uart_cpu_fdt.c revision 265998 
1/*-
2 * Copyright (c) 2009-2010 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Semihalf under sponsorship from
6 * the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
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 AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: stable/10/sys/dev/uart/uart_cpu_fdt.c 265998 2014-05-14 01:16:05Z ian $");
32
33#include "opt_platform.h"
34
35#include <sys/param.h>
36#include <sys/bus.h>
37#include <sys/kernel.h>
38#include <sys/module.h>
39#include <sys/systm.h>
40
41#include <vm/vm.h>
42#include <vm/pmap.h>
43
44#include <machine/bus.h>
45#include <machine/fdt.h>
46
47#include <dev/fdt/fdt_common.h>
48#include <dev/ofw/ofw_bus.h>
49#include <dev/ofw/ofw_bus_subr.h>
50#include <dev/uart/uart.h>
51#include <dev/uart/uart_bus.h>
52#include <dev/uart/uart_cpu.h>
53
54/*
55 * UART console routines.
56 */
57bus_space_tag_t uart_bus_space_io;
58bus_space_tag_t uart_bus_space_mem;
59
60static int
61uart_fdt_get_clock(phandle_t node, pcell_t *cell)
62{
63	pcell_t clock;
64
65	if ((OF_getprop(node, "clock-frequency", &clock,
66	    sizeof(clock))) <= 0)
67		return (ENXIO);
68
69	if (clock == 0)
70		/* Try to retrieve parent 'bus-frequency' */
71		/* XXX this should go to simple-bus fixup or so */
72		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
73		    sizeof(clock))) <= 0)
74			clock = 0;
75
76	*cell = fdt32_to_cpu(clock);
77	return (0);
78}
79
80static int
81uart_fdt_get_shift(phandle_t node, pcell_t *cell)
82{
83	pcell_t shift;
84
85	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
86		shift = 0;
87	*cell = fdt32_to_cpu(shift);
88	return (0);
89}
90
91int
92uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
93{
94
95	if (b1->bst != b2->bst)
96		return (0);
97	if (pmap_kextract(b1->bsh) == 0)
98		return (0);
99	if (pmap_kextract(b2->bsh) == 0)
100		return (0);
101	return ((pmap_kextract(b1->bsh) == pmap_kextract(b2->bsh)) ? 1 : 0);
102}
103
104static int
105phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
106{
107	char buf[64];
108
109	if (OF_getprop(chosen, name, buf, sizeof(buf)) <= 0)
110		return (ENXIO);
111	if ((*node = OF_finddevice(buf)) == -1)
112		return (ENXIO);
113
114	return (0);
115}
116
117int
118uart_cpu_getdev(int devtype, struct uart_devinfo *di)
119{
120	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
121	    "stdin-path", "stdin", NULL};
122	const char **name;
123	const struct ofw_compat_data *cd;
124	struct uart_class *class;
125	phandle_t node, chosen;
126	pcell_t shift, br, rclk;
127	u_long start, size, pbase, psize;
128	int err;
129
130	uart_bus_space_mem = fdtbus_bs_tag;
131	uart_bus_space_io = NULL;
132
133	/* Allow overriding the FDT using the environment. */
134	class = &uart_ns8250_class;
135	err = uart_getenv(devtype, di, class);
136	if (!err)
137		return (0);
138
139	if (devtype != UART_DEV_CONSOLE)
140		return (ENXIO);
141
142	/*
143	 * Retrieve /chosen/std{in,out}.
144	 */
145	node = -1;
146	if ((chosen = OF_finddevice("/chosen")) != -1) {
147		for (name = propnames; *name != NULL; name++) {
148			if (phandle_chosen_propdev(chosen, *name, &node) == 0)
149				break;
150		}
151	}
152	if (chosen == -1 || *name == NULL)
153		node = OF_finddevice("serial0"); /* Last ditch */
154
155	if (node == -1) /* Can't find anything */
156		return (ENXIO);
157
158	/*
159	 * Retrieve serial attributes.
160	 */
161	uart_fdt_get_shift(node, &shift);
162
163	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
164		br = 0;
165	br = fdt32_to_cpu(br);
166
167	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
168		return (err);
169	/*
170	 * Finalize configuration.
171	 */
172	for (cd = uart_fdt_compat_data; cd->ocd_str != NULL; ++cd) {
173		if (fdt_is_compatible(node, cd->ocd_str))
174			break;
175	}
176	if (cd->ocd_str == NULL)
177		return (ENXIO);
178	class = (struct uart_class *)cd->ocd_data;
179
180	di->bas.chan = 0;
181	di->bas.regshft = (u_int)shift;
182	di->baudrate = br;
183	di->bas.rclk = (u_int)rclk;
184	di->ops = uart_getops(class);
185	di->databits = 8;
186	di->stopbits = 1;
187	di->parity = UART_PARITY_NONE;
188	di->bas.bst = uart_bus_space_mem;
189
190	err = fdt_regsize(node, &start, &size);
191	if (err)
192		return (ENXIO);
193	err = fdt_get_range(OF_parent(node), 0, &pbase, &psize);
194	if (err)
195		pbase = 0;
196
197	start += pbase;
198
199	return (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh));
200}
201