1 #include <linux/config.h>
2 
3 #if defined(CONFIG_REMOTE_DEBUG)
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 
debugInit(uint32 baud,uint8 data,uint8 parity,uint8 stop)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 
getDebugChar(void)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 
putDebugChar(uint8 byte)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
127