add nix derivation for compiling with CMAKE

pin_control/CMakeLists.txt

@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(PinControl)
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(LIBGPIOD REQUIRED libgpiod)
+
+add_library(pin_control SHARED src/pin_control.c)
+
+target_include_directories(pin_control PUBLIC include/ PRIVATE ${LIBGPIOD_INCLUDE_DIRS})
+target_link_libraries(pin_control PUBLIC ${LIBGPIOD_LIBRARIES})
+set_target_properties(pin_control PROPERTIES POSITION_INDEPENDENT_CODE ON)
+
+target_compile_options(pin_control PUBLIC -Wall -Wextra -Werror)
+
+install(TARGETS pin_control LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
+install(FILES include/pin_control.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})

pin_control/default.nix

@@ -0,0 +1,10 @@
+{ stdenv, libgpiod, cmake, pkg-config }:
+stdenv.mkDerivation {
+  pname = "pin_control";
+  version = "0.0.1";
+  src = ./.;
+  buildInputs = [ libgpiod ];
+  nativeBuildInputs = [ cmake pkg-config ];
+
+  outputs = [ "out" "dev" ];
+}

pin_control/readme.md

@@ -1 +1,5 @@
-gcc -o pin_contro_test main.c pin_control.c -lgpiod
+Compilation command:
+
+```
+
+```

pin_control/src/pin_control.c

@@ -74,6 +74,8 @@ int turn_off_all_pins() {
 }
 
 int button_presssed(int event, unsigned int pin, const struct timespec * timestamp, void *data) {
+    (void) event;
+    (void) timestamp;
     * (int *) data = (int) pin;
     return GPIOD_CTXLESS_EVENT_POLL_RET_STOP;
 }
@@ -83,20 +85,20 @@ int wait_for_button_press(unsigned int pins[]) {
     
     int pressed_pin = -1;
 
-    struct timespec {
-        time_t  3600;  /* Seconds */
-        long    0; /* Nanoseconds */
-    } ts;
-    
-    gpiod_ctxless_event_monitor_multiple(chip,
+    struct timespec ts = {
+        .tv_sec = 3600,
+        .tv_nsec = 0,
+    };
+
+    return gpiod_ctxless_event_monitor_multiple(GPIO_CHIP,
                                         GPIOD_CTXLESS_EVENT_FALLING_EDGE,
                                         pins,
                                         5,
                                         true,
                                         "house-leds",
-                                        ts,     // big timout
+                                        &ts,     // big timout
                                         NULL,
                                         button_presssed,
                                         &pressed_pin
-                                        )
+                                        );
 }