096b7bdc86
All these files use the big kernel lock in a trivial way to serialize their private file operations, typically resulting from an earlier semi-automatic pushdown from VFS. None of these drivers appears to want to lock against other code, and they all use the BKL as the top-level lock in their file operations, meaning that there is no lock-order inversion problem. Consequently, we can remove the BKL completely, replacing it with a per-file mutex in every case. Using a scripted approach means we can avoid typos. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*<linux\/smp_lock.h>/d' ${file} else sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
853 lines
22 KiB
C
853 lines
22 KiB
C
/*!*****************************************************************************
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*!
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*! Implements an interface for i2c compatible eeproms to run under Linux.
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*! Supports 2k, 8k(?) and 16k. Uses adaptive timing adjustments by
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*! Johan.Adolfsson@axis.com
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*!
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*! Probing results:
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*! 8k or not is detected (the assumes 2k or 16k)
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*! 2k or 16k detected using test reads and writes.
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*!
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*!------------------------------------------------------------------------
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*! HISTORY
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*!
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*! DATE NAME CHANGES
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*! ---- ---- -------
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*! Aug 28 1999 Edgar Iglesias Initial Version
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*! Aug 31 1999 Edgar Iglesias Allow simultaneous users.
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*! Sep 03 1999 Edgar Iglesias Updated probe.
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*! Sep 03 1999 Edgar Iglesias Added bail-out stuff if we get interrupted
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*! in the spin-lock.
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*!
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*! (c) 1999 Axis Communications AB, Lund, Sweden
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*!*****************************************************************************/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/wait.h>
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#include <asm/uaccess.h>
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#include "i2c.h"
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#define D(x)
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/* If we should use adaptive timing or not: */
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/* #define EEPROM_ADAPTIVE_TIMING */
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#define EEPROM_MAJOR_NR 122 /* use a LOCAL/EXPERIMENTAL major for now */
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#define EEPROM_MINOR_NR 0
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/* Empirical sane initial value of the delay, the value will be adapted to
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* what the chip needs when using EEPROM_ADAPTIVE_TIMING.
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*/
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#define INITIAL_WRITEDELAY_US 4000
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#define MAX_WRITEDELAY_US 10000 /* 10 ms according to spec for 2KB EEPROM */
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/* This one defines how many times to try when eeprom fails. */
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#define EEPROM_RETRIES 10
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#define EEPROM_2KB (2 * 1024)
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/*#define EEPROM_4KB (4 * 1024)*/ /* Exists but not used in Axis products */
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#define EEPROM_8KB (8 * 1024 - 1 ) /* Last byte has write protection bit */
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#define EEPROM_16KB (16 * 1024)
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#define i2c_delay(x) udelay(x)
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/*
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* This structure describes the attached eeprom chip.
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* The values are probed for.
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*/
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struct eeprom_type
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{
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unsigned long size;
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unsigned long sequential_write_pagesize;
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unsigned char select_cmd;
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unsigned long usec_delay_writecycles; /* Min time between write cycles
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(up to 10ms for some models) */
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unsigned long usec_delay_step; /* For adaptive algorithm */
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int adapt_state; /* 1 = To high , 0 = Even, -1 = To low */
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/* this one is to keep the read/write operations atomic */
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struct mutex lock;
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int retry_cnt_addr; /* Used to keep track of number of retries for
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adaptive timing adjustments */
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int retry_cnt_read;
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};
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static int eeprom_open(struct inode * inode, struct file * file);
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static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig);
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static ssize_t eeprom_read(struct file * file, char * buf, size_t count,
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loff_t *off);
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static ssize_t eeprom_write(struct file * file, const char * buf, size_t count,
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loff_t *off);
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static int eeprom_close(struct inode * inode, struct file * file);
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static int eeprom_address(unsigned long addr);
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static int read_from_eeprom(char * buf, int count);
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static int eeprom_write_buf(loff_t addr, const char * buf, int count);
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static int eeprom_read_buf(loff_t addr, char * buf, int count);
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static void eeprom_disable_write_protect(void);
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static const char eeprom_name[] = "eeprom";
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/* chip description */
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static struct eeprom_type eeprom;
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/* This is the exported file-operations structure for this device. */
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const struct file_operations eeprom_fops =
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{
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.llseek = eeprom_lseek,
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.read = eeprom_read,
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.write = eeprom_write,
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.open = eeprom_open,
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.release = eeprom_close
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};
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/* eeprom init call. Probes for different eeprom models. */
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int __init eeprom_init(void)
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{
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mutex_init(&eeprom.lock);
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#ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE
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#define EETEXT "Found"
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#else
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#define EETEXT "Assuming"
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#endif
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if (register_chrdev(EEPROM_MAJOR_NR, eeprom_name, &eeprom_fops))
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{
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printk(KERN_INFO "%s: unable to get major %d for eeprom device\n",
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eeprom_name, EEPROM_MAJOR_NR);
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return -1;
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}
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printk("EEPROM char device v0.3, (c) 2000 Axis Communications AB\n");
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/*
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* Note: Most of this probing method was taken from the printserver (5470e)
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* codebase. It did not contain a way of finding the 16kB chips
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* (M24128 or variants). The method used here might not work
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* for all models. If you encounter problems the easiest way
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* is probably to define your model within #ifdef's, and hard-
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* code it.
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*/
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eeprom.size = 0;
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eeprom.usec_delay_writecycles = INITIAL_WRITEDELAY_US;
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eeprom.usec_delay_step = 128;
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eeprom.adapt_state = 0;
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#ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE
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i2c_start();
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i2c_outbyte(0x80);
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if(!i2c_getack())
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{
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/* It's not 8k.. */
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int success = 0;
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unsigned char buf_2k_start[16];
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/* Im not sure this will work... :) */
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/* assume 2kB, if failure go for 16kB */
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/* Test with 16kB settings.. */
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/* If it's a 2kB EEPROM and we address it outside it's range
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* it will mirror the address space:
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* 1. We read two locations (that are mirrored),
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* if the content differs * it's a 16kB EEPROM.
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* 2. if it doesn't differ - write different value to one of the locations,
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* check the other - if content still is the same it's a 2k EEPROM,
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* restore original data.
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*/
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#define LOC1 8
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#define LOC2 (0x1fb) /*1fb, 3ed, 5df, 7d1 */
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/* 2k settings */
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i2c_stop();
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eeprom.size = EEPROM_2KB;
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eeprom.select_cmd = 0xA0;
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eeprom.sequential_write_pagesize = 16;
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if( eeprom_read_buf( 0, buf_2k_start, 16 ) == 16 )
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{
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D(printk("2k start: '%16.16s'\n", buf_2k_start));
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}
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else
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{
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printk(KERN_INFO "%s: Failed to read in 2k mode!\n", eeprom_name);
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}
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/* 16k settings */
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eeprom.size = EEPROM_16KB;
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eeprom.select_cmd = 0xA0;
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eeprom.sequential_write_pagesize = 64;
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{
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unsigned char loc1[4], loc2[4], tmp[4];
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if( eeprom_read_buf(LOC2, loc2, 4) == 4)
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{
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if( eeprom_read_buf(LOC1, loc1, 4) == 4)
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{
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D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
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LOC1, loc1, LOC2, loc2));
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#if 0
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if (memcmp(loc1, loc2, 4) != 0 )
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{
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/* It's 16k */
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printk(KERN_INFO "%s: 16k detected in step 1\n", eeprom_name);
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eeprom.size = EEPROM_16KB;
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success = 1;
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}
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else
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#endif
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{
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/* Do step 2 check */
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/* Invert value */
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loc1[0] = ~loc1[0];
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if (eeprom_write_buf(LOC1, loc1, 1) == 1)
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{
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/* If 2k EEPROM this write will actually write 10 bytes
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* from pos 0
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*/
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D(printk("1 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
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LOC1, loc1, LOC2, loc2));
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if( eeprom_read_buf(LOC1, tmp, 4) == 4)
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{
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D(printk("2 loc1: (%i) '%4.4s' tmp '%4.4s'\n",
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LOC1, loc1, tmp));
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if (memcmp(loc1, tmp, 4) != 0 )
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{
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printk(KERN_INFO "%s: read and write differs! Not 16kB\n",
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eeprom_name);
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loc1[0] = ~loc1[0];
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if (eeprom_write_buf(LOC1, loc1, 1) == 1)
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{
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success = 1;
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}
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else
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{
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printk(KERN_INFO "%s: Restore 2k failed during probe,"
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" EEPROM might be corrupt!\n", eeprom_name);
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}
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i2c_stop();
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/* Go to 2k mode and write original data */
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eeprom.size = EEPROM_2KB;
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eeprom.select_cmd = 0xA0;
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eeprom.sequential_write_pagesize = 16;
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if( eeprom_write_buf(0, buf_2k_start, 16) == 16)
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{
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}
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else
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{
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printk(KERN_INFO "%s: Failed to write back 2k start!\n",
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eeprom_name);
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}
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eeprom.size = EEPROM_2KB;
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}
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}
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if(!success)
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{
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if( eeprom_read_buf(LOC2, loc2, 1) == 1)
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{
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D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
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LOC1, loc1, LOC2, loc2));
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if (memcmp(loc1, loc2, 4) == 0 )
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{
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/* Data the same, must be mirrored -> 2k */
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/* Restore data */
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printk(KERN_INFO "%s: 2k detected in step 2\n", eeprom_name);
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loc1[0] = ~loc1[0];
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if (eeprom_write_buf(LOC1, loc1, 1) == 1)
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{
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success = 1;
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}
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else
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{
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printk(KERN_INFO "%s: Restore 2k failed during probe,"
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" EEPROM might be corrupt!\n", eeprom_name);
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}
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eeprom.size = EEPROM_2KB;
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}
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else
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{
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printk(KERN_INFO "%s: 16k detected in step 2\n",
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eeprom_name);
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loc1[0] = ~loc1[0];
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/* Data differs, assume 16k */
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/* Restore data */
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if (eeprom_write_buf(LOC1, loc1, 1) == 1)
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{
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success = 1;
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}
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else
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{
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printk(KERN_INFO "%s: Restore 16k failed during probe,"
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" EEPROM might be corrupt!\n", eeprom_name);
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}
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eeprom.size = EEPROM_16KB;
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}
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}
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}
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}
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} /* read LOC1 */
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} /* address LOC1 */
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if (!success)
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{
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printk(KERN_INFO "%s: Probing failed!, using 2KB!\n", eeprom_name);
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eeprom.size = EEPROM_2KB;
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}
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} /* read */
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}
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}
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else
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{
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i2c_outbyte(0x00);
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if(!i2c_getack())
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{
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/* No 8k */
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eeprom.size = EEPROM_2KB;
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}
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else
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{
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i2c_start();
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i2c_outbyte(0x81);
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if (!i2c_getack())
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{
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eeprom.size = EEPROM_2KB;
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}
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else
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{
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/* It's a 8kB */
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i2c_inbyte();
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eeprom.size = EEPROM_8KB;
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}
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}
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}
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i2c_stop();
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#elif defined(CONFIG_ETRAX_I2C_EEPROM_16KB)
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eeprom.size = EEPROM_16KB;
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#elif defined(CONFIG_ETRAX_I2C_EEPROM_8KB)
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eeprom.size = EEPROM_8KB;
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#elif defined(CONFIG_ETRAX_I2C_EEPROM_2KB)
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eeprom.size = EEPROM_2KB;
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#endif
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switch(eeprom.size)
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{
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case (EEPROM_2KB):
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printk("%s: " EETEXT " i2c compatible 2kB eeprom.\n", eeprom_name);
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eeprom.sequential_write_pagesize = 16;
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eeprom.select_cmd = 0xA0;
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break;
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case (EEPROM_8KB):
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printk("%s: " EETEXT " i2c compatible 8kB eeprom.\n", eeprom_name);
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eeprom.sequential_write_pagesize = 16;
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eeprom.select_cmd = 0x80;
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break;
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case (EEPROM_16KB):
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printk("%s: " EETEXT " i2c compatible 16kB eeprom.\n", eeprom_name);
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eeprom.sequential_write_pagesize = 64;
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eeprom.select_cmd = 0xA0;
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break;
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default:
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eeprom.size = 0;
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printk("%s: Did not find a supported eeprom\n", eeprom_name);
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break;
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}
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eeprom_disable_write_protect();
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return 0;
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}
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/* Opens the device. */
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static int eeprom_open(struct inode * inode, struct file * file)
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{
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if(iminor(inode) != EEPROM_MINOR_NR)
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return -ENXIO;
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if(imajor(inode) != EEPROM_MAJOR_NR)
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return -ENXIO;
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if( eeprom.size > 0 )
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{
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/* OK */
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return 0;
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}
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/* No EEprom found */
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return -EFAULT;
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}
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/* Changes the current file position. */
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static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig)
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{
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/*
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* orig 0: position from begning of eeprom
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* orig 1: relative from current position
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* orig 2: position from last eeprom address
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*/
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switch (orig)
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{
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case 0:
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file->f_pos = offset;
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break;
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case 1:
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file->f_pos += offset;
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break;
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case 2:
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file->f_pos = eeprom.size - offset;
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break;
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default:
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return -EINVAL;
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}
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/* truncate position */
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if (file->f_pos < 0)
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{
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file->f_pos = 0;
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return(-EOVERFLOW);
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}
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if (file->f_pos >= eeprom.size)
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{
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file->f_pos = eeprom.size - 1;
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return(-EOVERFLOW);
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}
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return ( file->f_pos );
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}
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/* Reads data from eeprom. */
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static int eeprom_read_buf(loff_t addr, char * buf, int count)
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{
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return eeprom_read(NULL, buf, count, &addr);
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}
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/* Reads data from eeprom. */
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static ssize_t eeprom_read(struct file * file, char * buf, size_t count, loff_t *off)
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{
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int read=0;
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unsigned long p = *off;
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unsigned char page;
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if(p >= eeprom.size) /* Address i 0 - (size-1) */
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{
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return -EFAULT;
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}
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if (mutex_lock_interruptible(&eeprom.lock))
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return -EINTR;
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page = (unsigned char) (p >> 8);
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if(!eeprom_address(p))
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{
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printk(KERN_INFO "%s: Read failed to address the eeprom: "
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"0x%08X (%i) page: %i\n", eeprom_name, (int)p, (int)p, page);
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i2c_stop();
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/* don't forget to wake them up */
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mutex_unlock(&eeprom.lock);
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return -EFAULT;
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}
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if( (p + count) > eeprom.size)
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{
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/* truncate count */
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count = eeprom.size - p;
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}
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/* stop dummy write op and initiate the read op */
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i2c_start();
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/* special case for small eeproms */
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if(eeprom.size < EEPROM_16KB)
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{
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i2c_outbyte( eeprom.select_cmd | 1 | (page << 1) );
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}
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/* go on with the actual read */
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read = read_from_eeprom( buf, count);
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if(read > 0)
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{
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*off += read;
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}
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mutex_unlock(&eeprom.lock);
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return read;
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}
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/* Writes data to eeprom. */
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static int eeprom_write_buf(loff_t addr, const char * buf, int count)
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{
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return eeprom_write(NULL, buf, count, &addr);
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}
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/* Writes data to eeprom. */
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static ssize_t eeprom_write(struct file * file, const char * buf, size_t count,
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loff_t *off)
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{
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int i, written, restart=1;
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unsigned long p;
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if (!access_ok(VERIFY_READ, buf, count))
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{
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return -EFAULT;
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}
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/* bail out if we get interrupted */
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if (mutex_lock_interruptible(&eeprom.lock))
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return -EINTR;
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for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++)
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{
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restart = 0;
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written = 0;
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p = *off;
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while( (written < count) && (p < eeprom.size))
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{
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/* address the eeprom */
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if(!eeprom_address(p))
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{
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printk(KERN_INFO "%s: Write failed to address the eeprom: "
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"0x%08X (%i) \n", eeprom_name, (int)p, (int)p);
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i2c_stop();
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/* don't forget to wake them up */
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mutex_unlock(&eeprom.lock);
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return -EFAULT;
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}
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#ifdef EEPROM_ADAPTIVE_TIMING
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/* Adaptive algorithm to adjust timing */
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if (eeprom.retry_cnt_addr > 0)
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{
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/* To Low now */
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D(printk(">D=%i d=%i\n",
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eeprom.usec_delay_writecycles, eeprom.usec_delay_step));
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if (eeprom.usec_delay_step < 4)
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{
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eeprom.usec_delay_step++;
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eeprom.usec_delay_writecycles += eeprom.usec_delay_step;
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}
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else
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{
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if (eeprom.adapt_state > 0)
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{
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/* To Low before */
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eeprom.usec_delay_step *= 2;
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if (eeprom.usec_delay_step > 2)
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{
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eeprom.usec_delay_step--;
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}
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eeprom.usec_delay_writecycles += eeprom.usec_delay_step;
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}
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else if (eeprom.adapt_state < 0)
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{
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/* To High before (toggle dir) */
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eeprom.usec_delay_writecycles += eeprom.usec_delay_step;
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if (eeprom.usec_delay_step > 1)
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{
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eeprom.usec_delay_step /= 2;
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eeprom.usec_delay_step--;
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}
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}
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}
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eeprom.adapt_state = 1;
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}
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else
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{
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/* To High (or good) now */
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D(printk("<D=%i d=%i\n",
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eeprom.usec_delay_writecycles, eeprom.usec_delay_step));
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if (eeprom.adapt_state < 0)
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{
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/* To High before */
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if (eeprom.usec_delay_step > 1)
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{
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eeprom.usec_delay_step *= 2;
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eeprom.usec_delay_step--;
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if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step)
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{
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eeprom.usec_delay_writecycles -= eeprom.usec_delay_step;
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}
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}
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}
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else if (eeprom.adapt_state > 0)
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{
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/* To Low before (toggle dir) */
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if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step)
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{
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eeprom.usec_delay_writecycles -= eeprom.usec_delay_step;
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}
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if (eeprom.usec_delay_step > 1)
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{
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eeprom.usec_delay_step /= 2;
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eeprom.usec_delay_step--;
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}
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eeprom.adapt_state = -1;
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}
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if (eeprom.adapt_state > -100)
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{
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eeprom.adapt_state--;
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}
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else
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{
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/* Restart adaption */
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D(printk("#Restart\n"));
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eeprom.usec_delay_step++;
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}
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}
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#endif /* EEPROM_ADAPTIVE_TIMING */
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/* write until we hit a page boundary or count */
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do
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{
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i2c_outbyte(buf[written]);
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if(!i2c_getack())
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{
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restart=1;
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printk(KERN_INFO "%s: write error, retrying. %d\n", eeprom_name, i);
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i2c_stop();
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break;
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}
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written++;
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p++;
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} while( written < count && ( p % eeprom.sequential_write_pagesize ));
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/* end write cycle */
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i2c_stop();
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i2c_delay(eeprom.usec_delay_writecycles);
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} /* while */
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} /* for */
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mutex_unlock(&eeprom.lock);
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if (written == 0 && p >= eeprom.size){
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return -ENOSPC;
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}
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*off = p;
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return written;
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}
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/* Closes the device. */
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static int eeprom_close(struct inode * inode, struct file * file)
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{
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/* do nothing for now */
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return 0;
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}
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/* Sets the current address of the eeprom. */
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static int eeprom_address(unsigned long addr)
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{
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int i;
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unsigned char page, offset;
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page = (unsigned char) (addr >> 8);
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offset = (unsigned char) addr;
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for(i = 0; i < EEPROM_RETRIES; i++)
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{
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/* start a dummy write for addressing */
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i2c_start();
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if(eeprom.size == EEPROM_16KB)
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{
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i2c_outbyte( eeprom.select_cmd );
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i2c_getack();
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i2c_outbyte(page);
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}
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else
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{
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i2c_outbyte( eeprom.select_cmd | (page << 1) );
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}
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if(!i2c_getack())
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{
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/* retry */
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i2c_stop();
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/* Must have a delay here.. 500 works, >50, 100->works 5th time*/
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i2c_delay(MAX_WRITEDELAY_US / EEPROM_RETRIES * i);
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/* The chip needs up to 10 ms from write stop to next start */
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}
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else
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{
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i2c_outbyte(offset);
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if(!i2c_getack())
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{
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/* retry */
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i2c_stop();
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}
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else
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break;
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}
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}
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eeprom.retry_cnt_addr = i;
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D(printk("%i\n", eeprom.retry_cnt_addr));
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if(eeprom.retry_cnt_addr == EEPROM_RETRIES)
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{
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/* failed */
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return 0;
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}
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return 1;
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}
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/* Reads from current address. */
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static int read_from_eeprom(char * buf, int count)
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{
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int i, read=0;
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for(i = 0; i < EEPROM_RETRIES; i++)
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{
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if(eeprom.size == EEPROM_16KB)
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{
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i2c_outbyte( eeprom.select_cmd | 1 );
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}
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if(i2c_getack())
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{
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break;
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}
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}
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if(i == EEPROM_RETRIES)
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{
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printk(KERN_INFO "%s: failed to read from eeprom\n", eeprom_name);
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i2c_stop();
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return -EFAULT;
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}
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while( (read < count))
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{
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if (put_user(i2c_inbyte(), &buf[read++]))
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{
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i2c_stop();
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return -EFAULT;
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}
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/*
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* make sure we don't ack last byte or you will get very strange
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* results!
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*/
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if(read < count)
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{
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i2c_sendack();
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}
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}
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/* stop the operation */
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i2c_stop();
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return read;
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}
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/* Disables write protection if applicable. */
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#define DBP_SAVE(x)
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#define ax_printf printk
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static void eeprom_disable_write_protect(void)
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{
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/* Disable write protect */
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if (eeprom.size == EEPROM_8KB)
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{
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/* Step 1 Set WEL = 1 (write 00000010 to address 1FFFh */
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i2c_start();
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i2c_outbyte(0xbe);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false\n"));
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}
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i2c_outbyte(0xFF);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 2\n"));
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}
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i2c_outbyte(0x02);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 3\n"));
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}
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i2c_stop();
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i2c_delay(1000);
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/* Step 2 Set RWEL = 1 (write 00000110 to address 1FFFh */
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i2c_start();
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i2c_outbyte(0xbe);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 55\n"));
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}
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i2c_outbyte(0xFF);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 52\n"));
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}
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i2c_outbyte(0x06);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 53\n"));
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}
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i2c_stop();
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/* Step 3 Set BP1, BP0, and/or WPEN bits (write 00000110 to address 1FFFh */
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i2c_start();
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i2c_outbyte(0xbe);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 56\n"));
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}
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i2c_outbyte(0xFF);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 57\n"));
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}
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i2c_outbyte(0x06);
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if(!i2c_getack())
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{
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DBP_SAVE(ax_printf("Get ack returns false 58\n"));
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}
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i2c_stop();
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/* Write protect disabled */
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}
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}
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module_init(eeprom_init);
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