From b449f6de9dd504e010154450e4e5f4a39fa5c10b Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Wed, 26 May 2021 18:09:18 +0200
Subject: [PATCH] nrf/twim: deconfigure pins on drop

---
 embassy-nrf/src/gpio.rs | 13 +++++++++++++
 embassy-nrf/src/twim.rs |  7 ++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/embassy-nrf/src/gpio.rs b/embassy-nrf/src/gpio.rs
index 3ae160ca..b02e7787 100644
--- a/embassy-nrf/src/gpio.rs
+++ b/embassy-nrf/src/gpio.rs
@@ -12,6 +12,8 @@ use gpio::pin_cnf::DRIVE_A;
 use crate::pac;
 use crate::pac::p0 as gpio;
 
+use self::sealed::Pin as _;
+
 /// A GPIO port with up to 32 pins.
 #[derive(Debug, Eq, PartialEq)]
 pub enum Port {
@@ -487,6 +489,17 @@ impl OptionalPin for NoPin {
 
 // ====================
 
+pub(crate) fn deconfigure_pin(psel_bits: u32) {
+    if psel_bits & 0x8000_0000 != 0 {
+        return;
+    }
+    unsafe {
+        AnyPin::steal(psel_bits as _).conf().reset();
+    }
+}
+
+// ====================
+
 macro_rules! impl_pin {
     ($type:ident, $port_num:expr, $pin_num:expr) => {
         impl crate::gpio::Pin for peripherals::$type {}
diff --git a/embassy-nrf/src/twim.rs b/embassy-nrf/src/twim.rs
index 05c4c260..4812b353 100644
--- a/embassy-nrf/src/twim.rs
+++ b/embassy-nrf/src/twim.rs
@@ -13,10 +13,10 @@ use embassy::util::{AtomicWaker, Unborrow};
 use embassy_extras::unborrow;
 
 use crate::chip::{EASY_DMA_SIZE, FORCE_COPY_BUFFER_SIZE};
-use crate::fmt::*;
 use crate::gpio::Pin as GpioPin;
 use crate::pac;
 use crate::util::{slice_in_ram, slice_in_ram_or};
+use crate::{fmt::*, gpio};
 
 pub enum Frequency {
     #[doc = "26738688: 100 kbps"]
@@ -422,9 +422,10 @@ impl<'a, T: Instance> Drop for Twim<'a, T> {
         let r = T::regs();
         r.enable.write(|w| w.enable().disabled());
 
-        info!("uarte drop: done");
+        gpio::deconfigure_pin(r.psel.sda.read().bits());
+        gpio::deconfigure_pin(r.psel.scl.read().bits());
 
-        // TODO: disable pins
+        info!("twim drop: done");
     }
 }