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 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 } 99 100 static struct cdevsw backlight_cdevsw = { 101 .d_version = D_VERSION, 102 .d_ioctl = backlight_ioctl, 103 .d_name = "backlight", 104 }; 105 106 struct cdev * 107 backlight_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); 143 fail: 144 sx_xunlock(&backlight_sx); 145 return (NULL); 146 } 147 148 int 149 backlight_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 } 160 161 static void 162 backlight_drvinit(void *unused) 163 { 164 165 backlight_unit = new_unrhdr(0, INT_MAX, NULL); 166 sx_init(&backlight_sx, "Backlight sx"); 167 } 168 169 SYSINIT(backlightdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, backlight_drvinit, NULL); 170 MODULE_VERSION(backlight, 1); 171