xref: /freebsd/sys/dev/uart/uart_cpu_x86.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2003, 2004 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "opt_acpi.h"
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 
35 #include <machine/bus.h>
36 
37 #include <dev/uart/uart.h>
38 #include <dev/uart/uart_cpu.h>
39 #include <dev/uart/uart_cpu_acpi.h>
40 
41 bus_space_tag_t uart_bus_space_io = X86_BUS_SPACE_IO;
42 bus_space_tag_t uart_bus_space_mem = X86_BUS_SPACE_MEM;
43 
44 extern int late_console;
45 
46 int
47 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
48 {
49 
50 	return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
51 }
52 
53 int
54 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
55 {
56 	struct uart_class *class;
57 	unsigned int i, ivar;
58 
59 	class = &uart_ns8250_class;
60 	if (class == NULL)
61 		return (ENXIO);
62 
63 	/* Check the environment. */
64 	if (uart_getenv(devtype, di, class) == 0)
65 		return (0);
66 
67 #ifdef DEV_ACPI
68 	/*
69 	 * Check if SPCR can tell us what console to use.  If running with
70 	 * !late_console, we haven't set up our own page tables yet, so we
71 	 * can't map ACPI tables to look at them.
72 	 */
73 	if (late_console && uart_cpu_acpi_spcr(devtype, di) == 0)
74 		return (0);
75 #endif
76 
77 	/*
78 	 * Scan the hints. We only try units 0 to 3 (inclusive). This
79 	 * covers the ISA legacy where 4 UARTs had their resources
80 	 * predefined.
81 	 */
82 	for (i = 0; i < 4; i++) {
83 		if (resource_int_value("uart", i, "flags", &ivar))
84 			continue;
85 		if (devtype == UART_DEV_CONSOLE && !UART_FLAGS_CONSOLE(ivar))
86 			continue;
87 		if (devtype == UART_DEV_DBGPORT && !UART_FLAGS_DBGPORT(ivar))
88 			continue;
89 		/*
90 		 * We have a possible device. Make sure it's enabled and
91 		 * that we have an I/O port.
92 		 */
93 		if (resource_int_value("uart", i, "disabled", &ivar) == 0 &&
94 		    ivar != 0)
95 			continue;
96 		if (resource_int_value("uart", i, "port", &ivar) != 0 ||
97 		    ivar == 0)
98 			continue;
99 		/*
100 		 * Got it. Fill in the instance and return it. We only have
101 		 * ns8250 and successors on i386.
102 		 */
103 		di->ops = uart_getops(class);
104 		di->bas.chan = 0;
105 		di->bas.bst = uart_bus_space_io;
106 		if (bus_space_map(di->bas.bst, ivar, uart_getrange(class), 0,
107 		    &di->bas.bsh) != 0)
108 			continue;
109 		di->bas.regshft = 0;
110 		di->bas.rclk = 0;
111 		if (resource_int_value("uart", i, "baud", &ivar) != 0)
112 			ivar = 0;
113 		di->baudrate = ivar;
114 		di->databits = 8;
115 		di->stopbits = 1;
116 		di->parity = UART_PARITY_NONE;
117 		return (0);
118 	}
119 
120 	return (ENXIO);
121 }
122