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review.evervolv.com / android_kernel_oneplus_msm8996 / b920de1b77b72ca9432ac3f97edb26541e65e5dd / . / arch / mn10300 / kernel / gdb-io-serial.c
blob: 9a6d4e8ebe7396f058ccc740d48dfc3a0e14f979 [file] [log] [blame]
David Howellsb920de12008-02-08 04:19:31 -0800[diff] [blame^]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>
25#include <asm/unit/serial.h>
26
27/*
28 * initialise the GDB stub
29 */
30void 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 */
69void 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 */
86int 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;
102 if (ix == gdbstub_rx_inp) {
103 if (nonblock)
104 return -EAGAIN;
105#ifdef CONFIG_MN10300_WD_TIMER
106 watchdog_alert_counter = 0;
107#endif /* CONFIG_MN10300_WD_TIMER */
108 goto try_again;
109 }
110
111 ch = gdbstub_rx_buffer[ix++];
112 st = gdbstub_rx_buffer[ix++];
113 gdbstub_rx_outp = ix & 0x00000fff;
114
115 if (st & UART_LSR_BI) {
116 gdbstub_proto("### GDB Rx Break Detected ###\n");
117 return -EINTR;
118 } else if (st & (UART_LSR_FE | UART_LSR_OE | UART_LSR_PE)) {
119 gdbstub_proto("### GDB Rx Error (st=%02x) ###\n", st);
120 return -EIO;
121 } else {
122 gdbstub_proto("### GDB Rx %02x (st=%02x) ###\n", ch, st);
123 *_ch = ch & 0x7f;
124 return 0;
125 }
126}
127
128/*
129 * send a character to the debugger
130 */
131void gdbstub_io_tx_char(unsigned char ch)
132{
133 FLOWCTL_SET(DTR);
134 LSR_WAIT_FOR(THRE);
135 /* FLOWCTL_WAIT_FOR(CTS); */
136
137 if (ch == 0x0a) {
138 GDBPORT_SERIAL_TX = 0x0d;
139 LSR_WAIT_FOR(THRE);
140 /* FLOWCTL_WAIT_FOR(CTS); */
141 }
142 GDBPORT_SERIAL_TX = ch;
143
144 FLOWCTL_CLEAR(DTR);
145}
146
147/*
148 * send a character to the debugger
149 */
150void gdbstub_io_tx_flush(void)
151{
152 LSR_WAIT_FOR(TEMT);
153 LSR_WAIT_FOR(THRE);
154 FLOWCTL_CLEAR(DTR);
155}