From ca1b5688de2d1cb63bb9823e28b87c52f23df449 Mon Sep 17 00:00:00 2001
From: Marek NOVAK <novak@xxxxxxxxxx>
Date: Fri, 3 Sep 2021 18:41:02 +0200
Subject: [PATCH] Adding Lua 5.1 bindings as 'gpiod' Lua module
- Adding bindings directory with wrapper code
- Adding Makefile.am for building and distributing as a Lua module
- Adding --enable-bindings-lua option for autogen.sh
- Adding examples with basic lua gpioset and gpioget implementation
- Output, input and event input with new(), get(), set() and wait()
methods are implemented.
Signed-off-by: Marek NOVAK <novak@xxxxxxxxxx>
---
Makefile.am | 7 +
bindings/Makefile.am | 10 +
bindings/lua/Makefile.am | 20 +
bindings/lua/examples/Makefile.am | 6 +
bindings/lua/examples/gpioget.lua | 28 ++
bindings/lua/examples/gpioset.lua | 47 ++
bindings/lua/gpiod.c | 686 ++++++++++++++++++++++++++++++
configure.ac | 24 +-
8 files changed, 827 insertions(+), 1 deletion(-)
create mode 100644 bindings/Makefile.am
create mode 100644 bindings/lua/Makefile.am
create mode 100644 bindings/lua/examples/Makefile.am
create mode 100644 bindings/lua/examples/gpioget.lua
create mode 100644 bindings/lua/examples/gpioset.lua
create mode 100644 bindings/lua/gpiod.c
diff --git a/Makefile.am b/Makefile.am
index 9b1d00b..174f7a2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -20,6 +20,13 @@ SUBDIRS += tests
endif
+if WITH_BINDINGS_LUA
+
+SUBDIRS += bindings
+
+endif
+
+
if HAS_DOXYGEN
doc:
diff --git a/bindings/Makefile.am b/bindings/Makefile.am
new file mode 100644
index 0000000..753b377
--- /dev/null
+++ b/bindings/Makefile.am
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# SPDX-FileCopyrightText: 2021 Marek Novak <novak@xxxxxxxxxx>
+
+SUBDIRS = .
+
+if WITH_BINDINGS_LUA
+
+SUBDIRS += lua
+
+endif
diff --git a/bindings/lua/Makefile.am b/bindings/lua/Makefile.am
new file mode 100644
index 0000000..b66ae05
--- /dev/null
+++ b/bindings/lua/Makefile.am
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# SPDX-FileCopyrightText: 2021 Marek Novak <novak@xxxxxxxxxx>
+
+lualibdir = ${libdir}/lua/${LUA_VERSION}
+
+lualib_LTLIBRARIES = gpiod.la
+
+gpiod_la_SOURCES = gpiod.c
+gpiod_la_CFLAGS = -Wall -Wextra -g -fPIC -pedantic -std=c11 $(LUA_INCLUDE)
+gpiod_la_CFLAGS += -I$(top_srcdir)/include/
+gpiod_la_LDFLAGS = -std=c11 -shared -module -lgpiod -version-info 1:0:0
$(LUA_LDFLAGS)
+gpiod_la_LIBADD = $(LUA_LIB)
+
+SUBDIRS = .
+
+if WITH_EXAMPLES
+
+SUBDIRS += examples
+
+endif
diff --git a/bindings/lua/examples/Makefile.am
b/bindings/lua/examples/Makefile.am
new file mode 100644
index 0000000..b2abaf1
--- /dev/null
+++ b/bindings/lua/examples/Makefile.am
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# SPDX-FileCopyrightText: 2021 Marek Novak <novak@xxxxxxxxxx>
+
+EXTRA_DIST = \
+ gpioget.lua \
+ gpioset.lua
diff --git a/bindings/lua/examples/gpioget.lua
b/bindings/lua/examples/gpioget.lua
new file mode 100644
index 0000000..57c8051
--- /dev/null
+++ b/bindings/lua/examples/gpioget.lua
@@ -0,0 +1,28 @@
+-- SPDX-License-Identifier: GPL-2.0-or-later
+-- SPDX-FileCopyrightText: 2021 Marek Novak <novak@xxxxxxxxxx>
+
+-- Simplified reimplementation of the gpioget tool in Lua.
+
+require 'gpiod'
+
+
+chip = arg[1]
+offsets = {unpack(arg, 2)}
+if chip == nil or #offsets < 1 then
+ print("usage: gpioget.lua <gpiochip> <offset1> <offset2> ...")
+else
+ ans = ""
+ for index, offset in ipairs(offsets) do
+ line = gpiod:new({chip, offset, "in"})
+ if line == nil then
+ print("failed accessing gpio " .. tostring(chip) .. ":" ..
tostring(offset))
+ ans = nil
+ break
+ end
+
+ ans = ans .. line.get() .. " "
+ end
+ if ans ~= nil then
+ print(ans)
+ end
+end
diff --git a/bindings/lua/examples/gpioset.lua
b/bindings/lua/examples/gpioset.lua
new file mode 100644
index 0000000..c0be02a
--- /dev/null
+++ b/bindings/lua/examples/gpioset.lua
@@ -0,0 +1,47 @@
+-- SPDX-License-Identifier: GPL-2.0-or-later
+-- SPDX-FileCopyrightText: 2021 Marek Novak <novak@xxxxxxxxxx>
+
+-- Simplified reimplementation of the gpioset tool in Lua.
+
+require 'gpiod'
+
+-- helper split function
+function split(s, delimiter)
+ result = {};
+ for match in (s..delimiter):gmatch("(.-)"..delimiter) do
+ table.insert(result, match);
+ end
+ return result;
+end
+
+function usage()
+ print("usage: gpioset.lua <gpiochip> <offset1=value1>
<offset2=value2> ...")
+end
+
+
+chip = arg[1]
+offsets_values = {unpack(arg, 2)}
+if chip == nil or #offsets_values < 1 then
+ usage()
+else
+ print(offsets_values[1])
+ for index, offset_value in ipairs(offsets_values) do
+ offset_value_table = split(offset_value, "=")
+ if #offset_value_table ~= 2 then
+ usage()
+ break
+ end
+
+ offset = tonumber(offset_value_table[1])
+ value = tonumber(offset_value_table[2])
+
+ if offset == nil or (value ~= 0 and value ~= 1) then
+ usage()
+ break
+ end
+
+ line = gpiod:new({chip, offset, "in", value})
+ -- unnecessary - the value is set as default on previous line
+ -- line:set(value)
+ end
+end
diff --git a/bindings/lua/gpiod.c b/bindings/lua/gpiod.c
new file mode 100644
index 0000000..7e19af8
--- /dev/null
+++ b/bindings/lua/gpiod.c
@@ -0,0 +1,686 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+// SPDX-FileCopyrightText: 2021 Marek Novak <novak@xxxxxxxxxx>
+//
+// gpiod.c
+//
+// When this module is loaded, it registers new gpiod metatable
+// and makes it possible to control GPIOs using libgpiod.
+// Three GPIO line modes are available - in, out and event.
+// Out mode is used to output value to the line,
+// in mode is used to synchronously read the value and
+// event mode is used to wait for a rising or falling or both edges
+// and to read the time of event and type of event which happened.
+// By assigning a nil value to a line created using gpiod:new(),
+// it gets released eventually using the garbage collector or
+// you can force collection using collectgarbage().
+// On loading this module, all GPIO CHIPS/Ports are opened
+// and used later when allocating individual lines.
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <gpiod.h>
+
+#include <lua.h>
+#include <lauxlib.h>
+
+// macros
+#define GPIOD_METATABLE "gpiod"
+#define GPIOD_CONSUMER_NAME "Lua"
+#define MAX_GPIO_CHIPS (16)
+#define GPIOD_DBG(verbose, ...) dbg_print(verbose, __func__, __VA_ARGS__)
+// #define PULL_UP_DOWN_SUPPORTED // uncomment to enable pull-up and
pull-down support
+
+// typedefs
+struct gpiod_ud {
+ lua_Integer chip;
+ lua_Integer line;
+ const char *mode;
+ struct gpiod_chip *chip_obj;
+ struct gpiod_line *line_obj;
+ bool verbose;
+};
+
+// functions
+static int gpiod_mt_index(lua_State *L);
+static int gpiod_finalize(lua_State *L);
+static int gpiod_new(lua_State *L);
+static int gpiod_get(lua_State *L);
+static int gpiod_set(lua_State *L);
+static int gpiod_wait(lua_State *L);
+static void dbg_print(bool enable, const char *func_name, char *fmt, ...);
+
+// module global data
+static int gpiochips_opened; // zero since static
+static struct gpiod_chip *gpiochips[MAX_GPIO_CHIPS];
+
+// for verbose mode printing
+static void dbg_print(bool enable, const char *func_name, char *fmt, ...)
+{
+ va_list argptr;
+
+ if (!enable)
+ return;
+
+ va_start(argptr, fmt);
+ printf("[%s]: ", func_name);
+ vprintf(fmt, argptr);
+ printf("\n");
+ va_end(argptr);
+}
+
+// gpiod:new(p)
+static int gpiod_new(lua_State *L)
+{
+ int chip, line, def_val;
+ bool verbose = false;
+ const char *mode;
+ struct gpiod_chip *chip_obj;
+ struct gpiod_line *line_obj;
+ struct gpiod_line_bulk bulk;
+ bool is_rising_edge = false;
+ bool is_falling_edge = false;
+ bool is_open_drain = false;
+ bool is_open_source = false;
+ bool is_active_low = false;
+
+#ifdef PULL_UP_DOWN_SUPPORTED // not available in all versions of libgpiod
+ bool has_pull_up = false;
+ bool has_pull_down = false;
+#endif
+
+ int rv, flags = 0;
+ size_t arglen;
+
+ // Extract the gpiod initialization data from the stack.
+ luaL_checktype(L, 2, LUA_TTABLE);
+ arglen = lua_objlen(L, 2);
+
+ if (arglen < 3) {
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+ // stack = [self, p]
+ lua_rawgeti(L, 2, 1); // 2, 1 = idx in stack, idx in table
+ // stack = [self, p, p[1]]
+ lua_rawgeti(L, 2, 2);
+ // stack = [self, p, p[1], p[2]]
+ lua_rawgeti(L, 2, 3);
+ // stack = [self, p, p[1], p[2], p[3]]
+
+ chip = lua_tointeger(L, -3); // p[1]
+ line = lua_tointeger(L, -2); // p[2]
+ mode = lua_tostring(L, -1); // p[3]
+
+ if (!strcmp(mode, "out")) {
+
+ switch (lua_type(L, 3)) {
+
+ case LUA_TTABLE:
+ arglen = lua_objlen(L, 3);
+ switch (arglen) {
+ case 0:
+ def_val = 0;
+ break;
+
+ case 1:
+ lua_rawgeti(L, 3, 1);
+ def_val = lua_tointeger(L, -1);
+ break;
+
+ case 2:
+ lua_rawgeti(L, 3, 1);
+ lua_rawgeti(L, 3, 2);
+ def_val = lua_tointeger(L, -2);
+ if (lua_tointeger(L, -1)) // open drain ?
+ is_open_drain = true;
+
+ break;
+
+ case 3:
+ lua_rawgeti(L, 3, 1);
+ lua_rawgeti(L, 3, 2);
+ lua_rawgeti(L, 3, 3);
+ def_val = lua_tointeger(L, -3);
+ if (lua_tointeger(L, -2)) // open drain ?
+ is_open_drain = true;
+ if (lua_tointeger(L, -1)) // open source ?
+ is_open_source = true;
+ break;
+
+ case 4:
+ lua_rawgeti(L, 3, 1);
+ lua_rawgeti(L, 3, 2);
+ lua_rawgeti(L, 3, 3);
+ lua_rawgeti(L, 3, 4);
+ def_val = lua_tointeger(L, -4);
+ if (lua_tointeger(L, -3)) // open drain ?
+ is_open_drain = true;
+ if (lua_tointeger(L, -2)) // open source ?
+ is_open_source = true;
+ if (lua_tointeger(L, -1)) // active low ?
+ is_active_low = true;
+ break;
+
+ default:
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+ verbose = luaL_optinteger(L, 4, 0);
+ break;
+
+ case LUA_TNONE:
+ case LUA_TNUMBER:
+ verbose = luaL_optinteger(L, 3, 0);
+ def_val = 0;
+ break;
+
+ default:
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+ if (is_open_drain)
+ flags |= GPIOD_LINE_REQUEST_FLAG_OPEN_DRAIN;
+ if (is_open_source)
+ flags |= GPIOD_LINE_REQUEST_FLAG_OPEN_SOURCE;
+ if (is_active_low)
+ flags |= GPIOD_LINE_REQUEST_FLAG_ACTIVE_LOW;
+ } else if (!strcmp(mode, "in")) {
+
+ switch (lua_type(L, 3)) {
+
+ case LUA_TTABLE:
+
+ arglen = lua_objlen(L, 3);
+ switch (arglen) {
+ case 0:
+ break;
+
+#ifdef PULL_UP_DOWN_SUPPORTED // not available in all versions of libgpiod
+ case 1:
+ lua_rawgeti(L, 3, 1);
+ if (lua_tointeger(L, -1)) // pull up ?
+ has_pull_up = true;
+ break;
+
+ case 2:
+ lua_rawgeti(L, 3, 1);
+ lua_rawgeti(L, 3, 2);
+ if (lua_tointeger(L, -2)) // pull up ?
+ has_pull_up = true;
+
+ if (lua_tointeger(L, -1)) // pull down ?
+ has_pull_down = true;
+ break;
+#endif
+ default:
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+ verbose = luaL_optinteger(L, 4, 0);
+ break;
+
+ case LUA_TNONE:
+ case LUA_TNUMBER:
+ verbose = luaL_optinteger(L, 3, 0);
+ break;
+
+ default:
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+#ifdef PULL_UP_DOWN_SUPPORTED
+
+ if (has_pull_up)
+ flags |= GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP;
+ if (has_pull_down)
+ flags |= GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_DOWN;
+#endif
+
+ } else if (!strcmp(mode, "event")) {
+
+ switch (lua_type(L, 3)) {
+
+ case LUA_TTABLE:
+
+ arglen = lua_objlen(L, 3);
+ switch (arglen) {
+ case 0:
+ is_rising_edge = true;
+ is_falling_edge = false;
+ break;
+
+ case 1:
+ lua_rawgeti(L, 3, 1);
+ is_rising_edge = lua_tointeger(L, -1);
+ break;
+
+ case 2:
+ lua_rawgeti(L, 3, 1);
+ lua_rawgeti(L, 3, 2);
+ is_rising_edge = lua_tointeger(L, -2);
+ is_falling_edge = lua_tointeger(L, -1);
+ break;
+
+#ifdef PULL_UP_DOWN_SUPPORTED
+ case 3:
+ lua_rawgeti(L, 3, 1);
+ lua_rawgeti(L, 3, 2);
+ lua_rawgeti(L, 3, 3);
+ is_rising_edge = lua_tointeger(L, -3);
+ is_falling_edge = lua_tointeger(L, -2);
+ if (lua_tointeger(L, -1)) // pull up ?
+ has_pull_up = true;
+ break;
+
+ case 4:
+ lua_rawgeti(L, 3, 1);
+ lua_rawgeti(L, 3, 2);
+ lua_rawgeti(L, 3, 3);
+ is_rising_edge = lua_tointeger(L, -4);
+ is_falling_edge = lua_tointeger(L, -3);
+ if (lua_tointeger(L, -2)) // pull up ?
+ has_pull_up = true;
+ if (lua_tointeger(L, -1)) // pull down ?
+ has_pull_down = true;
+ break;
+#endif
+ default:
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+ verbose = luaL_optinteger(L, 4, 0);
+ break;
+
+ case LUA_TNONE:
+ case LUA_TNUMBER:
+ verbose = luaL_optinteger(L, 3, 0);
+ break;
+
+ default:
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+#ifdef PULL_UP_DOWN_SUPPORTED
+ if (has_pull_up)
+ flags |= GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP;
+ if (has_pull_down)
+ flags |= GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_DOWN;
+#endif
+
+ }
+
+ lua_settop(L, 0);
+ // stack = []
+
+ // validate chip number, line number and mode...
+ if (chip < gpiochips_opened)
+ chip_obj = gpiochips[chip];
+ else {
+ GPIOD_DBG(verbose, "Bad GPIOCHIP!");
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+ gpiod_line_bulk_init(&bulk);
+ line_obj = gpiod_chip_get_line(chip_obj, line);
+ if (!line_obj) {
+ GPIOD_DBG(verbose, "Failed to get line %d", line);
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+ gpiod_line_bulk_add(&bulk, line_obj);
+
+ if (!strcmp("out", mode)) {
+
+ rv = gpiod_line_request_bulk_output_flags(&bulk,
+ GPIOD_CONSUMER_NAME, flags, &def_val);
+
+ if (rv < 0) { // failed to open line
+ GPIOD_DBG(verbose,
+ "Fail: line %d, mode 'out', flags 0x%08X!",
+ line, flags);
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+ } else if (!strcmp("in", mode)) {
+ rv = gpiod_line_request_bulk_input_flags(&bulk,
+ GPIOD_CONSUMER_NAME, flags);
+ if (rv < 0) { // failed to open line
+ GPIOD_DBG(verbose,
+ "Fail: line %d, mode 'in', flags 0x%08X!",
+ line, flags);
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+ } else if (!strcmp("event", mode)) {
+ if (is_rising_edge)
+ rv = gpiod_line_request_bulk_rising_edge_events_flags(
+ &bulk, GPIOD_CONSUMER_NAME, flags);
+ else if (is_falling_edge)
+ rv = gpiod_line_request_bulk_falling_edge_events_flags(
+ &bulk, GPIOD_CONSUMER_NAME, flags);
+ else
+ rv = gpiod_line_request_bulk_both_edges_events_flags(
+ &bulk, GPIOD_CONSUMER_NAME, flags);
+
+ if (rv < 0) { // failed to open line
+ GPIOD_DBG(verbose,
+ "Fail: line %d, mode '%s', flags 0x%08X!",
+ (is_rising_edge)?"evt rising" :
+ (is_falling_edge)?"evt falling" :
+ "evt rising/falling",
+ line, flags);
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+ } else { // bad mode
+ GPIOD_DBG(verbose, "Bad mode '%s'!", mode);
+ lua_settop(L, 0);
+ lua_pushnil(L);
+ return 1;
+ }
+
+
+ // Create a gpiod instance and set its metatable.
+ struct gpiod_ud *gpiod = (struct gpiod_ud *)lua_newuserdata(L,
+ sizeof(struct gpiod_ud));
+ // stack = [gpiod]
+ luaL_getmetatable(L, GPIOD_METATABLE);
+ // stack = [gpiod, mt]
+ lua_setmetatable(L, 1);
+ // stack = [gpiod]
+
+ // Set up the C data.
+ gpiod->chip = chip;
+ gpiod->line = line;
+ gpiod->mode = mode;
+ gpiod->chip_obj = chip_obj;
+ gpiod->line_obj = line_obj;
+ gpiod->verbose = verbose;
+
+ GPIOD_DBG(gpiod->verbose,
+ "new line chip=%d, line=%d, mode='%s'", chip, line, mode);
+
+ return 1;
+}
+
+// gpiod:set(p)
+static int gpiod_set(lua_State *L)
+{
+ // Expected: stack = [self, key]
+ struct gpiod_ud *gpiod = (struct gpiod_ud *)luaL_checkudata(L, 1,
+ GPIOD_METATABLE);
+ int value = 0;
+ int rv;
+ int t = lua_type(L, 2);
+
+ if (t == LUA_TNUMBER) {
+ value = (int)lua_tointeger(L, 2);
+ value = !(!value);
+ } else {
+ GPIOD_DBG(gpiod->verbose,
+ "Number required as new value, bad type!");
+ return 0;
+ }
+
+ rv = gpiod_line_set_value(gpiod->line_obj, value);
+
+ if (rv)
+ GPIOD_DBG(gpiod->verbose, "Failed to set new value!");
+ else
+ GPIOD_DBG(gpiod->verbose, "GPIO %d.%d=%d",
+ gpiod->chip, gpiod->line, value);
+ return 0;
+}
+
+// gpiod:get(p)
+static int gpiod_get(lua_State *L)
+{
+ // Expected: stack = [self, key]
+ struct gpiod_ud *gpiod = (struct gpiod_ud *)luaL_checkudata(L, 1,
+ GPIOD_METATABLE);
+ int t = lua_type(L, 2);
+ int rv;
+
+ if (t != LUA_TNONE) {
+ GPIOD_DBG(gpiod->verbose, "No extra arguments required!");
+ return 0;
+ }
+
+ rv = gpiod_line_get_value(gpiod->line_obj);
+
+ if (rv < 0) {
+ GPIOD_DBG(gpiod->verbose, "Failed to set new value!");
+ return 0;
+ }
+
+ GPIOD_DBG(gpiod->verbose, "GPIO %d.%d=%d",
+ gpiod->chip, gpiod->line, rv);
+ lua_pushboolean(L, rv);
+ return 1;
+
+}
+
+// gpiod:wait(p)
+static int gpiod_wait(lua_State *L)
+{
+ // Expected: stack = [self, key]
+ struct gpiod_ud *gpiod = (struct gpiod_ud *)luaL_checkudata(L, 1,
GPIOD_METATABLE);
+
+ struct gpiod_line_event evt;
+ int timeout = 0;
+ int rv;
+ int t = lua_type(L, 2);
+ struct timespec tout;
+
+ if (t != LUA_TNUMBER) {
+ GPIOD_DBG(gpiod->verbose, "Expected numeric timeout value in sec");
+ return 0;
+ }
+
+ timeout = lua_tointeger(L, 2);
+
+ t = lua_type(L, 3);
+ if (t != LUA_TNONE) {
+ GPIOD_DBG(gpiod->verbose, "Only one argument expected!");
+ return 0;
+ }
+
+ tout.tv_nsec = 0;
+ tout.tv_sec = timeout;
+
+ rv = gpiod_line_event_wait(gpiod->line_obj, &tout);
+ if (rv < 0) {
+ GPIOD_DBG(gpiod->verbose, "Failed waiting for event!");
+ return 0;
+ } else if (rv == 0) {
+ GPIOD_DBG(gpiod->verbose, "Timed out waiting for event!");
+ return 0;
+ }
+
+ rv = gpiod_line_event_read(gpiod->line_obj, &evt);
+ if (rv < 0) {
+ GPIOD_DBG(gpiod->verbose,
+ "Failed reading event type!");
+ return 0;
+ }
+ if (evt.event_type == GPIOD_LINE_EVENT_RISING_EDGE)
+ lua_pushstring(L, "rising");
+ else
+ lua_pushstring(L, "falling");
+
+ lua_pushinteger(L, evt.ts.tv_sec);
+ lua_pushinteger(L, evt.ts.tv_nsec);
+
+ GPIOD_DBG(gpiod->verbose, "GPIO %d.%d -> %s @ %d.%09d",
+ gpiod->chip, gpiod->line,
+ (evt.event_type == GPIOD_LINE_EVENT_RISING_EDGE) ?
+ "rising" : "falling",
+ evt.ts.tv_sec, evt.ts.tv_nsec);
+
+ return 3;
+}
+
+// gpiod_mt:index(key)
+static int gpiod_mt_index(lua_State *L)
+{
+
+ // Expected: stack = [self, key]
+ struct gpiod_ud *gpiod = (struct gpiod_ud *)luaL_checkudata(L, 1,
+ GPIOD_METATABLE);
+ int t = lua_type(L, 2);
+ const char *str_key;
+
+ if (t != LUA_TSTRING) {
+ GPIOD_DBG(gpiod->verbose, "Bad property!");
+ lua_pushnil(L);
+ return 1;
+ }
+
+ str_key = lua_tostring(L, 2);
+
+ if (strcmp(str_key, "chip") == 0) {
+ lua_pushinteger(L, gpiod->chip);
+ return 1;
+ } else if (strcmp(str_key, "line") == 0) {
+ lua_pushinteger(L, gpiod->line);
+ return 1;
+ } else if (strcmp(str_key, "mode") == 0) {
+ lua_pushstring(L, gpiod->mode);
+ return 1;
+ }
+
+ if (!strcmp(gpiod->mode, "out")) {
+ static struct luaL_Reg fns_out[] = {
+ {"set", gpiod_set},
+ {NULL, NULL}};
+ for (int idx = 0; fns_out[idx].func; idx++) {
+ if (!strcmp(str_key, fns_out[idx].name)) {
+ lua_pushcfunction(L,
+ fns_out[idx].func);
+ return 1;
+ }
+ }
+ } else if (!strcmp(gpiod->mode, "in")) {
+ static struct luaL_Reg fns_in[] = {
+ {"get", gpiod_get},
+ {NULL, NULL}};
+
+ for (int idx = 0; fns_in[idx].func; idx++) {
+ if (!strcmp(str_key, fns_in[idx].name)) {
+ lua_pushcfunction(L, fns_in[idx].func);
+ return 1;
+ }
+ }
+ } else if (!strcmp(gpiod->mode, "event")) {
+ static struct luaL_Reg fns_event[] = {
+ {"wait", gpiod_wait},
+ {NULL, NULL}};
+
+ for (int idx = 0; fns_event[idx].func; idx++) {
+ if (!strcmp(str_key, fns_event[idx].name)) {
+ lua_pushcfunction(L,
+ fns_event[idx].func);
+ return 1;
+ }
+ }
+ }
+
+
+ GPIOD_DBG(gpiod->verbose, "Bad property!");
+ lua_pushnil(L);
+ return 1;
+}
+
+static int gpiod_finalize(lua_State *L)
+{
+ struct gpiod_ud *gpiod = (struct gpiod_ud *)luaL_checkudata(L, 1,
+ GPIOD_METATABLE);
+ GPIOD_DBG(gpiod->verbose, "finalizing GPIO %d.%d",
+ gpiod->chip, gpiod->line);
+ gpiod_line_release(gpiod->line_obj);
+ return 0;
+}
+
+
+
+// entrypoint
+int luaopen_gpiod(lua_State *L)
+{
+
+ // The user may pass in values here,
+ // but we'll ignore those values.
+ lua_settop(L, 0);
+
+ // stack = []
+
+ // If this metatable already exists, the library is already
+ // loaded.
+ if (luaL_newmetatable(L, GPIOD_METATABLE)) {
+ // stack = [mt]
+ static struct luaL_Reg metamethods[] = {
+ {"__index", gpiod_mt_index},
+ {"__gc", gpiod_finalize},
+ {NULL, NULL}};
+ lua_setglobal(L, GPIOD_METATABLE);
+ luaL_register(L, GPIOD_METATABLE, metamethods);
+ // in lua 5.2+ luaL_setfuncs(L, metamethods, 0);
+ lua_pop(L, 1); // The table is saved in the Lua's registry.
+
+ // stack = []
+ struct gpiod_chip_iter *iter;
+ struct gpiod_chip *chip;
+
+ iter = gpiod_chip_iter_new();
+ gpiochips_opened = 0;
+ if (!iter)
+ return 0;
+ gpiod_foreach_chip_noclose(iter, chip) {
+ gpiochips[gpiochips_opened] = chip;
+ gpiochips_opened++;
+ if (gpiochips_opened >= MAX_GPIO_CHIPS) {
+ GPIOD_DBG(true,
+ "Limiting number of GPIOCHIPS!");
+ break;
+ }
+ }
+
+ gpiod_chip_iter_free(iter);
+
+ }
+
+ static struct luaL_Reg fns[] = {
+ {"new", gpiod_new},
+ {"set", gpiod_set},
+ {"get", gpiod_get},
+ {"wait", gpiod_wait},
+ {NULL, NULL}};
+
+ luaL_register(L, GPIOD_METATABLE, fns); // Push a new table with fns
key/vals.
+ // lua 5.2+ luaL_newlib(L, fns);
+
+ // stack = [gpiod = {new = new}]
+
+ return 1; // Return the top item, the gpiod table.
+}
diff --git a/configure.ac b/configure.ac
index 523c21e..2ea0067 100644
--- a/configure.ac
+++ b/configure.ac
@@ -113,6 +113,25 @@ then
PKG_CHECK_MODULES([UDEV], [libudev >= 215])
fi
+AC_ARG_ENABLE([examples],
+ [AS_HELP_STRING([--enable-examples], [enable building code
examples[default=no]])],
+ [if test "x$enableval" = xyes; then with_examples=true; fi],
+ [with_examples=false])
+AM_CONDITIONAL([WITH_EXAMPLES], [test "x$with_examples" = xtrue])
+
+AC_ARG_ENABLE([bindings-lua],
+ [AS_HELP_STRING([--enable-bindings-lua],[enable lua 5.1 bindings
[default=no]])],
+ [if test "x$enableval" = xyes; then with_bindings_lua=true; fi],
+ [with_bindings_lua=false])
+AM_CONDITIONAL([WITH_BINDINGS_LUA], [test "x$with_bindings_lua" = xtrue])
+
+if test "x$with_bindings_lua" = xtrue
+then
+ AX_PROG_LUA([5.1], [5.2])
+ AX_LUA_HEADERS
+ AX_LUA_LIBS
+fi
+
AC_CHECK_PROG([has_doxygen], [doxygen], [true], [false])
AM_CONDITIONAL([HAS_DOXYGEN], [test "x$has_doxygen" = xtrue])
if test "x$has_doxygen" = xfalse
@@ -126,6 +145,9 @@ AC_CONFIG_FILES([libgpiod.pc
src/Makefile
src/lib/Makefile
src/tools/Makefile
- tests/Makefile])
+ tests/Makefile
+ bindings/Makefile
+ bindings/lua/Makefile
+ bindings/lua/examples/Makefile])
AC_OUTPUT
--
2.32.0
[libgpiod] Add Lua 5.1 binding for libgpiod v1.0.x branch
