Commit | Line | Data |
---|---|---|
b920de1b DH |
1 | /* 16550 serial driver for gdbstub I/O |
2 | * | |
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public Licence | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the Licence, or (at your option) any later version. | |
10 | */ | |
11 | #include <linux/string.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/signal.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/console.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/nmi.h> | |
19 | ||
20 | #include <asm/pgtable.h> | |
21 | #include <asm/system.h> | |
22 | #include <asm/gdb-stub.h> | |
23 | #include <asm/exceptions.h> | |
24 | #include <asm/serial-regs.h> | |
2f2a2132 | 25 | #include <unit/serial.h> |
b920de1b DH |
26 | |
27 | /* | |
28 | * initialise the GDB stub | |
29 | */ | |
30 | void gdbstub_io_init(void) | |
31 | { | |
32 | u16 tmp; | |
33 | ||
34 | /* set up the serial port */ | |
35 | GDBPORT_SERIAL_LCR = UART_LCR_WLEN8; /* 1N8 */ | |
36 | GDBPORT_SERIAL_FCR = (UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | | |
37 | UART_FCR_CLEAR_XMIT); | |
38 | ||
39 | FLOWCTL_CLEAR(DTR); | |
40 | FLOWCTL_SET(RTS); | |
41 | ||
42 | gdbstub_io_set_baud(115200); | |
43 | ||
44 | /* we want to get serial receive interrupts */ | |
45 | XIRQxICR(GDBPORT_SERIAL_IRQ) = 0; | |
46 | tmp = XIRQxICR(GDBPORT_SERIAL_IRQ); | |
47 | ||
48 | IVAR0 = EXCEP_IRQ_LEVEL0; | |
49 | set_intr_stub(EXCEP_IRQ_LEVEL0, gdbstub_io_rx_handler); | |
50 | ||
51 | XIRQxICR(GDBPORT_SERIAL_IRQ) &= ~GxICR_REQUEST; | |
52 | XIRQxICR(GDBPORT_SERIAL_IRQ) = GxICR_ENABLE | GxICR_LEVEL_0; | |
53 | tmp = XIRQxICR(GDBPORT_SERIAL_IRQ); | |
54 | ||
55 | GDBPORT_SERIAL_IER = UART_IER_RDI | UART_IER_RLSI; | |
56 | ||
57 | /* permit level 0 IRQs to take place */ | |
58 | asm volatile( | |
59 | " and %0,epsw \n" | |
60 | " or %1,epsw \n" | |
61 | : | |
62 | : "i"(~EPSW_IM), "i"(EPSW_IE | EPSW_IM_1) | |
63 | ); | |
64 | } | |
65 | ||
66 | /* | |
67 | * set up the GDB stub serial port baud rate timers | |
68 | */ | |
69 | void gdbstub_io_set_baud(unsigned baud) | |
70 | { | |
71 | unsigned value; | |
72 | u8 lcr; | |
73 | ||
74 | value = 18432000 / 16 / baud; | |
75 | ||
76 | lcr = GDBPORT_SERIAL_LCR; | |
77 | GDBPORT_SERIAL_LCR |= UART_LCR_DLAB; | |
78 | GDBPORT_SERIAL_DLL = value & 0xff; | |
79 | GDBPORT_SERIAL_DLM = (value >> 8) & 0xff; | |
80 | GDBPORT_SERIAL_LCR = lcr; | |
81 | } | |
82 | ||
83 | /* | |
84 | * wait for a character to come from the debugger | |
85 | */ | |
86 | int gdbstub_io_rx_char(unsigned char *_ch, int nonblock) | |
87 | { | |
88 | unsigned ix; | |
89 | u8 ch, st; | |
90 | ||
91 | *_ch = 0xff; | |
92 | ||
93 | if (gdbstub_rx_unget) { | |
94 | *_ch = gdbstub_rx_unget; | |
95 | gdbstub_rx_unget = 0; | |
96 | return 0; | |
97 | } | |
98 | ||
99 | try_again: | |
100 | /* pull chars out of the buffer */ | |
101 | ix = gdbstub_rx_outp; | |
004b50f4 | 102 | barrier(); |
b920de1b DH |
103 | if (ix == gdbstub_rx_inp) { |
104 | if (nonblock) | |
105 | return -EAGAIN; | |
106 | #ifdef CONFIG_MN10300_WD_TIMER | |
107 | watchdog_alert_counter = 0; | |
108 | #endif /* CONFIG_MN10300_WD_TIMER */ | |
109 | goto try_again; | |
110 | } | |
111 | ||
112 | ch = gdbstub_rx_buffer[ix++]; | |
113 | st = gdbstub_rx_buffer[ix++]; | |
004b50f4 | 114 | barrier(); |
b920de1b DH |
115 | gdbstub_rx_outp = ix & 0x00000fff; |
116 | ||
117 | if (st & UART_LSR_BI) { | |
118 | gdbstub_proto("### GDB Rx Break Detected ###\n"); | |
119 | return -EINTR; | |
120 | } else if (st & (UART_LSR_FE | UART_LSR_OE | UART_LSR_PE)) { | |
121 | gdbstub_proto("### GDB Rx Error (st=%02x) ###\n", st); | |
122 | return -EIO; | |
123 | } else { | |
124 | gdbstub_proto("### GDB Rx %02x (st=%02x) ###\n", ch, st); | |
125 | *_ch = ch & 0x7f; | |
126 | return 0; | |
127 | } | |
128 | } | |
129 | ||
130 | /* | |
131 | * send a character to the debugger | |
132 | */ | |
133 | void gdbstub_io_tx_char(unsigned char ch) | |
134 | { | |
135 | FLOWCTL_SET(DTR); | |
136 | LSR_WAIT_FOR(THRE); | |
137 | /* FLOWCTL_WAIT_FOR(CTS); */ | |
138 | ||
139 | if (ch == 0x0a) { | |
140 | GDBPORT_SERIAL_TX = 0x0d; | |
141 | LSR_WAIT_FOR(THRE); | |
142 | /* FLOWCTL_WAIT_FOR(CTS); */ | |
143 | } | |
144 | GDBPORT_SERIAL_TX = ch; | |
145 | ||
146 | FLOWCTL_CLEAR(DTR); | |
147 | } | |
148 | ||
149 | /* | |
150 | * send a character to the debugger | |
151 | */ | |
152 | void gdbstub_io_tx_flush(void) | |
153 | { | |
154 | LSR_WAIT_FOR(TEMT); | |
155 | LSR_WAIT_FOR(THRE); | |
156 | FLOWCTL_CLEAR(DTR); | |
157 | } |