1 /* $NetBSD: gpio.c,v 1.9 2014/07/19 18:38:34 lneto Exp $ */ 2 3 /* 4 * Copyright (c) 2011 Marc Balmer <marc (at) msys.ch> 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, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* GPIO interface for Lua */ 29 30 #include <errno.h> 31 #include <fcntl.h> 32 #include <stdarg.h> 33 #include <stdio.h> 34 #include <string.h> 35 #include <ctype.h> 36 #include <stdlib.h> 37 #include <unistd.h> 38 39 #include <lua.h> 40 #include <lauxlib.h> 41 #include <lualib.h> 42 43 #include <sys/gpio.h> 44 #include <sys/ioctl.h> 45 46 #define GPIO_METATABLE "GPIO object methods" 47 48 static __printflike(2, 3) void 49 gpio_error(lua_State *L, const char *fmt, ...) 50 { 51 va_list ap; 52 int len; 53 char *msg; 54 55 va_start(ap, fmt); 56 len = vasprintf(&msg, fmt, ap); 57 va_end(ap); 58 59 if (len != -1) { 60 lua_pushstring(L, msg); 61 free(msg); 62 } else 63 lua_pushstring(L, "vasprintf failed"); 64 lua_error(L); 65 } 66 67 static int 68 gpio_open(lua_State *L) 69 { 70 int *fd; 71 72 fd = lua_newuserdata(L, sizeof(int)); 73 *fd = open(luaL_checkstring(L, -2), O_RDWR); 74 if (*fd == -1) { 75 gpio_error(L, "%s", strerror(errno)); 76 /* NOTREACHED */ 77 return 0; 78 } 79 luaL_getmetatable(L, GPIO_METATABLE); 80 lua_setmetatable(L, -2); 81 return 1; 82 } 83 84 static int 85 gpio_close(lua_State *L) 86 { 87 int *fd; 88 89 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 90 if (*fd != -1) { 91 close(*fd); 92 *fd = -1; 93 } 94 return 0; 95 } 96 97 static int 98 gpio_info(lua_State *L) 99 { 100 struct gpio_info info; 101 int *fd; 102 103 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 104 if (ioctl(*fd, GPIOINFO, &info) == -1) 105 gpio_error(L, "GPIOINFO"); 106 lua_pushinteger(L, info.gpio_npins); 107 return 1; 108 } 109 110 static void 111 gpio_get_pin(lua_State *L, int n, struct gpio_req *req) 112 { 113 switch (lua_type(L, n)) { 114 case LUA_TNUMBER: 115 req->gp_pin = (int)lua_tointeger(L, n); /* not 1 based! */ 116 break; 117 case LUA_TSTRING: 118 strlcpy(req->gp_name, lua_tostring(L, n), sizeof(req->gp_name)); 119 break; 120 default: 121 luaL_argerror(L, n, "expected string or integer"); 122 /* NOTREACHED */ 123 } 124 } 125 126 static int 127 gpio_set(lua_State *L) 128 { 129 struct gpio_set set; 130 int *fd; 131 132 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 133 memset(&set, 0, sizeof(set)); 134 gpio_get_pin(L, 2, (void *)&set); 135 set.gp_flags = (int)luaL_checkinteger(L, 3); 136 if (ioctl(*fd, GPIOSET, &set) == -1) 137 gpio_error(L, "GPIOSET"); 138 return 0; 139 } 140 141 static int 142 gpio_unset(lua_State *L) 143 { 144 struct gpio_set set; 145 int *fd; 146 147 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 148 memset(&set, 0, sizeof(set)); 149 gpio_get_pin(L, 2, (void *)&set); 150 if (ioctl(*fd, GPIOUNSET, &set) == -1) 151 gpio_error(L, "GPIOUNSET"); 152 return 0; 153 } 154 155 static int 156 gpio_read(lua_State *L) 157 { 158 struct gpio_req req; 159 int *fd; 160 161 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 162 memset(&req, 0, sizeof(req)); 163 gpio_get_pin(L, 2, &req); 164 if (ioctl(*fd, GPIOREAD, &req) == -1) 165 gpio_error(L, "GPIOREAD"); 166 lua_pushinteger(L, req.gp_value); 167 return 1; 168 } 169 170 171 static int 172 gpio_write(lua_State *L) 173 { 174 struct gpio_req req; 175 int *fd, val; 176 177 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 178 val = (int)luaL_checkinteger(L, 3); 179 if (val != GPIO_PIN_HIGH && val != GPIO_PIN_LOW) 180 gpio_error(L, "%d: invalid value", val); 181 memset(&req, 0, sizeof(req)); 182 gpio_get_pin(L, 2, &req); 183 req.gp_value = val; 184 if (ioctl(*fd, GPIOWRITE, &req) == -1) 185 gpio_error(L, "GPIOWRITE"); 186 lua_pushinteger(L, req.gp_value); 187 return 1; 188 } 189 190 static int 191 gpio_toggle(lua_State *L) 192 { 193 struct gpio_req req; 194 int *fd; 195 196 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 197 memset(&req, 0, sizeof(req)); 198 gpio_get_pin(L, 2, &req); 199 if (ioctl(*fd, GPIOTOGGLE, &req) == -1) 200 gpio_error(L, "GPIOTOGGLE"); 201 lua_pushinteger(L, req.gp_value); 202 return 1; 203 } 204 205 static int 206 gpio_attach(lua_State *L) 207 { 208 struct gpio_attach attach; 209 int *fd; 210 211 fd = luaL_checkudata(L, 1, GPIO_METATABLE); 212 memset(&attach, 0, sizeof(attach)); 213 strlcpy(attach.ga_dvname, luaL_checkstring(L, 2), 214 sizeof(attach.ga_dvname)); 215 attach.ga_offset = (int)luaL_checkinteger(L, 3); 216 attach.ga_mask = (int)luaL_checkinteger(L, 4); 217 if (lua_gettop(L) > 4) 218 attach.ga_flags = (int)luaL_checkinteger(L, 5); 219 else 220 attach.ga_flags = 0; 221 222 if (ioctl(*fd, GPIOATTACH, &attach) == -1) 223 gpio_error(L, "GPIOATTACH"); 224 return 0; 225 } 226 227 struct constant { 228 const char *name; 229 int value; 230 }; 231 232 static const struct constant gpio_constant[] = { 233 /* GPIO pin states */ 234 { "PIN_LOW", GPIO_PIN_LOW }, 235 { "PIN_HIGH", GPIO_PIN_HIGH }, 236 237 /* GPIO pin configuration flags */ 238 { "PIN_INPUT", GPIO_PIN_INPUT }, 239 { "PIN_OUTPUT", GPIO_PIN_OUTPUT }, 240 { "PIN_INOUT", GPIO_PIN_INOUT }, 241 { "PIN_OPENDRAIN", GPIO_PIN_OPENDRAIN }, 242 { "PIN_PUSHPULL", GPIO_PIN_PUSHPULL }, 243 { "PIN_TRISTATE", GPIO_PIN_TRISTATE }, 244 { "PIN_PULLUP", GPIO_PIN_PULLUP }, 245 { "PIN_PULLDOWN", GPIO_PIN_PULLDOWN }, 246 { "PIN_INVIN", GPIO_PIN_INVIN }, 247 { "PIN_INVOUT", GPIO_PIN_INVOUT }, 248 { "PIN_USER", GPIO_PIN_USER }, 249 { "PIN_PULSATE", GPIO_PIN_PULSATE }, 250 { "PIN_SET", GPIO_PIN_SET }, 251 { NULL, 0 } 252 }; 253 254 static void 255 gpio_set_info(lua_State *L) 256 { 257 lua_pushliteral(L, "_COPYRIGHT"); 258 lua_pushliteral(L, "Copyright (C) 2011, 2013 Marc Balmer " 259 "<marc (at) msys.ch>"); 260 lua_settable(L, -3); 261 lua_pushliteral(L, "_DESCRIPTION"); 262 lua_pushliteral(L, "GPIO interface for Lua"); 263 lua_settable(L, -3); 264 lua_pushliteral(L, "_VERSION"); 265 lua_pushliteral(L, "gpio 1.0.2"); 266 lua_settable(L, -3); 267 } 268 269 int luaopen_gpio(lua_State*); 270 271 int 272 luaopen_gpio(lua_State* L) 273 { 274 static const struct luaL_Reg methods[] = { 275 { "open", gpio_open }, 276 { NULL, NULL } 277 }; 278 static const struct luaL_Reg gpio_methods[] = { 279 { "info", gpio_info }, 280 { "close", gpio_close }, 281 { "set", gpio_set }, 282 { "unset", gpio_unset }, 283 { "read", gpio_read }, 284 { "write", gpio_write }, 285 { "toggle", gpio_toggle }, 286 { "attach", gpio_attach }, 287 { NULL, NULL } 288 }; 289 int n; 290 291 luaL_newlib(L, methods); 292 luaL_setfuncs(L, gpio_methods, 0); 293 gpio_set_info(L); 294 295 /* The gpio metatable */ 296 if (luaL_newmetatable(L, GPIO_METATABLE)) { 297 luaL_setfuncs(L, gpio_methods, 0); 298 299 lua_pushliteral(L, "__gc"); 300 lua_pushcfunction(L, gpio_close); 301 lua_settable(L, -3); 302 303 lua_pushliteral(L, "__index"); 304 lua_pushvalue(L, -2); 305 lua_settable(L, -3); 306 307 lua_pushliteral(L, "__metatable"); 308 lua_pushliteral(L, "must not access this metatable"); 309 lua_settable(L, -3); 310 } 311 lua_pop(L, 1); 312 313 for (n = 0; gpio_constant[n].name != NULL; n++) { 314 lua_pushinteger(L, gpio_constant[n].value); 315 lua_setfield(L, -2, gpio_constant[n].name); 316 }; 317 return 1; 318 } 319
Indexes created Sun Sep 21 16:09:51 GMT 2025