mvme5500/GT64260/MVME5500I2C.c

0001 /*
0002  * To read information of the EEPROM via the I2C
0003  */
0004
0005 /*
0006  * Copyright (c) 2003, 2004 Brookhaven National Laboratory
0007  * Author:    S. Kate Feng <feng1@bnl.gov>
0008  * All rights reserved.
0009  *
0010  * The license and distribution terms for this file may be
0011  * found in the file LICENSE in this distribution.
0012  */
0013
0014 #include <bsp.h>
0015 #include <rtems/bspIo.h>      /* printk */
0016 #include <stdint.h>           /* uint32_t */
0017 #include "bsp/GT64260TWSI.h"
0018
0019 /* #define I2C_DEBUG*/
0020
0021 static unsigned char I2cAddrPack(unsigned char busAddr,uint32_t offset)
0022 {
0023   return(busAddr | ((offset & 0x700) >> 7));
0024 }
0025
0026 static unsigned char I2cDevByteAddr(uint32_t devA2A1A0, unsigned char byteNum)
0027 {
0028   return(( devA2A1A0 >>(byteNum*8)) & 0xff);
0029 }
0030 /****************************************************************************
0031 * I2Cread_eeprom - read EEPROM VPD from the I2C
0032 */
0033 int I2Cread_eeprom(
0034   unsigned char  I2cBusAddr,
0035   uint32_t       devA2A1A0,
0036   uint32_t       AddrBytes,
0037   unsigned char *pBuff,
0038   uint32_t       numBytes
0039 )
0040 {
0041   int status=0, lastByte=0;
0042
0043   switch (AddrBytes) {
0044     case 1:
0045       if ((status=GT64260TWSIstart()) != -1) {
0046         if ((status=GT64260TWSIwrite(I2cAddrPack(I2cBusAddr,devA2A1A0)))!= -1){
0047           if ((status=GT64260TWSIwrite(devA2A1A0))!=-1){
0048             if ((status=GT64260TWSIstart())!=-1)
0049                 status=GT64260TWSIwrite(I2cAddrPack((I2cBusAddr|0x01),devA2A1A0));
0050           }
0051         }
0052       }
0053       break;
0054     case 2:
0055       if ((status=GT64260TWSIstart())!=-1) {
0056         if ((status=GT64260TWSIwrite(I2cBusAddr))!= -1) {
0057           if ((status=GT64260TWSIwrite(I2cDevByteAddr(devA2A1A0,1)))!=-1) {
0058             if ((status=GT64260TWSIwrite(I2cDevByteAddr(devA2A1A0,0)))!= -1){
0059               if ((status=GT64260TWSIstart()) != -1) {
0060                 status = GT64260TWSIwrite((I2cBusAddr | 0x01));
0061               }
0062             }
0063           }
0064         }
0065       }
0066       break;
0067     case 3:
0068       if ((status = GT64260TWSIstart())!= -1) {
0069         if ((status = GT64260TWSIwrite(I2cBusAddr))!= -1) {
0070           if ((status=GT64260TWSIwrite(I2cDevByteAddr(devA2A1A0,2)))!= -1){
0071             if ((status=GT64260TWSIwrite(I2cDevByteAddr(devA2A1A0,1)))!= -1){
0072               if ((status=GT64260TWSIwrite(I2cDevByteAddr(devA2A1A0,0)))!= -1){
0073                   if ((status=GT64260TWSIstart())!= -1) {
0074                   status = GT64260TWSIwrite(I2cBusAddr | 0x01);
0075                 }
0076               }
0077             }
0078           }
0079         }
0080       }
0081       break;
0082     default:
0083       status=-1;
0084       break;
0085   }
0086   if (status !=-1) {
0087 #ifdef I2C_DEBUG
0088      printk("\n");
0089 #endif
0090      /* read data from device */
0091      for ( ; numBytes > 0; numBytes-- ) {
0092        if ( numBytes == 1) lastByte=1;
0093        if (GT64260TWSIread(pBuff,lastByte) == -1) return (-1);
0094 #ifdef I2C_DEBUG
0095        printk("%2x ", *pBuff);
0096        if ( (numBytes % 20)==0 ) printk("\n");
0097 #endif
0098        pBuff++;
0099      }
0100 #ifdef I2C_DEBUG
0101      printk("\n");
0102 #endif
0103      if (GT64260TWSIstop() == -1) return (-1);
0104   }
0105   return (status);
0106 }
0107