u-boot/board/socrates/nand.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2008
* Sergei Poselenov, Emcraft Systems, sposelenov@emcraft.com.
*/
#include <common.h>
#if defined(CONFIG_SYS_NAND_BASE)
#include <nand.h>
#include <linux/errno.h>
#include <linux/mtd/rawnand.h>
#include <asm/io.h>
static int state;
static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte);
static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len);
static u_char sc_nand_read_byte(struct mtd_info *mtd);
static u16 sc_nand_read_word(struct mtd_info *mtd);
static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len);
static int sc_nand_device_ready(struct mtd_info *mtdinfo);
#define FPGA_NAND_CMD_MASK (0x7 << 28)
#define FPGA_NAND_CMD_COMMAND (0x0 << 28)
#define FPGA_NAND_CMD_ADDR (0x1 << 28)
#define FPGA_NAND_CMD_READ (0x2 << 28)
#define FPGA_NAND_CMD_WRITE (0x3 << 28)
#define FPGA_NAND_BUSY (0x1 << 15)
#define FPGA_NAND_ENABLE (0x1 << 31)
#define FPGA_NAND_DATA_SHIFT 16
/**
* sc_nand_write_byte - write one byte to the chip
* @mtd: MTD device structure
* @byte: pointer to data byte to write
*/
static void sc_nand_write_byte(struct mtd_info *mtd, u_char byte)
{
sc_nand_write_buf(mtd, (const uchar *)&byte, sizeof(byte));
}
/**
* sc_nand_write_buf - write buffer to chip
* @mtd: MTD device structure
* @buf: data buffer
* @len: number of bytes to write
*/
static void sc_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
int i;
struct nand_chip *this = mtd_to_nand(mtd);
for (i = 0; i < len; i++) {
out_be32(this->IO_ADDR_W,
state | (buf[i] << FPGA_NAND_DATA_SHIFT));
}
}
/**
* sc_nand_read_byte - read one byte from the chip
* @mtd: MTD device structure
*/
static u_char sc_nand_read_byte(struct mtd_info *mtd)
{
u8 byte;
sc_nand_read_buf(mtd, (uchar *)&byte, sizeof(byte));
return byte;
}
/**
* sc_nand_read_word - read one word from the chip
* @mtd: MTD device structure
*/
static u16 sc_nand_read_word(struct mtd_info *mtd)
{
u16 word;
sc_nand_read_buf(mtd, (uchar *)&word, sizeof(word));
return word;
}
/**
* sc_nand_read_buf - read chip data into buffer
* @mtd: MTD device structure
* @buf: buffer to store date
* @len: number of bytes to read
*/
static void sc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
int i;
struct nand_chip *this = mtd_to_nand(mtd);
int val;
val = (state & FPGA_NAND_ENABLE) | FPGA_NAND_CMD_READ;
out_be32(this->IO_ADDR_W, val);
for (i = 0; i < len; i++) {
buf[i] = (in_be32(this->IO_ADDR_R) >> FPGA_NAND_DATA_SHIFT) & 0xff;
}
}
/**
* sc_nand_device_ready - Check the NAND device is ready for next command.
* @mtd: MTD device structure
*/
static int sc_nand_device_ready(struct mtd_info *mtdinfo)
{
struct nand_chip *this = mtd_to_nand(mtdinfo);
if (in_be32(this->IO_ADDR_W) & FPGA_NAND_BUSY)
return 0; /* busy */
return 1;
}
/**
* sc_nand_hwcontrol - NAND control functions wrapper.
* @mtd: MTD device structure
* @cmd: Command
*/
static void sc_nand_hwcontrol(struct mtd_info *mtdinfo, int cmd, unsigned int ctrl)
{
if (ctrl & NAND_CTRL_CHANGE) {
state &= ~(FPGA_NAND_CMD_MASK | FPGA_NAND_ENABLE);
switch (ctrl & (NAND_ALE | NAND_CLE)) {
case 0:
state |= FPGA_NAND_CMD_WRITE;
break;
case NAND_ALE:
state |= FPGA_NAND_CMD_ADDR;
break;
case NAND_CLE:
state |= FPGA_NAND_CMD_COMMAND;
break;
default:
printf("%s: unknown ctrl %#x\n", __FUNCTION__, ctrl);
}
if (ctrl & NAND_NCE)
state |= FPGA_NAND_ENABLE;
}
if (cmd != NAND_CMD_NONE)
sc_nand_write_byte(mtdinfo, cmd);
}
int board_nand_init(struct nand_chip *nand)
{
nand->cmd_ctrl = sc_nand_hwcontrol;
nand->ecc.mode = NAND_ECC_SOFT;
nand->dev_ready = sc_nand_device_ready;
nand->read_byte = sc_nand_read_byte;
nand->read_word = sc_nand_read_word;
nand->write_buf = sc_nand_write_buf;
nand->read_buf = sc_nand_read_buf;
return 0;
}
#endif