/* $NetBSD: eeprom.c,v 1.1.1.1 1997/01/14 20:57:02 gwr 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) * * XXX: Should just keep a copy of the EEPROM contents in RAM * (read it once at init time) to avoid the eeprom_uio hair. */ #include #include #include #include #include #include #include #include #include #include #define HZ 100 /* XXX */ #define OBIO_EEPROM_SIZE sizeof(struct eeprom) int ee_console; /* for convenience of drivers */ static int ee_update(caddr_t buf, int off, int cnt); static char *eeprom_va; static int ee_busy, ee_want; static int eeprom_match __P((struct device *, struct cfdata *, void *)); static void eeprom_attach __P((struct device *, struct device *, void *)); struct cfattach eeprom_ca = { sizeof(struct device), eeprom_match, eeprom_attach }; struct cfdriver eeprom_cd = { NULL, "eeprom", DV_DULL }; /* Called very early by internal_configure. */ void eeprom_init() { eeprom_va = obio_find_mapping(OBIO_EEPROM, OBIO_EEPROM_SIZE); ee_console = ((struct eeprom *)eeprom_va)->eeConsole; } static int eeprom_match(parent, cf, args) struct device *parent; struct cfdata *cf; void *args; { struct confargs *ca = args; /* This driver only supports one unit. */ if (cf->cf_unit != 0) return (0); /* Validate the given address. */ if (ca->ca_paddr != OBIO_EEPROM) return (0); if (eeprom_va == NULL) return (0); return (1); } static void eeprom_attach(parent, self, args) struct device *parent; struct device *self; void *args; { printf("\n"); } /* 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 */ goto out; } ee_busy = 1; out: return error; } /* Give the lock. */ static void ee_give __P((void)) { ee_busy = 0; if (ee_want) { ee_want = 0; wakeup(&ee_busy); } } /* * XXX - Just keep a soft copy of the eeprom? */ int eeprom_uio(struct uio *uio) { int error; int off; /* NOT off_t */ u_int cnt; caddr_t va; caddr_t buf = (caddr_t)0; off = uio->uio_offset; if (off >= OBIO_EEPROM_SIZE) return (EFAULT); cnt = uio->uio_resid; if (cnt > (OBIO_EEPROM_SIZE - off)) cnt = (OBIO_EEPROM_SIZE - off); if ((error = ee_take()) != 0) return (error); if (eeprom_va == NULL) { error = ENXIO; goto out; } va = eeprom_va; if (uio->uio_rw != UIO_READ) { /* Write requires a temporary buffer. */ buf = malloc(OBIO_EEPROM_SIZE, M_DEVBUF, M_WAITOK); if (!buf) { error = EAGAIN; goto out; } va = buf; } if ((error = uiomove(va + off, (int)cnt, uio)) != 0) goto out; if (uio->uio_rw != UIO_READ) error = ee_update(buf, off, cnt); out: if (buf) free(buf, M_DEVBUF); ee_give(); return (error); } /* * Update the EEPROM from the passed buf. */ static int ee_update(char *buf, int off, int cnt) { volatile char *ep; char *bp; if (eeprom_va == NULL) return (ENXIO); ep = eeprom_va + off; bp = buf + off; 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) return (EIO); ep++; bp++; cnt--; } return(0); } /* * Read a byte out of the EEPROM. This is called from * things like the zs driver very early to find out * which device should be used as the console. */ int ee_get_byte(int off, int canwait) { int c = -1; if ((off < 0) || (off >= OBIO_EEPROM_SIZE)) goto out; if (eeprom_va == NULL) goto out; if (canwait) { if (ee_take()) goto out; } else { if (ee_busy) goto out; } c = eeprom_va[off] & 0xFF; if (canwait) ee_give(); out: return c; }