252 lines
6.1 KiB
C
252 lines
6.1 KiB
C
/* $NetBSD: eeprom.c,v 1.31 2008/06/28 12:13:38 tsutsui Exp $ */
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/*-
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* Copyright (c) 1996 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Gordon W. Ross.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Access functions for the EEPROM (Electrically Eraseable PROM)
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* The main reason for the existence of this module is to
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* handle the painful task of updating the EEPROM contents.
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* After a write, it must not be touched for 10 milliseconds.
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* (See the Sun-3 Architecture Manual sec. 5.9)
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: eeprom.c,v 1.31 2008/06/28 12:13:38 tsutsui Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/device.h>
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#include <sys/conf.h>
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#include <sys/buf.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/kernel.h>
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#include <machine/autoconf.h>
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#include <machine/idprom.h>
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#include <machine/eeprom.h>
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#ifndef EEPROM_SIZE
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#define EEPROM_SIZE 0x800
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#endif
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struct eeprom *eeprom_copy; /* soft copy. */
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static int ee_update(int off, int cnt);
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static uint8_t *eeprom_va; /* mapping to actual device */
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static int ee_size; /* size of usable part. */
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static int ee_busy, ee_want; /* serialization */
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static int eeprom_match(device_t, cfdata_t, void *);
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static void eeprom_attach(device_t, device_t, void *);
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CFATTACH_DECL_NEW(eeprom, 0,
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eeprom_match, eeprom_attach, NULL, NULL);
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static int
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eeprom_match(device_t parent, cfdata_t cf, void *args)
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{
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struct confargs *ca = args;
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/* This driver only supports one instance. */
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if (eeprom_va != NULL)
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return 0;
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if (bus_peek(ca->ca_bustype, ca->ca_paddr, 1) == -1)
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return 0;
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return 1;
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}
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static void
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eeprom_attach(device_t parent, device_t self, void *args)
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{
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struct confargs *ca = args;
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uint8_t *src, *dst, *lim;
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aprint_normal("\n");
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#ifdef DIAGNOSTIC
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if (sizeof(struct eeprom) != EEPROM_SIZE)
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panic("eeprom struct wrong");
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#endif
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ee_size = EEPROM_SIZE;
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eeprom_va = bus_mapin(ca->ca_bustype, ca->ca_paddr, ee_size);
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if (eeprom_va == NULL)
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panic("%s: can't map va", __func__);
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/* Keep a "soft" copy of the EEPROM to make access simpler. */
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eeprom_copy = malloc(ee_size, M_DEVBUF, M_NOWAIT);
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if (eeprom_copy == NULL)
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panic("%s: malloc eeprom_copy", __func__);
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/*
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* On the 3/80, do not touch the last 40 bytes!
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* Writes there are ignored, reads show zero.
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* Reduce ee_size and clear the last part of the
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* soft copy. Note: ee_update obeys ee_size.
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*/
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if (cpu_machine_id == ID_SUN3X_80)
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ee_size -= 40;
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/* Do only byte access in the EEPROM. */
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src = eeprom_va;
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dst = (uint8_t *)eeprom_copy;
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lim = dst + ee_size;
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do {
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*dst++ = *src++;
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} while (dst < lim);
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if (ee_size < EEPROM_SIZE) {
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/* Clear out the last part. */
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memset(dst, 0, (EEPROM_SIZE - ee_size));
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}
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}
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/* Take the lock. */
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static int
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ee_take(void)
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{
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int error = 0;
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while (ee_busy) {
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ee_want = 1;
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error = tsleep(&ee_busy, PZERO | PCATCH, "eeprom", 0);
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ee_want = 0;
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if (error) /* interrupted */
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return error;
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}
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ee_busy = 1;
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return error;
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}
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/* Give the lock. */
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static void
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ee_give(void)
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{
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ee_busy = 0;
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if (ee_want) {
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ee_want = 0;
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wakeup(&ee_busy);
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}
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}
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/*
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* This is called by mem.c to handle /dev/eeprom
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*/
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int
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eeprom_uio(struct uio *uio)
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{
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int cnt, error;
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int off; /* NOT off_t */
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uint8_t *va;
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if (eeprom_copy == NULL)
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return ENXIO;
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off = uio->uio_offset;
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if ((off < 0) || (off > EEPROM_SIZE))
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return EFAULT;
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cnt = min(uio->uio_resid, (EEPROM_SIZE - off));
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if (cnt == 0)
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return 0; /* EOF */
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va = ((uint8_t *)eeprom_copy) + off;
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error = uiomove(va, (int)cnt, uio);
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/* If we wrote the rambuf, update the H/W. */
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if (error == 0 && (uio->uio_rw != UIO_READ)) {
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error = ee_take();
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if (error == 0)
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error = ee_update(off, cnt);
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ee_give();
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}
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return error;
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}
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/*
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* Update the EEPROM from the soft copy.
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* Other than the attach function, this is
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* the ONLY place we touch the EEPROM H/W.
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*/
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static int
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ee_update(int off, int cnt)
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{
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volatile uint8_t *ep;
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uint8_t *bp;
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int errcnt;
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if (eeprom_va == NULL)
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return (ENXIO);
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/*
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* This check is NOT redundant with the one in
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* eeprom_uio above if we are on a 3/80 where
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* ee_size < EEPROM_SIZE
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*/
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if (cnt > (ee_size - off))
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cnt = (ee_size - off);
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bp = ((uint8_t *)eeprom_copy) + off;
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ep = eeprom_va + off;
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errcnt = 0;
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while (cnt > 0) {
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/*
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* DO NOT WRITE IT UNLESS WE HAVE TO because the
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* EEPROM has a limited number of write cycles.
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* After some number of writes it just fails!
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*/
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if (*ep != *bp) {
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*ep = *bp;
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/*
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* We have written the EEPROM, so now we must
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* sleep for at least 10 milliseconds while
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* holding the lock to prevent all access to
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* the EEPROM while it recovers.
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*/
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(void)tsleep(eeprom_va, PZERO - 1, "eeprom", hz / 50);
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}
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/* Make sure the write worked. */
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if (*ep != *bp)
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errcnt++;
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ep++;
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bp++;
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cnt--;
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}
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return errcnt ? EIO : 0;
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}
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