xref: /freebsd/sys/dev/gpio/dwgpio/dwgpio_bus.c (revision a90b9d0159070121c221b966469c3e36d912bf82)
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/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/rman.h>
39 
40 #include <machine/bus.h>
41 
42 #include <dev/fdt/simplebus.h>
43 #include <dev/fdt/fdt_common.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include "dwgpio_if.h"
47 
48 struct dwgpiobus_softc {
49 	struct simplebus_softc	simplebus_sc;
50 	device_t		dev;
51 	struct resource		*res[1];
52 };
53 
54 static struct resource_spec dwgpio_spec[] = {
55 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
56 	{ -1, 0 }
57 };
58 
59 static int
60 dwgpiobus_probe(device_t dev)
61 {
62 
63 	if (!ofw_bus_is_compatible(dev, "snps,dw-apb-gpio"))
64 		return (ENXIO);
65 
66 	if (!ofw_bus_status_okay(dev))
67 		return (ENXIO);
68 
69 	device_set_desc(dev, "Synopsys® DesignWare® APB GPIO BUS");
70 
71 	return (BUS_PROBE_DEFAULT);
72 }
73 
74 static int
75 dwgpiobus_attach(device_t dev)
76 {
77 	struct dwgpiobus_softc *sc;
78 	phandle_t node;
79 
80 	sc = device_get_softc(dev);
81 	sc->dev = dev;
82 
83 	node = ofw_bus_get_node(dev);
84 	if (node == -1)
85 		return (ENXIO);
86 
87 	if (bus_alloc_resources(dev, dwgpio_spec, sc->res)) {
88 		device_printf(dev, "Could not allocate resources.\n");
89 		return (ENXIO);
90 	}
91 
92 	simplebus_init(dev, node);
93 
94 	/*
95 	 * Allow devices to identify.
96 	 */
97 	bus_generic_probe(dev);
98 
99 	/*
100 	 * Now walk the OFW tree and attach top-level devices.
101 	 */
102 	for (node = OF_child(node); node > 0; node = OF_peer(node))
103 		simplebus_add_device(dev, node, 0, NULL, -1, NULL);
104 
105 	return (bus_generic_attach(dev));
106 }
107 
108 static int
109 dwgpiobus_detach(device_t dev)
110 {
111 	struct dwgpiobus_softc *sc;
112 
113 	sc = device_get_softc(dev);
114 
115 	bus_release_resources(dev, dwgpio_spec, sc->res);
116 
117 	return (0);
118 }
119 
120 static int
121 dwgpiobus_write(device_t dev, bus_size_t offset, int val)
122 {
123 	struct dwgpiobus_softc *sc;
124 
125 	sc = device_get_softc(dev);
126 
127 	bus_write_4(sc->res[0], offset, val);
128 
129 	return (0);
130 };
131 
132 static int
133 dwgpiobus_read(device_t dev, bus_size_t offset)
134 {
135 	struct dwgpiobus_softc *sc;
136 	int val;
137 
138 	sc = device_get_softc(dev);
139 
140 	val = bus_read_4(sc->res[0], offset);
141 
142 	return (val);
143 };
144 
145 static device_method_t dwgpiobus_methods[] = {
146 	DEVMETHOD(device_probe,		dwgpiobus_probe),
147 	DEVMETHOD(device_attach,	dwgpiobus_attach),
148 	DEVMETHOD(device_detach,	dwgpiobus_detach),
149 
150 	DEVMETHOD(dwgpio_write,		dwgpiobus_write),
151 	DEVMETHOD(dwgpio_read,		dwgpiobus_read),
152 
153 	DEVMETHOD_END
154 };
155 
156 DEFINE_CLASS_1(dwgpiobus, dwgpiobus_driver, dwgpiobus_methods,
157     sizeof(struct dwgpiobus_softc), simplebus_driver);
158 
159 EARLY_DRIVER_MODULE(dwgpiobus, simplebus, dwgpiobus_driver, 0, 0,
160     BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);
161 MODULE_VERSION(dwgpiobus, 1);
162