From 8a03399dc3d357351b2bf0cfb295d23629a97ef3 Mon Sep 17 00:00:00 2001
From: Valentin Ochs <a@0au.de>
Date: Sat, 17 Jul 2021 00:18:18 +0200
Subject: [PATCH] Enable SYSCLK to set up EXTI...

---
 encoder.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/encoder.c b/encoder.c
index afc7a65..a18790a 100644
--- a/encoder.c
+++ b/encoder.c
@@ -20,6 +20,7 @@ static void check(void);
 
 void encoder_setup(void) {
         rcc_periph_clock_enable(PIN_RCC);
+        rcc_periph_clock_enable(RCC_SYSCFG);
 
         gpio_mode_setup(PIN_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, PIN_OPEN | PIN_CLOSE);
 
@@ -29,6 +30,9 @@ void encoder_setup(void) {
 
         nvic_enable_irq(PIN_OPEN_IRQ);
         nvic_enable_irq(PIN_CLOSE_IRQ);
+
+        // We've configured it, now we can turn it off again
+        rcc_periph_clock_disable(RCC_SYSCFG);
 }
 
 int encoder_get() {