1 /* $NetBSD: nvram.c,v 1.7 1998/01/12 18:04:14 thorpej 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 *, struct cfdata *, void *)); 66 67 struct cfattach nvr_ca = { 68 sizeof(struct nvr_softc), nvr_match, nvr_attach 69 }; 70 71 extern struct cfdriver nvr_cd; 72 73 /*ARGSUSED*/ 74 static int 75 nvr_match(pdp, cfp, auxp) 76 struct device *pdp; 77 struct cfdata *cfp; 78 void *auxp; 79 { 80 if (!strcmp((char *)auxp, "nvr")) 81 return (1); 82 return (0); 83 } 84 85 /*ARGSUSED*/ 86 static void 87 nvr_attach(pdp, dp, auxp) 88 struct device *pdp, *dp; 89 void *auxp; 90 { 91 struct nvr_softc *nvr_soft; 92 int nreg; 93 94 /* 95 * Check the validity of the NVram contents 96 */ 97 if (!nvram_csum_valid(nvram_csum())) { 98 printf(": Invalid checksum - re-initialized"); 99 for (nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 100 mc146818_write(RTC, nreg, 0); 101 nvram_set_csum(nvram_csum()); 102 } 103 nvr_soft = nvr_cd.cd_devs[0]; 104 nvr_soft->nvr_flags = NVR_CONFIGURED; 105 printf("\n"); 106 } 107 /* 108 * End of auto config stuff.... 109 */ 110 #endif /* NNVR > 0 */ 111 112 /* 113 * Kernel internal interface 114 */ 115 int 116 nvr_get_byte(byteno) 117 int byteno; 118 { 119 #if NNVR > 0 120 struct nvr_softc *nvr_soft; 121 122 nvr_soft = nvr_cd.cd_devs[0]; 123 if (!(nvr_soft->nvr_flags & NVR_CONFIGURED)) 124 return(NVR_INVALID); 125 return (mc146818_read(RTC, byteno + MC_NVRAM_START) & 0xff); 126 #else 127 return(NVR_INVALID); 128 #endif /* NNVR > 0 */ 129 } 130 131 #if NNVR > 0 132 133 int 134 nvram_uio(uio) 135 struct uio *uio; 136 { 137 int i; 138 off_t offset; 139 int nleft; 140 u_char buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1]; 141 u_char *p; 142 struct nvr_softc *nvr_soft; 143 144 nvr_soft = nvr_cd.cd_devs[0]; 145 if (!(nvr_soft->nvr_flags & NVR_CONFIGURED)) 146 return ENXIO; 147 148 #ifdef NV_DEBUG 149 printf("Request to transfer %d bytes offset: %d, %s nvram\n", 150 (long)uio->uio_resid, (long)uio->uio_offset, 151 (uio->uio_rw == UIO_READ) ? "from" : "to"); 152 #endif /* NV_DEBUG */ 153 154 offset = uio->uio_offset + MC_NVRAM_START; 155 nleft = uio->uio_resid; 156 if (offset + nleft >= MC_NVRAM_CSUM) { 157 if (offset == MC_NVRAM_CSUM) 158 return (0); 159 nleft = MC_NVRAM_CSUM - offset; 160 if (nleft <= 0) 161 return (EINVAL); 162 } 163 #ifdef NV_DEBUG 164 printf("Translated: offset = %d, bytes: %d\n", (long)offset, nleft); 165 #endif /* NV_DEBUG */ 166 167 if (uio->uio_rw == UIO_READ) { 168 for (i = 0, p = buf; i < nleft; i++, p++) 169 *p = mc146818_read(RTC, offset + i); 170 } 171 if ((i = uiomove(buf, nleft, uio)) != 0) 172 return (i); 173 if (uio->uio_rw == UIO_WRITE) { 174 for (i = 0, p = buf; i < nleft; i++, p++) 175 mc146818_write(RTC, offset + i, *p); 176 nvram_set_csum(nvram_csum()); 177 } 178 return(0); 179 } 180 181 static u_char 182 nvram_csum() 183 { 184 u_char csum; 185 int nreg; 186 187 for (csum = 0, nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 188 csum += mc146818_read(RTC, nreg); 189 return(csum); 190 } 191 192 static int 193 nvram_csum_valid(csum) 194 u_char csum; 195 { 196 if (((~csum & 0xff) != mc146818_read(RTC, MC_NVRAM_CSUM)) 197 || (csum != mc146818_read(RTC, MC_NVRAM_CSUM + 1))) 198 return 0; 199 return 1; 200 } 201 202 static void 203 nvram_set_csum(csum) 204 u_char csum; 205 { 206 mc146818_write(RTC, MC_NVRAM_CSUM, ~csum); 207 mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum); 208 } 209 #endif /* NNVR > 0 */ 210