board/v38b/ethaddr.c

   1 /*
   2  * (C) Copyright 2006
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <mpc5xxx.h>
  10
  11 /* For the V38B board the pin is GPIO_PSC_6 */
  12 #define GPIO_PIN        GPIO_PSC6_0
  13
  14 #define NO_ERROR        0
  15 #define ERR_NO_NUMBER   1
  16 #define ERR_BAD_NUMBER  2
  17
  18 static int is_high(void);
  19 static int check_device(void);
  20 static void io_out(int value);
  21 static void io_input(void);
  22 static void io_output(void);
  23 static void init_gpio(void);
  24 static void read_byte(unsigned char *data);
  25 static void write_byte(unsigned char command);
  26
  27 void read_2501_memory(unsigned char *psernum, unsigned char *perr);
  28 void board_get_enetaddr(uchar *enetaddr);
  29
  30
  31 static int is_high()
  32 {
  33         return (*((vu_long *) MPC5XXX_WU_GPIO_DATA_I) & GPIO_PIN);
  34 }
  35
  36 static void io_out(int value)
  37 {
  38         if (value)
  39                 *((vu_long *) MPC5XXX_WU_GPIO_DATA_O) |= GPIO_PIN;
  40         else
  41                 *((vu_long *) MPC5XXX_WU_GPIO_DATA_O) &= ~GPIO_PIN;
  42 }
  43
  44 static void io_input()
  45 {
  46         *((vu_long *) MPC5XXX_WU_GPIO_DIR) &= ~GPIO_PIN;
  47         udelay(3);      /* allow input to settle */
  48 }
  49
  50 static void io_output()
  51 {
  52         *((vu_long *) MPC5XXX_WU_GPIO_DIR) |= GPIO_PIN;
  53 }
  54
  55 static void init_gpio()
  56 {
  57         *((vu_long *) MPC5XXX_WU_GPIO_ENABLE) |= GPIO_PIN;      /* Enable appropriate pin */
  58 }
  59
  60 void read_2501_memory(unsigned char *psernum, unsigned char *perr)
  61 {
  62 #define NBYTES 28
  63         unsigned char crcval, i;
  64         unsigned char buf[NBYTES];
  65
  66         *perr = 0;
  67         crcval = 0;
  68
  69         for (i = 0; i < NBYTES; i++)
  70                 buf[i] = 0;
  71
  72         if (!check_device())
  73                 *perr = ERR_NO_NUMBER;
  74         else {
  75                 *perr = NO_ERROR;
  76                 write_byte(0xCC);               /* skip ROM (0xCC) */
  77                 write_byte(0xF0);               /* Read memory command 0xF0 */
  78                 write_byte(0x00);               /* Address TA1=0, TA2=0 */
  79                 write_byte(0x00);
  80                 read_byte(&crcval);             /* Read CRC of address and command */
  81
  82                 for (i = 0; i < NBYTES; i++)
  83                         read_byte(&buf[i]);
  84         }
  85         if (strncmp((const char *) &buf[11], "MAREL IEEE 802.3", 16)) {
  86                 *perr = ERR_BAD_NUMBER;
  87                 psernum[0] = 0x00;
  88                 psernum[1] = 0xE0;
  89                 psernum[2] = 0xEE;
  90                 psernum[3] = 0xFF;
  91                 psernum[4] = 0xFF;
  92                 psernum[5] = 0xFF;
  93         } else {
  94                 psernum[0] = 0x00;
  95                 psernum[1] = 0xE0;
  96                 psernum[2] = 0xEE;
  97                 psernum[3] = buf[7];
  98                 psernum[4] = buf[6];
  99                 psernum[5] = buf[5];
 100         }
 101 }
 102
 103 static int check_device()
 104 {
 105         int found;
 106
 107         io_output();
 108         io_out(0);
 109         udelay(500);  /* must be at least 480 us low pulse */
 110
 111         io_input();
 112         udelay(60);
 113
 114         found = (is_high() == 0) ? 1 : 0;
 115         udelay(500);  /* must be at least 480 us low pulse */
 116
 117         return found;
 118 }
 119
 120 static void write_byte(unsigned char command)
 121 {
 122         char i;
 123
 124         for (i = 0; i < 8; i++) {
 125                 /* 1 us to 15 us low pulse starts bit slot */
 126                 /* Start with high pulse for 3 us */
 127                 io_input();
 128                 udelay(3);
 129
 130                 io_out(0);
 131                 io_output();
 132                 udelay(3);
 133
 134                 if (command & 0x01) {
 135                         /* 60 us high for 1-bit */
 136                         io_input();
 137                         udelay(60);
 138                 } else
 139                         /* 60 us low for 0-bit */
 140                         udelay(60);
 141                 /*  Leave pin as input */
 142                 io_input();
 143
 144                 command = command >> 1;
 145         }
 146 }
 147
 148 static void read_byte(unsigned char *data)
 149 {
 150         unsigned char i, rdat = 0;
 151
 152         for (i = 0; i < 8; i++) {
 153                 /* read one bit from one-wire device */
 154
 155                 /* 1 - 15 us low starts bit slot */
 156                 io_out(0);
 157                 io_output();
 158                 udelay(0);
 159
 160                 /* allow line to be pulled high */
 161                 io_input();
 162
 163                 /* delay 10 us */
 164                 udelay(10);
 165
 166                 /* now sample input status */
 167                 if (is_high())
 168                         rdat = (rdat >> 1) | 0x80;
 169                 else
 170                         rdat = rdat >> 1;
 171
 172                 udelay(60);     /* at least 60 us */
 173         }
 174         /* copy the return value */
 175         *data = rdat;
 176 }
 177
 178 void board_get_enetaddr(uchar *enetaddr)
 179 {
 180         unsigned char sn[6], err = NO_ERROR;
 181
 182         init_gpio();
 183
 184         read_2501_memory(sn, &err);
 185
 186         if (err == NO_ERROR) {
 187                 sprintf((char *)enetaddr, "%02x:%02x:%02x:%02x:%02x:%02x",
 188                                 sn[0], sn[1], sn[2], sn[3], sn[4], sn[5]);
 189                 printf("MAC address: %s\n", enetaddr);
 190                 setenv("ethaddr", (char *)enetaddr);
 191         } else {
 192                 sprintf((char *)enetaddr, "00:01:02:03:04:05");
 193                 printf("Error reading MAC address.\n");
 194                 printf("Setting default to %s\n", enetaddr);
 195                 setenv("ethaddr", (char *)enetaddr);
 196         }
 197 }