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/*
* linux/arch/mips/tx4938/toshiba_rbtx4938/spi_eeprom.c
* Copyright (C) 2000-2001 Toshiba Corporation
*
* 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
* terms of the GNU General Public License version 2. This program is
* licensed "as is" without any warranty of any kind, whether express
* or implied.
*
* Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <asm/tx4938/spi.h>
#include <asm/tx4938/tx4938.h>
/* ATMEL 250x0 instructions */
#define ATMEL_WREN 0x06
#define ATMEL_WRDI 0x04
#define ATMEL_RDSR 0x05
#define ATMEL_WRSR 0x01
#define ATMEL_READ 0x03
#define ATMEL_WRITE 0x02
#define ATMEL_SR_BSY 0x01
#define ATMEL_SR_WEN 0x02
#define ATMEL_SR_BP0 0x04
#define ATMEL_SR_BP1 0x08
DEFINE_SPINLOCK(spi_eeprom_lock);
static struct spi_dev_desc seeprom_dev_desc = {
.baud = 1500000, /* 1.5Mbps */
.tcss = 1,
.tcsh = 1,
.tcsr = 1,
.byteorder = 1, /* MSB-First */
.polarity = 0, /* High-Active */
.phase = 0, /* Sample-Then-Shift */
};
static inline int
spi_eeprom_io(int chipid,
unsigned char **inbufs, unsigned int *incounts,
unsigned char **outbufs, unsigned int *outcounts)
{
return txx9_spi_io(chipid, &seeprom_dev_desc,
inbufs, incounts, outbufs, outcounts, 0);
}
int spi_eeprom_write_enable(int chipid, int enable)
{
unsigned char inbuf[1];
unsigned char *inbufs[1];
unsigned int incounts[2];
unsigned long flags;
int stat;
inbuf[0] = enable ? ATMEL_WREN : ATMEL_WRDI;
inbufs[0] = inbuf;
incounts[0] = sizeof(inbuf);
incounts[1] = 0;
spin_lock_irqsave(&spi_eeprom_lock, flags);
stat = spi_eeprom_io(chipid, inbufs, incounts, NULL, NULL);
spin_unlock_irqrestore(&spi_eeprom_lock, flags);
return stat;
}
static int spi_eeprom_read_status_nolock(int chipid)
{
unsigned char inbuf[2], outbuf[2];
unsigned char *inbufs[1], *outbufs[1];
unsigned int incounts[2], outcounts[2];
int stat;
inbuf[0] = ATMEL_RDSR;
inbuf[1] = 0;
inbufs[0] = inbuf;
incounts[0] = sizeof(inbuf);
incounts[1] = 0;
outbufs[0] = outbuf;
outcounts[0] = sizeof(outbuf);
outcounts[1] = 0;
stat = spi_eeprom_io(chipid, inbufs, incounts, outbufs, outcounts);
if (stat < 0)
return stat;
return outbuf[1];
}
int spi_eeprom_read_status(int chipid)
{
unsigned long flags;
int stat;
spin_lock_irqsave(&spi_eeprom_lock, flags);
stat = spi_eeprom_read_status_nolock(chipid);
spin_unlock_irqrestore(&spi_eeprom_lock, flags);
return stat;
}
int spi_eeprom_read(int chipid, int address, unsigned char *buf, int len)
{
unsigned char inbuf[2];
unsigned char *inbufs[2], *outbufs[2];
unsigned int incounts[2], outcounts[3];
unsigned long flags;
int stat;
inbuf[0] = ATMEL_READ;
inbuf[1] = address;
inbufs[0] = inbuf;
inbufs[1] = NULL;
incounts[0] = sizeof(inbuf);
incounts[1] = 0;
outbufs[0] = NULL;
outbufs[1] = buf;
outcounts[0] = 2;
outcounts[1] = len;
outcounts[2] = 0;
spin_lock_irqsave(&spi_eeprom_lock, flags);
stat = spi_eeprom_io(chipid, inbufs, incounts, outbufs, outcounts);
spin_unlock_irqrestore(&spi_eeprom_lock, flags);
return stat;
}
int spi_eeprom_write(int chipid, int address, unsigned char *buf, int len)
{
unsigned char inbuf[2];
unsigned char *inbufs[2];
unsigned int incounts[3];
unsigned long flags;
int i, stat;
if (address / 8 != (address + len - 1) / 8)
return -EINVAL;
stat = spi_eeprom_write_enable(chipid, 1);
if (stat < 0)
return stat;
stat = spi_eeprom_read_status(chipid);
if (stat < 0)
return stat;
if (!(stat & ATMEL_SR_WEN))
return -EPERM;
inbuf[0] = ATMEL_WRITE;
inbuf[1] = address;
inbufs[0] = inbuf;
inbufs[1] = buf;
incounts[0] = sizeof(inbuf);
incounts[1] = len;
incounts[2] = 0;
spin_lock_irqsave(&spi_eeprom_lock, flags);
stat = spi_eeprom_io(chipid, inbufs, incounts, NULL, NULL);
if (stat < 0)
goto unlock_return;
/* write start. max 10ms */
for (i = 10; i > 0; i--) {
int stat = spi_eeprom_read_status_nolock(chipid);
if (stat < 0)
goto unlock_return;
if (!(stat & ATMEL_SR_BSY))
break;
mdelay(1);
}
spin_unlock_irqrestore(&spi_eeprom_lock, flags);
if (i == 0)
return -EIO;
return len;
unlock_return:
spin_unlock_irqrestore(&spi_eeprom_lock, flags);
return stat;
}
#ifdef CONFIG_PROC_FS
#define MAX_SIZE 0x80 /* for ATMEL 25010 */
static int spi_eeprom_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
unsigned int size = MAX_SIZE;
if (spi_eeprom_read((int)data, 0, (unsigned char *)page, size) < 0)
size = 0;
return size;
}
static int spi_eeprom_write_proc(struct file *file, const char *buffer,
unsigned long count, void *data)
{
unsigned int size = MAX_SIZE;
int i;
if (file->f_pos >= size)
return -EIO;
if (file->f_pos + count > size)
count = size - file->f_pos;
for (i = 0; i < count; i += 8) {
int len = count - i < 8 ? count - i : 8;
if (spi_eeprom_write((int)data, file->f_pos,
(unsigned char *)buffer, len) < 0) {
count = -EIO;
break;
}
buffer += len;
file->f_pos += len;
}
return count;
}
__init void spi_eeprom_proc_create(struct proc_dir_entry *dir, int chipid)
{
struct proc_dir_entry *entry;
char name[128];
sprintf(name, "seeprom-%d", chipid);
entry = create_proc_entry(name, 0600, dir);
if (entry) {
entry->read_proc = spi_eeprom_read_proc;
entry->write_proc = spi_eeprom_write_proc;
entry->data = (void *)chipid;
}
}
#endif /* CONFIG_PROC_FS */
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