cpu: efm32: move LOW_POWER_ENABLED to efm32-features.mk

cpu/efm32/Makefile.features

@@ -15,4 +15,8 @@ ifeq (1,$(EFM32_UART_MODES))
   CFLAGS += -DEFM32_UART_MODES=1
 endif
 
+ifeq (1,$(EFM32_LEUART_ENABLED))
+  CFLAGS += -DEFM32_LEUART_ENABLED=1
+endif
+
 include $(RIOTCPU)/cortexm_common/Makefile.features

cpu/efm32/doc.txt

@@ -62,7 +62,12 @@
  * =======================
  *
  * The EFM32/EFR32/EZR32 MCUs have support for low-power peripherals. Support
- * is enabled by default, but can be disabled by setting LOW_POWER_ENABLED=0.
+ * is enabled by default, but can be disabled if not used.
+ *
+ * - Setting `EFM32_LEUART_ENABLED=0` will disable support for the LEUART
+ *   in the UART driver peripheral and save approximately 400 bytes.
+ *
+ * Refer to `cpu/efm32/efm32-features.mk` for more options.
  */
 
 /**

cpu/efm32/efm32-features.mk

@@ -2,3 +2,4 @@
 # should override them from the command line, or in your Makefile. Note that
 # some features may not be applicable to all EFM32 boards or CPUs.
 export EFM32_UART_MODES ?= 0
+export EFM32_LEUART_ENABLED ?= 1

cpu/efm32/include/periph_cpu.h

@@ -38,15 +38,6 @@
 extern "C" {
 #endif
 
-/**
- * @brief   Enable support for Low-power peripherals (if supported by CPU).
- * @{
- */
-#ifndef LOW_POWER_ENABLED
-#define LOW_POWER_ENABLED   (1)
-#endif
-/** @} */
-
 /**
  * @brief   Internal macro for combining ADC resolution (x) with number of
  *          shifts (y).

cpu/efm32/periph/uart.c

@@ -27,7 +27,15 @@
 
 #include "em_usart.h"
 #include "em_usart_utils.h"
-#if LOW_POWER_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+
+/**
+ * @brief   Defines whether LEUART is enabled and supported
+ */
+#if EFM32_LEUART_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+#define USE_LEUART
+#endif
+
+#ifdef USE_LEUART
 #include "em_leuart.h"
 #include "em_leuart_utils.h"
 #endif
@@ -37,6 +45,7 @@
  */
 static uart_isr_ctx_t isr_ctx[UART_NUMOF];
 
+#ifdef USE_LEUART
 /**
  * @brief   Check if device is a U(S)ART device.
  */
@@ -44,6 +53,7 @@ static inline bool _is_usart(uart_t dev)
 {
     return ((uint32_t) uart_config[dev].dev) < LEUART0_BASE;
 }
+#endif
 
 int uart_init(uart_t dev, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg)
 {
@@ -61,7 +71,7 @@ int uart_init(uart_t dev, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg)
     gpio_init(uart_config[dev].tx_pin, GPIO_OUT);
 
     /* initialize the UART/USART/LEUART device */
-#if LOW_POWER_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+#ifdef USE_LEUART
     if (_is_usart(dev)) {
 #endif
         USART_TypeDef *uart = (USART_TypeDef *) uart_config[dev].dev;
@@ -98,7 +108,7 @@ int uart_init(uart_t dev, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg)
 
         /* enable peripheral */
         USART_Enable(uart, usartEnable);
-#if LOW_POWER_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+#ifdef USE_LEUART
     } else {
         LEUART_TypeDef *leuart = (LEUART_TypeDef *) uart_config[dev].dev;
 
@@ -146,13 +156,13 @@ int uart_init(uart_t dev, uint32_t baudrate, uart_rx_cb_t rx_cb, void *arg)
 
 void uart_write(uart_t dev, const uint8_t *data, size_t len)
 {
-#if LOW_POWER_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+#ifdef USE_LEUART
     if (_is_usart(dev)) {
 #endif
         while (len--) {
             USART_Tx(uart_config[dev].dev, *(data++));
         }
-#if LOW_POWER_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+#ifdef USE_LEUART
     } else {
         while (len--) {
             LEUART_Tx(uart_config[dev].dev, *(data++));
@@ -173,13 +183,13 @@ void uart_poweroff(uart_t dev)
 
 static void rx_irq(uart_t dev)
 {
-#if LOW_POWER_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+#ifdef USE_LEUART
     if (_is_usart(dev)) {
 #endif
         if (USART_IntGet(uart_config[dev].dev) & USART_IF_RXDATAV) {
             isr_ctx[dev].rx_cb(isr_ctx[dev].arg, USART_RxDataGet(uart_config[dev].dev));
         }
-#if LOW_POWER_ENABLED && defined(LEUART_COUNT) && LEUART_COUNT > 0
+#ifdef USE_LEUART
     } else {
         if (LEUART_IntGet(uart_config[dev].dev) & LEUART_IF_RXDATAV) {
             isr_ctx[dev].rx_cb(isr_ctx[dev].arg, LEUART_RxDataGet(uart_config[dev].dev));