Commit | Line | Data |
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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> |
368dd5ac | 26 | #include <asm/smp.h> |
b920de1b DH |
27 | |
28 | /* | |
29 | * initialise the GDB stub | |
30 | */ | |
31 | void gdbstub_io_init(void) | |
32 | { | |
33 | u16 tmp; | |
34 | ||
35 | /* set up the serial port */ | |
36 | GDBPORT_SERIAL_LCR = UART_LCR_WLEN8; /* 1N8 */ | |
37 | GDBPORT_SERIAL_FCR = (UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | | |
38 | UART_FCR_CLEAR_XMIT); | |
39 | ||
40 | FLOWCTL_CLEAR(DTR); | |
41 | FLOWCTL_SET(RTS); | |
42 | ||
43 | gdbstub_io_set_baud(115200); | |
44 | ||
45 | /* we want to get serial receive interrupts */ | |
46 | XIRQxICR(GDBPORT_SERIAL_IRQ) = 0; | |
47 | tmp = XIRQxICR(GDBPORT_SERIAL_IRQ); | |
48 | ||
368dd5ac | 49 | #if CONFIG_GDBSTUB_IRQ_LEVEL == 0 |
b920de1b | 50 | IVAR0 = EXCEP_IRQ_LEVEL0; |
368dd5ac AT |
51 | #elif CONFIG_GDBSTUB_IRQ_LEVEL == 1 |
52 | IVAR1 = EXCEP_IRQ_LEVEL1; | |
53 | #elif CONFIG_GDBSTUB_IRQ_LEVEL == 2 | |
54 | IVAR2 = EXCEP_IRQ_LEVEL2; | |
55 | #elif CONFIG_GDBSTUB_IRQ_LEVEL == 3 | |
56 | IVAR3 = EXCEP_IRQ_LEVEL3; | |
57 | #elif CONFIG_GDBSTUB_IRQ_LEVEL == 4 | |
58 | IVAR4 = EXCEP_IRQ_LEVEL4; | |
59 | #elif CONFIG_GDBSTUB_IRQ_LEVEL == 5 | |
60 | IVAR5 = EXCEP_IRQ_LEVEL5; | |
61 | #else | |
62 | #error "Unknown irq level for gdbstub." | |
63 | #endif | |
64 | ||
65 | set_intr_stub(NUM2EXCEP_IRQ_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL), | |
66 | gdbstub_io_rx_handler); | |
b920de1b DH |
67 | |
68 | XIRQxICR(GDBPORT_SERIAL_IRQ) &= ~GxICR_REQUEST; | |
368dd5ac AT |
69 | XIRQxICR(GDBPORT_SERIAL_IRQ) = |
70 | GxICR_ENABLE | NUM2GxICR_LEVEL(CONFIG_GDBSTUB_IRQ_LEVEL); | |
b920de1b DH |
71 | tmp = XIRQxICR(GDBPORT_SERIAL_IRQ); |
72 | ||
73 | GDBPORT_SERIAL_IER = UART_IER_RDI | UART_IER_RLSI; | |
74 | ||
75 | /* permit level 0 IRQs to take place */ | |
368dd5ac | 76 | local_change_intr_mask_level(NUM2EPSW_IM(CONFIG_GDBSTUB_IRQ_LEVEL + 1)); |
b920de1b DH |
77 | } |
78 | ||
79 | /* | |
80 | * set up the GDB stub serial port baud rate timers | |
81 | */ | |
82 | void gdbstub_io_set_baud(unsigned baud) | |
83 | { | |
84 | unsigned value; | |
85 | u8 lcr; | |
86 | ||
87 | value = 18432000 / 16 / baud; | |
88 | ||
89 | lcr = GDBPORT_SERIAL_LCR; | |
90 | GDBPORT_SERIAL_LCR |= UART_LCR_DLAB; | |
91 | GDBPORT_SERIAL_DLL = value & 0xff; | |
92 | GDBPORT_SERIAL_DLM = (value >> 8) & 0xff; | |
93 | GDBPORT_SERIAL_LCR = lcr; | |
94 | } | |
95 | ||
96 | /* | |
97 | * wait for a character to come from the debugger | |
98 | */ | |
99 | int gdbstub_io_rx_char(unsigned char *_ch, int nonblock) | |
100 | { | |
101 | unsigned ix; | |
102 | u8 ch, st; | |
368dd5ac AT |
103 | #if defined(CONFIG_MN10300_WD_TIMER) |
104 | int cpu; | |
105 | #endif | |
b920de1b DH |
106 | |
107 | *_ch = 0xff; | |
108 | ||
109 | if (gdbstub_rx_unget) { | |
110 | *_ch = gdbstub_rx_unget; | |
111 | gdbstub_rx_unget = 0; | |
112 | return 0; | |
113 | } | |
114 | ||
115 | try_again: | |
116 | /* pull chars out of the buffer */ | |
117 | ix = gdbstub_rx_outp; | |
004b50f4 | 118 | barrier(); |
b920de1b DH |
119 | if (ix == gdbstub_rx_inp) { |
120 | if (nonblock) | |
121 | return -EAGAIN; | |
122 | #ifdef CONFIG_MN10300_WD_TIMER | |
368dd5ac AT |
123 | for (cpu = 0; cpu < NR_CPUS; cpu++) |
124 | watchdog_alert_counter[cpu] = 0; | |
125 | #endif | |
b920de1b DH |
126 | goto try_again; |
127 | } | |
128 | ||
129 | ch = gdbstub_rx_buffer[ix++]; | |
130 | st = gdbstub_rx_buffer[ix++]; | |
004b50f4 | 131 | barrier(); |
b920de1b DH |
132 | gdbstub_rx_outp = ix & 0x00000fff; |
133 | ||
134 | if (st & UART_LSR_BI) { | |
135 | gdbstub_proto("### GDB Rx Break Detected ###\n"); | |
136 | return -EINTR; | |
137 | } else if (st & (UART_LSR_FE | UART_LSR_OE | UART_LSR_PE)) { | |
138 | gdbstub_proto("### GDB Rx Error (st=%02x) ###\n", st); | |
139 | return -EIO; | |
140 | } else { | |
141 | gdbstub_proto("### GDB Rx %02x (st=%02x) ###\n", ch, st); | |
142 | *_ch = ch & 0x7f; | |
143 | return 0; | |
144 | } | |
145 | } | |
146 | ||
147 | /* | |
148 | * send a character to the debugger | |
149 | */ | |
150 | void gdbstub_io_tx_char(unsigned char ch) | |
151 | { | |
152 | FLOWCTL_SET(DTR); | |
153 | LSR_WAIT_FOR(THRE); | |
154 | /* FLOWCTL_WAIT_FOR(CTS); */ | |
155 | ||
156 | if (ch == 0x0a) { | |
157 | GDBPORT_SERIAL_TX = 0x0d; | |
158 | LSR_WAIT_FOR(THRE); | |
159 | /* FLOWCTL_WAIT_FOR(CTS); */ | |
160 | } | |
161 | GDBPORT_SERIAL_TX = ch; | |
162 | ||
163 | FLOWCTL_CLEAR(DTR); | |
164 | } | |
165 | ||
166 | /* | |
167 | * send a character to the debugger | |
168 | */ | |
169 | void gdbstub_io_tx_flush(void) | |
170 | { | |
171 | LSR_WAIT_FOR(TEMT); | |
172 | LSR_WAIT_FOR(THRE); | |
173 | FLOWCTL_CLEAR(DTR); | |
174 | } |