include/asm-arm/hardware/dcc.h

   1 /*
   2  *  linux/include/asm-armnommu/hardware/dcc.h
   3  *
   4  *  Copyright (C) 2004 Hyok S. Choi, Samsung Electronics Co.,Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #ifndef __DCC_PUTS__
  21 #define __DCC_PUTS__
  22 static void dcc_puts(const char *p)
  23 {
  24 #ifndef CONFIG_JTAG_DCC_OUTPUT_DISABLE
  25         /*
  26                 r0 = string     ; string address
  27                 r1 = 2          ; state check bit (write)
  28                 r4 = *string    ; character
  29         */
  30                 __asm__ __volatile__(
  31                         "       ldrb r4, [%0]                   @ load a char\n"
  32                         "1:     mrc     p14, 0, r3, c0, c0      @ read comms control reg\n"
  33                         "       and r3, r3, #2                  @ the write buffer status\n"
  34                         "       cmp r3, #2                      @ is it available?\n"
  35                         "       beq 1b                          @ is not, wait till then\n"
  36                         "       mcr p14, 0, r4, c1, c0          @ write it\n"
  37                         "       cmp r4, #0x0a                   @ is it LF?\n"
  38                         "       bne 2f                          @ if it is not, continue\n"
  39                         "       mov r4, #0x0d                   @ set the CR\n"
  40                         "       b   1b                          @ loop for writing CR\n"
  41                         "2:     ldrb r4, [%0, #1]!              @ load a char\n"
  42                         "       cmp r4, #0x0                    @ test is null\n"
  43                         "       bne 1b                          @ if it is not yet, loop"
  44                         : /* no output register */
  45                         : "r" (p)
  46                         : "r3", "r4");
  47 #endif
  48 }
  49 #endif