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/param.h> 31 #include <sys/systm.h> 32 #include <sys/limits.h> 33 #include <sys/bus.h> 34 #include <sys/conf.h> 35 #include <sys/device.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/module.h> 39 #include <sys/lock.h> 40 41 #include <dev/misc/backlight/backlight.h> 42 43 #include "backlight_if.h" 44 45 static struct lock backlight_lock; 46 static MALLOC_DEFINE(M_BACKLIGHT, "BACKLIGHT", "Backlight driver"); 47 static struct unrhdr *backlight_unit; 48 49 struct backlight_softc { 50 struct cdev *cdev; 51 struct cdev *alias; 52 int unit; 53 device_t dev; 54 uint32_t cached_brightness; 55 }; 56 57 static int 58 backlight_ioctl(struct dev_ioctl_args *ap) 59 { 60 struct backlight_softc *sc; 61 struct backlight_props props; 62 struct backlight_info info; 63 cdev_t dev = ap->a_head.a_dev; 64 int error = 0; 65 66 sc = dev->si_drv1; 67 68 switch (ap->a_cmd) { 69 case BACKLIGHTGETSTATUS: 70 /* Call the driver function so it fills up the props */ 71 bcopy(ap->a_data, &props, sizeof(struct backlight_props)); 72 error = BACKLIGHT_GET_STATUS(sc->dev, &props); 73 if (error == 0) { 74 bcopy(&props, ap->a_data, sizeof(struct backlight_props)); 75 sc->cached_brightness = props.brightness; 76 } 77 break; 78 case BACKLIGHTUPDATESTATUS: 79 bcopy(ap->a_data, &props, sizeof(struct backlight_props)); 80 if (props.brightness == sc->cached_brightness) 81 return (0); 82 error = BACKLIGHT_UPDATE_STATUS(sc->dev, &props); 83 if (error == 0) { 84 bcopy(&props, ap->a_data, sizeof(struct backlight_props)); 85 sc->cached_brightness = props.brightness; 86 } 87 break; 88 case BACKLIGHTGETINFO: 89 memset(&info, 0, sizeof(info)); 90 error = BACKLIGHT_GET_INFO(sc->dev, &info); 91 if (error == 0) 92 bcopy(&info, ap->a_data, sizeof(struct backlight_info)); 93 break; 94 } 95 96 return (error); 97 } 98 99 static struct dev_ops backlight_cdevsw = { 100 .head = { .name = "backlight", .flags = D_MPSAFE }, 101 .d_ioctl = backlight_ioctl, 102 }; 103 104 struct cdev * 105 backlight_register(const char *name, device_t dev) 106 { 107 struct backlight_softc *sc; 108 struct backlight_props props; 109 int error; 110 111 sc = kmalloc(sizeof(*sc), M_BACKLIGHT, M_WAITOK | M_ZERO); 112 113 lockmgr(&backlight_lock, LK_EXCLUSIVE); 114 sc->unit = alloc_unr(backlight_unit); 115 sc->dev = dev; 116 make_dev(&backlight_cdevsw, sc->unit, UID_ROOT, GID_VIDEO, 117 0660, "backlight/backlight%d", sc->unit); 118 sc->cdev->si_drv1 = sc; 119 make_dev_alias(sc->cdev, "backlight/%s%d", name, sc->unit); 120 121 lockmgr(&backlight_lock, LK_RELEASE); 122 123 error = BACKLIGHT_GET_STATUS(sc->dev, &props); 124 sc->cached_brightness = props.brightness; 125 126 return (sc->cdev); 127 } 128 129 int 130 backlight_destroy(struct cdev *dev) 131 { 132 struct backlight_softc *sc; 133 134 sc = dev->si_drv1; 135 lockmgr(&backlight_lock, LK_EXCLUSIVE); 136 free_unr(backlight_unit, sc->unit); 137 destroy_dev(dev); 138 lockmgr(&backlight_lock, LK_RELEASE); 139 return (0); 140 } 141 142 static void 143 backlight_drvinit(void *unused) 144 { 145 146 backlight_unit = new_unrhdr(0, INT_MAX, NULL); 147 lockuninit(&backlight_lock); 148 } 149 150 SYSINIT(backlightdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, backlight_drvinit, NULL); 151 MODULE_VERSION(backlight, 1); 152