852 lines
22 KiB
C
852 lines
22 KiB
C
|
/*!*****************************************************************************
|
||
|
|
*!
|
||
|
|
*! Implements an interface for i2c compatible eeproms to run under Linux.
|
||
|
|
*! Supports 2k, 8k(?) and 16k. Uses adaptive timing adjustments by
|
||
|
|
*! Johan.Adolfsson@axis.com
|
||
|
|
*!
|
||
|
|
*! Probing results:
|
||
|
|
*! 8k or not is detected (the assumes 2k or 16k)
|
||
|
|
*! 2k or 16k detected using test reads and writes.
|
||
|
|
*!
|
||
|
|
*!------------------------------------------------------------------------
|
||
|
|
*! HISTORY
|
||
|
|
*!
|
||
|
|
*! DATE NAME CHANGES
|
||
|
|
*! ---- ---- -------
|
||
|
|
*! Aug 28 1999 Edgar Iglesias Initial Version
|
||
|
|
*! Aug 31 1999 Edgar Iglesias Allow simultaneous users.
|
||
|
|
*! Sep 03 1999 Edgar Iglesias Updated probe.
|
||
|
|
*! Sep 03 1999 Edgar Iglesias Added bail-out stuff if we get interrupted
|
||
|
|
*! in the spin-lock.
|
||
|
|
*!
|
||
|
|
*! (c) 1999 Axis Communications AB, Lund, Sweden
|
||
|
|
*!*****************************************************************************/
|
||
|
|
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
#include <linux/fs.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <linux/delay.h>
|
||
|
|
#include <linux/interrupt.h>
|
||
|
|
#include <linux/wait.h>
|
||
|
|
#include <asm/uaccess.h>
|
||
|
|
#include "i2c.h"
|
||
|
|
|
||
|
|
#define D(x)
|
||
|
|
|
||
|
|
/* If we should use adaptive timing or not: */
|
||
|
|
/* #define EEPROM_ADAPTIVE_TIMING */
|
||
|
|
|
||
|
|
#define EEPROM_MAJOR_NR 122 /* use a LOCAL/EXPERIMENTAL major for now */
|
||
|
|
#define EEPROM_MINOR_NR 0
|
||
|
|
|
||
|
|
/* Empirical sane initial value of the delay, the value will be adapted to
|
||
|
|
* what the chip needs when using EEPROM_ADAPTIVE_TIMING.
|
||
|
|
*/
|
||
|
|
#define INITIAL_WRITEDELAY_US 4000
|
||
|
|
#define MAX_WRITEDELAY_US 10000 /* 10 ms according to spec for 2KB EEPROM */
|
||
|
|
|
||
|
|
/* This one defines how many times to try when eeprom fails. */
|
||
|
|
#define EEPROM_RETRIES 10
|
||
|
|
|
||
|
|
#define EEPROM_2KB (2 * 1024)
|
||
|
|
/*#define EEPROM_4KB (4 * 1024)*/ /* Exists but not used in Axis products */
|
||
|
|
#define EEPROM_8KB (8 * 1024 - 1 ) /* Last byte has write protection bit */
|
||
|
|
#define EEPROM_16KB (16 * 1024)
|
||
|
|
|
||
|
|
#define i2c_delay(x) udelay(x)
|
||
|
|
|
||
|
|
/*
|
||
|
|
* This structure describes the attached eeprom chip.
|
||
|
|
* The values are probed for.
|
||
|
|
*/
|
||
|
|
|
||
|
|
struct eeprom_type
|
||
|
|
{
|
||
|
|
unsigned long size;
|
||
|
|
unsigned long sequential_write_pagesize;
|
||
|
|
unsigned char select_cmd;
|
||
|
|
unsigned long usec_delay_writecycles; /* Min time between write cycles
|
||
|
|
(up to 10ms for some models) */
|
||
|
|
unsigned long usec_delay_step; /* For adaptive algorithm */
|
||
|
|
int adapt_state; /* 1 = To high , 0 = Even, -1 = To low */
|
||
|
|
|
||
|
|
/* this one is to keep the read/write operations atomic */
|
||
|
|
struct mutex lock;
|
||
|
|
int retry_cnt_addr; /* Used to keep track of number of retries for
|
||
|
|
adaptive timing adjustments */
|
||
|
|
int retry_cnt_read;
|
||
|
|
};
|
||
|
|
|
||
|
|
static int eeprom_open(struct inode * inode, struct file * file);
|
||
|
|
static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig);
|
||
|
|
static ssize_t eeprom_read(struct file * file, char * buf, size_t count,
|
||
|
|
loff_t *off);
|
||
|
|
static ssize_t eeprom_write(struct file * file, const char * buf, size_t count,
|
||
|
|
loff_t *off);
|
||
|
|
static int eeprom_close(struct inode * inode, struct file * file);
|
||
|
|
|
||
|
|
static int eeprom_address(unsigned long addr);
|
||
|
|
static int read_from_eeprom(char * buf, int count);
|
||
|
|
static int eeprom_write_buf(loff_t addr, const char * buf, int count);
|
||
|
|
static int eeprom_read_buf(loff_t addr, char * buf, int count);
|
||
|
|
|
||
|
|
static void eeprom_disable_write_protect(void);
|
||
|
|
|
||
|
|
|
||
|
|
static const char eeprom_name[] = "eeprom";
|
||
|
|
|
||
|
|
/* chip description */
|
||
|
|
static struct eeprom_type eeprom;
|
||
|
|
|
||
|
|
/* This is the exported file-operations structure for this device. */
|
||
|
|
const struct file_operations eeprom_fops =
|
||
|
|
{
|
||
|
|
.llseek = eeprom_lseek,
|
||
|
|
.read = eeprom_read,
|
||
|
|
.write = eeprom_write,
|
||
|
|
.open = eeprom_open,
|
||
|
|
.release = eeprom_close
|
||
|
|
};
|
||
|
|
|
||
|
|
/* eeprom init call. Probes for different eeprom models. */
|
||
|
|
|
||
|
|
int __init eeprom_init(void)
|
||
|
|
{
|
||
|
|
mutex_init(&eeprom.lock);
|
||
|
|
|
||
|
|
#ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE
|
||
|
|
#define EETEXT "Found"
|
||
|
|
#else
|
||
|
|
#define EETEXT "Assuming"
|
||
|
|
#endif
|
||
|
|
if (register_chrdev(EEPROM_MAJOR_NR, eeprom_name, &eeprom_fops))
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: unable to get major %d for eeprom device\n",
|
||
|
|
eeprom_name, EEPROM_MAJOR_NR);
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
printk("EEPROM char device v0.3, (c) 2000 Axis Communications AB\n");
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Note: Most of this probing method was taken from the printserver (5470e)
|
||
|
|
* codebase. It did not contain a way of finding the 16kB chips
|
||
|
|
* (M24128 or variants). The method used here might not work
|
||
|
|
* for all models. If you encounter problems the easiest way
|
||
|
|
* is probably to define your model within #ifdef's, and hard-
|
||
|
|
* code it.
|
||
|
|
*/
|
||
|
|
|
||
|
|
eeprom.size = 0;
|
||
|
|
eeprom.usec_delay_writecycles = INITIAL_WRITEDELAY_US;
|
||
|
|
eeprom.usec_delay_step = 128;
|
||
|
|
eeprom.adapt_state = 0;
|
||
|
|
|
||
|
|
#ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE
|
||
|
|
i2c_start();
|
||
|
|
i2c_outbyte(0x80);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
/* It's not 8k.. */
|
||
|
|
int success = 0;
|
||
|
|
unsigned char buf_2k_start[16];
|
||
|
|
|
||
|
|
/* Im not sure this will work... :) */
|
||
|
|
/* assume 2kB, if failure go for 16kB */
|
||
|
|
/* Test with 16kB settings.. */
|
||
|
|
/* If it's a 2kB EEPROM and we address it outside it's range
|
||
|
|
* it will mirror the address space:
|
||
|
|
* 1. We read two locations (that are mirrored),
|
||
|
|
* if the content differs * it's a 16kB EEPROM.
|
||
|
|
* 2. if it doesn't differ - write different value to one of the locations,
|
||
|
|
* check the other - if content still is the same it's a 2k EEPROM,
|
||
|
|
* restore original data.
|
||
|
|
*/
|
||
|
|
#define LOC1 8
|
||
|
|
#define LOC2 (0x1fb) /*1fb, 3ed, 5df, 7d1 */
|
||
|
|
|
||
|
|
/* 2k settings */
|
||
|
|
i2c_stop();
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
eeprom.select_cmd = 0xA0;
|
||
|
|
eeprom.sequential_write_pagesize = 16;
|
||
|
|
if( eeprom_read_buf( 0, buf_2k_start, 16 ) == 16 )
|
||
|
|
{
|
||
|
|
D(printk("2k start: '%16.16s'\n", buf_2k_start));
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Failed to read in 2k mode!\n", eeprom_name);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* 16k settings */
|
||
|
|
eeprom.size = EEPROM_16KB;
|
||
|
|
eeprom.select_cmd = 0xA0;
|
||
|
|
eeprom.sequential_write_pagesize = 64;
|
||
|
|
|
||
|
|
{
|
||
|
|
unsigned char loc1[4], loc2[4], tmp[4];
|
||
|
|
if( eeprom_read_buf(LOC2, loc2, 4) == 4)
|
||
|
|
{
|
||
|
|
if( eeprom_read_buf(LOC1, loc1, 4) == 4)
|
||
|
|
{
|
||
|
|
D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
|
||
|
|
LOC1, loc1, LOC2, loc2));
|
||
|
|
#if 0
|
||
|
|
if (memcmp(loc1, loc2, 4) != 0 )
|
||
|
|
{
|
||
|
|
/* It's 16k */
|
||
|
|
printk(KERN_INFO "%s: 16k detected in step 1\n", eeprom_name);
|
||
|
|
eeprom.size = EEPROM_16KB;
|
||
|
|
success = 1;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
/* Do step 2 check */
|
||
|
|
/* Invert value */
|
||
|
|
loc1[0] = ~loc1[0];
|
||
|
|
if (eeprom_write_buf(LOC1, loc1, 1) == 1)
|
||
|
|
{
|
||
|
|
/* If 2k EEPROM this write will actually write 10 bytes
|
||
|
|
* from pos 0
|
||
|
|
*/
|
||
|
|
D(printk("1 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
|
||
|
|
LOC1, loc1, LOC2, loc2));
|
||
|
|
if( eeprom_read_buf(LOC1, tmp, 4) == 4)
|
||
|
|
{
|
||
|
|
D(printk("2 loc1: (%i) '%4.4s' tmp '%4.4s'\n",
|
||
|
|
LOC1, loc1, tmp));
|
||
|
|
if (memcmp(loc1, tmp, 4) != 0 )
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: read and write differs! Not 16kB\n",
|
||
|
|
eeprom_name);
|
||
|
|
loc1[0] = ~loc1[0];
|
||
|
|
|
||
|
|
if (eeprom_write_buf(LOC1, loc1, 1) == 1)
|
||
|
|
{
|
||
|
|
success = 1;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Restore 2k failed during probe,"
|
||
|
|
" EEPROM might be corrupt!\n", eeprom_name);
|
||
|
|
|
||
|
|
}
|
||
|
|
i2c_stop();
|
||
|
|
/* Go to 2k mode and write original data */
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
eeprom.select_cmd = 0xA0;
|
||
|
|
eeprom.sequential_write_pagesize = 16;
|
||
|
|
if( eeprom_write_buf(0, buf_2k_start, 16) == 16)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Failed to write back 2k start!\n",
|
||
|
|
eeprom_name);
|
||
|
|
}
|
||
|
|
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if(!success)
|
||
|
|
{
|
||
|
|
if( eeprom_read_buf(LOC2, loc2, 1) == 1)
|
||
|
|
{
|
||
|
|
D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
|
||
|
|
LOC1, loc1, LOC2, loc2));
|
||
|
|
if (memcmp(loc1, loc2, 4) == 0 )
|
||
|
|
{
|
||
|
|
/* Data the same, must be mirrored -> 2k */
|
||
|
|
/* Restore data */
|
||
|
|
printk(KERN_INFO "%s: 2k detected in step 2\n", eeprom_name);
|
||
|
|
loc1[0] = ~loc1[0];
|
||
|
|
if (eeprom_write_buf(LOC1, loc1, 1) == 1)
|
||
|
|
{
|
||
|
|
success = 1;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Restore 2k failed during probe,"
|
||
|
|
" EEPROM might be corrupt!\n", eeprom_name);
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: 16k detected in step 2\n",
|
||
|
|
eeprom_name);
|
||
|
|
loc1[0] = ~loc1[0];
|
||
|
|
/* Data differs, assume 16k */
|
||
|
|
/* Restore data */
|
||
|
|
if (eeprom_write_buf(LOC1, loc1, 1) == 1)
|
||
|
|
{
|
||
|
|
success = 1;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Restore 16k failed during probe,"
|
||
|
|
" EEPROM might be corrupt!\n", eeprom_name);
|
||
|
|
}
|
||
|
|
|
||
|
|
eeprom.size = EEPROM_16KB;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} /* read LOC1 */
|
||
|
|
} /* address LOC1 */
|
||
|
|
if (!success)
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Probing failed!, using 2KB!\n", eeprom_name);
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
}
|
||
|
|
} /* read */
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
i2c_outbyte(0x00);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
/* No 8k */
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
i2c_start();
|
||
|
|
i2c_outbyte(0x81);
|
||
|
|
if (!i2c_getack())
|
||
|
|
{
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
/* It's a 8kB */
|
||
|
|
i2c_inbyte();
|
||
|
|
eeprom.size = EEPROM_8KB;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
i2c_stop();
|
||
|
|
#elif defined(CONFIG_ETRAX_I2C_EEPROM_16KB)
|
||
|
|
eeprom.size = EEPROM_16KB;
|
||
|
|
#elif defined(CONFIG_ETRAX_I2C_EEPROM_8KB)
|
||
|
|
eeprom.size = EEPROM_8KB;
|
||
|
|
#elif defined(CONFIG_ETRAX_I2C_EEPROM_2KB)
|
||
|
|
eeprom.size = EEPROM_2KB;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
switch(eeprom.size)
|
||
|
|
{
|
||
|
|
case (EEPROM_2KB):
|
||
|
|
printk("%s: " EETEXT " i2c compatible 2kB eeprom.\n", eeprom_name);
|
||
|
|
eeprom.sequential_write_pagesize = 16;
|
||
|
|
eeprom.select_cmd = 0xA0;
|
||
|
|
break;
|
||
|
|
case (EEPROM_8KB):
|
||
|
|
printk("%s: " EETEXT " i2c compatible 8kB eeprom.\n", eeprom_name);
|
||
|
|
eeprom.sequential_write_pagesize = 16;
|
||
|
|
eeprom.select_cmd = 0x80;
|
||
|
|
break;
|
||
|
|
case (EEPROM_16KB):
|
||
|
|
printk("%s: " EETEXT " i2c compatible 16kB eeprom.\n", eeprom_name);
|
||
|
|
eeprom.sequential_write_pagesize = 64;
|
||
|
|
eeprom.select_cmd = 0xA0;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
eeprom.size = 0;
|
||
|
|
printk("%s: Did not find a supported eeprom\n", eeprom_name);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
eeprom_disable_write_protect();
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Opens the device. */
|
||
|
|
static int eeprom_open(struct inode * inode, struct file * file)
|
||
|
|
{
|
||
|
|
if(iminor(inode) != EEPROM_MINOR_NR)
|
||
|
|
return -ENXIO;
|
||
|
|
if(imajor(inode) != EEPROM_MAJOR_NR)
|
||
|
|
return -ENXIO;
|
||
|
|
|
||
|
|
if( eeprom.size > 0 )
|
||
|
|
{
|
||
|
|
/* OK */
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* No EEprom found */
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Changes the current file position. */
|
||
|
|
|
||
|
|
static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig)
|
||
|
|
{
|
||
|
|
/*
|
||
|
|
* orig 0: position from beginning of eeprom
|
||
|
|
* orig 1: relative from current position
|
||
|
|
* orig 2: position from last eeprom address
|
||
|
|
*/
|
||
|
|
|
||
|
|
switch (orig)
|
||
|
|
{
|
||
|
|
case 0:
|
||
|
|
file->f_pos = offset;
|
||
|
|
break;
|
||
|
|
case 1:
|
||
|
|
file->f_pos += offset;
|
||
|
|
break;
|
||
|
|
case 2:
|
||
|
|
file->f_pos = eeprom.size - offset;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* truncate position */
|
||
|
|
if (file->f_pos < 0)
|
||
|
|
{
|
||
|
|
file->f_pos = 0;
|
||
|
|
return(-EOVERFLOW);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (file->f_pos >= eeprom.size)
|
||
|
|
{
|
||
|
|
file->f_pos = eeprom.size - 1;
|
||
|
|
return(-EOVERFLOW);
|
||
|
|
}
|
||
|
|
|
||
|
|
return ( file->f_pos );
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Reads data from eeprom. */
|
||
|
|
|
||
|
|
static int eeprom_read_buf(loff_t addr, char * buf, int count)
|
||
|
|
{
|
||
|
|
return eeprom_read(NULL, buf, count, &addr);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/* Reads data from eeprom. */
|
||
|
|
|
||
|
|
static ssize_t eeprom_read(struct file * file, char * buf, size_t count, loff_t *off)
|
||
|
|
{
|
||
|
|
int read=0;
|
||
|
|
unsigned long p = *off;
|
||
|
|
|
||
|
|
unsigned char page;
|
||
|
|
|
||
|
|
if(p >= eeprom.size) /* Address i 0 - (size-1) */
|
||
|
|
{
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (mutex_lock_interruptible(&eeprom.lock))
|
||
|
|
return -EINTR;
|
||
|
|
|
||
|
|
page = (unsigned char) (p >> 8);
|
||
|
|
|
||
|
|
if(!eeprom_address(p))
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Read failed to address the eeprom: "
|
||
|
|
"0x%08X (%i) page: %i\n", eeprom_name, (int)p, (int)p, page);
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
/* don't forget to wake them up */
|
||
|
|
mutex_unlock(&eeprom.lock);
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
|
||
|
|
if( (p + count) > eeprom.size)
|
||
|
|
{
|
||
|
|
/* truncate count */
|
||
|
|
count = eeprom.size - p;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* stop dummy write op and initiate the read op */
|
||
|
|
i2c_start();
|
||
|
|
|
||
|
|
/* special case for small eeproms */
|
||
|
|
if(eeprom.size < EEPROM_16KB)
|
||
|
|
{
|
||
|
|
i2c_outbyte( eeprom.select_cmd | 1 | (page << 1) );
|
||
|
|
}
|
||
|
|
|
||
|
|
/* go on with the actual read */
|
||
|
|
read = read_from_eeprom( buf, count);
|
||
|
|
|
||
|
|
if(read > 0)
|
||
|
|
{
|
||
|
|
*off += read;
|
||
|
|
}
|
||
|
|
|
||
|
|
mutex_unlock(&eeprom.lock);
|
||
|
|
return read;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Writes data to eeprom. */
|
||
|
|
|
||
|
|
static int eeprom_write_buf(loff_t addr, const char * buf, int count)
|
||
|
|
{
|
||
|
|
return eeprom_write(NULL, buf, count, &addr);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/* Writes data to eeprom. */
|
||
|
|
|
||
|
|
static ssize_t eeprom_write(struct file * file, const char * buf, size_t count,
|
||
|
|
loff_t *off)
|
||
|
|
{
|
||
|
|
int i, written, restart=1;
|
||
|
|
unsigned long p;
|
||
|
|
|
||
|
|
if (!access_ok(VERIFY_READ, buf, count))
|
||
|
|
{
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* bail out if we get interrupted */
|
||
|
|
if (mutex_lock_interruptible(&eeprom.lock))
|
||
|
|
return -EINTR;
|
||
|
|
for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++)
|
||
|
|
{
|
||
|
|
restart = 0;
|
||
|
|
written = 0;
|
||
|
|
p = *off;
|
||
|
|
|
||
|
|
|
||
|
|
while( (written < count) && (p < eeprom.size))
|
||
|
|
{
|
||
|
|
/* address the eeprom */
|
||
|
|
if(!eeprom_address(p))
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: Write failed to address the eeprom: "
|
||
|
|
"0x%08X (%i) \n", eeprom_name, (int)p, (int)p);
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
/* don't forget to wake them up */
|
||
|
|
mutex_unlock(&eeprom.lock);
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
#ifdef EEPROM_ADAPTIVE_TIMING
|
||
|
|
/* Adaptive algorithm to adjust timing */
|
||
|
|
if (eeprom.retry_cnt_addr > 0)
|
||
|
|
{
|
||
|
|
/* To Low now */
|
||
|
|
D(printk(">D=%i d=%i\n",
|
||
|
|
eeprom.usec_delay_writecycles, eeprom.usec_delay_step));
|
||
|
|
|
||
|
|
if (eeprom.usec_delay_step < 4)
|
||
|
|
{
|
||
|
|
eeprom.usec_delay_step++;
|
||
|
|
eeprom.usec_delay_writecycles += eeprom.usec_delay_step;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
|
||
|
|
if (eeprom.adapt_state > 0)
|
||
|
|
{
|
||
|
|
/* To Low before */
|
||
|
|
eeprom.usec_delay_step *= 2;
|
||
|
|
if (eeprom.usec_delay_step > 2)
|
||
|
|
{
|
||
|
|
eeprom.usec_delay_step--;
|
||
|
|
}
|
||
|
|
eeprom.usec_delay_writecycles += eeprom.usec_delay_step;
|
||
|
|
}
|
||
|
|
else if (eeprom.adapt_state < 0)
|
||
|
|
{
|
||
|
|
/* To High before (toggle dir) */
|
||
|
|
eeprom.usec_delay_writecycles += eeprom.usec_delay_step;
|
||
|
|
if (eeprom.usec_delay_step > 1)
|
||
|
|
{
|
||
|
|
eeprom.usec_delay_step /= 2;
|
||
|
|
eeprom.usec_delay_step--;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
eeprom.adapt_state = 1;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
/* To High (or good) now */
|
||
|
|
D(printk("<D=%i d=%i\n",
|
||
|
|
eeprom.usec_delay_writecycles, eeprom.usec_delay_step));
|
||
|
|
|
||
|
|
if (eeprom.adapt_state < 0)
|
||
|
|
{
|
||
|
|
/* To High before */
|
||
|
|
if (eeprom.usec_delay_step > 1)
|
||
|
|
{
|
||
|
|
eeprom.usec_delay_step *= 2;
|
||
|
|
eeprom.usec_delay_step--;
|
||
|
|
|
||
|
|
if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step)
|
||
|
|
{
|
||
|
|
eeprom.usec_delay_writecycles -= eeprom.usec_delay_step;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else if (eeprom.adapt_state > 0)
|
||
|
|
{
|
||
|
|
/* To Low before (toggle dir) */
|
||
|
|
if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step)
|
||
|
|
{
|
||
|
|
eeprom.usec_delay_writecycles -= eeprom.usec_delay_step;
|
||
|
|
}
|
||
|
|
if (eeprom.usec_delay_step > 1)
|
||
|
|
{
|
||
|
|
eeprom.usec_delay_step /= 2;
|
||
|
|
eeprom.usec_delay_step--;
|
||
|
|
}
|
||
|
|
|
||
|
|
eeprom.adapt_state = -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (eeprom.adapt_state > -100)
|
||
|
|
{
|
||
|
|
eeprom.adapt_state--;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
/* Restart adaption */
|
||
|
|
D(printk("#Restart\n"));
|
||
|
|
eeprom.usec_delay_step++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#endif /* EEPROM_ADAPTIVE_TIMING */
|
||
|
|
/* write until we hit a page boundary or count */
|
||
|
|
do
|
||
|
|
{
|
||
|
|
i2c_outbyte(buf[written]);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
restart=1;
|
||
|
|
printk(KERN_INFO "%s: write error, retrying. %d\n", eeprom_name, i);
|
||
|
|
i2c_stop();
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
written++;
|
||
|
|
p++;
|
||
|
|
} while( written < count && ( p % eeprom.sequential_write_pagesize ));
|
||
|
|
|
||
|
|
/* end write cycle */
|
||
|
|
i2c_stop();
|
||
|
|
i2c_delay(eeprom.usec_delay_writecycles);
|
||
|
|
} /* while */
|
||
|
|
} /* for */
|
||
|
|
|
||
|
|
mutex_unlock(&eeprom.lock);
|
||
|
|
if (written == 0 && p >= eeprom.size){
|
||
|
|
return -ENOSPC;
|
||
|
|
}
|
||
|
|
*off = p;
|
||
|
|
return written;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Closes the device. */
|
||
|
|
|
||
|
|
static int eeprom_close(struct inode * inode, struct file * file)
|
||
|
|
{
|
||
|
|
/* do nothing for now */
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Sets the current address of the eeprom. */
|
||
|
|
|
||
|
|
static int eeprom_address(unsigned long addr)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
unsigned char page, offset;
|
||
|
|
|
||
|
|
page = (unsigned char) (addr >> 8);
|
||
|
|
offset = (unsigned char) addr;
|
||
|
|
|
||
|
|
for(i = 0; i < EEPROM_RETRIES; i++)
|
||
|
|
{
|
||
|
|
/* start a dummy write for addressing */
|
||
|
|
i2c_start();
|
||
|
|
|
||
|
|
if(eeprom.size == EEPROM_16KB)
|
||
|
|
{
|
||
|
|
i2c_outbyte( eeprom.select_cmd );
|
||
|
|
i2c_getack();
|
||
|
|
i2c_outbyte(page);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
i2c_outbyte( eeprom.select_cmd | (page << 1) );
|
||
|
|
}
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
/* retry */
|
||
|
|
i2c_stop();
|
||
|
|
/* Must have a delay here.. 500 works, >50, 100->works 5th time*/
|
||
|
|
i2c_delay(MAX_WRITEDELAY_US / EEPROM_RETRIES * i);
|
||
|
|
/* The chip needs up to 10 ms from write stop to next start */
|
||
|
|
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
i2c_outbyte(offset);
|
||
|
|
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
/* retry */
|
||
|
|
i2c_stop();
|
||
|
|
}
|
||
|
|
else
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
eeprom.retry_cnt_addr = i;
|
||
|
|
D(printk("%i\n", eeprom.retry_cnt_addr));
|
||
|
|
if(eeprom.retry_cnt_addr == EEPROM_RETRIES)
|
||
|
|
{
|
||
|
|
/* failed */
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Reads from current address. */
|
||
|
|
|
||
|
|
static int read_from_eeprom(char * buf, int count)
|
||
|
|
{
|
||
|
|
int i, read=0;
|
||
|
|
|
||
|
|
for(i = 0; i < EEPROM_RETRIES; i++)
|
||
|
|
{
|
||
|
|
if(eeprom.size == EEPROM_16KB)
|
||
|
|
{
|
||
|
|
i2c_outbyte( eeprom.select_cmd | 1 );
|
||
|
|
}
|
||
|
|
|
||
|
|
if(i2c_getack())
|
||
|
|
{
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if(i == EEPROM_RETRIES)
|
||
|
|
{
|
||
|
|
printk(KERN_INFO "%s: failed to read from eeprom\n", eeprom_name);
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
|
||
|
|
while( (read < count))
|
||
|
|
{
|
||
|
|
if (put_user(i2c_inbyte(), &buf[read++]))
|
||
|
|
{
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
return -EFAULT;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* make sure we don't ack last byte or you will get very strange
|
||
|
|
* results!
|
||
|
|
*/
|
||
|
|
if(read < count)
|
||
|
|
{
|
||
|
|
i2c_sendack();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* stop the operation */
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
return read;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Disables write protection if applicable. */
|
||
|
|
|
||
|
|
#define DBP_SAVE(x)
|
||
|
|
#define ax_printf printk
|
||
|
|
static void eeprom_disable_write_protect(void)
|
||
|
|
{
|
||
|
|
/* Disable write protect */
|
||
|
|
if (eeprom.size == EEPROM_8KB)
|
||
|
|
{
|
||
|
|
/* Step 1 Set WEL = 1 (write 00000010 to address 1FFFh */
|
||
|
|
i2c_start();
|
||
|
|
i2c_outbyte(0xbe);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false\n"));
|
||
|
|
}
|
||
|
|
i2c_outbyte(0xFF);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 2\n"));
|
||
|
|
}
|
||
|
|
i2c_outbyte(0x02);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 3\n"));
|
||
|
|
}
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
i2c_delay(1000);
|
||
|
|
|
||
|
|
/* Step 2 Set RWEL = 1 (write 00000110 to address 1FFFh */
|
||
|
|
i2c_start();
|
||
|
|
i2c_outbyte(0xbe);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 55\n"));
|
||
|
|
}
|
||
|
|
i2c_outbyte(0xFF);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 52\n"));
|
||
|
|
}
|
||
|
|
i2c_outbyte(0x06);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 53\n"));
|
||
|
|
}
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
/* Step 3 Set BP1, BP0, and/or WPEN bits (write 00000110 to address 1FFFh */
|
||
|
|
i2c_start();
|
||
|
|
i2c_outbyte(0xbe);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 56\n"));
|
||
|
|
}
|
||
|
|
i2c_outbyte(0xFF);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 57\n"));
|
||
|
|
}
|
||
|
|
i2c_outbyte(0x06);
|
||
|
|
if(!i2c_getack())
|
||
|
|
{
|
||
|
|
DBP_SAVE(ax_printf("Get ack returns false 58\n"));
|
||
|
|
}
|
||
|
|
i2c_stop();
|
||
|
|
|
||
|
|
/* Write protect disabled */
|
||
|
|
}
|
||
|
|
}
|
||
|
|
device_initcall(eeprom_init);
|