arch/mips/momentum/ocelot_g/dbg_io.c

   1
   2 #include <asm/serial.h> /* For the serial port location and base baud */
   3
   4 /* --- CONFIG --- */
   5
   6 typedef unsigned char uint8;
   7 typedef unsigned int uint32;
   8
   9 /* --- END OF CONFIG --- */
  10
  11 #define         UART16550_BAUD_2400             2400
  12 #define         UART16550_BAUD_4800             4800
  13 #define         UART16550_BAUD_9600             9600
  14 #define         UART16550_BAUD_19200            19200
  15 #define         UART16550_BAUD_38400            38400
  16 #define         UART16550_BAUD_57600            57600
  17 #define         UART16550_BAUD_115200           115200
  18
  19 #define         UART16550_PARITY_NONE           0
  20 #define         UART16550_PARITY_ODD            0x08
  21 #define         UART16550_PARITY_EVEN           0x18
  22 #define         UART16550_PARITY_MARK           0x28
  23 #define         UART16550_PARITY_SPACE          0x38
  24
  25 #define         UART16550_DATA_5BIT             0x0
  26 #define         UART16550_DATA_6BIT             0x1
  27 #define         UART16550_DATA_7BIT             0x2
  28 #define         UART16550_DATA_8BIT             0x3
  29
  30 #define         UART16550_STOP_1BIT             0x0
  31 #define         UART16550_STOP_2BIT             0x4
  32
  33 /* ----------------------------------------------------- */
  34
  35 /* === CONFIG === */
  36
  37 /* [jsun] we use the second serial port for kdb */
  38 #define         BASE                    OCELOT_SERIAL1_BASE
  39 #define         MAX_BAUD                OCELOT_BASE_BAUD
  40
  41 /* === END OF CONFIG === */
  42
  43 #define         REG_OFFSET              4
  44
  45 /* register offset */
  46 #define         OFS_RCV_BUFFER          0
  47 #define         OFS_TRANS_HOLD          0
  48 #define         OFS_SEND_BUFFER         0
  49 #define         OFS_INTR_ENABLE         (1*REG_OFFSET)
  50 #define         OFS_INTR_ID             (2*REG_OFFSET)
  51 #define         OFS_DATA_FORMAT         (3*REG_OFFSET)
  52 #define         OFS_LINE_CONTROL        (3*REG_OFFSET)
  53 #define         OFS_MODEM_CONTROL       (4*REG_OFFSET)
  54 #define         OFS_RS232_OUTPUT        (4*REG_OFFSET)
  55 #define         OFS_LINE_STATUS         (5*REG_OFFSET)
  56 #define         OFS_MODEM_STATUS        (6*REG_OFFSET)
  57 #define         OFS_RS232_INPUT         (6*REG_OFFSET)
  58 #define         OFS_SCRATCH_PAD         (7*REG_OFFSET)
  59
  60 #define         OFS_DIVISOR_LSB         (0*REG_OFFSET)
  61 #define         OFS_DIVISOR_MSB         (1*REG_OFFSET)
  62
  63
  64 /* memory-mapped read/write of the port */
  65 #define         UART16550_READ(y)    (*((volatile uint8*)(BASE + y)))
  66 #define         UART16550_WRITE(y, z)  ((*((volatile uint8*)(BASE + y))) = z)
  67
  68 void debugInit(uint32 baud, uint8 data, uint8 parity, uint8 stop)
  69 {
  70         /* disable interrupts */
  71         UART16550_WRITE(OFS_INTR_ENABLE, 0);
  72
  73         /* set up baud rate */
  74         {
  75                 uint32 divisor;
  76
  77                 /* set DIAB bit */
  78                 UART16550_WRITE(OFS_LINE_CONTROL, 0x80);
  79
  80                 /* set divisor */
  81                 divisor = MAX_BAUD / baud;
  82                 UART16550_WRITE(OFS_DIVISOR_LSB, divisor & 0xff);
  83                 UART16550_WRITE(OFS_DIVISOR_MSB, (divisor & 0xff00) >> 8);
  84
  85                 /* clear DIAB bit */
  86                 UART16550_WRITE(OFS_LINE_CONTROL, 0x0);
  87         }
  88
  89         /* set data format */
  90         UART16550_WRITE(OFS_DATA_FORMAT, data | parity | stop);
  91 }
  92
  93 static int remoteDebugInitialized = 0;
  94
  95 uint8 getDebugChar(void)
  96 {
  97         if (!remoteDebugInitialized) {
  98                 remoteDebugInitialized = 1;
  99                 debugInit(UART16550_BAUD_38400,
 100                           UART16550_DATA_8BIT,
 101                           UART16550_PARITY_NONE, UART16550_STOP_1BIT);
 102         }
 103
 104         while ((UART16550_READ(OFS_LINE_STATUS) & 0x1) == 0);
 105         return UART16550_READ(OFS_RCV_BUFFER);
 106 }
 107
 108
 109 int putDebugChar(uint8 byte)
 110 {
 111         if (!remoteDebugInitialized) {
 112                 remoteDebugInitialized = 1;
 113                 debugInit(UART16550_BAUD_38400,
 114                           UART16550_DATA_8BIT,
 115                           UART16550_PARITY_NONE, UART16550_STOP_1BIT);
 116         }
 117
 118         while ((UART16550_READ(OFS_LINE_STATUS) & 0x20) == 0);
 119         UART16550_WRITE(OFS_SEND_BUFFER, byte);
 120         return 1;
 121 }