946 lines
24 KiB
C
946 lines
24 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 adjustents 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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*! $Log: eeprom.c,v $
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*! Revision 1.10 2003/09/11 07:29:48 starvik
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*! Merge of Linux 2.6.0-test5
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*!
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*! Revision 1.9 2003/07/04 08:27:37 starvik
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*! Merge of Linux 2.5.74
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*!
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*! Revision 1.8 2003/04/09 05:20:47 starvik
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*! Merge of Linux 2.5.67
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*!
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*! Revision 1.6 2003/02/10 07:19:28 starvik
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*! Removed misplaced ;
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*!
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*! Revision 1.5 2002/12/11 13:13:57 starvik
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*! Added arch/ to v10 specific includes
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*! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
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*!
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*! Revision 1.4 2002/11/20 11:56:10 starvik
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*! Merge of Linux 2.5.48
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*!
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*! Revision 1.3 2002/11/18 13:16:06 starvik
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*! Linux 2.5 port of latest 2.4 drivers
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*!
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*! Revision 1.8 2001/06/15 13:24:29 jonashg
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*! * Added verification of pointers from userspace in read and write.
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*! * Made busy counter volatile.
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*! * Added define for inital write delay.
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*! * Removed warnings by using loff_t instead of unsigned long.
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*!
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*! Revision 1.7 2001/06/14 15:26:54 jonashg
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*! Removed test because condition is always true.
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*!
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*! Revision 1.6 2001/06/14 15:18:20 jonashg
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*! Kb -> kB (makes quite a difference if you don't know if you have 2k or 16k).
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*!
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*! Revision 1.5 2001/06/14 14:39:51 jonashg
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*! Forgot to use name when registering the driver.
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*!
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*! Revision 1.4 2001/06/14 14:35:47 jonashg
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*! * Gave driver a name and used it in printk's.
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*! * Cleanup.
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*!
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*! Revision 1.3 2001/03/19 16:04:46 markusl
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*! Fixed init of fops struct
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*!
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*! Revision 1.2 2001/03/19 10:35:07 markusl
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*! 2.4 port of eeprom driver
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*!
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*! Revision 1.8 2000/05/18 10:42:25 edgar
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*! Make sure to end write cycle on _every_ write
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*!
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*! Revision 1.7 2000/01/17 17:41:01 johana
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*! Adjusted probing and return -ENOSPC when writing outside EEPROM
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*!
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*! Revision 1.6 2000/01/17 15:50:36 johana
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*! Added adaptive timing adjustments and fixed autoprobing for 2k and 16k(?)
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*! EEPROMs
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*!
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*! Revision 1.5 1999/09/03 15:07:37 edgar
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*! Added bail-out check to the spinlock
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*!
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*! Revision 1.4 1999/09/03 12:11:17 bjornw
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*! Proper atomicity (need to use spinlocks, not if's). users -> busy.
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*!
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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/config.h>
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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 <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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wait_queue_head_t wait_q;
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volatile int busy;
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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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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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init_waitqueue_head(&eeprom.wait_q);
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eeprom.busy = 0;
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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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|
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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(MINOR(inode->i_rdev) != EEPROM_MINOR_NR)
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return -ENXIO;
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if(MAJOR(inode->i_rdev) != EEPROM_MAJOR_NR)
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return -ENXIO;
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|
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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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|
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/* No EEprom found */
|
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return -EFAULT;
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}
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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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|
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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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|
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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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|
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return ( file->f_pos );
|
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}
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|
|
/* Reads data from eeprom. */
|
|
|
|
static int eeprom_read_buf(loff_t addr, char * buf, int count)
|
|
{
|
|
struct file f;
|
|
|
|
f.f_pos = addr;
|
|
return eeprom_read(&f, 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 = file->f_pos;
|
|
|
|
unsigned char page;
|
|
|
|
if(p >= eeprom.size) /* Address i 0 - (size-1) */
|
|
{
|
|
return -EFAULT;
|
|
}
|
|
|
|
while(eeprom.busy)
|
|
{
|
|
interruptible_sleep_on(&eeprom.wait_q);
|
|
|
|
/* bail out if we get interrupted */
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
|
|
}
|
|
eeprom.busy++;
|
|
|
|
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 */
|
|
eeprom.busy--;
|
|
wake_up_interruptible(&eeprom.wait_q);
|
|
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)
|
|
{
|
|
file->f_pos += read;
|
|
}
|
|
|
|
eeprom.busy--;
|
|
wake_up_interruptible(&eeprom.wait_q);
|
|
return read;
|
|
}
|
|
|
|
/* Writes data to eeprom. */
|
|
|
|
static int eeprom_write_buf(loff_t addr, const char * buf, int count)
|
|
{
|
|
struct file f;
|
|
|
|
f.f_pos = addr;
|
|
|
|
return eeprom_write(&f, 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;
|
|
}
|
|
|
|
while(eeprom.busy)
|
|
{
|
|
interruptible_sleep_on(&eeprom.wait_q);
|
|
/* bail out if we get interrupted */
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
}
|
|
eeprom.busy++;
|
|
for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++)
|
|
{
|
|
restart = 0;
|
|
written = 0;
|
|
p = file->f_pos;
|
|
|
|
|
|
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 */
|
|
eeprom.busy--;
|
|
wake_up_interruptible(&eeprom.wait_q);
|
|
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 */
|
|
|
|
eeprom.busy--;
|
|
wake_up_interruptible(&eeprom.wait_q);
|
|
if (written == 0 && file->f_pos >= eeprom.size){
|
|
return -ENOSPC;
|
|
}
|
|
file->f_pos += written;
|
|
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 */
|
|
}
|
|
}
|
|
|
|
module_init(eeprom_init);
|