xref: /freebsd/sys/dev/uart/uart_bus_fdt.c (revision bfb8efd0ed67bba02c0a82f6aef82c810ec7cf4c)
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("$FreeBSD$");
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 
49 static int uart_fdt_probe(device_t);
50 
51 static 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 
59 static 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  */
72 static struct ofw_compat_data compat_data[] = {
73 	{"arm,pl011",		(uintptr_t)&uart_pl011_class},
74 	{"atmel,at91rm9200-usart",(uintptr_t)&at91_usart_class},
75 	{"atmel,at91sam9260-usart",(uintptr_t)&at91_usart_class},
76 	{"cadence,uart",	(uintptr_t)&uart_cdnc_class},
77 	{"exynos",		(uintptr_t)&uart_s3c2410_class},
78 	{"fsl,imx6q-uart",	(uintptr_t)&uart_imx_class},
79 	{"fsl,imx53-uart",	(uintptr_t)&uart_imx_class},
80 	{"fsl,imx51-uart",	(uintptr_t)&uart_imx_class},
81 	{"fsl,imx31-uart",	(uintptr_t)&uart_imx_class},
82 	{"fsl,imx27-uart",	(uintptr_t)&uart_imx_class},
83 	{"fsl,imx25-uart",	(uintptr_t)&uart_imx_class},
84 	{"fsl,imx21-uart",	(uintptr_t)&uart_imx_class},
85 	{"fsl,mvf600-uart",	(uintptr_t)&uart_vybrid_class},
86 	{"lpc,uart",		(uintptr_t)&uart_lpc_class},
87 	{"ti,ns16550",		(uintptr_t)&uart_ti8250_class},
88 	{"ns16550",		(uintptr_t)&uart_ns8250_class},
89 	{NULL,			(uintptr_t)NULL},
90 };
91 
92 /* Export the compat_data table for use by the uart_cpu_fdt.c probe routine. */
93 const struct ofw_compat_data *uart_fdt_compat_data = compat_data;
94 
95 static int
96 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
97 {
98 	pcell_t clock;
99 
100 	/*
101 	 * clock-frequency is a FreeBSD-specific hack. Make its presence optional.
102 	 */
103 	if ((OF_getprop(node, "clock-frequency", &clock,
104 	    sizeof(clock))) <= 0)
105 		clock = 0;
106 
107 	if (clock == 0)
108 		/* Try to retrieve parent 'bus-frequency' */
109 		/* XXX this should go to simple-bus fixup or so */
110 		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
111 		    sizeof(clock))) <= 0)
112 			clock = 0;
113 
114 	*cell = fdt32_to_cpu(clock);
115 	return (0);
116 }
117 
118 static int
119 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
120 {
121 	pcell_t shift;
122 
123 	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
124 		shift = 0;
125 	*cell = fdt32_to_cpu(shift);
126 	return (0);
127 }
128 
129 static int
130 uart_fdt_probe(device_t dev)
131 {
132 	struct uart_softc *sc;
133 	phandle_t node;
134 	pcell_t clock, shift;
135 	int err;
136 	const struct ofw_compat_data * cd;
137 
138 	sc = device_get_softc(dev);
139 
140 	if (!ofw_bus_status_okay(dev))
141 		return (ENXIO);
142 
143 	cd = ofw_bus_search_compatible(dev, compat_data);
144 	if (cd->ocd_data == (uintptr_t)NULL)
145 		return (ENXIO);
146 
147 	sc->sc_class = (struct uart_class *)cd->ocd_data;
148 
149 	node = ofw_bus_get_node(dev);
150 
151 	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
152 		return (err);
153 	uart_fdt_get_shift(node, &shift);
154 
155 	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
156 }
157 
158 DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
159