1 /* $NetBSD: nvram.c,v 1.3 1996/04/18 08:52:08 leo 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 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Leo Weppelman. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Nvram driver 35 */ 36 37 #include <sys/param.h> 38 #include <sys/conf.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 #include <sys/systm.h> 42 #include <sys/device.h> 43 #include <sys/buf.h> 44 #include <sys/uio.h> 45 46 #include <machine/iomap.h> 47 #include <machine/cpu.h> 48 49 #include <atari/dev/clockreg.h> 50 #include <atari/dev/nvramvar.h> 51 52 #include "nvr.h" 53 54 #define MC_NVRAM_CSUM (MC_NVRAM_START + MC_NVRAM_SIZE - 2) 55 56 #if NNVR > 0 57 static void nvram_set_csum __P((u_char csum)); 58 static int nvram_csum_valid __P((u_char csum)); 59 static u_char nvram_csum __P((void)); 60 61 /* 62 * Auto config stuff.... 63 */ 64 static void nvr_attach __P((struct device *, struct device *, void *)); 65 static int nvr_match __P((struct device *, void *, void *)); 66 67 struct cfattach nvr_ca = { 68 sizeof(struct nvr_softc), nvr_match, nvr_attach 69 }; 70 71 struct cfdriver nvr_cd = { 72 NULL, "nvr", DV_DULL, NULL, 0 73 }; 74 75 /*ARGSUSED*/ 76 static int 77 nvr_match(pdp, match, auxp) 78 struct device *pdp; 79 void *match, *auxp; 80 { 81 if (!strcmp((char *)auxp, "nvr")) 82 return (1); 83 return (0); 84 } 85 86 /*ARGSUSED*/ 87 static void 88 nvr_attach(pdp, dp, auxp) 89 struct device *pdp, *dp; 90 void *auxp; 91 { 92 struct nvr_softc *nvr_soft; 93 int nreg; 94 95 /* 96 * Check the validity of the NVram contents 97 */ 98 if (!nvram_csum_valid(nvram_csum())) { 99 printf(": Invalid checksum - re-initialized"); 100 for (nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 101 mc146818_write(RTC, nreg, 0); 102 nvram_set_csum(nvram_csum()); 103 } 104 nvr_soft = nvr_cd.cd_devs[0]; 105 nvr_soft->nvr_flags = NVR_CONFIGURED; 106 printf("\n"); 107 } 108 /* 109 * End of auto config stuff.... 110 */ 111 #endif /* NNVR > 0 */ 112 113 /* 114 * Kernel internal interface 115 */ 116 int 117 nvr_get_byte(byteno) 118 int byteno; 119 { 120 #if NNVR > 0 121 struct nvr_softc *nvr_soft; 122 123 nvr_soft = nvr_cd.cd_devs[0]; 124 if (!(nvr_soft->nvr_flags & NVR_CONFIGURED)) 125 return(NVR_INVALID); 126 return (mc146818_read(RTC, byteno + MC_NVRAM_START) & 0xff); 127 #else 128 return(NVR_INVALID); 129 #endif /* NNVR > 0 */ 130 } 131 132 #if NNVR > 0 133 134 int 135 nvram_uio(uio) 136 struct uio *uio; 137 { 138 int i; 139 off_t offset; 140 int nleft; 141 u_char buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1]; 142 u_char *p; 143 struct nvr_softc *nvr_soft; 144 145 nvr_soft = nvr_cd.cd_devs[0]; 146 if (!(nvr_soft->nvr_flags & NVR_CONFIGURED)) 147 return ENXIO; 148 149 #ifdef NV_DEBUG 150 printf("Request to transfer %d bytes offset: %d, %s nvram\n", 151 (long)uio->uio_resid, (long)uio->uio_offset, 152 (uio->uio_rw == UIO_READ) ? "from" : "to"); 153 #endif /* NV_DEBUG */ 154 155 offset = uio->uio_offset + MC_NVRAM_START; 156 nleft = uio->uio_resid; 157 if (offset + nleft >= MC_NVRAM_CSUM) { 158 if (offset == MC_NVRAM_CSUM) 159 return (0); 160 nleft = MC_NVRAM_CSUM - offset; 161 if (nleft <= 0) 162 return (EINVAL); 163 } 164 #ifdef NV_DEBUG 165 printf("Translated: offset = %d, bytes: %d\n", (long)offset, nleft); 166 #endif /* NV_DEBUG */ 167 168 if (uio->uio_rw == UIO_READ) { 169 for (i = 0, p = buf; i < nleft; i++, p++) 170 *p = mc146818_read(RTC, offset + i); 171 } 172 if ((i = uiomove(buf, nleft, uio)) != 0) 173 return (i); 174 if (uio->uio_rw == UIO_WRITE) { 175 for (i = 0, p = buf; i < nleft; i++, p++) 176 mc146818_write(RTC, offset + i, *p); 177 nvram_set_csum(nvram_csum()); 178 } 179 return(0); 180 } 181 182 static u_char 183 nvram_csum() 184 { 185 u_char csum; 186 int nreg; 187 188 for (csum = 0, nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 189 csum += mc146818_read(RTC, nreg); 190 return(csum); 191 } 192 193 static int 194 nvram_csum_valid(csum) 195 u_char csum; 196 { 197 if (((~csum & 0xff) != mc146818_read(RTC, MC_NVRAM_CSUM)) 198 || (csum != mc146818_read(RTC, MC_NVRAM_CSUM + 1))) 199 return 0; 200 return 1; 201 } 202 203 static void 204 nvram_set_csum(csum) 205 u_char csum; 206 { 207 mc146818_write(RTC, MC_NVRAM_CSUM, ~csum); 208 mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum); 209 } 210 #endif /* NNVR > 0 */ 211