Nucleo-f402re: Add an option to use only a minimal set of joystick buttons. This eliminates some GPIO conflicts

configs/nucleo-f4x1re/Kconfig

@@ -2,3 +2,20 @@
 # For a description of the syntax of this configuration file,
 # see misc/tools/kconfig-language.txt.
 #
+
+if ARCH_BOARD_NUCLEO_F401RE
+
+config NUCLEO_F401RE_AJOY_MINBUTTONS
+	bool "Minimal Joystick Buttons"
+	default n if !STM32_USART1
+	default y if STM32_USART1
+	depends on AJOYSTICK
+	---help---
+		The Itead Joystick shield supports analog X/Y position and up to 5
+		buttons.  Some of these buttons may conflict with other resources
+		(Button F, for example, conflicts with the default USART1 pin usage).
+		Selecting this option will return the number of buttons to the
+		minimal set:  SELECT (joystick down), FIRE (BUTTON B), and JUMP
+		(BUTTON A).
+
+endif # ARCH_BOARD_NUCLEO_F401RE

configs/nucleo-f4x1re/README.txt

@@ -539,7 +539,8 @@ Shields
     NOTE: Button F cannot be used with the default USART1 configuration
     because PA9 is configured for USART1_RX by default.  Use select
     different USART1 pins in the board.h file or select a different
-    USART
+    USART or select CONFIG_NUCLEO_F401RE_AJOY_MINBUTTONS which will
+    eliminate all but buttons A, B, and C.
 
   Itead Joystick Signal interpretation:
 

configs/nucleo-f4x1re/src/nucleo-f4x1re.h

@@ -197,7 +197,8 @@
  *   NOTE: Button F cannot be used with the default USART1 configuration
  *   because PA9 is configured for USART1_RX by default.  Use select
  *   different USART1 pins in the board.h file or select a different
- *   USART
+ *   USART or select CONFIG_NUCLEO_F401RE_AJOY_MINBUTTONS which will
+ *   eliminate all but buttons A, B, and C.
  */
 
 #define ADC_XOUPUT   1 /* X output is on ADC channel 1 */

configs/nucleo-f4x1re/src/stm32_ajoystick.c

@@ -85,16 +85,27 @@
 #  define NJOYSTICK_CHANNELS 1
 #endif
 
+#ifdef CONFIG_NUCLEO_F401RE_AJOY_MINBUTTONS
 /* Number of Joystick buttons */
 
-#define AJOY_NGPIOS  7
+#  define AJOY_NGPIOS  3
 
 /* Bitset of supported Joystick buttons */
 
-#define AJOY_SUPPORTED (AJOY_BUTTON_1_BIT | AJOY_BUTTON_2_BIT | \
+#  define AJOY_SUPPORTED (AJOY_BUTTON_1_BIT | AJOY_BUTTON_2_BIT | \
-                        AJOY_BUTTON_3_BIT | AJOY_BUTTON_4_BIT | \
+                          AJOY_BUTTON_3_BIT)
-                        AJOY_BUTTON_5_BIT | AJOY_BUTTON_6_BIT | \
+#else
-                        AJOY_BUTTON_7_BIT )
+/* Number of Joystick buttons */
+
+#  define AJOY_NGPIOS  7
+
+/* Bitset of supported Joystick buttons */
+
+#  define AJOY_SUPPORTED (AJOY_BUTTON_1_BIT | AJOY_BUTTON_2_BIT | \
+                          AJOY_BUTTON_3_BIT | AJOY_BUTTON_4_BIT | \
+                          AJOY_BUTTON_5_BIT | AJOY_BUTTON_6_BIT | \
+                          AJOY_BUTTON_7_BIT )
+#endif
 
 /****************************************************************************
  * Private Types
@@ -122,11 +133,18 @@ static int ajoy_interrupt(int irq, FAR void *context);
  * button definitions in include/nuttx/input/ajoystick.h.
  */
 
+#ifdef CONFIG_NUCLEO_F401RE_AJOY_MINBUTTONS
+static const uint32_t g_joygpio[AJOY_NGPIOS] =
+{
+  GPIO_BUTTON_1, GPIO_BUTTON_2, GPIO_BUTTON_3
+};
+#else
 static const uint32_t g_joygpio[AJOY_NGPIOS] =
 {
   GPIO_BUTTON_1, GPIO_BUTTON_2, GPIO_BUTTON_3, GPIO_BUTTON_4,
   GPIO_BUTTON_5, GPIO_BUTTON_6, GPIO_BUTTON_7
 };
+#endif
 
 /* This is the button joystick lower half driver interface */