- 根目录:
- drivers
- mtd
- nand
- rtc_from4.c
/*
* drivers/mtd/nand/rtc_from4.c
*
* Copyright (C) 2004 Red Hat, Inc.
*
* Derived from drivers/mtd/nand/spia.c
* Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
*
* 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.
*
* Overview:
* This is a device driver for the AG-AND flash device found on the
* Renesas Technology Corp. Flash ROM 4-slot interface board (FROM_BOARD4),
* which utilizes the Renesas HN29V1G91T-30 part.
* This chip is a 1 GBibit (128MiB x 8 bits) AG-AND flash device.
*/
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/rslib.h>
#include <linux/bitrev.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
/*
* MTD structure for Renesas board
*/
static struct mtd_info *rtc_from4_mtd = NULL;
#define RTC_FROM4_MAX_CHIPS 2
/* HS77x9 processor register defines */
#define SH77X9_BCR1 ((volatile unsigned short *)(0xFFFFFF60))
#define SH77X9_BCR2 ((volatile unsigned short *)(0xFFFFFF62))
#define SH77X9_WCR1 ((volatile unsigned short *)(0xFFFFFF64))
#define SH77X9_WCR2 ((volatile unsigned short *)(0xFFFFFF66))
#define SH77X9_MCR ((volatile unsigned short *)(0xFFFFFF68))
#define SH77X9_PCR ((volatile unsigned short *)(0xFFFFFF6C))
#define SH77X9_FRQCR ((volatile unsigned short *)(0xFFFFFF80))
/*
* Values specific to the Renesas Technology Corp. FROM_BOARD4 (used with HS77x9 processor)
*/
/* Address where flash is mapped */
#define RTC_FROM4_FIO_BASE 0x14000000
/* CLE and ALE are tied to address lines 5 & 4, respectively */
#define RTC_FROM4_CLE (1 << 5)
#define RTC_FROM4_ALE (1 << 4)
/* address lines A24-A22 used for chip selection */
#define RTC_FROM4_NAND_ADDR_SLOT3 (0x00800000)
#define RTC_FROM4_NAND_ADDR_SLOT4 (0x00C00000)
#define RTC_FROM4_NAND_ADDR_FPGA (0x01000000)
/* mask address lines A24-A22 used for chip selection */
#define RTC_FROM4_NAND_ADDR_MASK (RTC_FROM4_NAND_ADDR_SLOT3 | RTC_FROM4_NAND_ADDR_SLOT4 | RTC_FROM4_NAND_ADDR_FPGA)
/* FPGA status register for checking device ready (bit zero) */
#define RTC_FROM4_FPGA_SR (RTC_FROM4_NAND_ADDR_FPGA | 0x00000002)
#define RTC_FROM4_DEVICE_READY 0x0001
/* FPGA Reed-Solomon ECC Control register */
#define RTC_FROM4_RS_ECC_CTL (RTC_FROM4_NAND_ADDR_FPGA | 0x00000050)
#define RTC_FROM4_RS_ECC_CTL_CLR (1 << 7)
#define RTC_FROM4_RS_ECC_CTL_GEN (1 << 6)
#define RTC_FROM4_RS_ECC_CTL_FD_E (1 << 5)
/* FPGA Reed-Solomon ECC code base */
#define RTC_FROM4_RS_ECC (RTC_FROM4_NAND_ADDR_FPGA | 0x00000060)
#define RTC_FROM4_RS_ECCN (RTC_FROM4_NAND_ADDR_FPGA | 0x00000080)
/* FPGA Reed-Solomon ECC check register */
#define RTC_FROM4_RS_ECC_CHK (RTC_FROM4_NAND_ADDR_FPGA | 0x00000070)
#define RTC_FROM4_RS_ECC_CHK_ERROR (1 << 7)
#define ERR_STAT_ECC_AVAILABLE 0x20
/* Undefine for software ECC */
#define RTC_FROM4_HWECC 1
/* Define as 1 for no virtual erase blocks (in JFFS2) */
#define RTC_FROM4_NO_VIRTBLOCKS 0
/*
* Module stuff
*/
static void __iomem *rtc_from4_fio_base = (void *)P2SEGADDR(RTC_FROM4_FIO_BASE);
static const struct mtd_partition partition_info[] = {
{
.name = "Renesas flash partition 1",
.offset = 0,
.size = MTDPART_SIZ_FULL},
};
#define NUM_PARTITIONS 1
/*
* hardware specific flash bbt decriptors
* Note: this is to allow debugging by disabling
* NAND_BBT_CREATE and/or NAND_BBT_WRITE
*
*/
static uint8_t bbt_pattern[] = { 'B', 'b', 't', '0' };
static uint8_t mirror_pattern[] = { '1', 't', 'b', 'B' };
static struct nand_bbt_descr rtc_from4_bbt_main_descr = {
.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
.offs = 40,
.len = 4,
.veroffs = 44,
.maxblocks = 4,
.pattern = bbt_pattern
};
static struct nand_bbt_descr rtc_from4_bbt_mirror_descr = {
.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
.offs = 40,
.len = 4,
.veroffs = 44,
.maxblocks = 4,
.pattern = mirror_pattern
};
#ifdef RTC_FROM4_HWECC
/* the Reed Solomon control structure */
static struct rs_control *rs_decoder;
/*
* hardware specific Out Of Band information
*/
static struct nand_ecclayout rtc_from4_nand_oobinfo = {
.eccbytes = 32,
.eccpos = {
0, 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},
.oobfree = {{32, 32}}
};
#endif
/*
* rtc_from4_hwcontrol - hardware specific access to control-lines
* @mtd: MTD device structure
* @cmd: hardware control command
*
* Address lines (A5 and A4) are used to control Command and Address Latch
* Enable on this board, so set the read/write address appropriately.
*
* Chip Enable is also controlled by the Chip Select (CS5) and
* Address lines (A24-A22), so no action is required here.
*
*/
static void rtc_from4_hwcontrol(struct mtd_info *mtd, int cmd,
unsigned int ctrl)
{
struct nand_chip *chip = (mtd->priv);
if (cmd == NAND_CMD_NONE)
return;
if (ctrl & NAND_CLE)
writeb(cmd, chip->IO_ADDR_W | RTC_FROM4_CLE);
else
writeb(cmd, chip->IO_ADDR_W | RTC_FROM4_ALE);
}
/*
* rtc_from4_nand_select_chip - hardware specific chip select
* @mtd: MTD device structure
* @chip: Chip to select (0 == slot 3, 1 == slot 4)
*
* The chip select is based on address lines A24-A22.
* This driver uses flash slots 3 and 4 (A23-A22).
*
*/
static void rtc_from4_nand_select_chip(struct mtd_info *mtd, int chip)
{
struct nand_chip *this = mtd->priv;
this->IO_ADDR_R = (void __iomem *)((unsigned long)this->IO_ADDR_R & ~RTC_FROM4_NAND_ADDR_MASK);
this->IO_ADDR_W = (void __iomem *)((unsigned long)this->IO_ADDR_W & ~RTC_FROM4_NAND_ADDR_MASK);
switch (chip) {
case 0: /* select slot 3 chip */
this->IO_ADDR_R = (void __iomem *)((unsigned long)this->IO_ADDR_R | RTC_FROM4_NAND_ADDR_SLOT3);
this->IO_ADDR_W = (void __iomem *)((unsigned long)this->IO_ADDR_W | RTC_FROM4_NAND_ADDR_SLOT3);
break;
case 1: /* select slot 4 chip */
this->IO_ADDR_R = (void __iomem *)((unsigned long)this->IO_ADDR_R | RTC_FROM4_NAND_ADDR_SLOT4);
this->IO_ADDR_W = (void __iomem *)((unsigned long)this->IO_ADDR_W | RTC_FROM4_NAND_ADDR_SLOT4);
break;
}
}
/*
* rtc_from4_nand_device_ready - hardware specific ready/busy check
* @mtd: MTD device structure
*
* This board provides the Ready/Busy state in the status register
* of the FPGA. Bit zero indicates the RDY(1)/BSY(0) signal.
*
*/
static int rtc_from4_nand_device_ready(struct mtd_info *mtd)
{
unsigned short status;
status = *((volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_FPGA_SR));
return (status & RTC_FROM4_DEVICE_READY);
}
/*
* deplete - code to perform device recovery in case there was a power loss
* @mtd: MTD device structure
* @chip: Chip to select (0 == slot 3, 1 == slot 4)
*
* If there was a sudden loss of power during an erase operation, a
* "device recovery" operation must be performed when power is restored
* to ensure correct operation. This routine performs the required steps
* for the requested chip.
*
* See page 86 of the data sheet for details.
*
*/
static void deplete(struct mtd_info *mtd, int chip)
{
struct nand_chip *this = mtd->priv;
/* wait until device is ready */
while (!this->dev_ready(mtd)) ;
this->select_chip(mtd, chip);
/* Send the commands for device recovery, phase 1 */
this->cmdfunc(mtd, NAND_CMD_DEPLETE1, 0x0000, 0x0000);
this->cmdfunc(mtd, NAND_CMD_DEPLETE2, -1, -1);
/* Send the commands for device recovery, phase 2 */
this->cmdfunc(mtd, NAND_CMD_DEPLETE1, 0x0000, 0x0004);
this->cmdfunc(mtd, NAND_CMD_DEPLETE2, -1, -1);
}
#ifdef RTC_FROM4_HWECC
/*
* rtc_from4_enable_hwecc - hardware specific hardware ECC enable function
* @mtd: MTD device structure
* @mode: I/O mode; read or write
*
* enable hardware ECC for data read or write
*
*/
static void rtc_from4_enable_hwecc(struct mtd_info *mtd, int mode)
{
volatile unsigned short *rs_ecc_ctl = (volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECC_CTL);
unsigned short status;
switch (mode) {
case NAND_ECC_READ:
status = RTC_FROM4_RS_ECC_CTL_CLR | RTC_FROM4_RS_ECC_CTL_FD_E;
*rs_ecc_ctl = status;
break;
case NAND_ECC_READSYN:
status = 0x00;
*rs_ecc_ctl = status;
break;
case NAND_ECC_WRITE:
status = RTC_FROM4_RS_ECC_CTL_CLR | RTC_FROM4_RS_ECC_CTL_GEN | RTC_FROM4_RS_ECC_CTL_FD_E;
*rs_ecc_ctl = status;
break;
default:
BUG();
break;
}
}
/*
* rtc_from4_calculate_ecc - hardware specific code to read ECC code
* @mtd: MTD device structure
* @dat: buffer containing the data to generate ECC codes
* @ecc_code ECC codes calculated
*
* The ECC code is calculated by the FPGA. All we have to do is read the values
* from the FPGA registers.
*
* Note: We read from the inverted registers, since data is inverted before
* the code is calculated. So all 0xff data (blank page) results in all 0xff rs code
*
*/
static void rtc_from4_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code)
{
volatile unsigned short *rs_eccn = (volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECCN);
unsigned short value;
int i;
for (i = 0; i < 8; i++) {
value = *rs_eccn;
ecc_code[i] = (unsigned char)value;
rs_eccn++;
}
ecc_code[7] |= 0x0f; /* set the last four bits (not used) */
}
/*
* rtc_from4_correct_data - hardware specific code to correct data using ECC code
* @mtd: MTD device structure
* @buf: buffer containing the data to generate ECC codes
* @ecc1 ECC codes read
* @ecc2 ECC codes calculated
*
* The FPGA tells us fast, if there's an error or not. If no, we go back happy
* else we read the ecc results from the fpga and call the rs library to decode
* and hopefully correct the error.
*
*/
static int rtc_from4_correct_data(struct mtd_info *mtd, const u_char *buf, u_char *ecc1, u_char *ecc2)
{
int i, j, res;
unsigned short status;
uint16_t par[6], syn[6];
uint8_t ecc[8];
volatile unsigned short *rs_ecc;
status = *((volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECC_CHK));
if (!(status & RTC_FROM4_RS_ECC_CHK_ERROR)) {
return 0;
}
/* Read the syndrom pattern from the FPGA and correct the bitorder */
rs_ecc = (volatile unsigned short *)(rtc_from4_fio_base + RTC_FROM4_RS_ECC);
for (i = 0; i < 8; i++) {
ecc[i] = bitrev8(*rs_ecc);
rs_ecc++;
}
/* convert into 6 10bit syndrome fields */
par[5] = rs_decoder->index_of[(((uint16_t) ecc[0] >> 0) & 0x0ff) | (((uint16_t) ecc[1] << 8) & 0x300)];
par[4] = rs_decoder->index_of[(((uint16_t) ecc[1] >> 2) & 0x03f) | (((uint16_t) ecc[2] << 6) & 0x3c0)];
par[3] = rs_decoder->index_of[(((uint16_t) ecc[2] >> 4) & 0x00f) | (((uint16_t) ecc[3] << 4) & 0x3f0)];
par[2] = rs_decoder->index_of[(((uint16_t) ecc[3] >> 6) & 0x003) | (((uint16_t) ecc[4] << 2) & 0x3fc)];
par[1] = rs_decoder->index_of[(((uint16_t) ecc[5] >> 0) & 0x0ff) | (((uint16_t) ecc[6] << 8) & 0x300)];
par[0] = (((uint16_t) ecc[6] >> 2) & 0x03f) | (((uint16_t) ecc[7] << 6) & 0x3c0);
/* Convert to computable syndrome */
for (i = 0; i < 6; i++) {
syn[i] = par[0];
for (j = 1; j < 6; j++)
if (par[j] != rs_decoder->nn)
syn[i] ^= rs_decoder->alpha_to[rs_modnn(rs_decoder, par[j] + i * j)];
/* Convert to index form */
syn[i] = rs_decoder->index_of[syn[i]];
}
/* Let the library code do its magic. */
res = decode_rs8(rs_decoder, (uint8_t *) buf, par, 512, syn, 0, NULL, 0xff, NULL);
if (res > 0) {
DEBUG(MTD_DEBUG_LEVEL0, "rtc_from4_correct_data: " "ECC corrected %d errors on read\n", res);
}
return res;
}
/**
* rtc_from4_errstat - perform additional error status checks
* @mtd: MTD device structure
* @this: NAND chip structure
* @state: state or the operation
* @status: status code returned from read status
* @page: startpage inside the chip, must be called with (page & this->pagemask)
*
* Perform additional error status checks on erase and write failures
* to determine if errors are correctable. For this device, correctable
* 1-bit errors on erase and write are considered acceptable.
*
* note: see pages 34..37 of data sheet for details.
*
*/
static int rtc_from4_errstat(struct mtd_info *mtd, struct nand_chip *this,
int state, int status, int page)
{
int er_stat = 0;
int rtn, retlen;
size_t len;
uint8_t *buf;
int i;
this->cmdfunc(mtd, NAND_CMD_STATUS_CLEAR, -1, -1);
if (state == FL_ERASING) {
for (i = 0; i < 4; i++) {
if (!(status & 1 << (i + 1)))
continue;
this->cmdfunc(mtd, (NAND_CMD_STATUS_ERROR + i + 1),
-1, -1);
rtn = this->read_byte(mtd);
this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1);
/* err_ecc_not_avail */
if (!(rtn & ERR_STAT_ECC_AVAILABLE))
er_stat |= 1 << (i + 1);
}
} else if (state == FL_WRITING) {
unsigned long corrected = mtd->ecc_stats.corrected;
/* single bank write logic */
this->cmdfunc(mtd, NAND_CMD_STATUS_ERROR, -1, -1);
rtn = this->read_byte(mtd);
this->cmdfunc(mtd, NAND_CMD_STATUS_RESET, -1, -1);
if (!(rtn & ERR_STAT_ECC_AVAILABLE)) {
/* err_ecc_not_avail */
er_stat |= 1 << 1;
goto out;
}
len = mtd->writesize;
buf = kmalloc(len, GFP_KERNEL);
if (!buf) {
printk(KERN_ERR "rtc_from4_errstat: Out of memory!\n");
er_stat = 1;
goto out;
}
/* recovery read */
rtn = nand_do_read(mtd, page, len, &retlen, buf);
/* if read failed or > 1-bit error corrected */
if (rtn || (mtd->ecc_stats.corrected - corrected) > 1)
er_stat |= 1 << 1;
kfree(buf);
}
out:
rtn = status;
if (er_stat == 0) { /* if ECC is available */
rtn = (status & ~NAND_STATUS_FAIL); /* clear the error bit */
}
return rtn;
}
#endif
/*
* Main initialization routine
*/
static int __init rtc_from4_init(void)
{
struct nand_chip *this;
unsigned short bcr1, bcr2, wcr2;
int i;
int ret;
/* Allocate memory for MTD device structure and private data */
rtc_from4_mtd = kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip), GFP_KERNEL);
if (!rtc_from4_mtd) {
printk("Unable to allocate Renesas NAND MTD device structure.\n");
return -ENOMEM;
}
/* Get pointer to private data */
this = (struct nand_chip *)(&rtc_from4_mtd[1]);
/* Initialize structures */
memset(rtc_from4_mtd, 0, sizeof(struct mtd_info));
memset(this, 0, sizeof(struct nand_chip));
/* Link the private data with the MTD structure */
rtc_from4_mtd->priv = this;
rtc_from4_mtd->owner = THIS_MODULE;
/* set area 5 as PCMCIA mode to clear the spec of tDH(Data hold time;9ns min) */
bcr1 = *SH77X9_BCR1 & ~0x0002;
bcr1 |= 0x0002;
*SH77X9_BCR1 = bcr1;
/* set */
bcr2 = *SH77X9_BCR2 & ~0x0c00;
bcr2 |= 0x0800;
*SH77X9_BCR2 = bcr2;
/* set area 5 wait states */
wcr2 = *SH77X9_WCR2 & ~0x1c00;
wcr2 |= 0x1c00;
*SH77X9_WCR2 = wcr2;
/* Set address of NAND IO lines */
this->IO_ADDR_R = rtc_from4_fio_base;
this->IO_ADDR_W = rtc_from4_fio_base;
/* Set address of hardware control function */
this->cmd_ctrl = rtc_from4_hwcontrol;
/* Set address of chip select function */
this->select_chip = rtc_from4_nand_select_chip;
/* command delay time (in us) */
this->chip_delay = 100;
/* return the status of the Ready/Busy line */
this->dev_ready = rtc_from4_nand_device_ready;
#ifdef RTC_FROM4_HWECC
printk(KERN_INFO "rtc_from4_init: using hardware ECC detection.\n");
this->ecc.mode = NAND_ECC_HW_SYNDROME;
this->ecc.size = 512;
this->ecc.bytes = 8;
/* return the status of extra status and ECC checks */
this->errstat = rtc_from4_errstat;
/* set the nand_oobinfo to support FPGA H/W error detection */
this->ecc.layout = &rtc_from4_nand_oobinfo;
this->ecc.hwctl = rtc_from4_enable_hwecc;
this->ecc.calculate = rtc_from4_calculate_ecc;
this->ecc.correct = rtc_from4_correct_data;
/* We could create the decoder on demand, if memory is a concern.
* This way we have it handy, if an error happens
*
* Symbolsize is 10 (bits)
* Primitve polynomial is x^10+x^3+1
* first consecutive root is 0
* primitve element to generate roots = 1
* generator polinomial degree = 6
*/
rs_decoder = init_rs(10, 0x409, 0, 1, 6);
if (!rs_decoder) {
printk(KERN_ERR "Could not create a RS decoder\n");
ret = -ENOMEM;
goto err_1;
}
#else
printk(KERN_INFO "rtc_from4_init: using software ECC detection.\n");
this->ecc.mode = NAND_ECC_SOFT;
#endif
/* set the bad block tables to support debugging */
this->bbt_td = &rtc_from4_bbt_main_descr;
this->bbt_md = &rtc_from4_bbt_mirror_descr;
/* Scan to find existence of the device */
if (nand_scan(rtc_from4_mtd, RTC_FROM4_MAX_CHIPS)) {
ret = -ENXIO;
goto err_2;
}
/* Perform 'device recovery' for each chip in case there was a power loss. */
for (i = 0; i < this->numchips; i++) {
deplete(rtc_from4_mtd, i);
}
#if RTC_FROM4_NO_VIRTBLOCKS
/* use a smaller erase block to minimize wasted space when a block is bad */
/* note: this uses eight times as much RAM as using the default and makes */
/* mounts take four times as long. */
rtc_from4_mtd->flags |= MTD_NO_VIRTBLOCKS;
#endif
/* Register the partitions */
ret = mtd_device_register(rtc_from4_mtd, partition_info,
NUM_PARTITIONS);
if (ret)
goto err_3;
/* Return happy */
return 0;
err_3:
nand_release(rtc_from4_mtd);
err_2:
free_rs(rs_decoder);
err_1:
kfree(rtc_from4_mtd);
return ret;
}
module_init(rtc_from4_init);
/*
* Clean up routine
*/
static void __exit rtc_from4_cleanup(void)
{
/* Release resource, unregister partitions */
nand_release(rtc_from4_mtd);
/* Free the MTD device structure */
kfree(rtc_from4_mtd);
#ifdef RTC_FROM4_HWECC
/* Free the reed solomon resources */
if (rs_decoder) {
free_rs(rs_decoder);
}
#endif
}
module_exit(rtc_from4_cleanup);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("d.marlin <dmarlin@redhat.com");
MODULE_DESCRIPTION("Board-specific glue layer for AG-AND flash on Renesas FROM_BOARD4");