arch/arm-raspi/boot/vc_mb.c

   1 /*
   2     Copyright � 2013-2015, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: VideoCore mailbox support routines
   6     Lang: english
   7 */
   8
   9 #include <hardware/bcm2708.h>
  10
  11 #undef ARM_PERIIOBASE
  12
  13 #include <hardware/videocore.h>
  14 #include <stdint.h>
  15
  16 #define ARM_PERIIOBASE (__arm_periiobase)
  17 extern uint32_t __arm_periiobase;
  18
  19 volatile unsigned int *vcmb_read(void *mb, unsigned int chan)
  20 {
  21     unsigned int try = 0x20000000;
  22     unsigned int msg;
  23
  24     if (chan <= VCMB_CHAN_MAX)
  25     {
  26         while(1)
  27         {
  28             while ((*((volatile unsigned int *)(mb + VCMB_STATUS)) & VCMB_STATUS_READREADY) != 0)
  29             {
  30                 /* Data synchronization barrier */
  31                 asm volatile ("mcr p15, 0, %[r], c7, c10, 4" : : [r] "r" (0) );
  32
  33                 if(try-- == 0)
  34                 {
  35                     break;
  36                 }
  37             }
  38
  39             asm volatile ("mcr p15, #0, %[r], c7, c10, #5" : : [r] "r" (0) );
  40
  41             msg = *((volatile unsigned int *)(mb + VCMB_READ));
  42
  43             asm volatile ("mcr p15, #0, %[r], c7, c10, #5" : : [r] "r" (0) );
  44
  45             if ((msg & VCMB_CHAN_MASK) == chan)
  46                 return (volatile unsigned int *)(msg & ~VCMB_CHAN_MASK);
  47         }
  48     }
  49     return (volatile unsigned int *)-1;
  50 }
  51
  52 void vcmb_write(void *mb, unsigned int chan, void *msg)
  53 {
  54     if ((((unsigned int)msg & VCMB_CHAN_MASK) == 0) && (chan <= VCMB_CHAN_MAX))
  55     {
  56         while ((*((volatile unsigned int *)(mb + VCMB_STATUS)) & VCMB_STATUS_WRITEREADY) != 0)
  57         {
  58                 /* Data synchronization barrier */
  59                 asm volatile ("mcr p15, 0, %[r], c7, c10, 4" : : [r] "r" (0) );
  60         }
  61
  62         asm volatile ("mcr p15, #0, %[r], c7, c10, #5" : : [r] "r" (0) );
  63
  64         *((volatile unsigned int *)(mb + VCMB_WRITE)) = ((unsigned int)msg | chan);
  65     }
  66 }