/* $NetBSD: eeprom.c,v 1.24 2002/10/02 16:02:25 thorpej Exp $ */ /*- * Copyright (c) 1996 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Gordon W. Ross. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Access functions for the EEPROM (Electrically Eraseable PROM) * The main reason for the existence of this module is to * handle the painful task of updating the EEPROM contents. * After a write, it must not be touched for 10 milliseconds. * (See the Sun-3 Architecture Manual sec. 5.9) */ #include #include #include #include #include #include #include #include #include #include #include #ifndef EEPROM_SIZE #define EEPROM_SIZE 0x800 #endif struct eeprom *eeprom_copy; /* soft copy. */ static int ee_update(int off, int cnt); static char *eeprom_va; /* mapping to actual device */ static int ee_size; /* size of usable part. */ static int ee_busy, ee_want; /* serialization */ static int eeprom_match __P((struct device *, struct cfdata *, void *)); static void eeprom_attach __P((struct device *, struct device *, void *)); CFATTACH_DECL(eeprom, sizeof(struct device), eeprom_match, eeprom_attach, NULL, NULL); static int eeprom_match(parent, cf, args) struct device *parent; struct cfdata *cf; void *args; { struct confargs *ca = args; /* This driver only supports one instance. */ if (eeprom_va != NULL) return (0); if (bus_peek(ca->ca_bustype, ca->ca_paddr, 1) == -1) return (0); return (1); } static void eeprom_attach(parent, self, args) struct device *parent; struct device *self; void *args; { struct confargs *ca = args; char *src, *dst, *lim; printf("\n"); #ifdef DIAGNOSTIC if (sizeof(struct eeprom) != EEPROM_SIZE) panic("eeprom struct wrong"); #endif ee_size = EEPROM_SIZE; eeprom_va = bus_mapin(ca->ca_bustype, ca->ca_paddr, ee_size); if (!eeprom_va) panic("eeprom_attach"); /* Keep a "soft" copy of the EEPROM to make access simpler. */ eeprom_copy = malloc(ee_size, M_DEVBUF, M_NOWAIT); if (eeprom_copy == 0) panic("eeprom_attach: malloc eeprom_copy"); /* * On the 3/80, do not touch the last 40 bytes! * Writes there are ignored, reads show zero. * Reduce ee_size and clear the last part of the * soft copy. Note: ee_update obeys ee_size. */ if (cpu_machine_id == SUN3X_MACH_80) ee_size -= 40; /* Do only byte access in the EEPROM. */ src = eeprom_va; dst = (char*) eeprom_copy; lim = dst + ee_size; do *dst++ = *src++; while (dst < lim); if (ee_size < EEPROM_SIZE) { /* Clear out the last part. */ memset(dst, 0, (EEPROM_SIZE - ee_size)); } } /* Take the lock. */ static int ee_take __P((void)) { int error = 0; while (ee_busy) { ee_want = 1; error = tsleep(&ee_busy, PZERO | PCATCH, "eeprom", 0); ee_want = 0; if (error) /* interrupted */ return error; } ee_busy = 1; return error; } /* Give the lock. */ static void ee_give __P((void)) { ee_busy = 0; if (ee_want) { ee_want = 0; wakeup(&ee_busy); } } /* * This is called by mem.c to handle /dev/eeprom */ int eeprom_uio(struct uio *uio) { int cnt, error; int off; /* NOT off_t */ caddr_t va; if (eeprom_copy == NULL) return (ENXIO); off = uio->uio_offset; if ((off < 0) || (off > EEPROM_SIZE)) return (EFAULT); cnt = min(uio->uio_resid, (EEPROM_SIZE - off)); if (cnt == 0) return (0); /* EOF */ va = ((char*)eeprom_copy) + off; error = uiomove(va, (int)cnt, uio); /* If we wrote the rambuf, update the H/W. */ if (!error && (uio->uio_rw != UIO_READ)) { error = ee_take(); if (!error) error = ee_update(off, cnt); ee_give(); } return (error); } /* * Update the EEPROM from the soft copy. * Other than the attach function, this is * the ONLY place we touch the EEPROM H/W. */ static int ee_update(int off, int cnt) { volatile char *ep; char *bp; int errcnt; if (eeprom_va == NULL) return (ENXIO); /* * This check is NOT redundant with the one in * eeprom_uio above if we are on a 3/80 where * ee_size < EEPROM_SIZE */ if (cnt > (ee_size - off)) cnt = (ee_size - off); bp = ((char*)eeprom_copy) + off; ep = eeprom_va + off; errcnt = 0; while (cnt > 0) { /* * DO NOT WRITE IT UNLESS WE HAVE TO because the * EEPROM has a limited number of write cycles. * After some number of writes it just fails! */ if (*ep != *bp) { *ep = *bp; /* * We have written the EEPROM, so now we must * sleep for at least 10 milliseconds while * holding the lock to prevent all access to * the EEPROM while it recovers. */ (void)tsleep(eeprom_va, PZERO-1, "eeprom", hz/50); } /* Make sure the write worked. */ if (*ep != *bp) errcnt++; ep++; bp++; cnt--; } return (errcnt ? EIO : 0); }