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eeprom.c revision 1.32
      1  1.32  riastrad /*	$NetBSD: eeprom.c,v 1.32 2018/09/03 16:29:28 riastradh Exp $	*/
      2   1.2       cgd 
      3  1.12       gwr /*-
      4  1.12       gwr  * Copyright (c) 1996 The NetBSD Foundation, Inc.
      5   1.1       gwr  * All rights reserved.
      6   1.1       gwr  *
      7  1.12       gwr  * This code is derived from software contributed to The NetBSD Foundation
      8  1.12       gwr  * by Gordon W. Ross.
      9  1.12       gwr  *
     10   1.1       gwr  * Redistribution and use in source and binary forms, with or without
     11   1.1       gwr  * modification, are permitted provided that the following conditions
     12   1.1       gwr  * are met:
     13   1.1       gwr  * 1. Redistributions of source code must retain the above copyright
     14   1.1       gwr  *    notice, this list of conditions and the following disclaimer.
     15   1.1       gwr  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.1       gwr  *    notice, this list of conditions and the following disclaimer in the
     17   1.1       gwr  *    documentation and/or other materials provided with the distribution.
     18   1.1       gwr  *
     19  1.12       gwr  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  1.12       gwr  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  1.12       gwr  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  1.14       gwr  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  1.14       gwr  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  1.12       gwr  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  1.12       gwr  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  1.12       gwr  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  1.12       gwr  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  1.12       gwr  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  1.12       gwr  * POSSIBILITY OF SUCH DAMAGE.
     30   1.1       gwr  */
     31   1.1       gwr 
     32   1.1       gwr /*
     33   1.1       gwr  * Access functions for the EEPROM (Electrically Eraseable PROM)
     34   1.1       gwr  * The main reason for the existence of this module is to
     35   1.1       gwr  * handle the painful task of updating the EEPROM contents.
     36   1.1       gwr  * After a write, it must not be touched for 10 milliseconds.
     37   1.1       gwr  * (See the Sun-3 Architecture Manual sec. 5.9)
     38   1.1       gwr  */
     39  1.25     lukem 
     40  1.25     lukem #include <sys/cdefs.h>
     41  1.32  riastrad __KERNEL_RCSID(0, "$NetBSD: eeprom.c,v 1.32 2018/09/03 16:29:28 riastradh Exp $");
     42   1.1       gwr 
     43   1.1       gwr #include <sys/param.h>
     44   1.4       gwr #include <sys/systm.h>
     45   1.4       gwr #include <sys/device.h>
     46   1.1       gwr #include <sys/conf.h>
     47   1.1       gwr #include <sys/buf.h>
     48   1.1       gwr #include <sys/malloc.h>
     49  1.13       gwr #include <sys/proc.h>
     50  1.20   thorpej #include <sys/kernel.h>
     51   1.1       gwr 
     52   1.4       gwr #include <machine/autoconf.h>
     53  1.18       gwr #include <machine/idprom.h>
     54   1.1       gwr #include <machine/eeprom.h>
     55   1.1       gwr 
     56  1.18       gwr #ifndef EEPROM_SIZE
     57  1.18       gwr #define EEPROM_SIZE 0x800
     58  1.15       gwr #endif
     59   1.1       gwr 
     60  1.18       gwr struct eeprom *eeprom_copy; 	/* soft copy. */
     61  1.18       gwr 
     62  1.15       gwr static int ee_update(int off, int cnt);
     63   1.1       gwr 
     64  1.31   tsutsui static uint8_t *eeprom_va; /* mapping to actual device */
     65  1.18       gwr static int ee_size;     /* size of usable part. */
     66  1.18       gwr 
     67  1.18       gwr static int ee_busy, ee_want; /* serialization */
     68   1.1       gwr 
     69  1.31   tsutsui static int  eeprom_match(device_t, cfdata_t, void *);
     70  1.31   tsutsui static void eeprom_attach(device_t, device_t, void *);
     71   1.4       gwr 
     72  1.31   tsutsui CFATTACH_DECL_NEW(eeprom, 0,
     73  1.24   thorpej     eeprom_match, eeprom_attach, NULL, NULL);
     74   1.4       gwr 
     75  1.26       chs static int
     76  1.31   tsutsui eeprom_match(device_t parent, cfdata_t cf, void *args)
     77   1.4       gwr {
     78   1.4       gwr 	struct confargs *ca = args;
     79   1.4       gwr 
     80  1.19       chs 	/* This driver only supports one instance. */
     81  1.19       chs 	if (eeprom_va != NULL)
     82  1.31   tsutsui 		return 0;
     83   1.8       gwr 
     84  1.16       gwr 	if (bus_peek(ca->ca_bustype, ca->ca_paddr, 1) == -1)
     85  1.31   tsutsui 		return 0;
     86   1.8       gwr 
     87  1.31   tsutsui 	return 1;
     88   1.4       gwr }
     89   1.4       gwr 
     90  1.26       chs static void
     91  1.31   tsutsui eeprom_attach(device_t parent, device_t self, void *args)
     92   1.4       gwr {
     93  1.16       gwr 	struct confargs *ca = args;
     94  1.31   tsutsui 	uint8_t *src, *dst, *lim;
     95   1.4       gwr 
     96  1.31   tsutsui 	aprint_normal("\n");
     97  1.18       gwr #ifdef	DIAGNOSTIC
     98  1.18       gwr 	if (sizeof(struct eeprom) != EEPROM_SIZE)
     99  1.18       gwr 		panic("eeprom struct wrong");
    100  1.18       gwr #endif
    101  1.16       gwr 
    102  1.18       gwr 	ee_size = EEPROM_SIZE;
    103  1.18       gwr 	eeprom_va = bus_mapin(ca->ca_bustype, ca->ca_paddr, ee_size);
    104  1.31   tsutsui 	if (eeprom_va == NULL)
    105  1.31   tsutsui 		panic("%s: can't map va", __func__);
    106  1.15       gwr 
    107  1.15       gwr 	/* Keep a "soft" copy of the EEPROM to make access simpler. */
    108  1.18       gwr 	eeprom_copy = malloc(ee_size, M_DEVBUF, M_NOWAIT);
    109  1.31   tsutsui 	if (eeprom_copy == NULL)
    110  1.31   tsutsui 		panic("%s: malloc eeprom_copy", __func__);
    111  1.18       gwr 
    112  1.18       gwr 	/*
    113  1.18       gwr 	 * On the 3/80, do not touch the last 40 bytes!
    114  1.18       gwr 	 * Writes there are ignored, reads show zero.
    115  1.18       gwr 	 * Reduce ee_size and clear the last part of the
    116  1.18       gwr 	 * soft copy.  Note: ee_update obeys ee_size.
    117  1.18       gwr 	 */
    118  1.27   thorpej 	if (cpu_machine_id == ID_SUN3X_80)
    119  1.18       gwr 		ee_size -= 40;
    120  1.15       gwr 
    121  1.15       gwr 	/* Do only byte access in the EEPROM. */
    122  1.15       gwr 	src = eeprom_va;
    123  1.31   tsutsui 	dst = (uint8_t *)eeprom_copy;
    124  1.18       gwr 	lim = dst + ee_size;
    125  1.18       gwr 
    126  1.31   tsutsui 	do {
    127  1.31   tsutsui 		*dst++ = *src++;
    128  1.31   tsutsui 	} while (dst < lim);
    129  1.18       gwr 
    130  1.18       gwr 	if (ee_size < EEPROM_SIZE) {
    131  1.18       gwr 		/* Clear out the last part. */
    132  1.21   tsutsui 		memset(dst, 0, (EEPROM_SIZE - ee_size));
    133  1.18       gwr 	}
    134   1.4       gwr }
    135   1.4       gwr 
    136   1.1       gwr 
    137  1.13       gwr /* Take the lock. */
    138  1.13       gwr static int
    139  1.26       chs ee_take(void)
    140   1.1       gwr {
    141   1.1       gwr 	int error = 0;
    142  1.26       chs 
    143   1.1       gwr 	while (ee_busy) {
    144   1.1       gwr 		ee_want = 1;
    145   1.1       gwr 		error = tsleep(&ee_busy, PZERO | PCATCH, "eeprom", 0);
    146   1.1       gwr 		ee_want = 0;
    147   1.1       gwr 		if (error)	/* interrupted */
    148  1.15       gwr 			return error;
    149   1.1       gwr 	}
    150   1.1       gwr 	ee_busy = 1;
    151   1.1       gwr 	return error;
    152   1.1       gwr }
    153   1.1       gwr 
    154  1.13       gwr /* Give the lock. */
    155  1.13       gwr static void
    156  1.26       chs ee_give(void)
    157   1.1       gwr {
    158   1.1       gwr 	ee_busy = 0;
    159   1.1       gwr 	if (ee_want) {
    160   1.1       gwr 		ee_want = 0;
    161   1.1       gwr 		wakeup(&ee_busy);
    162   1.1       gwr 	}
    163   1.1       gwr }
    164   1.1       gwr 
    165  1.13       gwr /*
    166  1.15       gwr  * This is called by mem.c to handle /dev/eeprom
    167  1.13       gwr  */
    168  1.13       gwr int
    169  1.13       gwr eeprom_uio(struct uio *uio)
    170   1.1       gwr {
    171  1.15       gwr 	int cnt, error;
    172   1.1       gwr 	int off;	/* NOT off_t */
    173  1.31   tsutsui 	uint8_t *va;
    174  1.15       gwr 
    175  1.18       gwr 	if (eeprom_copy == NULL)
    176  1.31   tsutsui 		return ENXIO;
    177   1.1       gwr 
    178   1.1       gwr 	off = uio->uio_offset;
    179  1.18       gwr 	if ((off < 0) || (off > EEPROM_SIZE))
    180  1.31   tsutsui 		return EFAULT;
    181   1.1       gwr 
    182  1.32  riastrad 	cnt = uimin(uio->uio_resid, (EEPROM_SIZE - off));
    183  1.15       gwr 	if (cnt == 0)
    184  1.31   tsutsui 		return 0;	/* EOF */
    185  1.15       gwr 
    186  1.31   tsutsui 	va = ((uint8_t *)eeprom_copy) + off;
    187  1.15       gwr 	error = uiomove(va, (int)cnt, uio);
    188  1.15       gwr 
    189  1.15       gwr 	/* If we wrote the rambuf, update the H/W. */
    190  1.31   tsutsui 	if (error == 0 && (uio->uio_rw != UIO_READ)) {
    191  1.15       gwr 		error = ee_take();
    192  1.31   tsutsui 		if (error == 0)
    193  1.15       gwr 			error = ee_update(off, cnt);
    194  1.15       gwr 		ee_give();
    195   1.1       gwr 	}
    196   1.1       gwr 
    197  1.31   tsutsui 	return error;
    198   1.1       gwr }
    199   1.1       gwr 
    200   1.1       gwr /*
    201  1.15       gwr  * Update the EEPROM from the soft copy.
    202  1.15       gwr  * Other than the attach function, this is
    203  1.15       gwr  * the ONLY place we touch the EEPROM H/W.
    204   1.1       gwr  */
    205  1.13       gwr static int
    206  1.15       gwr ee_update(int off, int cnt)
    207   1.1       gwr {
    208  1.31   tsutsui 	volatile uint8_t *ep;
    209  1.31   tsutsui 	uint8_t *bp;
    210  1.15       gwr 	int errcnt;
    211   1.1       gwr 
    212   1.1       gwr 	if (eeprom_va == NULL)
    213   1.1       gwr 		return (ENXIO);
    214   1.1       gwr 
    215  1.18       gwr 	/*
    216  1.18       gwr 	 * This check is NOT redundant with the one in
    217  1.18       gwr 	 * eeprom_uio above if we are on a 3/80 where
    218  1.18       gwr 	 * ee_size < EEPROM_SIZE
    219  1.18       gwr 	 */
    220  1.18       gwr 	if (cnt > (ee_size - off))
    221  1.18       gwr 		cnt = (ee_size - off);
    222  1.18       gwr 
    223  1.31   tsutsui 	bp = ((uint8_t *)eeprom_copy) + off;
    224   1.1       gwr 	ep = eeprom_va + off;
    225  1.15       gwr 	errcnt = 0;
    226   1.1       gwr 
    227   1.1       gwr 	while (cnt > 0) {
    228   1.1       gwr 		/*
    229   1.1       gwr 		 * DO NOT WRITE IT UNLESS WE HAVE TO because the
    230   1.1       gwr 		 * EEPROM has a limited number of write cycles.
    231   1.1       gwr 		 * After some number of writes it just fails!
    232   1.1       gwr 		 */
    233   1.1       gwr 		if (*ep != *bp) {
    234  1.31   tsutsui 			*ep = *bp;
    235   1.1       gwr 			/*
    236   1.1       gwr 			 * We have written the EEPROM, so now we must
    237   1.1       gwr 			 * sleep for at least 10 milliseconds while
    238   1.1       gwr 			 * holding the lock to prevent all access to
    239   1.1       gwr 			 * the EEPROM while it recovers.
    240   1.1       gwr 			 */
    241  1.31   tsutsui 			(void)tsleep(eeprom_va, PZERO - 1, "eeprom", hz / 50);
    242   1.1       gwr 		}
    243   1.1       gwr 		/* Make sure the write worked. */
    244   1.1       gwr 		if (*ep != *bp)
    245  1.15       gwr 			errcnt++;
    246   1.1       gwr 		ep++;
    247   1.1       gwr 		bp++;
    248   1.1       gwr 		cnt--;
    249   1.1       gwr 	}
    250  1.31   tsutsui 	return errcnt ? EIO : 0;
    251   1.1       gwr }
    252