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 <linux/config.h>
  35
  36 #if defined(CONFIG_KGDB)
  37 #include <asm/serial.h>
  38
  39 /*
  40  * Baud rate, Parity, Data and Stop bit settings for the
  41  * serial port on the Yosemite. Note that the Early printk
  42  * patch has been added. So, we should be all set to go
  43  */
  44 #define YOSEMITE_BAUD_2400      2400
  45 #define YOSEMITE_BAUD_4800      4800
  46 #define YOSEMITE_BAUD_9600      9600
  47 #define YOSEMITE_BAUD_19200     19200
  48 #define YOSEMITE_BAUD_38400     38400
  49 #define YOSEMITE_BAUD_57600     57600
  50 #define YOSEMITE_BAUD_115200    115200
  51
  52 #define YOSEMITE_PARITY_NONE    0
  53 #define YOSEMITE_PARITY_ODD     0x08
  54 #define YOSEMITE_PARITY_EVEN    0x18
  55 #define YOSEMITE_PARITY_MARK    0x28
  56 #define YOSEMITE_PARITY_SPACE   0x38
  57
  58 #define YOSEMITE_DATA_5BIT      0x0
  59 #define YOSEMITE_DATA_6BIT      0x1
  60 #define YOSEMITE_DATA_7BIT      0x2
  61 #define YOSEMITE_DATA_8BIT      0x3
  62
  63 #define YOSEMITE_STOP_1BIT      0x0
  64 #define YOSEMITE_STOP_2BIT      0x4
  65
  66 /* This is crucial */
  67 #define SERIAL_REG_OFS          0x1
  68
  69 #define SERIAL_RCV_BUFFER       0x0
  70 #define SERIAL_TRANS_HOLD       0x0
  71 #define SERIAL_SEND_BUFFER      0x0
  72 #define SERIAL_INTR_ENABLE      (1 * SERIAL_REG_OFS)
  73 #define SERIAL_INTR_ID          (2 * SERIAL_REG_OFS)
  74 #define SERIAL_DATA_FORMAT      (3 * SERIAL_REG_OFS)
  75 #define SERIAL_LINE_CONTROL     (3 * SERIAL_REG_OFS)
  76 #define SERIAL_MODEM_CONTROL    (4 * SERIAL_REG_OFS)
  77 #define SERIAL_RS232_OUTPUT     (4 * SERIAL_REG_OFS)
  78 #define SERIAL_LINE_STATUS      (5 * SERIAL_REG_OFS)
  79 #define SERIAL_MODEM_STATUS     (6 * SERIAL_REG_OFS)
  80 #define SERIAL_RS232_INPUT      (6 * SERIAL_REG_OFS)
  81 #define SERIAL_SCRATCH_PAD      (7 * SERIAL_REG_OFS)
  82
  83 #define SERIAL_DIVISOR_LSB      (0 * SERIAL_REG_OFS)
  84 #define SERIAL_DIVISOR_MSB      (1 * SERIAL_REG_OFS)
  85
  86 /*
  87  * Functions to READ and WRITE to serial port 0
  88  */
  89 #define SERIAL_READ(ofs)                (*((volatile unsigned char*)    \
  90                                         (TITAN_SERIAL_BASE + ofs)))
  91
  92 #define SERIAL_WRITE(ofs, val)          ((*((volatile unsigned char*)   \
  93                                         (TITAN_SERIAL_BASE + ofs))) = val)
  94
  95 /*
  96  * Functions to READ and WRITE to serial port 1
  97  */
  98 #define SERIAL_READ_1(ofs)              (*((volatile unsigned char*)    \
  99                                         (TITAN_SERIAL_BASE_1 + ofs)
 100
 101 #define SERIAL_WRITE_1(ofs, val)        ((*((volatile unsigned char*)   \
 102                                         (TITAN_SERIAL_BASE_1 + ofs))) = val)
 103
 104 /*
 105  * Second serial port initialization
 106  */
 107 void init_second_port(void)
 108 {
 109         /* Disable Interrupts */
 110         SERIAL_WRITE_1(SERIAL_LINE_CONTROL, 0x0);
 111         SERIAL_WRITE_1(SERIAL_INTR_ENABLE, 0x0);
 112
 113         {
 114                 unsigned int divisor;
 115
 116                 SERIAL_WRITE_1(SERIAL_LINE_CONTROL, 0x80);
 117                 divisor = TITAN_SERIAL_BASE_BAUD / YOSEMITE_BAUD_115200;
 118                 SERIAL_WRITE_1(SERIAL_DIVISOR_LSB, divisor & 0xff);
 119
 120                 SERIAL_WRITE_1(SERIAL_DIVISOR_MSB,
 121                                (divisor & 0xff00) >> 8);
 122                 SERIAL_WRITE_1(SERIAL_LINE_CONTROL, 0x0);
 123         }
 124
 125         SERIAL_WRITE_1(SERIAL_DATA_FORMAT, YOSEMITE_DATA_8BIT |
 126                        YOSEMITE_PARITY_NONE | YOSEMITE_STOP_1BIT);
 127
 128         /* Enable Interrupts */
 129         SERIAL_WRITE_1(SERIAL_INTR_ENABLE, 0xf);
 130 }
 131
 132 /* Initialize the serial port for KGDB debugging */
 133 void debugInit(unsigned int baud, unsigned char data, unsigned char parity,
 134                unsigned char stop)
 135 {
 136         /* Disable Interrupts */
 137         SERIAL_WRITE(SERIAL_LINE_CONTROL, 0x0);
 138         SERIAL_WRITE(SERIAL_INTR_ENABLE, 0x0);
 139
 140         {
 141                 unsigned int divisor;
 142
 143                 SERIAL_WRITE(SERIAL_LINE_CONTROL, 0x80);
 144
 145                 divisor = TITAN_SERIAL_BASE_BAUD / baud;
 146                 SERIAL_WRITE(SERIAL_DIVISOR_LSB, divisor & 0xff);
 147
 148                 SERIAL_WRITE(SERIAL_DIVISOR_MSB, (divisor & 0xff00) >> 8);
 149                 SERIAL_WRITE(SERIAL_LINE_CONTROL, 0x0);
 150         }
 151
 152         SERIAL_WRITE(SERIAL_DATA_FORMAT, data | parity | stop);
 153 }
 154
 155 static int remoteDebugInitialized = 0;
 156
 157 unsigned char getDebugChar(void)
 158 {
 159         if (!remoteDebugInitialized) {
 160                 remoteDebugInitialized = 1;
 161                 debugInit(YOSEMITE_BAUD_115200,
 162                           YOSEMITE_DATA_8BIT,
 163                           YOSEMITE_PARITY_NONE, YOSEMITE_STOP_1BIT);
 164         }
 165
 166         while ((SERIAL_READ(SERIAL_LINE_STATUS) & 0x1) == 0);
 167         return SERIAL_READ(SERIAL_RCV_BUFFER);
 168 }
 169
 170 int putDebugChar(unsigned char byte)
 171 {
 172         if (!remoteDebugInitialized) {
 173                 remoteDebugInitialized = 1;
 174                 debugInit(YOSEMITE_BAUD_115200,
 175                           YOSEMITE_DATA_8BIT,
 176                           YOSEMITE_PARITY_NONE, YOSEMITE_STOP_1BIT);
 177         }
 178
 179         while ((SERIAL_READ(SERIAL_LINE_STATUS) & 0x20) == 0);
 180         SERIAL_WRITE(SERIAL_SEND_BUFFER, byte);
 181
 182         return 1;
 183 }
 184 #endif