arch/arm-raspi/kernel/maygetchar.c

   1 /*
   2     Copyright © 2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/kernel.h>
   7
   8 #include <asm/bcm2835.h>
   9 #include <hardware/pl011uart.h>
  10
  11 #include <kernel_base.h>
  12 #include <kernel_debug.h>
  13
  14 /*****************************************************************************
  15
  16     NAME */
  17 #include <proto/kernel.h>
  18
  19 AROS_LH0(int, KrnMayGetChar,
  20
  21 /*  SYNOPSIS */
  22
  23 /*  LOCATION */
  24         struct KernelBase *, KernelBase, 26, Kernel)
  25
  26 /*  FUNCTION
  27         Read a single character from low-level debug input stream
  28
  29     INPUTS
  30         None
  31
  32     RESULT
  33         An ASCII code of the character or -1 if there's no character
  34         available
  35
  36     NOTES
  37         This function never waits. If there is no character available on
  38         the stream it just returns with -1
  39
  40     EXAMPLE
  41
  42     BUGS
  43
  44     SEE ALSO
  45
  46     INTERNALS
  47
  48 ******************************************************************************/
  49 {
  50     AROS_LIBFUNC_INIT
  51
  52     if ((*(volatile uint32_t *)(PL011_0_BASE + PL011_FR) & PL011_FR_RXFE) == 0)
  53         return (int)*(volatile uint32_t *)(PL011_0_BASE + PL011_DR);
  54
  55     return -1;
  56
  57     AROS_LIBFUNC_EXIT
  58 }