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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/cris/arch-v10/drivers/eeprom.c
downloadlinux-stericsson-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/cris/arch-v10/drivers/eeprom.c')
-rw-r--r--arch/cris/arch-v10/drivers/eeprom.c945
1 files changed, 945 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/drivers/eeprom.c b/arch/cris/arch-v10/drivers/eeprom.c
new file mode 100644
index 000000000000..316ca15d6802
--- /dev/null
+++ b/arch/cris/arch-v10/drivers/eeprom.c
@@ -0,0 +1,945 @@
+/*!*****************************************************************************
+*!
+*! Implements an interface for i2c compatible eeproms to run under linux.
+*! Supports 2k, 8k(?) and 16k. Uses adaptive timing adjustents by
+*! Johan.Adolfsson@axis.com
+*!
+*! Probing results:
+*! 8k or not is detected (the assumes 2k or 16k)
+*! 2k or 16k detected using test reads and writes.
+*!
+*!------------------------------------------------------------------------
+*! HISTORY
+*!
+*! DATE NAME CHANGES
+*! ---- ---- -------
+*! Aug 28 1999 Edgar Iglesias Initial Version
+*! Aug 31 1999 Edgar Iglesias Allow simultaneous users.
+*! Sep 03 1999 Edgar Iglesias Updated probe.
+*! Sep 03 1999 Edgar Iglesias Added bail-out stuff if we get interrupted
+*! in the spin-lock.
+*!
+*! $Log: eeprom.c,v $
+*! Revision 1.10 2003/09/11 07:29:48 starvik
+*! Merge of Linux 2.6.0-test5
+*!
+*! Revision 1.9 2003/07/04 08:27:37 starvik
+*! Merge of Linux 2.5.74
+*!
+*! Revision 1.8 2003/04/09 05:20:47 starvik
+*! Merge of Linux 2.5.67
+*!
+*! Revision 1.6 2003/02/10 07:19:28 starvik
+*! Removed misplaced ;
+*!
+*! Revision 1.5 2002/12/11 13:13:57 starvik
+*! Added arch/ to v10 specific includes
+*! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
+*!
+*! Revision 1.4 2002/11/20 11:56:10 starvik
+*! Merge of Linux 2.5.48
+*!
+*! Revision 1.3 2002/11/18 13:16:06 starvik
+*! Linux 2.5 port of latest 2.4 drivers
+*!
+*! Revision 1.8 2001/06/15 13:24:29 jonashg
+*! * Added verification of pointers from userspace in read and write.
+*! * Made busy counter volatile.
+*! * Added define for inital write delay.
+*! * Removed warnings by using loff_t instead of unsigned long.
+*!
+*! Revision 1.7 2001/06/14 15:26:54 jonashg
+*! Removed test because condition is always true.
+*!
+*! Revision 1.6 2001/06/14 15:18:20 jonashg
+*! Kb -> kB (makes quite a difference if you don't know if you have 2k or 16k).
+*!
+*! Revision 1.5 2001/06/14 14:39:51 jonashg
+*! Forgot to use name when registering the driver.
+*!
+*! Revision 1.4 2001/06/14 14:35:47 jonashg
+*! * Gave driver a name and used it in printk's.
+*! * Cleanup.
+*!
+*! Revision 1.3 2001/03/19 16:04:46 markusl
+*! Fixed init of fops struct
+*!
+*! Revision 1.2 2001/03/19 10:35:07 markusl
+*! 2.4 port of eeprom driver
+*!
+*! Revision 1.8 2000/05/18 10:42:25 edgar
+*! Make sure to end write cycle on _every_ write
+*!
+*! Revision 1.7 2000/01/17 17:41:01 johana
+*! Adjusted probing and return -ENOSPC when writing outside EEPROM
+*!
+*! Revision 1.6 2000/01/17 15:50:36 johana
+*! Added adaptive timing adjustments and fixed autoprobing for 2k and 16k(?)
+*! EEPROMs
+*!
+*! Revision 1.5 1999/09/03 15:07:37 edgar
+*! Added bail-out check to the spinlock
+*!
+*! Revision 1.4 1999/09/03 12:11:17 bjornw
+*! Proper atomicity (need to use spinlocks, not if's). users -> busy.
+*!
+*!
+*! (c) 1999 Axis Communications AB, Lund, Sweden
+*!*****************************************************************************/
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <asm/uaccess.h>
+#include "i2c.h"
+
+#define D(x)
+
+/* If we should use adaptive timing or not: */
+//#define EEPROM_ADAPTIVE_TIMING
+
+#define EEPROM_MAJOR_NR 122 /* use a LOCAL/EXPERIMENTAL major for now */
+#define EEPROM_MINOR_NR 0
+
+/* Empirical sane initial value of the delay, the value will be adapted to
+ * what the chip needs when using EEPROM_ADAPTIVE_TIMING.
+ */
+#define INITIAL_WRITEDELAY_US 4000
+#define MAX_WRITEDELAY_US 10000 /* 10 ms according to spec for 2KB EEPROM */
+
+/* This one defines how many times to try when eeprom fails. */
+#define EEPROM_RETRIES 10
+
+#define EEPROM_2KB (2 * 1024)
+/*#define EEPROM_4KB (4 * 1024)*/ /* Exists but not used in Axis products */
+#define EEPROM_8KB (8 * 1024 - 1 ) /* Last byte has write protection bit */
+#define EEPROM_16KB (16 * 1024)
+
+#define i2c_delay(x) udelay(x)
+
+/*
+ * This structure describes the attached eeprom chip.
+ * The values are probed for.
+ */
+
+struct eeprom_type
+{
+ unsigned long size;
+ unsigned long sequential_write_pagesize;
+ unsigned char select_cmd;
+ unsigned long usec_delay_writecycles; /* Min time between write cycles
+ (up to 10ms for some models) */
+ unsigned long usec_delay_step; /* For adaptive algorithm */
+ int adapt_state; /* 1 = To high , 0 = Even, -1 = To low */
+
+ /* this one is to keep the read/write operations atomic */
+ wait_queue_head_t wait_q;
+ volatile int busy;
+ int retry_cnt_addr; /* Used to keep track of number of retries for
+ adaptive timing adjustments */
+ int retry_cnt_read;
+};
+
+static int eeprom_open(struct inode * inode, struct file * file);
+static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig);
+static ssize_t eeprom_read(struct file * file, char * buf, size_t count,
+ loff_t *off);
+static ssize_t eeprom_write(struct file * file, const char * buf, size_t count,
+ loff_t *off);
+static int eeprom_close(struct inode * inode, struct file * file);
+
+static int eeprom_address(unsigned long addr);
+static int read_from_eeprom(char * buf, int count);
+static int eeprom_write_buf(loff_t addr, const char * buf, int count);
+static int eeprom_read_buf(loff_t addr, char * buf, int count);
+
+static void eeprom_disable_write_protect(void);
+
+
+static const char eeprom_name[] = "eeprom";
+
+/* chip description */
+static struct eeprom_type eeprom;
+
+/* This is the exported file-operations structure for this device. */
+struct file_operations eeprom_fops =
+{
+ .llseek = eeprom_lseek,
+ .read = eeprom_read,
+ .write = eeprom_write,
+ .open = eeprom_open,
+ .release = eeprom_close
+};
+
+/* eeprom init call. Probes for different eeprom models. */
+
+int __init eeprom_init(void)
+{
+ init_waitqueue_head(&eeprom.wait_q);
+ eeprom.busy = 0;
+
+#ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE
+#define EETEXT "Found"
+#else
+#define EETEXT "Assuming"
+#endif
+ if (register_chrdev(EEPROM_MAJOR_NR, eeprom_name, &eeprom_fops))
+ {
+ printk(KERN_INFO "%s: unable to get major %d for eeprom device\n",
+ eeprom_name, EEPROM_MAJOR_NR);
+ return -1;
+ }
+
+ printk("EEPROM char device v0.3, (c) 2000 Axis Communications AB\n");
+
+ /*
+ * Note: Most of this probing method was taken from the printserver (5470e)
+ * codebase. It did not contain a way of finding the 16kB chips
+ * (M24128 or variants). The method used here might not work
+ * for all models. If you encounter problems the easiest way
+ * is probably to define your model within #ifdef's, and hard-
+ * code it.
+ */
+
+ eeprom.size = 0;
+ eeprom.usec_delay_writecycles = INITIAL_WRITEDELAY_US;
+ eeprom.usec_delay_step = 128;
+ eeprom.adapt_state = 0;
+
+#ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE
+ i2c_start();
+ i2c_outbyte(0x80);
+ if(!i2c_getack())
+ {
+ /* It's not 8k.. */
+ int success = 0;
+ unsigned char buf_2k_start[16];
+
+ /* Im not sure this will work... :) */
+ /* assume 2kB, if failure go for 16kB */
+ /* Test with 16kB settings.. */
+ /* If it's a 2kB EEPROM and we address it outside it's range
+ * it will mirror the address space:
+ * 1. We read two locations (that are mirrored),
+ * if the content differs * it's a 16kB EEPROM.
+ * 2. if it doesn't differ - write different value to one of the locations,
+ * check the other - if content still is the same it's a 2k EEPROM,
+ * restore original data.
+ */
+#define LOC1 8
+#define LOC2 (0x1fb) /*1fb, 3ed, 5df, 7d1 */
+
+ /* 2k settings */
+ i2c_stop();
+ eeprom.size = EEPROM_2KB;
+ eeprom.select_cmd = 0xA0;
+ eeprom.sequential_write_pagesize = 16;
+ if( eeprom_read_buf( 0, buf_2k_start, 16 ) == 16 )
+ {
+ D(printk("2k start: '%16.16s'\n", buf_2k_start));
+ }
+ else
+ {
+ printk(KERN_INFO "%s: Failed to read in 2k mode!\n", eeprom_name);
+ }
+
+ /* 16k settings */
+ eeprom.size = EEPROM_16KB;
+ eeprom.select_cmd = 0xA0;
+ eeprom.sequential_write_pagesize = 64;
+
+ {
+ unsigned char loc1[4], loc2[4], tmp[4];
+ if( eeprom_read_buf(LOC2, loc2, 4) == 4)
+ {
+ if( eeprom_read_buf(LOC1, loc1, 4) == 4)
+ {
+ D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
+ LOC1, loc1, LOC2, loc2));
+#if 0
+ if (memcmp(loc1, loc2, 4) != 0 )
+ {
+ /* It's 16k */
+ printk(KERN_INFO "%s: 16k detected in step 1\n", eeprom_name);
+ eeprom.size = EEPROM_16KB;
+ success = 1;
+ }
+ else
+#endif
+ {
+ /* Do step 2 check */
+ /* Invert value */
+ loc1[0] = ~loc1[0];
+ if (eeprom_write_buf(LOC1, loc1, 1) == 1)
+ {
+ /* If 2k EEPROM this write will actually write 10 bytes
+ * from pos 0
+ */
+ D(printk("1 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
+ LOC1, loc1, LOC2, loc2));
+ if( eeprom_read_buf(LOC1, tmp, 4) == 4)
+ {
+ D(printk("2 loc1: (%i) '%4.4s' tmp '%4.4s'\n",
+ LOC1, loc1, tmp));
+ if (memcmp(loc1, tmp, 4) != 0 )
+ {
+ printk(KERN_INFO "%s: read and write differs! Not 16kB\n",
+ eeprom_name);
+ loc1[0] = ~loc1[0];
+
+ if (eeprom_write_buf(LOC1, loc1, 1) == 1)
+ {
+ success = 1;
+ }
+ else
+ {
+ printk(KERN_INFO "%s: Restore 2k failed during probe,"
+ " EEPROM might be corrupt!\n", eeprom_name);
+
+ }
+ i2c_stop();
+ /* Go to 2k mode and write original data */
+ eeprom.size = EEPROM_2KB;
+ eeprom.select_cmd = 0xA0;
+ eeprom.sequential_write_pagesize = 16;
+ if( eeprom_write_buf(0, buf_2k_start, 16) == 16)
+ {
+ }
+ else
+ {
+ printk(KERN_INFO "%s: Failed to write back 2k start!\n",
+ eeprom_name);
+ }
+
+ eeprom.size = EEPROM_2KB;
+ }
+ }
+
+ if(!success)
+ {
+ if( eeprom_read_buf(LOC2, loc2, 1) == 1)
+ {
+ D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n",
+ LOC1, loc1, LOC2, loc2));
+ if (memcmp(loc1, loc2, 4) == 0 )
+ {
+ /* Data the same, must be mirrored -> 2k */
+ /* Restore data */
+ printk(KERN_INFO "%s: 2k detected in step 2\n", eeprom_name);
+ loc1[0] = ~loc1[0];
+ if (eeprom_write_buf(LOC1, loc1, 1) == 1)
+ {
+ success = 1;
+ }
+ else
+ {
+ printk(KERN_INFO "%s: Restore 2k failed during probe,"
+ " EEPROM might be corrupt!\n", eeprom_name);
+
+ }
+
+ eeprom.size = EEPROM_2KB;
+ }
+ else
+ {
+ printk(KERN_INFO "%s: 16k detected in step 2\n",
+ eeprom_name);
+ loc1[0] = ~loc1[0];
+ /* Data differs, assume 16k */
+ /* Restore data */
+ if (eeprom_write_buf(LOC1, loc1, 1) == 1)
+ {
+ success = 1;
+ }
+ else
+ {
+ printk(KERN_INFO "%s: Restore 16k failed during probe,"
+ " EEPROM might be corrupt!\n", eeprom_name);
+ }
+
+ eeprom.size = EEPROM_16KB;
+ }
+ }
+ }
+ }
+ } /* read LOC1 */
+ } /* address LOC1 */
+ if (!success)
+ {
+ printk(KERN_INFO "%s: Probing failed!, using 2KB!\n", eeprom_name);
+ eeprom.size = EEPROM_2KB;
+ }
+ } /* read */
+ }
+ }
+ else
+ {
+ i2c_outbyte(0x00);
+ if(!i2c_getack())
+ {
+ /* No 8k */
+ eeprom.size = EEPROM_2KB;
+ }
+ else
+ {
+ i2c_start();
+ i2c_outbyte(0x81);
+ if (!i2c_getack())
+ {
+ eeprom.size = EEPROM_2KB;
+ }
+ else
+ {
+ /* It's a 8kB */
+ i2c_inbyte();
+ eeprom.size = EEPROM_8KB;
+ }
+ }
+ }
+ i2c_stop();
+#elif defined(CONFIG_ETRAX_I2C_EEPROM_16KB)
+ eeprom.size = EEPROM_16KB;
+#elif defined(CONFIG_ETRAX_I2C_EEPROM_8KB)
+ eeprom.size = EEPROM_8KB;
+#elif defined(CONFIG_ETRAX_I2C_EEPROM_2KB)
+ eeprom.size = EEPROM_2KB;
+#endif
+
+ switch(eeprom.size)
+ {
+ case (EEPROM_2KB):
+ printk("%s: " EETEXT " i2c compatible 2kB eeprom.\n", eeprom_name);
+ eeprom.sequential_write_pagesize = 16;
+ eeprom.select_cmd = 0xA0;
+ break;
+ case (EEPROM_8KB):
+ printk("%s: " EETEXT " i2c compatible 8kB eeprom.\n", eeprom_name);
+ eeprom.sequential_write_pagesize = 16;
+ eeprom.select_cmd = 0x80;
+ break;
+ case (EEPROM_16KB):
+ printk("%s: " EETEXT " i2c compatible 16kB eeprom.\n", eeprom_name);
+ eeprom.sequential_write_pagesize = 64;
+ eeprom.select_cmd = 0xA0;
+ break;
+ default:
+ eeprom.size = 0;
+ printk("%s: Did not find a supported eeprom\n", eeprom_name);
+ break;
+ }
+
+
+
+ eeprom_disable_write_protect();
+
+ return 0;
+}
+
+/* Opens the device. */
+
+static int eeprom_open(struct inode * inode, struct file * file)
+{
+
+ if(MINOR(inode->i_rdev) != EEPROM_MINOR_NR)
+ return -ENXIO;
+ if(MAJOR(inode->i_rdev) != EEPROM_MAJOR_NR)
+ return -ENXIO;
+
+ if( eeprom.size > 0 )
+ {
+ /* OK */
+ return 0;
+ }
+
+ /* No EEprom found */
+ return -EFAULT;
+}
+
+/* Changes the current file position. */
+
+static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig)
+{
+/*
+ * orig 0: position from begning of eeprom
+ * orig 1: relative from current position
+ * orig 2: position from last eeprom address
+ */
+
+ switch (orig)
+ {
+ case 0:
+ file->f_pos = offset;
+ break;
+ case 1:
+ file->f_pos += offset;
+ break;
+ case 2:
+ file->f_pos = eeprom.size - offset;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* truncate position */
+ if (file->f_pos < 0)
+ {
+ file->f_pos = 0;
+ return(-EOVERFLOW);
+ }
+
+ if (file->f_pos >= eeprom.size)
+ {
+ file->f_pos = eeprom.size - 1;
+ return(-EOVERFLOW);
+ }
+
+ return ( file->f_pos );
+}
+
+/* Reads data from eeprom. */
+
+static int eeprom_read_buf(loff_t addr, char * buf, int count)
+{
+ 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);