xref: /freebsd/sys/dev/uart/uart_cpu_x86.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
1 /*-
2  * Copyright (c) 2003, 2004 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 
34 #include <machine/bus.h>
35 
36 #include <dev/uart/uart.h>
37 #include <dev/uart/uart_cpu.h>
38 
39 bus_space_tag_t uart_bus_space_io = X86_BUS_SPACE_IO;
40 bus_space_tag_t uart_bus_space_mem = X86_BUS_SPACE_MEM;
41 
42 int
43 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
44 {
45 
46 	return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
47 }
48 
49 int
50 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
51 {
52 	struct uart_class *class;
53 	unsigned int i, ivar;
54 
55 	class = &uart_ns8250_class;
56 	if (class == NULL)
57 		return (ENXIO);
58 
59 	/* Check the environment. */
60 	if (uart_getenv(devtype, di, class) == 0)
61 		return (0);
62 
63 	/*
64 	 * Scan the hints. We only try units 0 to 3 (inclusive). This
65 	 * covers the ISA legacy where 4 UARTs had their resources
66 	 * predefined.
67 	 */
68 	for (i = 0; i < 4; i++) {
69 		if (resource_int_value("uart", i, "flags", &ivar))
70 			continue;
71 		if (devtype == UART_DEV_CONSOLE && !UART_FLAGS_CONSOLE(ivar))
72 			continue;
73 		if (devtype == UART_DEV_DBGPORT && !UART_FLAGS_DBGPORT(ivar))
74 			continue;
75 		/*
76 		 * We have a possible device. Make sure it's enabled and
77 		 * that we have an I/O port.
78 		 */
79 		if (resource_int_value("uart", i, "disabled", &ivar) == 0 &&
80 		    ivar != 0)
81 			continue;
82 		if (resource_int_value("uart", i, "port", &ivar) != 0 ||
83 		    ivar == 0)
84 			continue;
85 		/*
86 		 * Got it. Fill in the instance and return it. We only have
87 		 * ns8250 and successors on i386.
88 		 */
89 		di->ops = uart_getops(class);
90 		di->bas.chan = 0;
91 		di->bas.bst = uart_bus_space_io;
92 		if (bus_space_map(di->bas.bst, ivar, uart_getrange(class), 0,
93 		    &di->bas.bsh) != 0)
94 			continue;
95 		di->bas.regshft = 0;
96 		di->bas.rclk = 0;
97 		if (resource_int_value("uart", i, "baud", &ivar) != 0)
98 			ivar = 0;
99 		di->baudrate = ivar;
100 		di->databits = 8;
101 		di->stopbits = 1;
102 		di->parity = UART_PARITY_NONE;
103 		return (0);
104 	}
105 
106 	return (ENXIO);
107 }
108