uart_cpu_x86.c revision 331722 
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: stable/11/sys/dev/uart/uart_cpu_x86.c 331722 2018-03-29 02:50:57Z eadler $");
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
39bus_space_tag_t uart_bus_space_io = X86_BUS_SPACE_IO;
40bus_space_tag_t uart_bus_space_mem = X86_BUS_SPACE_MEM;
41
42int
43uart_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
49int
50uart_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