAP;
phys_addr = dma_map_single(dma_dev->dev, p, len, dir);
if (dma_mapping_error(dma_dev->dev, phys_addr)) {
dev_err(host->dev, "Failed to dma_map_single\n");
goto err_buf;
}
if (is_read) {
dma_src_addr = host->io_phys;
dma_dst_addr = phys_addr;
} else {
dma_src_addr = phys_addr;
dma_dst_addr = host->io_phys;
}
tx = dma_dev->device_prep_dma_memcpy(host->dma_chan, dma_dst_addr,
dma_src_addr, len, flags);
if (!tx) {
dev_err(host->dev, "Failed to prepare DMA memcpy\n");
goto err_dma;
}
init_completion(&host->comp);
tx->callback = dma_complete_func;
tx->callback_param = &host->comp;
cookie = tx->tx_submit(tx);
if (dma_submit_error(cookie)) {
dev_err(host->dev, "Failed to do DMA tx_submit\n");
goto err_dma;
}
dma_async_issue_pending(host->dma_chan);
wait_for_completion(&host->comp);
err = 0;
err_dma:
dma_unmap_single(dma_dev->dev, phys_addr, len, dir);
err_buf:
if (err != 0)
dev_warn(host->dev, "Fall back to CPU I/O\n");
return err;
}
static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
{
struct nand_chip *chip = mtd->priv;
struct atmel_nand_host *host = chip->priv;
if (use_dma && len > mtd->oobsize)
/* only use DMA for bigger than oob size: better performances */
if (atmel_nand_dma_op(mtd, buf, len, 1) == 0)
return;
if (host->board->bus_width_16)
atmel_read_buf16(mtd, buf, len);
else
atmel_read_buf8(mtd, buf, len);
}
static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
{
struct nand_chip *chip = mtd->priv;
struct atmel_nand_host *host = chip->priv;
if (use_dma && len > mtd->oobsize)
/* only use DMA for bigger than oob size: better performances */
if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0)
return;
if (host->board->bus_width_16)
atmel_write_buf16(mtd, buf, len);
else
atmel_write_buf8(mtd, buf, len);
}
/*
* Calculate HW ECC
*
* function called after a write
*
* mtd: MTD block structure
* dat: raw data (unused)
* ecc_code: buffer for ECC
*/
static int atmel_nand_calculate(struct mtd_info *mtd,
const u_char *dat, unsigned char *ecc_code)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
unsigned int ecc_value;
/* get the first 2 ECC bytes */
ecc_value = ecc_readl(host->ecc, PR);
ecc_code[0] = ecc_value & 0xFF;
ecc_code[1] = (ecc_value >> 8) & 0xFF;
/* get the last 2 ECC bytes */
ecc_value = ecc_readl(host->ecc, NPR) & ATMEL_ECC_NPARITY;
ecc_code[2] = ecc_value & 0xFF;
ecc_code[3] = (ecc_value >> 8) & 0xFF;
return 0;
}
/*
* HW ECC read page function
*
* mtd: mtd info structure
* chip: nand chip info structure
* buf: buffer to store read data
*/
static int atmel_nand_read_page(struct mtd_info *mtd,
struct nand_chip *chip, uint8_t *buf, int page)
{
int eccsize = chip->ecc.size;
int eccbytes = chip->ecc.bytes;
uint32_t *eccpos = chip->ecc.layout->eccpos;
uint8_t *p = buf;
uint8_t *oob = chip->oob_poi;
uint8_t *ecc_pos;
int stat;
/*
* Errata: ALE is incorrectly wired up to the ECC controller
* on the AP7000, so it will include the address cycles in the
* ECC calculation.
*
* Workaround: Reset the parity registers before reading the
* actual data.
*/
if (cpu_is_at32ap7000()) {
struct atmel_nand_host *host = chip->priv;
ecc_writel(host->ecc, CR, ATMEL_ECC_RST);
}
/* read the page */
chip->read_buf(mtd, p, eccsize);
/* move to ECC position if needed */
if (eccpos[0] != 0) {
/* This only works on large pages
* because the ECC controller waits for
* NAND_CMD_RNDOUTSTART after the
* NAND_CMD_RNDOUT.
* anyway, for small pages, the eccpos[0] == 0
*/
chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
mtd->writesize + eccpos[0], -1);
}
/* the ECC controller needs to read the ECC just after the data */
ecc_pos = oob + eccpos[0];
chip->read_buf(mtd, ecc_pos, eccbytes);
/* check if there's an error */
stat = chip->ecc.correct(mtd, p, oob, NULL);
if (stat < 0)
mtd->ecc_stats.failed++;
else
mtd->ecc_stats.corrected += stat;
/* get back to oob start (end of page) */
chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
/* read the oob */
chip->read_buf(mtd, oob, mtd->oobsize);
return 0;
}
/*
* HW ECC Correction
*
* function called after a read
*
* mtd: MTD block structure
* dat: raw data read from the chip
* read_ecc: ECC from the chip (unused)
* isnull: unused
*
* Detect and correct a 1 bit error for a page
*/
static int atmel_nand_correct(struct mtd_info *mtd, u_char *dat,
u_char *read_ecc, u_char *isnull)
{
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
unsigned int ecc_status;
unsigned int ecc_word, ecc_bit;
/* get the status from the Status Register */
ecc_status = ecc_readl(host->ecc, SR);
/* if there's no error */
if (likely(!(ecc_status & ATMEL_ECC_RECERR)))
return 0;
/* get error bit offset (4 bits) */
ecc_bit = ecc_readl(host->ecc, PR) & ATMEL_ECC_BITADDR;
/* get word address (12 bits) */
ecc_word = ecc_readl(host->ecc, PR) & ATMEL_ECC_WORDADDR;
ecc_word >>= 4;
/* if there are multiple errors */
if (ecc_status & ATMEL_ECC_MULERR) {
/* check if it is a freshly erased block
* (filled with 0xff) */
if ((ecc_bit == ATMEL_ECC_BITADDR)
&& (ecc_word == (ATMEL_ECC_WORDADDR >> 4))) {
/* the block has just been erased, return OK */
return 0;
}
/* it doesn't seems to be a freshly
* erased block.
* We can't correct so many errors */
dev_dbg(host->dev, "atmel_nand : multiple errors detected."
" Unable to correct.\n");
return -EIO;
}
/* if there's a single bit error : we can correct it */
if (ecc_status & ATMEL_ECC_ECCERR) {
/* there's nothing much to do here.
* the bit error is on the ECC itself.
*/
dev_dbg(host->dev, "atmel_nand : one bit error on ECC code."
" Nothing to correct\n");
return 0;
}
dev_dbg(host->dev, "atmel_nand : one bit error on data."
" (word offset in the page :"
" 0x%x bit offset : 0x%x)\n",
ecc_word, ecc_bit);
/* correct the error */
if (nand_chip->options & NAND_BUSWIDTH_16) {
/* 16 bits words */
((unsigned short *) dat)[ecc_word] ^= (1 << ecc_bit);
} else {
/* 8 bits words */
dat[ecc_word] ^= (1 << ecc_bit);
}
dev_dbg(host->dev, "atmel_nand : error corrected\n");
return 1;
}
/*
* Enable HW ECC : unused on most chips
*/
static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
{
if (cpu_is_at32ap7000()) {
struct nand_chip *nand_chip = mtd->priv;
struct atmel_nand_host *host = nand_chip->priv;
ecc_writel(host->ecc, CR, ATMEL_ECC_RST);
}
}
/*
* Probe for the NAND device.
*/
static int __init atmel_nand_probe(struct platform_device *pdev)
{
struct atmel_nand_host *host;
struct mtd_info *mtd;
struct nand_chip *nand_chip;
struct resource *regs;
struct resource *mem;
int res;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem) {
printk(KERN_ERR "atmel_nand: can't get I/O resource mem\n");
return -ENXIO;
}
/* Allocate memory for the device structure (and zero it) */
host = kzalloc(sizeof(struct atmel_nand_host), GFP_KERNEL);
if (!host) {
printk(KERN_ERR "atmel_nand: failed to allocate device structure.\n");
return -ENOMEM;
}
host->io_phys = (dma_addr_t)mem->start;
host->io_base = ioremap(mem->start, resource_size(mem));
if (host->io_base == NULL) {
printk(KERN_ERR "atmel_nand: ioremap failed\n");
res = -EIO;
goto err_nand_ioremap;
}
mtd = &host->mtd;
nand_chip = &host->nand_chip;
host->board = pdev->dev.platform_data;
host->dev = &pdev->dev;
nand_chip->priv = host; /* link the private data structures */
mtd->priv = nand_chip;
mtd->owner = THIS_MODULE;
/* Set address of NAND IO lines */
nand_chip->IO_ADDR_R = host->io_base;
nand_chip->IO_ADDR_W = host->io_base;
nand_chip->cmd_ctrl = atmel_nand_cmd_ctrl;
if (gpio_is_valid(host->board->rdy_pin))
nand_chip->dev_ready = atmel_nand_device_ready;
regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!regs && hard_ecc) {
printk(KERN_ERR "atmel_nand: can't get I/O resource "
"regs\nFalling back on software ECC\n");
}
nand_chip->ecc.mode = NAND_ECC_SOFT; /* enable ECC */
if (no_ecc)
nand_chip->ecc.mode = NAND_ECC_NONE;
if (hard_ecc && regs) {
host->ecc = ioremap(regs->start, resource_size(regs));
if (host->ecc == NULL) {
printk(KERN_ERR "atmel_nand: ioremap failed\n");
res = -EIO;
goto err_ecc_ioremap;
}
nand_chip->ecc.mode = NAND_ECC_HW;
nand_chip->ecc.calculate = atmel_nand_calculate;
nand_chip->ecc.correct = atmel_nand_correct;
nand_chip->ecc.hwctl = atmel_nand_hwctl;
nand_chip->ecc.read_page = atmel_nand_read_page;
nand_chip->ecc.bytes = 4;
}
nand_chip->chip_delay = 20; /* 20us command delay time */
if (host->board->bus_width_16) /* 16-bit bus width */
nand_chip->options |= NAND_BUSWIDTH_16;
nand_chip->read_buf = atmel_read_buf;
nand_chip->write_buf = atmel_write_buf;
platform_set_drvdata(pdev, host);
atmel_nand_enable(host);
if (gpio_is_valid(host->board->det_pin)) {
if (gpio_get_value(host->board->det_pin)) {
printk(KERN_INFO "No SmartMedia card inserted.\n");
res = -ENXIO;
goto err_no_card;
}
}
if (on_flash_bbt) {
printk(KERN_INFO "atmel_nand: Use On Flash BBT\n");
nand_chip->bbt_options |= NAND_BBT_USE_FLASH;
}
if (!cpu_has_dma())
use_dma = 0;
if (use_dma) {
dma_cap_mask_t mask;
dma_cap_zero(mask);
dma_cap_set(DMA_MEMCPY, mask);
host->dma_chan = dma_request_channel(mask, NULL, NULL);
if (!host->dma_chan) {
dev_err(host->dev, "Failed to request DMA channel\n");
use_dma = 0;
}
}
if (use_dma)
dev_info(host->dev, "Using %s for DMA transfers.\n",
dma_chan_name(host->dma_chan));
else
dev_info(host->dev, "No DMA support for NAND access.\n");
/* first scan to find the device and get the page size */
if (nand_scan_ident(mtd, 1, NULL)) {
res = -ENXIO;
goto err_scan_ident;
}
if (nand_chip->ecc.mode == NAND_ECC_HW) {
/* ECC is calculated for the whole page (1 step) */
nand_chip->ecc.size = mtd->writesize;
/* set ECC page size and oob layout */
switch (mtd->writesize) {
case 512:
nand_chip->ecc.layout = &atmel_oobinfo_small;
ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_528);
break;
case 1024:
nand_chip->ecc.layout = &atmel_oobinfo_large;
ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_1056);
break;
case 2048:
nand_chip->ecc.layout = &atmel_oobinfo_large;
ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_2112);
break;
case 4096:
nand_chip->ecc.layout = &atmel_oobinfo_large;
ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_4224);
break;
default:
/* page size not handled by HW ECC */
/* switching back to soft ECC */
nand_chip->ecc.mode = NAND_ECC_SOFT;
nand_chip->ecc.calculate = NULL;
nand_chip->ecc.correct = NULL;
nand_chip->ecc.hwctl = NULL;
nand_chip->ecc.read_page = NULL;
nand_chip->ecc.postpad = 0;
nand_chip->ecc.prepad = 0;
nand_chip->ecc.bytes = 0;
break;
}
}
/* second phase scan */
if (nand_scan_tail(mtd)) {
res = -ENXIO;
goto err_scan_tail;
}
mtd->name = "atmel_nand";
res = mtd_device_parse_register(mtd, NULL, 0,
host->board->parts, host->board->num_parts);
if (!res)
return res;
err_scan_tail:
err_scan_ident:
err_no_card:
atmel_nand_disable(host);
platform_set_drvdata(pdev, NULL);
if (host->dma_chan)
dma_release_channel(host->dma_chan);
if (host->ecc)
iounmap(host->ecc);
err_ecc_ioremap:
iounmap(host->io_base);
err_nand_ioremap:
kfree(host);
return res;
}
/*
* Remove a NAND device.
*/
static int __exit atmel_nand_remove(struct platform_device *pdev)
{
struct atmel_nand_host *host = platform_get_drvdata(pdev);
struct mtd_info *mtd = &host->mtd;
nand_release(mtd);
atmel_nand_disable(host);
if (host->ecc)
iounmap(host->ecc);
if (host->dma_chan)
dma_release_channel(host->dma_chan);
iounmap(host->io_base);
kfree(host);
return 0;
}
static struct platform_driver atmel_nand_driver = {
.remove = __exit_p(atmel_nand_remove),
.driver = {
.name = "atmel_nand",
.owner = THIS_MODULE,
},
};
static int __init atmel_nand_init(void)
{
return platform_driver_probe(&atmel_nand_driver, atmel_nand_probe);
}
static void __exit atmel_nand_exit(void)
{
platform_driver_unregister(&atmel_nand_driver);
}
module_init(atmel_nand_init);
module_exit(atmel_nand_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Rick Bronson");
MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91 / AVR32");
MODULE_ALIAS("platform:atmel_nand");