1 /* $NetBSD: fdt_gpio.c,v 1.4 2016/10/15 08:30:42 maxv Exp $ */ 2 3 /*- 4 * Copyright (c) 2015 Jared D. 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: fdt_gpio.c,v 1.4 2016/10/15 08:30:42 maxv Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/kmem.h> 35 36 #include <libfdt.h> 37 #include <dev/fdt/fdtvar.h> 38 39 struct fdtbus_gpio_controller { 40 device_t gc_dev; 41 int gc_phandle; 42 const struct fdtbus_gpio_controller_func *gc_funcs; 43 44 struct fdtbus_gpio_controller *gc_next; 45 }; 46 47 static struct fdtbus_gpio_controller *fdtbus_gc = NULL; 48 49 int 50 fdtbus_register_gpio_controller(device_t dev, int phandle, 51 const struct fdtbus_gpio_controller_func *funcs) 52 { 53 struct fdtbus_gpio_controller *gc; 54 55 gc = kmem_alloc(sizeof(*gc), KM_SLEEP); 56 gc->gc_dev = dev; 57 gc->gc_phandle = phandle; 58 gc->gc_funcs = funcs; 59 60 gc->gc_next = fdtbus_gc; 61 fdtbus_gc = gc; 62 63 return 0; 64 } 65 66 static struct fdtbus_gpio_controller * 67 fdtbus_get_gpio_controller(int phandle) 68 { 69 struct fdtbus_gpio_controller *gc; 70 71 for (gc = fdtbus_gc; gc; gc = gc->gc_next) { 72 if (gc->gc_phandle == phandle) { 73 return gc; 74 } 75 } 76 77 return NULL; 78 } 79 80 struct fdtbus_gpio_pin * 81 fdtbus_gpio_acquire(int phandle, const char *prop, int flags) 82 { 83 struct fdtbus_gpio_controller *gc; 84 struct fdtbus_gpio_pin *gp; 85 int gpio_phandle, len; 86 u_int *data; 87 88 gpio_phandle = fdtbus_get_phandle(phandle, prop); 89 if (gpio_phandle == -1) { 90 return NULL; 91 } 92 93 gc = fdtbus_get_gpio_controller(gpio_phandle); 94 if (gc == NULL) { 95 return NULL; 96 } 97 98 len = OF_getproplen(phandle, prop); 99 if (len < 4) { 100 return NULL; 101 } 102 103 data = kmem_alloc(len, KM_SLEEP); 104 if (OF_getprop(phandle, prop, data, len) != len) { 105 kmem_free(data, len); 106 return NULL; 107 } 108 109 gp = kmem_alloc(sizeof(*gp), KM_SLEEP); 110 gp->gp_gc = gc; 111 gp->gp_priv = gc->gc_funcs->acquire(gc->gc_dev, data, len, flags); 112 if (gp->gp_priv == NULL) { 113 kmem_free(data, len); 114 kmem_free(gp, sizeof(*gp)); 115 return NULL; 116 } 117 118 return gp; 119 } 120 121 void 122 fdtbus_gpio_release(struct fdtbus_gpio_pin *gp) 123 { 124 struct fdtbus_gpio_controller *gc = gp->gp_gc; 125 126 gc->gc_funcs->release(gc->gc_dev, gp->gp_priv); 127 kmem_free(gp, sizeof(*gp)); 128 } 129 130 int 131 fdtbus_gpio_read(struct fdtbus_gpio_pin *gp) 132 { 133 struct fdtbus_gpio_controller *gc = gp->gp_gc; 134 135 return gc->gc_funcs->read(gc->gc_dev, gp->gp_priv, false); 136 } 137 138 void 139 fdtbus_gpio_write(struct fdtbus_gpio_pin *gp, int val) 140 { 141 struct fdtbus_gpio_controller *gc = gp->gp_gc; 142 143 gc->gc_funcs->write(gc->gc_dev, gp->gp_priv, val, false); 144 } 145 146 int 147 fdtbus_gpio_read_raw(struct fdtbus_gpio_pin *gp) 148 { 149 struct fdtbus_gpio_controller *gc = gp->gp_gc; 150 151 return gc->gc_funcs->read(gc->gc_dev, gp->gp_priv, true); 152 } 153 154 void 155 fdtbus_gpio_write_raw(struct fdtbus_gpio_pin *gp, int val) 156 { 157 struct fdtbus_gpio_controller *gc = gp->gp_gc; 158 159 gc->gc_funcs->write(gc->gc_dev, gp->gp_priv, val, true); 160 } 161