arch/mips/momentum/ocelot_c/dbg_io.c

   1 #include <linux/config.h>
   2
   3 #ifdef CONFIG_KGDB
   4
   5 #include <asm/serial.h> /* For the serial port location and base baud */
   6
   7 /* --- CONFIG --- */
   8
   9 typedef unsigned char uint8;
  10 typedef unsigned int uint32;
  11
  12 /* --- END OF CONFIG --- */
  13
  14 #define         UART16550_BAUD_2400             2400
  15 #define         UART16550_BAUD_4800             4800
  16 #define         UART16550_BAUD_9600             9600
  17 #define         UART16550_BAUD_19200            19200
  18 #define         UART16550_BAUD_38400            38400
  19 #define         UART16550_BAUD_57600            57600
  20 #define         UART16550_BAUD_115200           115200
  21
  22 #define         UART16550_PARITY_NONE           0
  23 #define         UART16550_PARITY_ODD            0x08
  24 #define         UART16550_PARITY_EVEN           0x18
  25 #define         UART16550_PARITY_MARK           0x28
  26 #define         UART16550_PARITY_SPACE          0x38
  27
  28 #define         UART16550_DATA_5BIT             0x0
  29 #define         UART16550_DATA_6BIT             0x1
  30 #define         UART16550_DATA_7BIT             0x2
  31 #define         UART16550_DATA_8BIT             0x3
  32
  33 #define         UART16550_STOP_1BIT             0x0
  34 #define         UART16550_STOP_2BIT             0x4
  35
  36 /* ----------------------------------------------------- */
  37
  38 /* === CONFIG === */
  39
  40 /* [jsun] we use the second serial port for kdb */
  41 #define         BASE                    OCELOT_SERIAL1_BASE
  42 #define         MAX_BAUD                OCELOT_BASE_BAUD
  43
  44 /* === END OF CONFIG === */
  45
  46 #define         REG_OFFSET              4
  47
  48 /* register offset */
  49 #define         OFS_RCV_BUFFER          0
  50 #define         OFS_TRANS_HOLD          0
  51 #define         OFS_SEND_BUFFER         0
  52 #define         OFS_INTR_ENABLE         (1*REG_OFFSET)
  53 #define         OFS_INTR_ID             (2*REG_OFFSET)
  54 #define         OFS_DATA_FORMAT         (3*REG_OFFSET)
  55 #define         OFS_LINE_CONTROL        (3*REG_OFFSET)
  56 #define         OFS_MODEM_CONTROL       (4*REG_OFFSET)
  57 #define         OFS_RS232_OUTPUT        (4*REG_OFFSET)
  58 #define         OFS_LINE_STATUS         (5*REG_OFFSET)
  59 #define         OFS_MODEM_STATUS        (6*REG_OFFSET)
  60 #define         OFS_RS232_INPUT         (6*REG_OFFSET)
  61 #define         OFS_SCRATCH_PAD         (7*REG_OFFSET)
  62
  63 #define         OFS_DIVISOR_LSB         (0*REG_OFFSET)
  64 #define         OFS_DIVISOR_MSB         (1*REG_OFFSET)
  65
  66
  67 /* memory-mapped read/write of the port */
  68 #define         UART16550_READ(y)    (*((volatile uint8*)(BASE + y)))
  69 #define         UART16550_WRITE(y, z)  ((*((volatile uint8*)(BASE + y))) = z)
  70
  71 void debugInit(uint32 baud, uint8 data, uint8 parity, uint8 stop)
  72 {
  73         /* disable interrupts */
  74         UART16550_WRITE(OFS_INTR_ENABLE, 0);
  75
  76         /* set up buad rate */
  77         {
  78                 uint32 divisor;
  79
  80                 /* set DIAB bit */
  81                 UART16550_WRITE(OFS_LINE_CONTROL, 0x80);
  82
  83                 /* set divisor */
  84                 divisor = MAX_BAUD / baud;
  85                 UART16550_WRITE(OFS_DIVISOR_LSB, divisor & 0xff);
  86                 UART16550_WRITE(OFS_DIVISOR_MSB, (divisor & 0xff00) >> 8);
  87
  88                 /* clear DIAB bit */
  89                 UART16550_WRITE(OFS_LINE_CONTROL, 0x0);
  90         }
  91
  92         /* set data format */
  93         UART16550_WRITE(OFS_DATA_FORMAT, data | parity | stop);
  94 }
  95
  96 static int remoteDebugInitialized = 0;
  97
  98 uint8 getDebugChar(void)
  99 {
 100         if (!remoteDebugInitialized) {
 101                 remoteDebugInitialized = 1;
 102                 debugInit(UART16550_BAUD_38400,
 103                           UART16550_DATA_8BIT,
 104                           UART16550_PARITY_NONE, UART16550_STOP_1BIT);
 105         }
 106
 107         while ((UART16550_READ(OFS_LINE_STATUS) & 0x1) == 0);
 108         return UART16550_READ(OFS_RCV_BUFFER);
 109 }
 110
 111
 112 int putDebugChar(uint8 byte)
 113 {
 114         if (!remoteDebugInitialized) {
 115                 remoteDebugInitialized = 1;
 116                 debugInit(UART16550_BAUD_38400,
 117                           UART16550_DATA_8BIT,
 118                           UART16550_PARITY_NONE, UART16550_STOP_1BIT);
 119         }
 120
 121         while ((UART16550_READ(OFS_LINE_STATUS) & 0x20) == 0);
 122         UART16550_WRITE(OFS_SEND_BUFFER, byte);
 123         return 1;
 124 }
 125
 126 #endif