From ea36d121db8dc71ebd205040cdd4b99fe5c2086c Mon Sep 17 00:00:00 2001
From: Felipe Balbi <febalbi@microsoft.com>
Date: Thu, 22 May 2025 14:01:40 -0700
Subject: [PATCH] embassy-rp: implement input/output inversion

RP2040/RP23xx support inversion in HW of the inputs and
outputs. Implement minimal support for that.
---
 embassy-rp/src/gpio.rs   | 38 ++++++++++++++++++++++++++++++++++++++
 tests/rp/src/bin/gpio.rs | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/embassy-rp/src/gpio.rs b/embassy-rp/src/gpio.rs
index 2fb2d65c2..9b5faac15 100644
--- a/embassy-rp/src/gpio.rs
+++ b/embassy-rp/src/gpio.rs
@@ -146,6 +146,12 @@ impl<'d> Input<'d> {
         self.pin.get_level()
     }
 
+    /// Configure the input logic inversion of this pin.
+    #[inline]
+    pub fn set_inversion(&mut self, invert: bool) {
+        self.pin.set_input_inversion(invert)
+    }
+
     /// Wait until the pin is high. If it is already high, return immediately.
     #[inline]
     pub async fn wait_for_high(&mut self) {
@@ -382,6 +388,12 @@ impl<'d> Output<'d> {
         self.pin.set_slew_rate(slew_rate)
     }
 
+    /// Configure the output logic inversion of this pin.
+    #[inline]
+    pub fn set_inversion(&mut self, invert: bool) {
+        self.pin.set_output_inversion(invert)
+    }
+
     /// Set the output as high.
     #[inline]
     pub fn set_high(&mut self) {
@@ -685,6 +697,30 @@ impl<'d> Flex<'d> {
         self.pin.sio_oe().value_xor().write_value(self.bit())
     }
 
+    /// Configure the input logic inversion of this pin.
+    #[inline]
+    pub fn set_input_inversion(&mut self, invert: bool) {
+        self.pin.gpio().ctrl().modify(|w| {
+            w.set_inover(if invert {
+                pac::io::vals::Inover::INVERT
+            } else {
+                pac::io::vals::Inover::NORMAL
+            })
+        });
+    }
+
+    /// Configure the output logic inversion of this pin.
+    #[inline]
+    pub fn set_output_inversion(&mut self, invert: bool) {
+        self.pin.gpio().ctrl().modify(|w| {
+            w.set_outover(if invert {
+                pac::io::vals::Outover::INVERT
+            } else {
+                pac::io::vals::Outover::NORMAL
+            })
+        });
+    }
+
     /// Get whether the pin input level is high.
     #[inline]
     pub fn is_high(&self) -> bool {
@@ -815,6 +851,8 @@ impl<'d> Drop for Flex<'d> {
         self.pin.pad_ctrl().write(|_| {});
         self.pin.gpio().ctrl().write(|w| {
             w.set_funcsel(pac::io::vals::Gpio0ctrlFuncsel::NULL as _);
+            w.set_inover(pac::io::vals::Inover::NORMAL);
+            w.set_outover(pac::io::vals::Outover::NORMAL);
         });
         self.pin.io().int_dormant_wake().inte(idx / 8).write_clear(|w| {
             w.set_edge_high(idx % 8, true);
diff --git a/tests/rp/src/bin/gpio.rs b/tests/rp/src/bin/gpio.rs
index 614b6317a..8bd0df8d8 100644
--- a/tests/rp/src/bin/gpio.rs
+++ b/tests/rp/src/bin/gpio.rs
@@ -67,6 +67,40 @@ async fn main(_spawner: Spawner) {
         }
     }
 
+    // Test input inversion
+    {
+        let mut b = Input::new(b.reborrow(), Pull::None);
+        b.set_inversion(true);
+        // no pull, the status is undefined
+
+        let mut a = Output::new(a.reborrow(), Level::Low);
+        delay();
+        assert!(b.is_high());
+        a.set_high();
+        delay();
+        assert!(b.is_low());
+
+        b.set_inversion(false);
+        a.set_inversion(true);
+
+        a.set_low();
+        delay();
+        assert!(b.is_high());
+
+        a.set_high();
+        delay();
+        assert!(b.is_low());
+
+        b.set_inversion(true);
+        a.set_high();
+        delay();
+        assert!(b.is_high());
+
+        a.set_high();
+        delay();
+        assert!(b.is_high());
+    }
+
     // Test input no pull
     {
         let b = Input::new(b.reborrow(), Pull::None);