arch/mips/mips-boards/generic/gdb_hook.c

   1 /*
   2  * Carsten Langgaard, carstenl@mips.com
   3  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
   4  *
   5  *  This program is free software; you can distribute it and/or modify it
   6  *  under the terms of the GNU General Public License (Version 2) as
   7  *  published by the Free Software Foundation.
   8  *
   9  *  This program is distributed in the hope it will be useful, but WITHOUT
  10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  17  *
  18  * This is the interface to the remote debugger stub.
  19  */
  20 #include <linux/types.h>
  21 #include <linux/serial.h>
  22 #include <linux/serialP.h>
  23 #include <linux/serial_reg.h>
  24
  25 #include <asm/serial.h>
  26 #include <asm/io.h>
  27
  28 static struct serial_state rs_table[] = {
  29         SERIAL_PORT_DFNS        /* Defined in serial.h */
  30 };
  31
  32 static struct async_struct kdb_port_info = {0};
  33
  34 int (*generic_putDebugChar)(char);
  35 char (*generic_getDebugChar)(void);
  36
  37 static __inline__ unsigned int serial_in(struct async_struct *info, int offset)
  38 {
  39         return inb(info->port + offset);
  40 }
  41
  42 static __inline__ void serial_out(struct async_struct *info, int offset,
  43                                 int value)
  44 {
  45         outb(value, info->port+offset);
  46 }
  47
  48 int rs_kgdb_hook(int tty_no, int speed) {
  49         int t;
  50         struct serial_state *ser = &rs_table[tty_no];
  51
  52         kdb_port_info.state = ser;
  53         kdb_port_info.magic = SERIAL_MAGIC;
  54         kdb_port_info.port = ser->port;
  55         kdb_port_info.flags = ser->flags;
  56
  57         /*
  58          * Clear all interrupts
  59          */
  60         serial_in(&kdb_port_info, UART_LSR);
  61         serial_in(&kdb_port_info, UART_RX);
  62         serial_in(&kdb_port_info, UART_IIR);
  63         serial_in(&kdb_port_info, UART_MSR);
  64
  65         /*
  66          * Now, initialize the UART
  67          */
  68         serial_out(&kdb_port_info, UART_LCR, UART_LCR_WLEN8);   /* reset DLAB */
  69         if (kdb_port_info.flags & ASYNC_FOURPORT) {
  70                 kdb_port_info.MCR = UART_MCR_DTR | UART_MCR_RTS;
  71                 t = UART_MCR_DTR | UART_MCR_OUT1;
  72         } else {
  73                 kdb_port_info.MCR
  74                         = UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2;
  75                 t = UART_MCR_DTR | UART_MCR_RTS;
  76         }
  77
  78         kdb_port_info.MCR = t;          /* no interrupts, please */
  79         serial_out(&kdb_port_info, UART_MCR, kdb_port_info.MCR);
  80
  81         /*
  82          * and set the speed of the serial port
  83          */
  84         if (speed == 0)
  85                 speed = 9600;
  86
  87         t = kdb_port_info.state->baud_base / speed;
  88         /* set DLAB */
  89         serial_out(&kdb_port_info, UART_LCR, UART_LCR_WLEN8 | UART_LCR_DLAB);
  90         serial_out(&kdb_port_info, UART_DLL, t & 0xff);/* LS of divisor */
  91         serial_out(&kdb_port_info, UART_DLM, t >> 8);  /* MS of divisor */
  92         /* reset DLAB */
  93         serial_out(&kdb_port_info, UART_LCR, UART_LCR_WLEN8);
  94
  95         return speed;
  96 }
  97
  98 int putDebugChar(char c)
  99 {
 100         return generic_putDebugChar(c);
 101 }
 102
 103 char getDebugChar(void)
 104 {
 105         return generic_getDebugChar();
 106 }
 107
 108 int rs_putDebugChar(char c)
 109 {
 110
 111         if (!kdb_port_info.state) {     /* need to init device first */
 112                 return 0;
 113         }
 114
 115         while ((serial_in(&kdb_port_info, UART_LSR) & UART_LSR_THRE) == 0)
 116                 ;
 117
 118         serial_out(&kdb_port_info, UART_TX, c);
 119
 120         return 1;
 121 }
 122
 123 char rs_getDebugChar(void)
 124 {
 125         if (!kdb_port_info.state) {     /* need to init device first */
 126                 return 0;
 127         }
 128
 129         while (!(serial_in(&kdb_port_info, UART_LSR) & 1))
 130                 ;
 131
 132         return serial_in(&kdb_port_info, UART_RX);
 133 }