arch/arm-raspi/i2c/i2c-bcm2835.c

   1 /*
   2     Copyright © 2010-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/symbolsets.h>
   7 #include <aros/debug.h>
   8 #include <proto/exec.h>
   9
  10 #include <hidd/i2c.h>
  11
  12 #include <asm/bcm2835.h>
  13 #include <asm/io.h>
  14
  15 #include "i2c-bcm2835.h"
  16
  17 void METHOD(I2CBCM2835, Hidd_I2C, PutByte)
  18 {
  19     while (!((*(volatile UBYTE *)BSC0_STATUS) & BSC_STATUS_DONE))
  20     {
  21         asm volatile ("mov r2,r2\n");
  22     }
  23
  24     *(volatile UBYTE *)BSC0_DATALEN = 1;
  25     *(volatile UBYTE *)BSC0_FIFO = msg->data;
  26
  27     *(volatile UBYTE *)BSC0_STATUS = BSC_CLEAR;
  28     *(volatile UBYTE *)BSC0_CONTROL = BSC_WRITE;
  29 }
  30
  31 void METHOD(I2CBCM2835, Hidd_I2C, GetByte)
  32 {
  33     while (!((*(volatile UBYTE *)BSC0_STATUS) & BSC_STATUS_DONE))
  34     {
  35         asm volatile ("mov r2,r2\n");
  36     }
  37
  38     *(volatile UBYTE *)BSC0_DATALEN = 1;
  39     *(volatile UBYTE *)BSC0_STATUS = BSC_CLEAR;
  40     *(volatile UBYTE *)BSC0_CONTROL = BSC_READ;
  41
  42     *msg->data = *(volatile UBYTE *)BSC0_FIFO;
  43 }
  44
  45 void I2CBCM2835_Init(void)
  46 {
  47     /* BSC0 is on GPIO 0 & 1 */
  48     *(volatile UBYTE *)GPFSEL0 &= ~0x3f; // Mask out bits 0-5
  49     *(volatile UBYTE *)GPFSEL0 |= 0x24;  // Set bits 0-5 to binary '100100'
  50 }
  51
  52
  53 ADD2LIBS((STRPTR)"i2c.hidd", 0, static struct Library *, I2CBase);