pinmux: stm32f4: Compile out unused pinmux

It is useless to include the pinmux for a peripheral if it is not
enabled in the Kconfig. This is unnecessary and it increases the size of
the binary.

Define macros that will default to void if the associated Kconfig is not
enabled.

Change-Id: I0857fcef335c75b8bb6d537fd859f93d5be4a228
Signed-off-by: Florian Vaussard <florian.vaussard@heig-vd.ch>

Author: Florian Vaussard

arch/arm/soc/st_stm32/stm32f4/soc_pinmux.c

@@ -15,32 +15,63 @@
 #define PAD(AF, func)				\
 				[AF - 1] = func
 
+#define PINMUX_PWM(port, chan, pin)		\
+	PAD(STM32F4_PINMUX_FUNC_##pin##_PWM##port##_CH##chan,\
+	    STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+
+#define PINMUX_UART(port, dir, pin)		\
+	PAD(STM32F4_PINMUX_FUNC_##pin##_##port##_##dir, \
+	    STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+
+/* Blank pinmux by default */
+#define PINMUX_PWM2(pin, chan)
+#define PINMUX_UART1(dir, pin)
+#define PINMUX_UART2(dir, pin)
+
+#ifdef CONFIG_PWM_STM32_2
+	#undef PINMUX_PWM2
+	#define PINMUX_PWM2(pin, chan)		PINMUX_PWM(2, chan, pin)
+#endif
+
+#ifdef CONFIG_UART_STM32_PORT_1
+	#undef PINMUX_UART1
+	#define PINMUX_UART1(dir, pin)		PINMUX_UART(USART1, dir, pin)
+#endif
+
+#ifdef CONFIG_UART_STM32_PORT_2
+	#undef PINMUX_UART2
+	#define PINMUX_UART2(dir, pin)		PINMUX_UART(USART2, dir, pin)
+#endif
+
+#define PINMUX_UART_TX(pin, port)		PINMUX_UART##port(TX, pin)
+#define PINMUX_UART_RX(pin, port)		PINMUX_UART##port(RX, pin)
+
 static const stm32_pin_func_t pin_pa0_funcs[] = {
-	PAD(STM32F4_PINMUX_FUNC_PA0_PWM2_CH1, STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+	PINMUX_PWM2(PA0, 1)
 };
 
 static const stm32_pin_func_t pin_pa2_funcs[] = {
-	PAD(STM32F4_PINMUX_FUNC_PA2_USART2_TX, STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+	PINMUX_UART_TX(PA2, 2)
 };
 
 static const stm32_pin_func_t pin_pa3_funcs[] = {
-	PAD(STM32F4_PINMUX_FUNC_PA3_USART2_RX, STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+	PINMUX_UART_RX(PA3, 2)
 };
 
 static const stm32_pin_func_t pin_pa9_funcs[] = {
-	PAD(STM32F4_PINMUX_FUNC_PA9_USART1_TX, STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+	PINMUX_UART_TX(PA9, 1)
 };
 
 static const stm32_pin_func_t pin_pa10_funcs[] = {
-	PAD(STM32F4_PINMUX_FUNC_PA10_USART1_RX, STM32F4X_PIN_CONFIG_AF_PUSH_UP)
+	PINMUX_UART_RX(PA10, 1)
 };
 
 static const stm32_pin_func_t pin_pb6_funcs[] = {
-	PAD(STM32F4_PINMUX_FUNC_PB6_USART1_TX, STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+	PINMUX_UART_TX(PB6, 1)
 };
 
 static const stm32_pin_func_t pin_pb7_funcs[] = {
-	PAD(STM32F4_PINMUX_FUNC_PB7_USART1_RX, STM32F4X_PIN_CONFIG_AF_PUSH_UP),
+	PINMUX_UART_RX(PB7, 1)
 };
 
 /**