[init] Show startup and shutdown function names in debug messages
[ipxe.git] / src / core / serial.c
1 /*
2 * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 /** @file
27 *
28 * Serial console
29 *
30 */
31
32 #include <stddef.h>
33 #include <string.h>
34 #include <ipxe/init.h>
35 #include <ipxe/uart.h>
36 #include <ipxe/console.h>
37 #include <ipxe/serial.h>
38 #include <config/console.h>
39 #include <config/serial.h>
40
41 /* Set default console usage if applicable */
42 #if ! ( defined ( CONSOLE_SERIAL ) && CONSOLE_EXPLICIT ( CONSOLE_SERIAL ) )
43 #undef CONSOLE_SERIAL
44 #define CONSOLE_SERIAL ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
45 #endif
46
47 /* UART port number */
48 #ifdef COMCONSOLE
49 #define CONSOLE_PORT COMCONSOLE
50 #else
51 #define CONSOLE_PORT 0
52 #endif
53
54 /* UART baud rate */
55 #ifdef COMPRESERVE
56 #define CONSOLE_BAUD 0
57 #else
58 #define CONSOLE_BAUD COMSPEED
59 #endif
60
61 /* UART line control register value */
62 #ifdef COMPRESERVE
63 #define CONSOLE_LCR 0
64 #else
65 #define CONSOLE_LCR UART_LCR_WPS ( COMDATA, COMPARITY, COMSTOP )
66 #endif
67
68 /** Serial console UART */
69 struct uart serial_console;
70
71 /**
72 * Print a character to serial console
73 *
74 * @v character Character to be printed
75 */
76 static void serial_putchar ( int character ) {
77
78 /* Do nothing if we have no UART */
79 if ( ! serial_console.base )
80 return;
81
82 /* Transmit character */
83 uart_transmit ( &serial_console, character );
84 }
85
86 /**
87 * Get character from serial console
88 *
89 * @ret character Character read from console
90 */
91 static int serial_getchar ( void ) {
92 uint8_t data;
93
94 /* Do nothing if we have no UART */
95 if ( ! serial_console.base )
96 return 0;
97
98 /* Wait for data to be ready */
99 while ( ! uart_data_ready ( &serial_console ) ) {}
100
101 /* Receive data */
102 data = uart_receive ( &serial_console );
103
104 /* Strip any high bit and convert DEL to backspace */
105 data &= 0x7f;
106 if ( data == 0x7f )
107 data = 0x08;
108
109 return data;
110 }
111
112 /**
113 * Check for character ready to read from serial console
114 *
115 * @ret True Character available to read
116 * @ret False No character available to read
117 */
118 static int serial_iskey ( void ) {
119
120 /* Do nothing if we have no UART */
121 if ( ! serial_console.base )
122 return 0;
123
124 /* Check UART */
125 return uart_data_ready ( &serial_console );
126 }
127
128 /** Serial console */
129 struct console_driver serial_console_driver __console_driver = {
130 .putchar = serial_putchar,
131 .getchar = serial_getchar,
132 .iskey = serial_iskey,
133 .usage = CONSOLE_SERIAL,
134 };
135
136 /** Initialise serial console */
137 static void serial_init ( void ) {
138 int rc;
139
140 /* Do nothing if we have no default port */
141 if ( ! CONSOLE_PORT )
142 return;
143
144 /* Select UART */
145 if ( ( rc = uart_select ( &serial_console, CONSOLE_PORT ) ) != 0 ) {
146 DBG ( "Could not select UART %d: %s\n",
147 CONSOLE_PORT, strerror ( rc ) );
148 return;
149 }
150
151 /* Initialise UART */
152 if ( ( rc = uart_init ( &serial_console, CONSOLE_BAUD,
153 CONSOLE_LCR ) ) != 0 ) {
154 DBG ( "Could not initialise UART %d baud %d LCR %#02x: %s\n",
155 CONSOLE_PORT, CONSOLE_BAUD, CONSOLE_LCR, strerror ( rc ));
156 return;
157 }
158 }
159
160 /**
161 * Shut down serial console
162 *
163 * @v flags Shutdown flags
164 */
165 static void serial_shutdown ( int flags __unused ) {
166
167 /* Do nothing if we have no UART */
168 if ( ! serial_console.base )
169 return;
170
171 /* Flush any pending output */
172 uart_flush ( &serial_console );
173
174 /* Leave console enabled; it's still usable */
175 }
176
177 /** Serial console initialisation function */
178 struct init_fn serial_console_init_fn __init_fn ( INIT_CONSOLE ) = {
179 .initialise = serial_init,
180 };
181
182 /** Serial console startup function */
183 struct startup_fn serial_startup_fn __startup_fn ( STARTUP_EARLY ) = {
184 .name = "serial",
185 .shutdown = serial_shutdown,
186 };