release/src-rt-6.x/linux/linux-2.6/arch/mips/brcm-boards/generic/gdb_hook.c

   1 /*
   2  * Copyright (C) 2011, Broadcom Corporation. All Rights Reserved.
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  11  * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  13  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  14  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  *
  16  * Carsten Langgaard, carstenl@mips.com
  17  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
  18  *
  19  * ########################################################################
  20  *
  21  *  This program is free software; you can distribute it and/or modify it
  22  *  under the terms of the GNU General Public License (Version 2) as
  23  *  published by the Free Software Foundation.
  24  *
  25  *  This program is distributed in the hope it will be useful, but WITHOUT
  26  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  27  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  28  *  for more details.
  29  *
  30  *  You should have received a copy of the GNU General Public License along
  31  *  with this program; if not, write to the Free Software Foundation, Inc.,
  32  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  33  *
  34  * ########################################################################
  35  *
  36  * This is the interface to the remote debugger stub.
  37  *
  38  */
  39
  40 #include <linux/serial.h>
  41 #include <linux/serial_core.h>
  42 #include <linux/serialP.h>
  43 #include <linux/serial_reg.h>
  44
  45 #include <asm/serial.h>
  46 #include <asm/io.h>
  47
  48 static struct async_struct kdb_port_info = {0};
  49
  50 static __inline__ unsigned int serial_in(struct async_struct *info, int offset)
  51 {
  52         return readb(info->iomem_base + (offset<<info->iomem_reg_shift));
  53 }
  54
  55 static __inline__ void serial_out(struct async_struct *info, int offset,
  56                                   int value)
  57 {
  58         writeb(value, info->iomem_base + (offset<<info->iomem_reg_shift));
  59 }
  60
  61 void rs_kgdb_hook(struct uart_port *ser) {
  62         int t;
  63
  64         kdb_port_info.state = (struct serial_state *)ser;
  65         kdb_port_info.magic = SERIAL_MAGIC;
  66         kdb_port_info.port = ser->line;
  67         kdb_port_info.flags = ser->flags;
  68         kdb_port_info.iomem_base = ser->membase;
  69         kdb_port_info.iomem_reg_shift = ser->regshift;
  70         kdb_port_info.MCR = UART_MCR_DTR | UART_MCR_RTS;
  71
  72         /*
  73          * Clear all interrupts
  74          */
  75         serial_in(&kdb_port_info, UART_LSR);
  76         serial_in(&kdb_port_info, UART_RX);
  77         serial_in(&kdb_port_info, UART_IIR);
  78         serial_in(&kdb_port_info, UART_MSR);
  79
  80         /*
  81          * Now, initialize the UART
  82          */
  83         serial_out(&kdb_port_info, UART_LCR, UART_LCR_WLEN8);   /* reset DLAB */
  84         serial_out(&kdb_port_info, UART_MCR, kdb_port_info.MCR);
  85
  86         /*
  87          * and set the speed of the serial port
  88          * (currently hardwired to 115200 8N1
  89          */
  90
  91         /* baud rate is fixed to 115200 (is this sufficient?)*/
  92         t = ser->uartclk / 115200;
  93         /* set DLAB */
  94         serial_out(&kdb_port_info, UART_LCR, UART_LCR_WLEN8 | UART_LCR_DLAB);
  95         serial_out(&kdb_port_info, UART_DLL, t & 0xff);/* LS of divisor */
  96         serial_out(&kdb_port_info, UART_DLM, t >> 8);  /* MS of divisor */
  97         /* reset DLAB */
  98         serial_out(&kdb_port_info, UART_LCR, UART_LCR_WLEN8);
  99 }
 100
 101 int putDebugChar(char c)
 102 {
 103
 104         if (!kdb_port_info.state) {     /* need to init device first */
 105                 return 0;
 106         }
 107
 108         while ((serial_in(&kdb_port_info, UART_LSR) & UART_LSR_THRE) == 0)
 109                 ;
 110
 111         serial_out(&kdb_port_info, UART_TX, c);
 112
 113         return 1;
 114 }
 115
 116 char getDebugChar(void)
 117 {
 118         if (!kdb_port_info.state) {     /* need to init device first */
 119                 return 0;
 120         }
 121
 122         while (!(serial_in(&kdb_port_info, UART_LSR) & 1))
 123                 ;
 124
 125         return(serial_in(&kdb_port_info, UART_RX));
 126 }