arch/mips/pmc-sierra/yosemite/dbg_io.c

   1 /*
   2  * Copyright 2003 PMC-Sierra
   3  * Author: Manish Lachwani (lachwani@pmc-sierra.com)
   4  *
   5  *  This program is free software; you can redistribute  it and/or modify it
   6  *  under  the terms of  the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the  License, or (at your
   8  *  option) any later version.
   9  *
  10  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  11  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  12  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  13  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  14  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  15  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  16  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  17  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  18  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  19  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  20  *
  21  *  You should have received a copy of the  GNU General Public License along
  22  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  23  *  675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 /*
  27  * Support for KGDB for the Yosemite board. We make use of single serial
  28  * port to be used for KGDB as well as console. The second serial port
  29  * seems to be having a problem. Single IRQ is allocated for both the
  30  * ports. Hence, the interrupt routing code needs to figure out whether
  31  * the interrupt came from channel A or B.
  32  */
  33
  34 #include <asm/serial.h>
  35
  36 /*
  37  * Baud rate, Parity, Data and Stop bit settings for the
  38  * serial port on the Yosemite. Note that the Early printk
  39  * patch has been added. So, we should be all set to go
  40  */
  41 #define YOSEMITE_BAUD_2400      2400
  42 #define YOSEMITE_BAUD_4800      4800
  43 #define YOSEMITE_BAUD_9600      9600
  44 #define YOSEMITE_BAUD_19200     19200
  45 #define YOSEMITE_BAUD_38400     38400
  46 #define YOSEMITE_BAUD_57600     57600
  47 #define YOSEMITE_BAUD_115200    115200
  48
  49 #define YOSEMITE_PARITY_NONE    0
  50 #define YOSEMITE_PARITY_ODD     0x08
  51 #define YOSEMITE_PARITY_EVEN    0x18
  52 #define YOSEMITE_PARITY_MARK    0x28
  53 #define YOSEMITE_PARITY_SPACE   0x38
  54
  55 #define YOSEMITE_DATA_5BIT      0x0
  56 #define YOSEMITE_DATA_6BIT      0x1
  57 #define YOSEMITE_DATA_7BIT      0x2
  58 #define YOSEMITE_DATA_8BIT      0x3
  59
  60 #define YOSEMITE_STOP_1BIT      0x0
  61 #define YOSEMITE_STOP_2BIT      0x4
  62
  63 /* This is crucial */
  64 #define SERIAL_REG_OFS          0x1
  65
  66 #define SERIAL_RCV_BUFFER       0x0
  67 #define SERIAL_TRANS_HOLD       0x0
  68 #define SERIAL_SEND_BUFFER      0x0
  69 #define SERIAL_INTR_ENABLE      (1 * SERIAL_REG_OFS)
  70 #define SERIAL_INTR_ID          (2 * SERIAL_REG_OFS)
  71 #define SERIAL_DATA_FORMAT      (3 * SERIAL_REG_OFS)
  72 #define SERIAL_LINE_CONTROL     (3 * SERIAL_REG_OFS)
  73 #define SERIAL_MODEM_CONTROL    (4 * SERIAL_REG_OFS)
  74 #define SERIAL_RS232_OUTPUT     (4 * SERIAL_REG_OFS)
  75 #define SERIAL_LINE_STATUS      (5 * SERIAL_REG_OFS)
  76 #define SERIAL_MODEM_STATUS     (6 * SERIAL_REG_OFS)
  77 #define SERIAL_RS232_INPUT      (6 * SERIAL_REG_OFS)
  78 #define SERIAL_SCRATCH_PAD      (7 * SERIAL_REG_OFS)
  79
  80 #define SERIAL_DIVISOR_LSB      (0 * SERIAL_REG_OFS)
  81 #define SERIAL_DIVISOR_MSB      (1 * SERIAL_REG_OFS)
  82
  83 /*
  84  * Functions to READ and WRITE to serial port 0
  85  */
  86 #define SERIAL_READ(ofs)                (*((volatile unsigned char*)    \
  87                                         (TITAN_SERIAL_BASE + ofs)))
  88
  89 #define SERIAL_WRITE(ofs, val)          ((*((volatile unsigned char*)   \
  90                                         (TITAN_SERIAL_BASE + ofs))) = val)
  91
  92 /*
  93  * Functions to READ and WRITE to serial port 1
  94  */
  95 #define SERIAL_READ_1(ofs)              (*((volatile unsigned char*)    \
  96                                         (TITAN_SERIAL_BASE_1 + ofs)))
  97
  98 #define SERIAL_WRITE_1(ofs, val)        ((*((volatile unsigned char*)   \
  99                                         (TITAN_SERIAL_BASE_1 + ofs))) = val)
 100
 101 /*
 102  * Second serial port initialization
 103  */
 104 void init_second_port(void)
 105 {
 106         /* Disable Interrupts */
 107         SERIAL_WRITE_1(SERIAL_LINE_CONTROL, 0x0);
 108         SERIAL_WRITE_1(SERIAL_INTR_ENABLE, 0x0);
 109
 110         {
 111                 unsigned int divisor;
 112
 113                 SERIAL_WRITE_1(SERIAL_LINE_CONTROL, 0x80);
 114                 divisor = TITAN_SERIAL_BASE_BAUD / YOSEMITE_BAUD_115200;
 115                 SERIAL_WRITE_1(SERIAL_DIVISOR_LSB, divisor & 0xff);
 116
 117                 SERIAL_WRITE_1(SERIAL_DIVISOR_MSB,
 118                                (divisor & 0xff00) >> 8);
 119                 SERIAL_WRITE_1(SERIAL_LINE_CONTROL, 0x0);
 120         }
 121
 122         SERIAL_WRITE_1(SERIAL_DATA_FORMAT, YOSEMITE_DATA_8BIT |
 123                        YOSEMITE_PARITY_NONE | YOSEMITE_STOP_1BIT);
 124
 125         /* Enable Interrupts */
 126         SERIAL_WRITE_1(SERIAL_INTR_ENABLE, 0xf);
 127 }
 128
 129 /* Initialize the serial port for KGDB debugging */
 130 void debugInit(unsigned int baud, unsigned char data, unsigned char parity,
 131                unsigned char stop)
 132 {
 133         /* Disable Interrupts */
 134         SERIAL_WRITE(SERIAL_LINE_CONTROL, 0x0);
 135         SERIAL_WRITE(SERIAL_INTR_ENABLE, 0x0);
 136
 137         {
 138                 unsigned int divisor;
 139
 140                 SERIAL_WRITE(SERIAL_LINE_CONTROL, 0x80);
 141
 142                 divisor = TITAN_SERIAL_BASE_BAUD / baud;
 143                 SERIAL_WRITE(SERIAL_DIVISOR_LSB, divisor & 0xff);
 144
 145                 SERIAL_WRITE(SERIAL_DIVISOR_MSB, (divisor & 0xff00) >> 8);
 146                 SERIAL_WRITE(SERIAL_LINE_CONTROL, 0x0);
 147         }
 148
 149         SERIAL_WRITE(SERIAL_DATA_FORMAT, data | parity | stop);
 150 }
 151
 152 static int remoteDebugInitialized = 0;
 153
 154 unsigned char getDebugChar(void)
 155 {
 156         if (!remoteDebugInitialized) {
 157                 remoteDebugInitialized = 1;
 158                 debugInit(YOSEMITE_BAUD_115200,
 159                           YOSEMITE_DATA_8BIT,
 160                           YOSEMITE_PARITY_NONE, YOSEMITE_STOP_1BIT);
 161         }
 162
 163         while ((SERIAL_READ(SERIAL_LINE_STATUS) & 0x1) == 0);
 164         return SERIAL_READ(SERIAL_RCV_BUFFER);
 165 }
 166
 167 int putDebugChar(unsigned char byte)
 168 {
 169         if (!remoteDebugInitialized) {
 170                 remoteDebugInitialized = 1;
 171                 debugInit(YOSEMITE_BAUD_115200,
 172                           YOSEMITE_DATA_8BIT,
 173                           YOSEMITE_PARITY_NONE, YOSEMITE_STOP_1BIT);
 174         }
 175
 176         while ((SERIAL_READ(SERIAL_LINE_STATUS) & 0x20) == 0);
 177         SERIAL_WRITE(SERIAL_SEND_BUFFER, byte);
 178
 179         return 1;
 180 }