1 /*-
2 * Copyright (c) 2015-2016 Oleksandr Tymoshenko <gonzo@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 #include "opt_platform.h"
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/gpio.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/mutex.h>
39 #include <sys/sysctl.h>
40
41 #include <dev/fdt/fdt_common.h>
42 #include <dev/ofw/ofw_bus.h>
43
44 #include <dev/gpio/gpiobusvar.h>
45
46 struct gpiobacklight_softc
47 {
48 gpio_pin_t sc_pin;
49 struct sysctl_oid *sc_oid;
50 bool sc_brightness;
51 };
52
53 static int gpiobacklight_sysctl(SYSCTL_HANDLER_ARGS);
54 static void gpiobacklight_update_brightness(struct gpiobacklight_softc *);
55 static int gpiobacklight_probe(device_t);
56 static int gpiobacklight_attach(device_t);
57 static int gpiobacklight_detach(device_t);
58
59 static void
gpiobacklight_update_brightness(struct gpiobacklight_softc * sc)60 gpiobacklight_update_brightness(struct gpiobacklight_softc *sc)
61 {
62
63 if (sc->sc_pin)
64 gpio_pin_set_active(sc->sc_pin, sc->sc_brightness);
65 }
66
67 static int
gpiobacklight_sysctl(SYSCTL_HANDLER_ARGS)68 gpiobacklight_sysctl(SYSCTL_HANDLER_ARGS)
69 {
70 struct gpiobacklight_softc *sc;
71 int error;
72 int brightness;
73
74 sc = (struct gpiobacklight_softc*)arg1;
75
76 brightness = sc->sc_brightness;
77 error = sysctl_handle_int(oidp, &brightness, 0, req);
78
79 if (error != 0 || req->newptr == NULL)
80 return (error);
81
82 sc->sc_brightness = (brightness > 0);
83 gpiobacklight_update_brightness(sc);
84
85 return (0);
86 }
87
88 static int
gpiobacklight_probe(device_t dev)89 gpiobacklight_probe(device_t dev)
90 {
91
92 if (!ofw_bus_is_compatible(dev, "gpio-backlight"))
93 return (ENXIO);
94
95 device_set_desc(dev, "GPIO backlight");
96
97 return (0);
98 }
99
100 static int
gpiobacklight_attach(device_t dev)101 gpiobacklight_attach(device_t dev)
102 {
103 struct gpiobacklight_softc *sc;
104 struct sysctl_ctx_list *ctx;
105 struct sysctl_oid *tree;
106 phandle_t node;
107
108 sc = device_get_softc(dev);
109
110 if ((node = ofw_bus_get_node(dev)) == -1)
111 return (ENXIO);
112
113 if (OF_hasprop(node, "default-on"))
114 sc->sc_brightness = true;
115 else
116 sc->sc_brightness = false;
117
118 gpio_pin_get_by_ofw_idx(dev, node, 0, &sc->sc_pin);
119 if (sc->sc_pin == NULL) {
120 device_printf(dev, "failed to map GPIO pin\n");
121 return (ENXIO);
122 }
123
124 gpio_pin_setflags(sc->sc_pin, GPIO_PIN_OUTPUT);
125
126 gpiobacklight_update_brightness(sc);
127
128 /* Init backlight interface */
129 ctx = device_get_sysctl_ctx(dev);
130 tree = device_get_sysctl_tree(dev);
131 sc->sc_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
132 "brightness", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
133 gpiobacklight_sysctl, "I", "backlight brightness");
134
135 return (0);
136 }
137
138 static int
gpiobacklight_detach(device_t dev)139 gpiobacklight_detach(device_t dev)
140 {
141 struct gpiobacklight_softc *sc;
142
143 sc = device_get_softc(dev);
144
145 if (sc->sc_pin)
146 gpio_pin_release(sc->sc_pin);
147
148 return (0);
149 }
150
151 static device_method_t gpiobacklight_methods[] = {
152 /* Device interface */
153 DEVMETHOD(device_probe, gpiobacklight_probe),
154 DEVMETHOD(device_attach, gpiobacklight_attach),
155 DEVMETHOD(device_detach, gpiobacklight_detach),
156
157 DEVMETHOD_END
158 };
159
160 static driver_t gpiobacklight_driver = {
161 "gpiobacklight",
162 gpiobacklight_methods,
163 sizeof(struct gpiobacklight_softc),
164 };
165
166 DRIVER_MODULE(gpiobacklight, simplebus, gpiobacklight_driver, 0, 0);
167 MODULE_DEPEND(gpiobacklight, gpiobus, 1, 1, 1);
168