1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2020 Emmanuel Vadot <manu@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/limits.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/module.h>
41 #include <sys/lock.h>
42 #include <sys/sx.h>
43
44 #include <dev/backlight/backlight.h>
45
46 #include "backlight_if.h"
47
48 static struct sx backlight_sx;
49 static MALLOC_DEFINE(M_BACKLIGHT, "BACKLIGHT", "Backlight driver");
50 static struct unrhdr *backlight_unit;
51
52 struct backlight_softc {
53 struct cdev *cdev;
54 struct cdev *alias;
55 int unit;
56 device_t dev;
57 uint32_t cached_brightness;
58 };
59
60 static int
61 backlight_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
62 int fflag, struct thread *td)
63 {
64 struct backlight_softc *sc;
65 struct backlight_props props;
66 struct backlight_info info;
67 int error;
68
69 sc = dev->si_drv1;
70
71 switch (cmd) {
72 case BACKLIGHTGETSTATUS:
73 /* Call the driver function so it fills up the props */
74 bcopy(data, &props, sizeof(struct backlight_props));
75 error = BACKLIGHT_GET_STATUS(sc->dev, &props);
76 if (error == 0) {
77 bcopy(&props, data, sizeof(struct backlight_props));
78 sc->cached_brightness = props.brightness;
79 }
80 break;
81 case BACKLIGHTUPDATESTATUS:
82 bcopy(data, &props, sizeof(struct backlight_props));
83 if (props.brightness == sc->cached_brightness)
84 return (0);
85 error = BACKLIGHT_UPDATE_STATUS(sc->dev, &props);
86 if (error == 0) {
87 bcopy(&props, data, sizeof(struct backlight_props));
88 sc->cached_brightness = props.brightness;
89 }
90 break;
91 case BACKLIGHTGETINFO:
92 memset(&info, 0, sizeof(info));
93 error = BACKLIGHT_GET_INFO(sc->dev, &info);
94 if (error == 0)
95 bcopy(&info, data, sizeof(struct backlight_info));
96 break;
97 }
98
99 return (error);
100 }
101
102 static struct cdevsw backlight_cdevsw = {
103 .d_version = D_VERSION,
104 .d_ioctl = backlight_ioctl,
105 .d_name = "backlight",
106 };
107
108 struct cdev *
109 backlight_register(const char *name, device_t dev)
110 {
111 struct make_dev_args args;
112 struct backlight_softc *sc;
113 struct backlight_props props;
114 int error;
115
116 sc = malloc(sizeof(*sc), M_BACKLIGHT, M_WAITOK | M_ZERO);
117
118 sx_xlock(&backlight_sx);
119 sc->unit = alloc_unr(backlight_unit);
120 sc->dev = dev;
121 make_dev_args_init(&args);
122 args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK;
123 args.mda_devsw = &backlight_cdevsw;
124 args.mda_uid = UID_ROOT;
125 args.mda_gid = GID_VIDEO;
126 args.mda_mode = 0660;
127 args.mda_si_drv1 = sc;
128 error = make_dev_s(&args, &sc->cdev, "backlight/backlight%d", sc->unit);
129
130 if (error != 0)
131 goto fail;
132
133 error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
134 &sc->alias, sc->cdev, "backlight/%s%d", name, sc->unit);
135 if (error != 0)
136 device_printf(dev, "Cannot register with alias %s%d\n", name,
137 sc->unit);
138
139 sx_xunlock(&backlight_sx);
140
141 error = BACKLIGHT_GET_STATUS(sc->dev, &props);
142 sc->cached_brightness = props.brightness;
143
144 return (sc->cdev);
145 fail:
146 sx_xunlock(&backlight_sx);
147 return (NULL);
148 }
149
150 int
151 backlight_destroy(struct cdev *dev)
152 {
153 struct backlight_softc *sc;
154
155 sc = dev->si_drv1;
156 sx_xlock(&backlight_sx);
157 free_unr(backlight_unit, sc->unit);
158 destroy_dev(dev);
159 sx_xunlock(&backlight_sx);
160 return (0);
161 }
162
163 static void
164 backlight_drvinit(void *unused)
165 {
166
167 backlight_unit = new_unrhdr(0, INT_MAX, NULL);
168 sx_init(&backlight_sx, "Backlight sx");
169 }
170
171 SYSINIT(backlightdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, backlight_drvinit, NULL);
172 MODULE_VERSION(backlight, 1);
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