1 files changed, 67 insertions, 0 deletions
diff --git a/stmhal/usrsw.c b/stmhal/usrsw.c
new file mode 100644
index 000000000..69a03b2cc
--- /dev/null
+++ b/stmhal/usrsw.c
@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stm32f4xx_hal.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "runtime.h"
+#include "usrsw.h"
+
+#include "exti.h"
+#include "gpio.h"
+#include "pin.h"
+#include "build/pins.h"
+
+// Usage Model:
+//
+// pyb.switch() returns True if the user switch is pressed, False otherwise.
+//
+// pyb.switch(callback) will register a callback to be called when the user
+//                      switch is pressed.
+//
+// pyb.switch(None) will remove the callback.
+//
+// Example:
+//
+// def switch_pressed():
+//     print("User Switch pressed")
+//
+// pyb.switch(switch_pressed)
+
+static mp_obj_t switch_user_callback_obj;
+
+static mp_obj_t switch_callback(mp_obj_t line) {
+    if (switch_user_callback_obj != mp_const_none) {
+        rt_call_function_0(switch_user_callback_obj);
+    }
+    return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(switch_callback_obj, switch_callback);
+
+void switch_init(void) {
+    switch_user_callback_obj = mp_const_none;
+    exti_register((mp_obj_t)&USRSW_PIN,
+                  MP_OBJ_NEW_SMALL_INT(USRSW_EXTI_MODE),
+                  MP_OBJ_NEW_SMALL_INT(USRSW_PULL),
+                  (mp_obj_t)&switch_callback_obj,
+                  NULL);
+}
+
+int switch_get(void) {
+    int val = ((USRSW_PIN.gpio->IDR & USRSW_PIN.pin_mask) != 0);
+    return val == USRSW_PRESSED;
+}
+
+/******************************************************************************/
+/* Micro Python bindings                                                      */
+
+static mp_obj_t pyb_switch(uint n_args, mp_obj_t *args) {
+    if (n_args == 0) {
+        return switch_get() ? mp_const_true : mp_const_false;
+    }
+    switch_user_callback_obj = args[0];
+    return mp_const_none;
+}
+
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_switch_obj, 0, 1, pyb_switch);