uart_bus_fdt.c revision 266084 
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 266084 2014-05-14 19:18:58Z 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
49static int uart_fdt_probe(device_t);
50
51static device_method_t uart_fdt_methods[] = {
52	/* Device interface */
53	DEVMETHOD(device_probe,		uart_fdt_probe),
54	DEVMETHOD(device_attach,	uart_bus_attach),
55	DEVMETHOD(device_detach,	uart_bus_detach),
56	{ 0, 0 }
57};
58
59static driver_t uart_fdt_driver = {
60	uart_driver_name,
61	uart_fdt_methods,
62	sizeof(struct uart_softc),
63};
64
65/*
66 * Compatible devices.  Keep this sorted in most- to least-specific order first,
67 * alphabetical second.  That is, "zwie,ns16550" should appear before "ns16550"
68 * on the theory that the zwie driver knows how to make better use of the
69 * hardware than the generic driver.  Likewise with chips within a family, the
70 * highest-numbers / most recent models should probably appear earlier.
71 */
72static struct ofw_compat_data compat_data[] = {
73	{"arm,pl011",		(uintptr_t)&uart_pl011_class},
74	{"cadence,uart",	(uintptr_t)&uart_cdnc_class},
75	{"exynos",		(uintptr_t)&uart_s3c2410_class},
76	{"fsl,imx6q-uart",	(uintptr_t)&uart_imx_class},
77	{"fsl,imx53-uart",	(uintptr_t)&uart_imx_class},
78	{"fsl,imx51-uart",	(uintptr_t)&uart_imx_class},
79	{"fsl,imx31-uart",	(uintptr_t)&uart_imx_class},
80	{"fsl,imx27-uart",	(uintptr_t)&uart_imx_class},
81	{"fsl,imx25-uart",	(uintptr_t)&uart_imx_class},
82	{"fsl,imx21-uart",	(uintptr_t)&uart_imx_class},
83	{"lpc,uart",		(uintptr_t)&uart_lpc_class},
84	{"ti,ns16550",		(uintptr_t)&uart_ti8250_class},
85	{"ns16550",		(uintptr_t)&uart_ns8250_class},
86	{NULL,			(uintptr_t)NULL},
87};
88
89/* Export the compat_data table for use by the uart_cpu_fdt.c probe routine. */
90const struct ofw_compat_data *uart_fdt_compat_data = compat_data;
91
92static int
93uart_fdt_get_clock(phandle_t node, pcell_t *cell)
94{
95	pcell_t clock;
96
97	if ((OF_getprop(node, "clock-frequency", &clock,
98	    sizeof(clock))) <= 0)
99		return (ENXIO);
100
101	if (clock == 0)
102		/* Try to retrieve parent 'bus-frequency' */
103		/* XXX this should go to simple-bus fixup or so */
104		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
105		    sizeof(clock))) <= 0)
106			clock = 0;
107
108	*cell = fdt32_to_cpu(clock);
109	return (0);
110}
111
112static int
113uart_fdt_get_shift(phandle_t node, pcell_t *cell)
114{
115	pcell_t shift;
116
117	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
118		shift = 0;
119	*cell = fdt32_to_cpu(shift);
120	return (0);
121}
122
123static int
124uart_fdt_probe(device_t dev)
125{
126	struct uart_softc *sc;
127	phandle_t node;
128	pcell_t clock, shift;
129	int err;
130	const struct ofw_compat_data * cd;
131
132	sc = device_get_softc(dev);
133
134	cd = ofw_bus_search_compatible(dev, compat_data);
135	if (cd->ocd_data == (uintptr_t)NULL)
136		return (ENXIO);
137
138	sc->sc_class = (struct uart_class *)cd->ocd_data;
139
140	node = ofw_bus_get_node(dev);
141
142	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
143		return (err);
144	uart_fdt_get_shift(node, &shift);
145
146	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
147}
148
149DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
150