1/* $NetBSD: nvram.c,v 1.18 2010/04/13 09:51:07 tsutsui Exp $ */ 2 3/* 4 * Copyright (c) 1995 Leo Weppelman. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28/* 29 * Nvram driver 30 */ 31 32#include <sys/cdefs.h> 33__KERNEL_RCSID(0, "$NetBSD: nvram.c,v 1.18 2010/04/13 09:51:07 tsutsui Exp $"); 34 35#include <sys/param.h> 36#include <sys/conf.h> 37#include <sys/kernel.h> 38#include <sys/proc.h> 39#include <sys/systm.h> 40#include <sys/device.h> 41#include <sys/buf.h> 42#include <sys/uio.h> 43 44#include <machine/iomap.h> 45#include <machine/cpu.h> 46 47#include <atari/dev/clockreg.h> 48#include <atari/dev/nvramvar.h> 49 50#include "ioconf.h" 51 52#include "nvr.h" 53 54#define MC_NVRAM_CSUM (MC_NVRAM_START + MC_NVRAM_SIZE - 2) 55 56#if NNVR > 0 57static void nvram_set_csum(u_char csum); 58static int nvram_csum_valid(u_char csum); 59static u_char nvram_csum(void); 60 61/* 62 * Auto config stuff.... 63 */ 64static void nvr_attach(device_t, device_t, void *); 65static int nvr_match(device_t, cfdata_t, void *); 66 67CFATTACH_DECL_NEW(nvr, sizeof(struct nvr_softc), 68 nvr_match, nvr_attach, NULL, NULL); 69 70/*ARGSUSED*/ 71static int 72nvr_match(device_t parent, cfdata_t cf, void *aux) 73{ 74 if (!strcmp((char *)aux, "nvr")) 75 return (1); 76 return (0); 77} 78 79/*ARGSUSED*/ 80static void 81nvr_attach(device_t parent, device_t self, void *aux) 82{ 83 struct nvr_softc *sc; 84 int nreg; 85 86 /* 87 * Check the validity of the NVram contents 88 */ 89 if (!nvram_csum_valid(nvram_csum())) { 90 printf(": Invalid checksum - re-initialized"); 91 for (nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 92 mc146818_write(RTC, nreg, 0); 93 nvram_set_csum(nvram_csum()); 94 } 95 sc = device_private(self); 96 sc->sc_dev = self; 97 sc->sc_flags = NVR_CONFIGURED; 98 printf("\n"); 99} 100/* 101 * End of auto config stuff.... 102 */ 103#endif /* NNVR > 0 */ 104 105/* 106 * Kernel internal interface 107 */ 108int 109nvr_get_byte(int byteno) 110{ 111#if NNVR > 0 112 struct nvr_softc *sc; 113 114 sc = device_lookup_private(&nvr_cd, 0); 115 if (!(sc->sc_flags & NVR_CONFIGURED)) 116 return(NVR_INVALID); 117 return (mc146818_read(RTC, byteno + MC_NVRAM_START) & 0xff); 118#else 119 return(NVR_INVALID); 120#endif /* NNVR > 0 */ 121} 122 123#if NNVR > 0 124 125int 126nvram_uio(struct uio *uio) 127{ 128 int i; 129 off_t offset; 130 int nleft; 131 u_char buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1]; 132 u_char *p; 133 struct nvr_softc *sc; 134 135 sc = device_lookup_private(&nvr_cd,0); 136 if (!(sc->sc_flags & NVR_CONFIGURED)) 137 return ENXIO; 138 139#ifdef NV_DEBUG 140 printf("Request to transfer %d bytes offset: %d, %s nvram\n", 141 (long)uio->uio_resid, (long)uio->uio_offset, 142 (uio->uio_rw == UIO_READ) ? "from" : "to"); 143#endif /* NV_DEBUG */ 144 145 offset = uio->uio_offset + MC_NVRAM_START; 146 nleft = uio->uio_resid; 147 if (offset + nleft >= MC_NVRAM_CSUM) { 148 if (offset == MC_NVRAM_CSUM) 149 return (0); 150 nleft = MC_NVRAM_CSUM - offset; 151 if (nleft <= 0) 152 return (EINVAL); 153 } 154#ifdef NV_DEBUG 155 printf("Translated: offset = %d, bytes: %d\n", (long)offset, nleft); 156#endif /* NV_DEBUG */ 157 158 if (uio->uio_rw == UIO_READ) { 159 for (i = 0, p = buf; i < nleft; i++, p++) 160 *p = mc146818_read(RTC, offset + i); 161 } 162 if ((i = uiomove(buf, nleft, uio)) != 0) 163 return (i); 164 if (uio->uio_rw == UIO_WRITE) { 165 for (i = 0, p = buf; i < nleft; i++, p++) 166 mc146818_write(RTC, offset + i, *p); 167 nvram_set_csum(nvram_csum()); 168 } 169 return(0); 170} 171 172static u_char 173nvram_csum(void) 174{ 175 u_char csum; 176 int nreg; 177 178 for (csum = 0, nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 179 csum += mc146818_read(RTC, nreg); 180 return(csum); 181} 182 183static int 184nvram_csum_valid(u_char csum) 185{ 186 if (((~csum & 0xff) != mc146818_read(RTC, MC_NVRAM_CSUM)) 187 || (csum != mc146818_read(RTC, MC_NVRAM_CSUM + 1))) 188 return 0; 189 return 1; 190} 191 192static void 193nvram_set_csum(u_char csum) 194{ 195 mc146818_write(RTC, MC_NVRAM_CSUM, ~csum); 196 mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum); 197} 198#endif /* NNVR > 0 */ 199