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
48static struct sx backlight_sx;
49static MALLOC_DEFINE(M_BACKLIGHT, "BACKLIGHT", "Backlight driver");
50static struct unrhdr *backlight_unit;
51
52struct backlight_softc {
53	struct cdev *cdev;
54	struct cdev *alias;
55	int unit;
56	device_t dev;
57	uint32_t cached_brightness;
58};
59
60static int
61backlight_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		break;
79	case BACKLIGHTUPDATESTATUS:
80		bcopy(data, &props, sizeof(struct backlight_props));
81		if (props.brightness == sc->cached_brightness)
82			return (0);
83		error = BACKLIGHT_UPDATE_STATUS(sc->dev, &props);
84		if (error == 0) {
85			bcopy(&props, data, sizeof(struct backlight_props));
86			sc->cached_brightness = props.brightness;
87		}
88		break;
89	case BACKLIGHTGETINFO:
90		memset(&info, 0, sizeof(info));
91		error = BACKLIGHT_GET_INFO(sc->dev, &info);
92		if (error == 0)
93			bcopy(&info, data, sizeof(struct backlight_info));
94		break;
95	}
96
97	return (error);
98}
99
100static struct cdevsw backlight_cdevsw = {
101	.d_version =	D_VERSION,
102	.d_ioctl =	backlight_ioctl,
103	.d_name =	"backlight",
104};
105
106struct cdev *
107backlight_register(const char *name, device_t dev)
108{
109	struct make_dev_args args;
110	struct backlight_softc *sc;
111	struct backlight_props props;
112	int error;
113
114	sc = malloc(sizeof(*sc), M_BACKLIGHT, M_WAITOK | M_ZERO);
115
116	sx_xlock(&backlight_sx);
117	sc->unit = alloc_unr(backlight_unit);
118	sc->dev = dev;
119	make_dev_args_init(&args);
120	args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK;
121	args.mda_devsw = &backlight_cdevsw;
122	args.mda_uid = UID_ROOT;
123	args.mda_gid = GID_VIDEO;
124	args.mda_mode = 0660;
125	args.mda_si_drv1 = sc;
126	error = make_dev_s(&args, &sc->cdev, "backlight/backlight%d", sc->unit);
127
128	if (error != 0)
129		goto fail;
130
131	error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
132	  &sc->alias, sc->cdev, "backlight/%s%d", name, sc->unit);
133	if (error != 0)
134		device_printf(dev, "Cannot register with alias %s%d\n", name,
135		    sc->unit);
136
137	sx_xunlock(&backlight_sx);
138
139	error = BACKLIGHT_GET_STATUS(sc->dev, &props);
140	sc->cached_brightness = props.brightness;
141
142	return (sc->cdev);
143fail:
144	sx_xunlock(&backlight_sx);
145	return (NULL);
146}
147
148int
149backlight_destroy(struct cdev *dev)
150{
151	struct backlight_softc *sc;
152
153	sc = dev->si_drv1;
154	sx_xlock(&backlight_sx);
155	free_unr(backlight_unit, sc->unit);
156	destroy_dev(dev);
157	sx_xunlock(&backlight_sx);
158	return (0);
159}
160
161static void
162backlight_drvinit(void *unused)
163{
164
165	backlight_unit = new_unrhdr(0, INT_MAX, NULL);
166	sx_init(&backlight_sx, "Backlight sx");
167}
168
169SYSINIT(backlightdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, backlight_drvinit, NULL);
170MODULE_VERSION(backlight, 1);
171