1 /* $NetBSD: nvram.c,v 1.23 2023/01/06 10:28:28 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 1.23 2023/01/06 10:28:28 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 #ifdef NVRAM_DEBUG 55 #define DPRINTF(a) printf a 56 #else 57 #define DPRINTF(a) 58 #endif 59 60 #define MC_NVRAM_CSUM (MC_NVRAM_START + MC_NVRAM_SIZE - 2) 61 62 #if NNVR > 0 63 static void nvram_set_csum(u_char csum); 64 static int nvram_csum_valid(u_char csum); 65 static u_char nvram_csum(void); 66 67 /* 68 * Auto config stuff.... 69 */ 70 static void nvr_attach(device_t, device_t, void *); 71 static int nvr_match(device_t, cfdata_t, void *); 72 73 CFATTACH_DECL_NEW(nvr, sizeof(struct nvr_softc), 74 nvr_match, nvr_attach, NULL, NULL); 75 76 /*ARGSUSED*/ 77 static int 78 nvr_match(device_t parent, cfdata_t cf, void *aux) 79 { 80 81 if (!strcmp((char *)aux, "nvr")) 82 return 1; 83 return 0; 84 } 85 86 /*ARGSUSED*/ 87 static void 88 nvr_attach(device_t parent, device_t self, void *aux) 89 { 90 struct nvr_softc *sc; 91 int nreg; 92 93 /* 94 * Check the validity of the NVram contents 95 */ 96 /* XXX: Milan's firmware seems to use different check method */ 97 if ((machineid & ATARI_MILAN) == 0) { 98 if (!nvram_csum_valid(nvram_csum())) { 99 aprint_error(": Invalid checksum - re-initialized"); 100 for (nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; 101 nreg++) 102 mc146818_write(RTC, nreg, 0); 103 nvram_set_csum(nvram_csum()); 104 } 105 } 106 sc = device_private(self); 107 sc->sc_dev = self; 108 sc->sc_flags = NVR_CONFIGURED; 109 aprint_normal("\n"); 110 } 111 /* 112 * End of auto config stuff.... 113 */ 114 #endif /* NNVR > 0 */ 115 116 /* 117 * Kernel internal interface 118 */ 119 int 120 nvr_get_byte(int byteno) 121 { 122 #if NNVR > 0 123 struct nvr_softc *sc; 124 125 sc = device_lookup_private(&nvr_cd, 0); 126 if ((sc->sc_flags & NVR_CONFIGURED) == 0) 127 return NVR_INVALID; 128 return mc146818_read(RTC, byteno + MC_NVRAM_START) & 0xff; 129 #else 130 return NVR_INVALID; 131 #endif /* NNVR > 0 */ 132 } 133 134 #if NNVR > 0 135 136 int 137 nvram_uio(struct uio *uio) 138 { 139 int i; 140 off_t offset; 141 int nleft; 142 uint8_t buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1]; 143 uint8_t *p; 144 struct nvr_softc *sc; 145 146 sc = device_lookup_private(&nvr_cd,0); 147 if ((sc->sc_flags & NVR_CONFIGURED) == 0) 148 return ENXIO; 149 150 DPRINTF(("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")); 153 154 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 DPRINTF(("Translated: offset = %d, bytes: %d\n", (long)offset, nleft)); 164 165 if (uio->uio_rw == UIO_READ) { 166 for (i = 0, p = buf; i < nleft; i++, p++) 167 *p = mc146818_read(RTC, offset + i); 168 } 169 if ((i = uiomove(buf, nleft, uio)) != 0) 170 return i; 171 if (uio->uio_rw == UIO_WRITE) { 172 for (i = 0, p = buf; i < nleft; i++, p++) 173 mc146818_write(RTC, offset + i, *p); 174 nvram_set_csum(nvram_csum()); 175 } 176 return 0; 177 } 178 179 static u_char 180 nvram_csum(void) 181 { 182 uint8_t csum; 183 int nreg; 184 185 for (csum = 0, nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++) 186 csum += mc146818_read(RTC, nreg); 187 return csum; 188 } 189 190 static int 191 nvram_csum_valid(u_char csum) 192 { 193 194 if (((~csum & 0xff) != mc146818_read(RTC, MC_NVRAM_CSUM)) 195 || (csum != mc146818_read(RTC, MC_NVRAM_CSUM + 1))) 196 return 0; 197 return 1; 198 } 199 200 static void 201 nvram_set_csum(u_char csum) 202 { 203 204 mc146818_write(RTC, MC_NVRAM_CSUM, ~csum); 205 mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum); 206 } 207 #endif /* NNVR > 0 */ 208
Indexes created Sat Sep 20 22:09:52 GMT 2025