1 files changed, 24 insertions, 0 deletions
diff --git a/src/random.c b/src/random.c
new file mode 100644
index 0000000..9c1e0d1
--- /dev/null
+++ b/src/random.c
@@ -0,0 +1,24 @@
+#include <random.h>
+
+#include <stm32l476xx.h>
+#include <clock.h>
+
+void random_init(void)
+{
+	// setup and enable RNG clock
+	RCC->CCIPR &= ~(RCC_CCIPR_CLK48SEL);
+	RCC->CCIPR |= RCC_CCIPR_CLK48SEL_1;
+	RCC->AHB2ENR |= RCC_AHB2ENR_RNGEN;
+	RNG->CR |= RNG_CR_RNGEN;
+}
+
+uint32_t random_get(void)
+{
+	if (RNG->SR & (RNG_SR_SEIS | RNG_SR_CEIS))
+		return 0;
+
+	while (!(RNG->SR & RNG_SR_DRDY))
+		delay(1);
+
+	return RNG->DR;
+}