board/mbx8xx/vpd.c

   1 /*
   2  * (C) Copyright 2000
   3  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   4  * Marius Groeger <mgroeger@sysgo.de>
   5  *
   6  * Code in faintly related to linux/arch/ppc/8xx_io:
   7  * MPC8xx CPM I2C interface. Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
   8  *
   9  * This file implements functions to read the MBX's Vital Product Data
  10  * (VPD). I can't use the more general i2c code in mpc8xx/... since I need
  11  * the VPD at a time where there is no RAM available yet. Hence the VPD is
  12  * read into a special area in the DPRAM (see config_MBX.h::CFG_DPRAMVPD).
  13  *
  14  * -----------------------------------------------------------------
  15  * See file CREDITS for list of people who contributed to this
  16  * project.
  17  *
  18  * This program is free software; you can redistribute it and/or
  19  * modify it under the terms of the GNU General Public License as
  20  * published by the Free Software Foundation; either version 2 of
  21  * the License, or (at your option) any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program; if not, write to the Free Software
  30  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  31  * MA 02111-1307 USA
  32  */
  33
  34 #include <common.h>
  35 #ifdef CONFIG_8xx
  36 #include <commproc.h>
  37 #endif
  38 #include "vpd.h"
  39
  40 /* Location of receive/transmit buffer descriptors
  41  * Allocate one transmit bd and one receive bd.
  42  * IIC_BD_FREE points to free bd space which we'll use as tx buffer.
  43  */
  44 #define IIC_BD_TX1     (BD_IIC_START + 0*sizeof(cbd_t))
  45 #define IIC_BD_TX2     (BD_IIC_START + 1*sizeof(cbd_t))
  46 #define IIC_BD_RX      (BD_IIC_START + 2*sizeof(cbd_t))
  47 #define IIC_BD_FREE    (BD_IIC_START + 3*sizeof(cbd_t))
  48
  49 /* FIXME -- replace 0x2000 with offsetof */
  50 #define VPD_P ((vpd_t *)(CFG_IMMR + 0x2000 + CFG_DPRAMVPD))
  51
  52 /* transmit/receive buffers */
  53 #define IIC_RX_LENGTH 128
  54
  55 #define WITH_MICROCODE_PATCH
  56
  57 vpd_packet_t * vpd_find_packet(u_char ident)
  58 {
  59     vpd_packet_t *packet;
  60     vpd_t *vpd = VPD_P;
  61
  62     packet = (vpd_packet_t *)&vpd->packets;
  63     while ((packet->identifier != ident) && packet->identifier != 0xFF)
  64     {
  65         packet = (vpd_packet_t *)((char *)packet + packet->size + 2);
  66     }
  67     return packet;
  68 }
  69
  70 void vpd_init(void)
  71 {
  72     volatile immap_t  *im = (immap_t *)CFG_IMMR;
  73     volatile cpm8xx_t *cp = &(im->im_cpm);
  74     volatile i2c8xx_t *i2c = (i2c8xx_t *)&(im->im_i2c);
  75     volatile iic_t *iip;
  76 #ifdef WITH_MICROCODE_PATCH
  77     ulong reloc = 0;
  78 #endif
  79
  80     iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
  81
  82     /*
  83      * kludge: when running from flash, no microcode patch can be
  84      * installed. However, the DPMEM usually contains non-zero
  85      * garbage at the relocatable patch base location, so lets clear
  86      * it now. This way the rest of the code can support the microcode
  87      * patch dynamically.
  88      */
  89     if ((ulong)vpd_init & 0xff000000)
  90       iip->iic_rpbase = 0;
  91
  92 #ifdef WITH_MICROCODE_PATCH
  93     /* Check for and use a microcode relocation patch. */
  94     if ((reloc = iip->iic_rpbase))
  95       iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
  96 #endif
  97     /* Initialize Port B IIC pins */
  98     cp->cp_pbpar |= 0x00000030;
  99     cp->cp_pbdir |= 0x00000030;
 100     cp->cp_pbodr |= 0x00000030;
 101
 102     i2c->i2c_i2mod = 0x04;  /* filter clock */
 103     i2c->i2c_i2add = 0x34;      /* select an arbitrary (unique) address */
 104     i2c->i2c_i2brg = 0x07;  /* make clock run maximum slow      */
 105     i2c->i2c_i2cmr = 0x00;  /* disable interrupts */
 106     i2c->i2c_i2cer = 0x1f;  /* clear events */
 107     i2c->i2c_i2com = 0x01;  /* configure i2c to work as master */
 108
 109     if (vpd_read(0xa4, (uchar*)VPD_P, VPD_EEPROM_SIZE, 0) != VPD_EEPROM_SIZE)
 110     {
 111         hang();
 112     }
 113 }
 114
 115
 116 /* Read from I2C.
 117  * This is a two step process.  First, we send the "dummy" write
 118  * to set the device offset for the read.  Second, we perform
 119  * the read operation.
 120  */
 121 int vpd_read(uint iic_device, uchar *buf, int count, int offset)
 122 {
 123     volatile immap_t  *im = (immap_t *)CFG_IMMR;
 124     volatile cpm8xx_t *cp = &(im->im_cpm);
 125     volatile i2c8xx_t *i2c = (i2c8xx_t *)&(im->im_i2c);
 126     volatile iic_t *iip;
 127     volatile cbd_t *tbdf1, *tbdf2, *rbdf;
 128     uchar *tb;
 129     uchar event;
 130 #ifdef WITH_MICROCODE_PATCH
 131     ulong reloc = 0;
 132 #endif
 133
 134     iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
 135 #ifdef WITH_MICROCODE_PATCH
 136     /* Check for and use a microcode relocation patch. */
 137     if ((reloc = iip->iic_rpbase))
 138       iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
 139 #endif
 140     tbdf1 = (cbd_t *)&cp->cp_dpmem[IIC_BD_TX1];
 141     tbdf2 = (cbd_t *)&cp->cp_dpmem[IIC_BD_TX2];
 142     rbdf  = (cbd_t *)&cp->cp_dpmem[IIC_BD_RX];
 143
 144     /* Send a "dummy write" operation.  This is a write request with
 145      * only the offset sent, followed by another start condition.
 146      * This will ensure we start reading from the first location
 147      * of the EEPROM.
 148      */
 149     tb = (uchar*)&cp->cp_dpmem[IIC_BD_FREE];
 150     tb[0] = iic_device & 0xfe;  /* device address */
 151     tb[1] = offset;             /* offset */
 152     tbdf1->cbd_bufaddr = (uint)tb;
 153     tbdf1->cbd_datlen = 2;
 154     tbdf1->cbd_sc = 0x8400;
 155
 156     tb += 2;
 157     tb[0] = iic_device | 1;     /* device address */
 158     tbdf2->cbd_bufaddr = (uint)tb;
 159     tbdf2->cbd_datlen = count+1;
 160     tbdf2->cbd_sc = 0xbc00;
 161
 162     rbdf->cbd_bufaddr = (uint)buf;
 163     rbdf->cbd_datlen = 0;
 164     rbdf->cbd_sc = 0xb000;
 165
 166     iip->iic_tbase = IIC_BD_TX1;
 167     iip->iic_tbptr = IIC_BD_TX1;
 168     iip->iic_rbase = IIC_BD_RX;
 169     iip->iic_rbptr = IIC_BD_RX;
 170     iip->iic_rfcr = 0x15;
 171     iip->iic_tfcr = 0x15;
 172     iip->iic_mrblr = count;
 173     iip->iic_rstate = 0;
 174     iip->iic_tstate = 0;
 175
 176     i2c->i2c_i2cer = 0x1f;  /* clear event mask */
 177     i2c->i2c_i2mod |= 1;    /* enable iic operation */
 178     i2c->i2c_i2com |= 0x80;     /* start master */
 179
 180     /* wait for IIC transfer */
 181     do {
 182         __asm__ volatile ("eieio");
 183         event = i2c->i2c_i2cer;
 184     } while (event == 0);
 185
 186     if ((event & 0x10) || (event & 0x04)) {
 187         count = -1;
 188         goto bailout;
 189     }
 190
 191 bailout:
 192     i2c->i2c_i2mod &= ~1;   /* turn off iic operation */
 193     i2c->i2c_i2cer = 0x1f;  /* clear event mask */
 194
 195     return count;
 196 }