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/cdefs.h> 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/limits.h> 32 #include <sys/bus.h> 33 #include <sys/conf.h> 34 #include <sys/kernel.h> 35 #include <sys/malloc.h> 36 #include <sys/module.h> 37 #include <sys/lock.h> 38 #include <sys/sx.h> 39 40 #include <dev/backlight/backlight.h> 41 42 #include "backlight_if.h" 43 44 static struct sx backlight_sx; 45 static MALLOC_DEFINE(M_BACKLIGHT, "BACKLIGHT", "Backlight driver"); 46 static struct unrhdr *backlight_unit; 47 48 struct backlight_softc { 49 struct cdev *cdev; 50 struct cdev *alias; 51 int unit; 52 device_t dev; 53 uint32_t cached_brightness; 54 }; 55 56 static int 57 backlight_ioctl(struct cdev *dev, u_long cmd, caddr_t data, 58 int fflag, struct thread *td) 59 { 60 struct backlight_softc *sc; 61 struct backlight_props props; 62 struct backlight_info info; 63 int error; 64 65 sc = dev->si_drv1; 66 67 switch (cmd) { 68 case BACKLIGHTGETSTATUS: 69 /* Call the driver function so it fills up the props */ 70 bcopy(data, &props, sizeof(struct backlight_props)); 71 error = BACKLIGHT_GET_STATUS(sc->dev, &props); 72 if (error == 0) { 73 bcopy(&props, data, sizeof(struct backlight_props)); 74 sc->cached_brightness = props.brightness; 75 } 76 break; 77 case BACKLIGHTUPDATESTATUS: 78 bcopy(data, &props, sizeof(struct backlight_props)); 79 if (props.brightness == sc->cached_brightness) 80 return (0); 81 error = BACKLIGHT_UPDATE_STATUS(sc->dev, &props); 82 if (error == 0) { 83 bcopy(&props, data, sizeof(struct backlight_props)); 84 sc->cached_brightness = props.brightness; 85 } 86 break; 87 case BACKLIGHTGETINFO: 88 memset(&info, 0, sizeof(info)); 89 error = BACKLIGHT_GET_INFO(sc->dev, &info); 90 if (error == 0) 91 bcopy(&info, data, sizeof(struct backlight_info)); 92 break; 93 } 94 95 return (error); 96 } 97 98 static struct cdevsw backlight_cdevsw = { 99 .d_version = D_VERSION, 100 .d_ioctl = backlight_ioctl, 101 .d_name = "backlight", 102 }; 103 104 struct cdev * 105 backlight_register(const char *name, device_t dev) 106 { 107 struct make_dev_args args; 108 struct backlight_softc *sc; 109 struct backlight_props props; 110 int error; 111 112 sc = malloc(sizeof(*sc), M_BACKLIGHT, M_WAITOK | M_ZERO); 113 114 sx_xlock(&backlight_sx); 115 sc->unit = alloc_unr(backlight_unit); 116 sc->dev = dev; 117 make_dev_args_init(&args); 118 args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK; 119 args.mda_devsw = &backlight_cdevsw; 120 args.mda_uid = UID_ROOT; 121 args.mda_gid = GID_VIDEO; 122 args.mda_mode = 0660; 123 args.mda_si_drv1 = sc; 124 error = make_dev_s(&args, &sc->cdev, "backlight/backlight%d", sc->unit); 125 126 if (error != 0) 127 goto fail; 128 129 error = make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, 130 &sc->alias, sc->cdev, "backlight/%s%d", name, sc->unit); 131 if (error != 0) 132 device_printf(dev, "Cannot register with alias %s%d\n", name, 133 sc->unit); 134 135 sx_xunlock(&backlight_sx); 136 137 error = BACKLIGHT_GET_STATUS(sc->dev, &props); 138 sc->cached_brightness = props.brightness; 139 140 return (sc->cdev); 141 fail: 142 sx_xunlock(&backlight_sx); 143 return (NULL); 144 } 145 146 int 147 backlight_destroy(struct cdev *dev) 148 { 149 struct backlight_softc *sc; 150 151 sc = dev->si_drv1; 152 sx_xlock(&backlight_sx); 153 free_unr(backlight_unit, sc->unit); 154 destroy_dev(dev); 155 sx_xunlock(&backlight_sx); 156 return (0); 157 } 158 159 static void 160 backlight_drvinit(void *unused) 161 { 162 163 backlight_unit = new_unrhdr(0, INT_MAX, NULL); 164 sx_init(&backlight_sx, "Backlight sx"); 165 } 166 167 SYSINIT(backlightdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, backlight_drvinit, NULL); 168 MODULE_VERSION(backlight, 1); 169