xref: /freebsd/sys/dev/gpio/dwgpio/dwgpio_bus.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019 Ruslan Bukin <br@bsdpad.com>
5  *
6  * This software was developed by SRI International and the University of
7  * Cambridge Computer Laboratory (Department of Computer Science and
8  * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
9  * DARPA SSITH research programme.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/rman.h>
40 
41 #include <machine/bus.h>
42 
43 #include <dev/fdt/simplebus.h>
44 #include <dev/fdt/fdt_common.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 
47 #include "dwgpio_if.h"
48 
49 struct dwgpiobus_softc {
50 	struct simplebus_softc	simplebus_sc;
51 	device_t		dev;
52 	struct resource		*res[1];
53 };
54 
55 static struct resource_spec dwgpio_spec[] = {
56 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
57 	{ -1, 0 }
58 };
59 
60 static int
61 dwgpiobus_probe(device_t dev)
62 {
63 
64 	if (!ofw_bus_is_compatible(dev, "snps,dw-apb-gpio"))
65 		return (ENXIO);
66 
67 	if (!ofw_bus_status_okay(dev))
68 		return (ENXIO);
69 
70 	device_set_desc(dev, "Synopsys® DesignWare® APB GPIO BUS");
71 
72 	return (BUS_PROBE_DEFAULT);
73 }
74 
75 static int
76 dwgpiobus_attach(device_t dev)
77 {
78 	struct dwgpiobus_softc *sc;
79 	phandle_t node;
80 
81 	sc = device_get_softc(dev);
82 	sc->dev = dev;
83 
84 	node = ofw_bus_get_node(dev);
85 	if (node == -1)
86 		return (ENXIO);
87 
88 	if (bus_alloc_resources(dev, dwgpio_spec, sc->res)) {
89 		device_printf(dev, "Could not allocate resources.\n");
90 		return (ENXIO);
91 	}
92 
93 	simplebus_init(dev, node);
94 
95 	/*
96 	 * Allow devices to identify.
97 	 */
98 	bus_generic_probe(dev);
99 
100 	/*
101 	 * Now walk the OFW tree and attach top-level devices.
102 	 */
103 	for (node = OF_child(node); node > 0; node = OF_peer(node))
104 		simplebus_add_device(dev, node, 0, NULL, -1, NULL);
105 
106 	return (bus_generic_attach(dev));
107 }
108 
109 static int
110 dwgpiobus_detach(device_t dev)
111 {
112 	struct dwgpiobus_softc *sc;
113 
114 	sc = device_get_softc(dev);
115 
116 	bus_release_resources(dev, dwgpio_spec, sc->res);
117 
118 	return (0);
119 }
120 
121 static int
122 dwgpiobus_write(device_t dev, bus_size_t offset, int val)
123 {
124 	struct dwgpiobus_softc *sc;
125 
126 	sc = device_get_softc(dev);
127 
128 	bus_write_4(sc->res[0], offset, val);
129 
130 	return (0);
131 };
132 
133 static int
134 dwgpiobus_read(device_t dev, bus_size_t offset)
135 {
136 	struct dwgpiobus_softc *sc;
137 	int val;
138 
139 	sc = device_get_softc(dev);
140 
141 	val = bus_read_4(sc->res[0], offset);
142 
143 	return (val);
144 };
145 
146 static device_method_t dwgpiobus_methods[] = {
147 	DEVMETHOD(device_probe,		dwgpiobus_probe),
148 	DEVMETHOD(device_attach,	dwgpiobus_attach),
149 	DEVMETHOD(device_detach,	dwgpiobus_detach),
150 
151 	DEVMETHOD(dwgpio_write,		dwgpiobus_write),
152 	DEVMETHOD(dwgpio_read,		dwgpiobus_read),
153 
154 	DEVMETHOD_END
155 };
156 
157 DEFINE_CLASS_1(dwgpiobus, dwgpiobus_driver, dwgpiobus_methods,
158     sizeof(struct dwgpiobus_softc), simplebus_driver);
159 
160 EARLY_DRIVER_MODULE(dwgpiobus, simplebus, dwgpiobus_driver, 0, 0,
161     BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);
162 MODULE_VERSION(dwgpiobus, 1);
163