arch/mips/txx9/jmr3927/kgdb_io.c

   1 /*
   2  * BRIEF MODULE DESCRIPTION
   3  *      Low level uart routines to directly access a TX[34]927 SIO.
   4  *
   5  * Copyright 2001 MontaVista Software Inc.
   6  * Author: MontaVista Software, Inc.
   7  *              ahennessy@mvista.com or source@mvista.com
   8  *
   9  * Based on arch/mips/ddb5xxx/ddb5477/kgdb_io.c
  10  *
  11  * Copyright (C) 2000-2001 Toshiba Corporation
  12  *
  13  *  This program is free software; you can redistribute  it and/or modify it
  14  *  under  the terms of  the GNU General  Public License as published by the
  15  *  Free Software Foundation;  either version 2 of the  License, or (at your
  16  *  option) any later version.
  17  *
  18  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  19  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  20  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  21  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  22  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  24  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  25  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  26  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  *  You should have received a copy of the  GNU General Public License along
  30  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  31  *  675 Mass Ave, Cambridge, MA 02139, USA.
  32  */
  33
  34 #include <asm/txx9/jmr3927.h>
  35
  36 #define TIMEOUT       0xffffff
  37
  38 static int remoteDebugInitialized = 0;
  39 static void debugInit(int baud);
  40
  41 int putDebugChar(unsigned char c)
  42 {
  43         int i = 0;
  44
  45         if (!remoteDebugInitialized) {
  46                 remoteDebugInitialized = 1;
  47                 debugInit(38400);
  48         }
  49
  50         do {
  51             slow_down();
  52             i++;
  53             if (i>TIMEOUT) {
  54                 break;
  55             }
  56         } while (!(tx3927_sioptr(0)->cisr & TXx927_SICISR_TXALS));
  57         tx3927_sioptr(0)->tfifo = c;
  58
  59         return 1;
  60 }
  61
  62 unsigned char getDebugChar(void)
  63 {
  64         int i = 0;
  65         int dicr;
  66         char c;
  67
  68         if (!remoteDebugInitialized) {
  69                 remoteDebugInitialized = 1;
  70                 debugInit(38400);
  71         }
  72
  73         /* diable RX int. */
  74         dicr = tx3927_sioptr(0)->dicr;
  75         tx3927_sioptr(0)->dicr = 0;
  76
  77         do {
  78             slow_down();
  79             i++;
  80             if (i>TIMEOUT) {
  81                 break;
  82             }
  83         } while (tx3927_sioptr(0)->disr & TXx927_SIDISR_UVALID)
  84                 ;
  85         c = tx3927_sioptr(0)->rfifo;
  86
  87         /* clear RX int. status */
  88         tx3927_sioptr(0)->disr &= ~TXx927_SIDISR_RDIS;
  89         /* enable RX int. */
  90         tx3927_sioptr(0)->dicr = dicr;
  91
  92         return c;
  93 }
  94
  95 static void debugInit(int baud)
  96 {
  97         tx3927_sioptr(0)->lcr = 0x020;
  98         tx3927_sioptr(0)->dicr = 0;
  99         tx3927_sioptr(0)->disr = 0x4100;
 100         tx3927_sioptr(0)->cisr = 0x014;
 101         tx3927_sioptr(0)->fcr = 0;
 102         tx3927_sioptr(0)->flcr = 0x02;
 103         tx3927_sioptr(0)->bgr = ((JMR3927_BASE_BAUD + baud / 2) / baud) |
 104                 TXx927_SIBGR_BCLK_T0;
 105 }