sys/arch/atari/dev/nvram.c

   1 /*      $NetBSD: nvram.c,v 1.16 2009/03/18 10:22:24 cegger 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 1.16 2009/03/18 10:22:24 cegger 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 */