Merge pull request #10660 from aabadie/pr/periph/stm32_lpuart_l496zg

boards/nucleo-l496zg: use lpuart1 as stdio interface

boards/nucleo-l496zg/Makefile.dep

+FEATURES_REQUIRED += periph_lpuart
+
 include $(RIOTBOARD)/common/nucleo/Makefile.dep

boards/nucleo-l496zg/Makefile.features

@@ -4,7 +4,7 @@ FEATURES_PROVIDED += periph_rtc
 FEATURES_PROVIDED += periph_rtt
 FEATURES_PROVIDED += periph_spi
 FEATURES_PROVIDED += periph_timer
-FEATURES_PROVIDED += periph_uart
+FEATURES_PROVIDED += periph_uart periph_lpuart
 
 # load the common Makefile.features for Nucleo boards
 include $(RIOTBOARD)/common/nucleo144/Makefile.features

boards/nucleo-l496zg/Makefile.include

@@ -4,7 +4,7 @@ export CPU_MODEL = stm32l496zg
 
 # stdio is not available over st-link but on the Arduino TX/RX pins
 # A serial to USB converter plugged to the host is required
-PORT_LINUX ?= /dev/ttyUSB0
+PORT_LINUX ?= /dev/ttyACM0
 PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbmodem*)))
 
 # load the common Makefile.include for Nucleo boards

boards/nucleo-l496zg/include/periph_conf.h

@@ -112,6 +112,18 @@ static const timer_conf_t timer_config[] = {
  * @{
  */
 static const uart_conf_t uart_config[] = {
+    {
+        .dev        = LPUART1,
+        .rcc_mask   = RCC_APB1ENR2_LPUART1EN,
+        .rx_pin     = GPIO_PIN(PORT_G, 8),
+        .tx_pin     = GPIO_PIN(PORT_G, 7),
+        .rx_af      = GPIO_AF8,
+        .tx_af      = GPIO_AF8,
+        .bus        = APB12,
+        .irqn       = LPUART1_IRQn,
+        .type       = STM32_LPUART,
+        .clk_src    = 0,
+    },
     {
         .dev        = USART3,
         .rcc_mask   = RCC_APB1ENR1_USART3EN,
@@ -130,8 +142,9 @@ static const uart_conf_t uart_config[] = {
     }
 };
 
-#define UART_0_ISR          (isr_usart3)
-#define UART_0_DMA_ISR      (isr_dma1_stream5)
+#define UART_0_ISR          (isr_lpuart1)
+#define UART_1_ISR          (isr_usart3)
+#define UART_1_DMA_ISR      (isr_dma1_stream5)
 
 #define UART_NUMOF          (sizeof(uart_config) / sizeof(uart_config[0]))
 /** @} */

cpu/stm32_common/periph/gpio.c

@@ -85,6 +85,13 @@ int gpio_init(gpio_t pin, gpio_mode_t mode)
     periph_clk_en(IOP, (RCC_IOPENR_GPIOAEN << _port_num(pin)));
 #elif defined (CPU_FAM_STM32L4)
     periph_clk_en(AHB2, (RCC_AHB2ENR_GPIOAEN << _port_num(pin)));
+#ifdef PWR_CR2_IOSV
+    if (port == GPIOG) {
+        /* Port G requires external power supply */
+        periph_clk_en(APB1, RCC_APB1ENR1_PWREN);
+        PWR->CR2 |= PWR_CR2_IOSV;
+    }
+#endif /* PWR_CR2_IOSV */
 #else
     periph_clk_en(AHB1, (RCC_AHB1ENR_GPIOAEN << _port_num(pin)));
 #endif