uart_bus_fdt.c revision 283327 
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_bus_fdt.c 283327 2015-05-23 20:54:25Z 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
40#include <machine/bus.h>
41
42#include <dev/fdt/fdt_common.h>
43#include <dev/ofw/ofw_bus.h>
44#include <dev/ofw/ofw_bus_subr.h>
45#include <dev/uart/uart.h>
46#include <dev/uart/uart_bus.h>
47#include <dev/uart/uart_cpu.h>
48#include <dev/uart/uart_cpu_fdt.h>
49
50static int uart_fdt_probe(device_t);
51
52static device_method_t uart_fdt_methods[] = {
53	/* Device interface */
54	DEVMETHOD(device_probe,		uart_fdt_probe),
55	DEVMETHOD(device_attach,	uart_bus_attach),
56	DEVMETHOD(device_detach,	uart_bus_detach),
57	{ 0, 0 }
58};
59
60static driver_t uart_fdt_driver = {
61	uart_driver_name,
62	uart_fdt_methods,
63	sizeof(struct uart_softc),
64};
65
66static int
67uart_fdt_get_clock(phandle_t node, pcell_t *cell)
68{
69	pcell_t clock;
70
71	/*
72	 * clock-frequency is a FreeBSD-specific hack. Make its presence optional.
73	 */
74	if ((OF_getprop(node, "clock-frequency", &clock,
75	    sizeof(clock))) <= 0)
76		clock = 0;
77
78	if (clock == 0)
79		/* Try to retrieve parent 'bus-frequency' */
80		/* XXX this should go to simple-bus fixup or so */
81		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
82		    sizeof(clock))) <= 0)
83			clock = 0;
84
85	*cell = fdt32_to_cpu(clock);
86	return (0);
87}
88
89static int
90uart_fdt_get_shift(phandle_t node, pcell_t *cell)
91{
92	pcell_t shift;
93
94	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
95		shift = 0;
96	*cell = fdt32_to_cpu(shift);
97	return (0);
98}
99
100static uintptr_t
101uart_fdt_find_device(device_t dev)
102{
103	struct ofw_compat_data **cd;
104	const struct ofw_compat_data *ocd;
105
106	SET_FOREACH(cd, uart_fdt_class_and_device_set) {
107		ocd = ofw_bus_search_compatible(dev, *cd);
108		if (ocd->ocd_data != 0)
109			return (ocd->ocd_data);
110	}
111	return (0);
112}
113
114static int
115uart_fdt_probe(device_t dev)
116{
117	struct uart_softc *sc;
118	phandle_t node;
119	pcell_t clock, shift;
120	int err;
121
122	sc = device_get_softc(dev);
123
124	if (!ofw_bus_status_okay(dev))
125		return (ENXIO);
126
127	sc->sc_class = (struct uart_class *)uart_fdt_find_device(dev);
128	if (sc->sc_class == NULL)
129		return (ENXIO);
130
131	node = ofw_bus_get_node(dev);
132
133	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
134		return (err);
135	uart_fdt_get_shift(node, &shift);
136
137	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
138}
139
140DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
141DRIVER_MODULE(uart, ofwbus, uart_fdt_driver, uart_devclass, 0, 0);
142