1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/limits.h>
31 #include <sys/bus.h>
32 #include <sys/conf.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/module.h>
36 #include <sys/lock.h>
37 #include <sys/sx.h>
38
39 #include <dev/backlight/backlight.h>
40
41 #include "backlight_if.h"
42
43 static struct sx backlight_sx;
44 static MALLOC_DEFINE(M_BACKLIGHT, "BACKLIGHT", "Backlight driver");
45 static struct unrhdr *backlight_unit;
46
47 struct backlight_softc {
48 struct cdev *cdev;
49 struct cdev *alias;
50 int unit;
51 device_t dev;
52 uint32_t cached_brightness;
53 };
54
55 static int
backlight_ioctl(struct cdev * dev,u_long cmd,caddr_t data,int fflag,struct thread * td)56 backlight_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
57 int fflag, struct thread *td)
58 {
59 struct backlight_softc *sc;
60 struct backlight_props props;
61 struct backlight_info info;
62 int error;
63
64 sc = dev->si_drv1;
65
66 switch (cmd) {
67 case BACKLIGHTGETSTATUS:
68 /* Call the driver function so it fills up the props */
69 bcopy(data, &props, sizeof(struct backlight_props));
70 error = BACKLIGHT_GET_STATUS(sc->dev, &props);
71 if (error == 0) {
72 bcopy(&props, data, sizeof(struct backlight_props));
73 sc->cached_brightness = props.brightness;
74 }
75 break;
76 case BACKLIGHTUPDATESTATUS:
77 bcopy(data, &props, sizeof(struct backlight_props));
78 if (props.brightness == sc->cached_brightness)
79 return (0);
80 error = BACKLIGHT_UPDATE_STATUS(sc->dev, &props);
81 if (error == 0) {
82 bcopy(&props, data, sizeof(struct backlight_props));
83 sc->cached_brightness = props.brightness;
84 }
85 break;
86 case BACKLIGHTGETINFO:
87 memset(&info, 0, sizeof(info));
88 error = BACKLIGHT_GET_INFO(sc->dev, &info);
89 if (error == 0)
90 bcopy(&info, data, sizeof(struct backlight_info));
91 break;
92 }
93
94 return (error);
95 }
96
97 static struct cdevsw backlight_cdevsw = {
98 .d_version = D_VERSION,
99 .d_ioctl = backlight_ioctl,
100 .d_name = "backlight",
101 };
102
103 struct cdev *
backlight_register(const char * name,device_t dev)104 backlight_register(const char *name, device_t dev)
105 {
106 struct make_dev_args args;
107 struct backlight_softc *sc;
108 struct backlight_props props;
109 int error;
110
111 sc = malloc(sizeof(*sc), M_BACKLIGHT, M_WAITOK | M_ZERO);
112
113 sx_xlock(&backlight_sx);
114 sc->unit = alloc_unr(backlight_unit);
115 sc->dev = dev;
116 make_dev_args_init(&args);
117 args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK;
118 args.mda_devsw = &backlight_cdevsw;
119 args.mda_uid = UID_ROOT;
120 args.mda_gid = GID_VIDEO;
121 args.mda_mode = 0660;
122 args.mda_si_drv1 = sc;
123 error = make_dev_s(&args, &sc->cdev, "backlight/backlight%d", sc->unit);
124
125 if (error != 0)
126 goto fail;
127
128 error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
129 &sc->alias, sc->cdev, "backlight/%s%d", name, sc->unit);
130 if (error != 0)
131 device_printf(dev, "Cannot register with alias %s%d\n", name,
132 sc->unit);
133
134 sx_xunlock(&backlight_sx);
135
136 error = BACKLIGHT_GET_STATUS(sc->dev, &props);
137 sc->cached_brightness = props.brightness;
138
139 return (sc->cdev);
140 fail:
141 sx_xunlock(&backlight_sx);
142 return (NULL);
143 }
144
145 int
backlight_destroy(struct cdev * dev)146 backlight_destroy(struct cdev *dev)
147 {
148 struct backlight_softc *sc;
149
150 sc = dev->si_drv1;
151 sx_xlock(&backlight_sx);
152 free_unr(backlight_unit, sc->unit);
153 destroy_dev(dev);
154 sx_xunlock(&backlight_sx);
155 return (0);
156 }
157
158 static void
backlight_drvinit(void * unused)159 backlight_drvinit(void *unused)
160 {
161
162 backlight_unit = new_unrhdr(0, INT_MAX, NULL);
163 sx_init(&backlight_sx, "Backlight sx");
164 }
165
166 SYSINIT(backlightdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, backlight_drvinit, NULL);
167 MODULE_VERSION(backlight, 1);
168