xref: /freebsd/sys/dev/gpio/dwgpio/dwgpio_bus.c (revision 38effe887ee979f91ad5abf42a2291558e7ff8d1)
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 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/rman.h>
42 
43 #include <machine/bus.h>
44 
45 #include <dev/fdt/simplebus.h>
46 #include <dev/fdt/fdt_common.h>
47 #include <dev/ofw/ofw_bus_subr.h>
48 
49 #include "dwgpio_if.h"
50 
51 struct dwgpiobus_softc {
52 	struct simplebus_softc	simplebus_sc;
53 	device_t		dev;
54 	struct resource		*res[1];
55 };
56 
57 static struct resource_spec dwgpio_spec[] = {
58 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
59 	{ -1, 0 }
60 };
61 
62 static int
63 dwgpiobus_probe(device_t dev)
64 {
65 
66 	if (!ofw_bus_is_compatible(dev, "snps,dw-apb-gpio"))
67 		return (ENXIO);
68 
69 	if (!ofw_bus_status_okay(dev))
70 		return (ENXIO);
71 
72 	device_set_desc(dev, "Synopsys® DesignWare® APB GPIO BUS");
73 
74 	return (BUS_PROBE_DEFAULT);
75 }
76 
77 static int
78 dwgpiobus_attach(device_t dev)
79 {
80 	struct dwgpiobus_softc *sc;
81 	phandle_t node;
82 
83 	sc = device_get_softc(dev);
84 	sc->dev = dev;
85 
86 	node = ofw_bus_get_node(dev);
87 	if (node == -1)
88 		return (ENXIO);
89 
90 	if (bus_alloc_resources(dev, dwgpio_spec, sc->res)) {
91 		device_printf(dev, "Could not allocate resources.\n");
92 		return (ENXIO);
93 	}
94 
95 	simplebus_init(dev, node);
96 
97 	/*
98 	 * Allow devices to identify.
99 	 */
100 	bus_generic_probe(dev);
101 
102 	/*
103 	 * Now walk the OFW tree and attach top-level devices.
104 	 */
105 	for (node = OF_child(node); node > 0; node = OF_peer(node))
106 		simplebus_add_device(dev, node, 0, NULL, -1, NULL);
107 
108 	return (bus_generic_attach(dev));
109 }
110 
111 static int
112 dwgpiobus_detach(device_t dev)
113 {
114 	struct dwgpiobus_softc *sc;
115 
116 	sc = device_get_softc(dev);
117 
118 	bus_release_resources(dev, dwgpio_spec, sc->res);
119 
120 	return (0);
121 }
122 
123 static int
124 dwgpiobus_write(device_t dev, bus_size_t offset, int val)
125 {
126 	struct dwgpiobus_softc *sc;
127 
128 	sc = device_get_softc(dev);
129 
130 	bus_write_4(sc->res[0], offset, val);
131 
132 	return (0);
133 };
134 
135 static int
136 dwgpiobus_read(device_t dev, bus_size_t offset)
137 {
138 	struct dwgpiobus_softc *sc;
139 	int val;
140 
141 	sc = device_get_softc(dev);
142 
143 	val = bus_read_4(sc->res[0], offset);
144 
145 	return (val);
146 };
147 
148 static device_method_t dwgpiobus_methods[] = {
149 	DEVMETHOD(device_probe,		dwgpiobus_probe),
150 	DEVMETHOD(device_attach,	dwgpiobus_attach),
151 	DEVMETHOD(device_detach,	dwgpiobus_detach),
152 
153 	DEVMETHOD(dwgpio_write,		dwgpiobus_write),
154 	DEVMETHOD(dwgpio_read,		dwgpiobus_read),
155 
156 	DEVMETHOD_END
157 };
158 
159 DEFINE_CLASS_1(dwgpiobus, dwgpiobus_driver, dwgpiobus_methods,
160     sizeof(struct dwgpiobus_softc), simplebus_driver);
161 
162 static devclass_t dwgpiobus_devclass;
163 
164 EARLY_DRIVER_MODULE(dwgpiobus, simplebus, dwgpiobus_driver, dwgpiobus_devclass,
165     0, 0, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);
166 MODULE_VERSION(dwgpiobus, 1);
167