arch/mips/ite-boards/generic/dbg_io.c

   1
   2 #include <linux/config.h>
   3
   4 #ifdef CONFIG_KGDB
   5
   6 /* --- CONFIG --- */
   7
   8 /* we need uint32 uint8 */
   9 /* #include "types.h" */
  10 typedef unsigned char uint8;
  11 typedef unsigned int uint32;
  12
  13 /* --- END OF CONFIG --- */
  14
  15 #define         UART16550_BAUD_2400             2400
  16 #define         UART16550_BAUD_4800             4800
  17 #define         UART16550_BAUD_9600             9600
  18 #define         UART16550_BAUD_19200            19200
  19 #define         UART16550_BAUD_38400            38400
  20 #define         UART16550_BAUD_57600            57600
  21 #define         UART16550_BAUD_115200           115200
  22
  23 #define         UART16550_PARITY_NONE           0
  24 #define         UART16550_PARITY_ODD            0x08
  25 #define         UART16550_PARITY_EVEN           0x18
  26 #define         UART16550_PARITY_MARK           0x28
  27 #define         UART16550_PARITY_SPACE          0x38
  28
  29 #define         UART16550_DATA_5BIT             0x0
  30 #define         UART16550_DATA_6BIT             0x1
  31 #define         UART16550_DATA_7BIT             0x2
  32 #define         UART16550_DATA_8BIT             0x3
  33
  34 #define         UART16550_STOP_1BIT             0x0
  35 #define         UART16550_STOP_2BIT             0x4
  36
  37 /* ----------------------------------------------------- */
  38
  39 /* === CONFIG === */
  40
  41 /* [stevel] we use the IT8712 serial port for kgdb */
  42 #define DEBUG_BASE  0xB40003F8  /* 8712 serial port 1 base address */
  43 #define MAX_BAUD    115200
  44
  45 /* === END OF CONFIG === */
  46
  47 /* register offset */
  48 #define         OFS_RCV_BUFFER          0
  49 #define         OFS_TRANS_HOLD          0
  50 #define         OFS_SEND_BUFFER         0
  51 #define         OFS_INTR_ENABLE         1
  52 #define         OFS_INTR_ID             2
  53 #define         OFS_DATA_FORMAT         3
  54 #define         OFS_LINE_CONTROL        3
  55 #define         OFS_MODEM_CONTROL       4
  56 #define         OFS_RS232_OUTPUT        4
  57 #define         OFS_LINE_STATUS         5
  58 #define         OFS_MODEM_STATUS        6
  59 #define         OFS_RS232_INPUT         6
  60 #define         OFS_SCRATCH_PAD         7
  61
  62 #define         OFS_DIVISOR_LSB         0
  63 #define         OFS_DIVISOR_MSB         1
  64
  65
  66 /* memory-mapped read/write of the port */
  67 #define UART16550_READ(y)    (*((volatile uint8*)(DEBUG_BASE + y)))
  68 #define UART16550_WRITE(y,z) ((*((volatile uint8*)(DEBUG_BASE + y))) = z)
  69
  70 void debugInit(uint32 baud, uint8 data, uint8 parity, uint8 stop)
  71 {
  72         /* disable interrupts */
  73         UART16550_WRITE(OFS_INTR_ENABLE, 0);
  74
  75         /* set up buad rate */
  76         {
  77                 uint32 divisor;
  78
  79                 /* set DIAB bit */
  80                 UART16550_WRITE(OFS_LINE_CONTROL, 0x80);
  81
  82                 /* set divisor */
  83                 divisor = MAX_BAUD / baud;
  84                 UART16550_WRITE(OFS_DIVISOR_LSB, divisor & 0xff);
  85                 UART16550_WRITE(OFS_DIVISOR_MSB, (divisor & 0xff00) >> 8);
  86
  87                 /* clear DIAB bit */
  88                 UART16550_WRITE(OFS_LINE_CONTROL, 0x0);
  89         }
  90
  91         /* set data format */
  92         UART16550_WRITE(OFS_DATA_FORMAT, data | parity | stop);
  93 }
  94
  95 static int remoteDebugInitialized = 0;
  96
  97 uint8 getDebugChar(void)
  98 {
  99         if (!remoteDebugInitialized) {
 100                 remoteDebugInitialized = 1;
 101                 debugInit(UART16550_BAUD_115200,
 102                           UART16550_DATA_8BIT,
 103                           UART16550_PARITY_NONE, UART16550_STOP_1BIT);
 104         }
 105
 106         while ((UART16550_READ(OFS_LINE_STATUS) & 0x1) == 0);
 107         return UART16550_READ(OFS_RCV_BUFFER);
 108 }
 109
 110
 111 int putDebugChar(uint8 byte)
 112 {
 113         if (!remoteDebugInitialized) {
 114                 remoteDebugInitialized = 1;
 115                 debugInit(UART16550_BAUD_115200,
 116                           UART16550_DATA_8BIT,
 117                           UART16550_PARITY_NONE, UART16550_STOP_1BIT);
 118         }
 119
 120         while ((UART16550_READ(OFS_LINE_STATUS) & 0x20) == 0);
 121         UART16550_WRITE(OFS_SEND_BUFFER, byte);
 122         return 1;
 123 }
 124
 125 #endif