stm32_uart: add write_blocking helper

A nice easy basic helper for "I just wannna wite a char now!"

1 files changed, 6 insertions, 0 deletions

diff --git a/uart/stm32_uart.h b/uart/stm32_uart.h
index 08f93d1..c4ba582 100644
--- a/uart/stm32_uart.h
+++ b/uart/stm32_uart.h
@@ -44,4 +44,10 @@ template <typename T>
 class STM32_UART_t : public mmio_ptr<T> {
     public:
         using mmio_ptr<T>::ptr;
+
+	void write_blocking(uint8_t data) const {
+		// wait for TXE/TXFNF
+		while (!(ptr()->ISR & (1<<7)));
+		ptr()->TDR = data;
+	}
 };