1 /* $NetBSD: gpio.c,v 1.9 2014/07/19 18:38:34 lneto Exp $ */
2
3 /*
4 * Copyright (c) 2011 Marc Balmer <marc@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
gpio_error(lua_State * L,const char * fmt,...)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
gpio_open(lua_State * L)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
gpio_close(lua_State * L)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
gpio_info(lua_State * L)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
gpio_get_pin(lua_State * L,int n,struct gpio_req * req)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
gpio_set(lua_State * L)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
gpio_unset(lua_State * L)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
gpio_read(lua_State * L)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
gpio_write(lua_State * L)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
gpio_toggle(lua_State * L)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
gpio_attach(lua_State * L)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
gpio_set_info(lua_State * L)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@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
luaopen_gpio(lua_State * L)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