board/v38b/ethaddr.c

   1 /*
   2  * (C) Copyright 2006
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 #include <common.h>
  25 #include <mpc5xxx.h>
  26
  27 /* For the V38B board the pin is GPIO_PSC_6 */
  28 #define GPIO_PIN        GPIO_PSC6_0
  29
  30 #define NO_ERROR        0
  31 #define ERR_NO_NUMBER   1
  32 #define ERR_BAD_NUMBER  2
  33
  34 static int is_high(void);
  35 static int check_device(void);
  36 static void io_out(int value);
  37 static void io_input(void);
  38 static void io_output(void);
  39 static void init_gpio(void);
  40 static void read_byte(unsigned char *data);
  41 static void write_byte(unsigned char command);
  42
  43 void read_2501_memory(unsigned char *psernum, unsigned char *perr);
  44 void board_get_enetaddr(uchar *enetaddr);
  45
  46
  47 static int is_high()
  48 {
  49         return (*((vu_long *) MPC5XXX_WU_GPIO_DATA_I) & GPIO_PIN);
  50 }
  51
  52 static void io_out(int value)
  53 {
  54         if (value)
  55                 *((vu_long *) MPC5XXX_WU_GPIO_DATA_O) |= GPIO_PIN;
  56         else
  57                 *((vu_long *) MPC5XXX_WU_GPIO_DATA_O) &= ~GPIO_PIN;
  58 }
  59
  60 static void io_input()
  61 {
  62         *((vu_long *) MPC5XXX_WU_GPIO_DIR) &= ~GPIO_PIN;
  63         udelay(3);      /* allow input to settle */
  64 }
  65
  66 static void io_output()
  67 {
  68         *((vu_long *) MPC5XXX_WU_GPIO_DIR) |= GPIO_PIN;
  69 }
  70
  71 static void init_gpio()
  72 {
  73         *((vu_long *) MPC5XXX_WU_GPIO_ENABLE) |= GPIO_PIN;      /* Enable appropriate pin */
  74 }
  75
  76 void read_2501_memory(unsigned char *psernum, unsigned char *perr)
  77 {
  78 #define NBYTES 28
  79         unsigned char crcval, i;
  80         unsigned char buf[NBYTES];
  81
  82         *perr = 0;
  83         crcval = 0;
  84
  85         for (i = 0; i < NBYTES; i++)
  86                 buf[i] = 0;
  87
  88         if (!check_device())
  89                 *perr = ERR_NO_NUMBER;
  90         else {
  91                 *perr = NO_ERROR;
  92                 write_byte(0xCC);               /* skip ROM (0xCC) */
  93                 write_byte(0xF0);               /* Read memory command 0xF0 */
  94                 write_byte(0x00);               /* Address TA1=0, TA2=0 */
  95                 write_byte(0x00);
  96                 read_byte(&crcval);             /* Read CRC of address and command */
  97
  98                 for (i = 0; i < NBYTES; i++)
  99                         read_byte(&buf[i]);
 100         }
 101         if (strncmp((const char *) &buf[11], "MAREL IEEE 802.3", 16)) {
 102                 *perr = ERR_BAD_NUMBER;
 103                 psernum[0] = 0x00;
 104                 psernum[1] = 0xE0;
 105                 psernum[2] = 0xEE;
 106                 psernum[3] = 0xFF;
 107                 psernum[4] = 0xFF;
 108                 psernum[5] = 0xFF;
 109         } else {
 110                 psernum[0] = 0x00;
 111                 psernum[1] = 0xE0;
 112                 psernum[2] = 0xEE;
 113                 psernum[3] = buf[7];
 114                 psernum[4] = buf[6];
 115                 psernum[5] = buf[5];
 116         }
 117 }
 118
 119 static int check_device()
 120 {
 121         int found;
 122
 123         io_output();
 124         io_out(0);
 125         udelay(500);  /* must be at least 480 us low pulse */
 126
 127         io_input();
 128         udelay(60);
 129
 130         found = (is_high() == 0) ? 1 : 0;
 131         udelay(500);  /* must be at least 480 us low pulse */
 132
 133         return found;
 134 }
 135
 136 static void write_byte(unsigned char command)
 137 {
 138         char i;
 139
 140         for (i = 0; i < 8; i++) {
 141                 /* 1 us to 15 us low pulse starts bit slot */
 142                 /* Start with high pulse for 3 us */
 143                 io_input();
 144                 udelay(3);
 145
 146                 io_out(0);
 147                 io_output();
 148                 udelay(3);
 149
 150                 if (command & 0x01) {
 151                         /* 60 us high for 1-bit */
 152                         io_input();
 153                         udelay(60);
 154                 } else
 155                         /* 60 us low for 0-bit */
 156                         udelay(60);
 157                 /*  Leave pin as input */
 158                 io_input();
 159
 160                 command = command >> 1;
 161         }
 162 }
 163
 164 static void read_byte(unsigned char *data)
 165 {
 166         unsigned char i, rdat = 0;
 167
 168         for (i = 0; i < 8; i++) {
 169                 /* read one bit from one-wire device */
 170
 171                 /* 1 - 15 us low starts bit slot */
 172                 io_out(0);
 173                 io_output();
 174                 udelay(0);
 175
 176                 /* allow line to be pulled high */
 177                 io_input();
 178
 179                 /* delay 10 us */
 180                 udelay(10);
 181
 182                 /* now sample input status */
 183                 if (is_high())
 184                         rdat = (rdat >> 1) | 0x80;
 185                 else
 186                         rdat = rdat >> 1;
 187
 188                 udelay(60);     /* at least 60 us */
 189         }
 190         /* copy the return value */
 191         *data = rdat;
 192 }
 193
 194 void board_get_enetaddr(uchar *enetaddr)
 195 {
 196         unsigned char sn[6], err = NO_ERROR;
 197
 198         init_gpio();
 199
 200         read_2501_memory(sn, &err);
 201
 202         if (err == NO_ERROR) {
 203                 sprintf((char *)enetaddr, "%02x:%02x:%02x:%02x:%02x:%02x",
 204                                 sn[0], sn[1], sn[2], sn[3], sn[4], sn[5]);
 205                 printf("MAC address: %s\n", enetaddr);
 206                 setenv("ethaddr", (char *)enetaddr);
 207         } else {
 208                 sprintf((char *)enetaddr, "00:01:02:03:04:05");
 209                 printf("Error reading MAC address.\n");
 210                 printf("Setting default to %s\n", enetaddr);
 211                 setenv("ethaddr", (char *)enetaddr);
 212         }
 213 }