1 /* $NetBSD: nvram.c,v 1.17 2009/10/20 19:10:11 snj 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 1.17 2009/10/20 19:10:11 snj 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 "nvr.h" 51 52 #define MC_NVRAM_CSUM (MC_NVRAM_START + MC_NVRAM_SIZE - 2) 53 54 #if NNVR > 0 55 static void nvram_set_csum(u_char csum); 56 static int nvram_csum_valid(u_char csum); 57 static u_char nvram_csum(void); 58 59 /* 60 * Auto config stuff.... 61 */ 62 static void nvr_attach(struct device *, struct device *, void *); 63 static int nvr_match(struct device *, struct cfdata *, void *); 64 65 CFATTACH_DECL(nvr, sizeof(struct nvr_softc), 66 nvr_match, nvr_attach, NULL, NULL); 67 68 extern struct cfdriver nvr_cd; 69 70 /*ARGSUSED*/ 71 static int 72 nvr_match(struct device *pdp, struct cfdata *cfp, void *auxp) 73 { 74 if (!strcmp((char *)auxp, "nvr")) 75 return (1); 76 return (0); 77 } 78 79 /*ARGSUSED*/ 80 static void 81 nvr_attach(device_t pdp, device_t dp, void *auxp) 82 { 83 struct nvr_softc *nvr_soft; 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 nvr_soft = device_lookup_private(&nvr_cd, 0); 96 nvr_soft->nvr_flags = NVR_CONFIGURED; 97 printf("\n"); 98 } 99 /* 100 * End of auto config stuff.... 101 */ 102 #endif /* NNVR > 0 */ 103 104 /* 105 * Kernel internal interface 106 */ 107 int 108 nvr_get_byte(int byteno) 109 { 110 #if NNVR > 0 111 struct nvr_softc *nvr_soft; 112 113 nvr_soft = device_lookup_private(&nvr_cd, 0); 114 if (!(nvr_soft->nvr_flags & NVR_CONFIGURED)) 115 return(NVR_INVALID); 116 return (mc146818_read(RTC, byteno + MC_NVRAM_START) & 0xff); 117 #else 118 return(NVR_INVALID); 119 #endif /* NNVR > 0 */ 120 } 121 122 #if NNVR > 0 123 124 int 125 nvram_uio(struct uio *uio) 126 { 127 int i; 128 off_t offset; 129 int nleft; 130 u_char buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1]; 131 u_char *p; 132 struct nvr_softc *nvr_soft; 133 134 nvr_soft = device_lookup_private(&nvr_cd,0); 135 if (!(nvr_soft->nvr_flags & NVR_CONFIGURED)) 136 return ENXIO; 137 138 #ifdef NV_DEBUG 139 printf("Request to transfer %d bytes offset: %d, %s nvram\n", 140 (long)uio->uio_resid, (long)uio->uio_offset, 141 (uio->uio_rw == UIO_READ) ? "from" : "to"); 142 #endif /* NV_DEBUG */ 143 144 offset = uio->uio_offset + MC_NVRAM_START; 145 nleft = uio->uio_resid; 146 if (offset + nleft >= MC_NVRAM_CSUM) { 147 if (offset == MC_NVRAM_CSUM) 148 return (0); 149 nleft = MC_NVRAM_CSUM - offset; 150 if (nleft <= 0) 151 return (EINVAL); 152 } 153 #ifdef NV_DEBUG 154 printf("Translated: offset = %d, bytes: %d\n", (long)offset, nleft); 155 #endif /* NV_DEBUG */ 156 157 if (uio->uio_rw == UIO_READ) { 158 for (i = 0, p = buf; i < nleft; i++, p++) 159 *p = mc146818_read(RTC, offset + i); 160 } 161 if ((i = uiomove(buf, nleft, uio)) != 0) 162 return (i); 163 if (uio->uio_rw == UIO_WRITE) { 164 for (i = 0, p = buf; i < nleft; i++, p++) 165 mc146818_write(RTC, offset + i, *p); 166 nvram_set_csum(nvram_csum()); 167 } 168 return(0); 169 } 170 171 static u_char 172 nvram_csum(void) 173 { 174 u_char csum; 175 int nreg; 176 177 for (csum = 0, nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 178 csum += mc146818_read(RTC, nreg); 179 return(csum); 180 } 181 182 static int 183 nvram_csum_valid(u_char csum) 184 { 185 if (((~csum & 0xff) != mc146818_read(RTC, MC_NVRAM_CSUM)) 186 || (csum != mc146818_read(RTC, MC_NVRAM_CSUM + 1))) 187 return 0; 188 return 1; 189 } 190 191 static void 192 nvram_set_csum(u_char csum) 193 { 194 mc146818_write(RTC, MC_NVRAM_CSUM, ~csum); 195 mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum); 196 } 197 #endif /* NNVR > 0 */ 198