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 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 * 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 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 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