1 /* $NetBSD: led.c,v 1.2 2017/07/08 19:25:37 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: led.c,v 1.2 2017/07/08 19:25:37 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/device.h> 35 #include <sys/kmem.h> 36 #include <sys/queue.h> 37 #include <sys/sysctl.h> 38 #include <sys/once.h> 39 40 #include <dev/led.h> 41 42 struct led_device { 43 char *name; 44 led_getstate_fn getstate; 45 led_setstate_fn setstate; 46 void *priv; 47 48 struct sysctllog *slog; 49 50 TAILQ_ENTRY(led_device) devices; 51 }; 52 53 static TAILQ_HEAD(, led_device) led_devices = 54 TAILQ_HEAD_INITIALIZER(led_devices); 55 static kmutex_t led_lock; 56 57 static int 58 led_init(void) 59 { 60 mutex_init(&led_lock, MUTEX_DEFAULT, IPL_NONE); 61 62 return 0; 63 } 64 65 static struct led_device * 66 led_lookup(const char *name) 67 { 68 struct led_device *led; 69 70 KASSERT(mutex_owned(&led_lock)); 71 72 TAILQ_FOREACH(led, &led_devices, devices) 73 if (strcmp(led->name, name) == 0) 74 return led; 75 76 return NULL; 77 } 78 79 static void 80 led_normalize_name(char *name) 81 { 82 unsigned char *p; 83 84 for (p = (unsigned char *)name; *p; p++) 85 if (!isalpha(*p) && !isdigit(*p) && *p != '-' && *p != '_') 86 *p = '_'; 87 } 88 89 static void 90 led_free(struct led_device *led) 91 { 92 KASSERT(mutex_owned(&led_lock)); 93 94 kmem_free(led->name, strlen(led->name) + 1); 95 kmem_free(led, sizeof(*led)); 96 } 97 98 static int 99 led_sysctl_handler(SYSCTLFN_ARGS) 100 { 101 struct sysctlnode node; 102 struct led_device *led; 103 int error, state; 104 105 mutex_enter(&led_lock); 106 107 node = *rnode; 108 led = node.sysctl_data; 109 state = led->getstate(led->priv); 110 node.sysctl_data = &state; 111 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 112 if (error || newp == NULL) { 113 mutex_exit(&led_lock); 114 return error; 115 } 116 117 if (state < LED_STATE_OFF || state > LED_STATE_ON) { 118 mutex_exit(&led_lock); 119 return EINVAL; 120 } 121 122 led->setstate(led->priv, state); 123 124 mutex_exit(&led_lock); 125 126 return 0; 127 } 128 129 void * 130 led_attach(const char *name, void *priv, led_getstate_fn getstate, 131 led_setstate_fn setstate) 132 { 133 static ONCE_DECL(control); 134 struct led_device *led; 135 const struct sysctlnode *node; 136 int error; 137 138 if (RUN_ONCE(&control, led_init) != 0) 139 return NULL; 140 141 led = kmem_zalloc(sizeof(*led), KM_SLEEP); 142 led->name = kmem_asprintf("%s", name); 143 led->getstate = getstate; 144 led->setstate = setstate; 145 led->priv = priv; 146 147 /* Convert invalid sysctl node name characters to underscores */ 148 led_normalize_name(led->name); 149 150 mutex_enter(&led_lock); 151 if (led_lookup(name) != NULL) { 152 led_free(led); 153 led = NULL; 154 } else { 155 error = sysctl_createv(&led->slog, 0, NULL, &node, 156 CTLFLAG_PERMANENT, CTLTYPE_NODE, "led", NULL, 157 NULL, 0, NULL, 0, 158 CTL_HW, CTL_CREATE, CTL_EOL); 159 if (error == 0) { 160 error = sysctl_createv(&led->slog, 0, &node, NULL, 161 CTLFLAG_READWRITE, CTLTYPE_BOOL, led->name, NULL, 162 led_sysctl_handler, 0, 163 (void *)led, 0, 164 CTL_CREATE, CTL_EOL); 165 } 166 if (error != 0) { 167 printf("led: failed to create sysctl hw.led.%s: %d\n", 168 led->name, error); 169 led_free(led); 170 led = NULL; 171 } 172 } 173 if (led != NULL) 174 TAILQ_INSERT_TAIL(&led_devices, led, devices); 175 mutex_exit(&led_lock); 176 177 return led; 178 } 179 180 void 181 led_detach(void *handle) 182 { 183 struct led_device *led = handle; 184 185 mutex_enter(&led_lock); 186 187 TAILQ_REMOVE(&led_devices, led, devices); 188 sysctl_teardown(&led->slog); 189 led_free(led); 190 191 mutex_exit(&led_lock); 192 } 193