Turn off input_enable for ADC capable pins

on-target-tests/Cargo.toml

@@ -36,6 +36,10 @@ harness = false
 name = "i2c_loopback_async"
 harness = false
 
+[[test]]
+name = "gpio"
+harness = false
+
 [dependencies]
 cortex-m = "0.7"
 cortex-m-rt = "0.7"

on-target-tests/tests/gpio.rs

@@ -0,0 +1,103 @@
+#![no_std]
+#![no_main]
+#![cfg(test)]
+
+use defmt_rtt as _; // defmt transport
+use defmt_test as _;
+use panic_probe as _;
+use rp2040_hal as hal; // memory layout // panic handler
+
+/// The linker will place this boot block at the start of our program image. We
+/// need this to help the ROM bootloader get our code up and running.
+/// Note: This boot block is not necessary when using a rp-hal based BSP
+/// as the BSPs already perform this step.
+#[link_section = ".boot2"]
+#[used]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_GENERIC_03H;
+
+/// External high-speed crystal on the Raspberry Pi Pico board is 12 MHz. Adjust
+/// if your board has a different frequency
+const XTAL_FREQ_HZ: u32 = 12_000_000u32;
+
+#[defmt_test::tests]
+mod tests {
+    use crate::hal;
+    use crate::hal::clocks::init_clocks_and_plls;
+    use crate::hal::pac;
+    use crate::XTAL_FREQ_HZ;
+    use hal::watchdog::Watchdog;
+
+    #[init]
+    fn setup() -> () {
+        unsafe {
+            hal::sio::spinlock_reset();
+        }
+        let mut pac = pac::Peripherals::take().unwrap();
+        let _core = pac::CorePeripherals::take().unwrap();
+        let mut watchdog = Watchdog::new(pac.WATCHDOG);
+
+        let _clocks = init_clocks_and_plls(
+            XTAL_FREQ_HZ,
+            pac.XOSC,
+            pac.CLOCKS,
+            pac.PLL_SYS,
+            pac.PLL_USB,
+            &mut pac.RESETS,
+            &mut watchdog,
+        )
+        .ok()
+        .unwrap();
+
+        let sio = hal::Sio::new(pac.SIO);
+
+        let _pins = hal::gpio::Pins::new(
+            pac.IO_BANK0,
+            pac.PADS_BANK0,
+            sio.gpio_bank0,
+            &mut pac.RESETS,
+        );
+    }
+
+    #[test]
+    fn check_ie() {
+        // Safety: Test cases do not run in parallel
+        let pac = unsafe { pac::Peripherals::steal() };
+        for id in 0..=29 {
+            assert!(pac.PADS_BANK0.gpio(id).read().ie().bit_is_clear());
+        }
+    }
+
+    #[test]
+    fn check_ie_gets_enabled() {
+        // Safety: Test cases do not run in parallel
+        let pac = unsafe { pac::Peripherals::steal() };
+        for id in 0..=29 {
+            let pin = unsafe {
+                hal::gpio::new_pin(hal::gpio::DynPinId {
+                    bank: hal::gpio::DynBankId::Bank0,
+                    num: id as u8,
+                })
+            };
+            let pin = pin
+                .try_into_function::<hal::gpio::FunctionSioInput>()
+                .ok()
+                .unwrap();
+            assert!(pac.PADS_BANK0.gpio(id).read().ie().bit_is_set());
+            let pin = pin
+                .try_into_function::<hal::gpio::FunctionNull>()
+                .ok()
+                .unwrap();
+            assert!(pac.PADS_BANK0.gpio(id).read().ie().bit_is_clear());
+            let pin = pin
+                .try_into_function::<hal::gpio::FunctionPio0>()
+                .ok()
+                .unwrap();
+            assert!(pac.PADS_BANK0.gpio(id).read().ie().bit_is_set());
+            let _pin = pin
+                .try_into_function::<hal::gpio::FunctionNull>()
+                .ok()
+                .unwrap();
+            assert!(pac.PADS_BANK0.gpio(id).read().ie().bit_is_clear());
+        }
+    }
+}

rp2040-hal/CHANGELOG.md

@@ -18,6 +18,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   more slowly than on the Raspberry Pico.
 - Some reorganization of ADC code, making sure that AdcPin can only
   be created for pins that can actually be used as ADC channels.
+- Breaking change: Clear the input-enable flag of all pins on bank 0 in `Pins::new`.
+  They will automatically be enabled when setting a pin function, so most users
+  won't be affected by that change. Notable exception: If you rely on the fact that
+  PIO can read all pins as input even if the pin is not configured to the PIO function,
+  you may need to set the input-enable flag manually. - #755 @jannic
 
 ## [0.9.1]
 

rp2040-hal/src/gpio/mod.rs

@@ -1015,6 +1015,20 @@ pub trait DefaultTypeState: crate::typelevel::Sealed {
     type PullType: PullType;
 }
 
+// Clear input enable for pins of bank0.
+// Pins 26-29 are ADC pins. If the pins are connected to an analog input,
+// the signal level may not be valid for a digital input. Therefore, input
+// should be disabled by default.
+// For the other GPIO pins, the same setting is applied for consistency.
+macro_rules! reset_ie {
+    ( Bank0, $pads:ident ) => {
+        for id in (0..=29) {
+            $pads.gpio(id).modify(|_, w| w.ie().clear_bit());
+        }
+    };
+    ( Qspi, $pads:ident ) => {};
+}
+
 macro_rules! gpio {
     ( $bank:ident:$prefix:ident, [ $(($id:expr, $pull_type:ident, $func:ident)),* ] ) => {
         paste::paste!{
@@ -1035,8 +1049,10 @@ macro_rules! gpio {
 
                 impl Pins {
                     /// Take ownership of the PAC peripherals and SIO slice and split it into discrete [`Pin`]s
+                    ///
+                    /// This clears the input-enable flag for all Bank0 pads.
                     pub fn new(io : [<IO_ $bank:upper>], pads: [<PADS_ $bank:upper>], sio: [<SioGpio $bank>], reset : &mut $crate::pac::RESETS) -> Self {
-                        use crate::resets::SubsystemReset;
+                        use $crate::resets::SubsystemReset;
                         pads.reset_bring_down(reset);
                         io.reset_bring_down(reset);
 
@@ -1055,6 +1071,7 @@ macro_rules! gpio {
 
                         io.reset_bring_up(reset);
                         pads.reset_bring_up(reset);
+                        reset_ie!($bank, pads);
                         gpio!(members: io, pads, sio, $(([<$prefix $id>], $func, $pull_type)),+)
                     }
                 }

rp2040-hal/src/gpio/pin.rs

@@ -153,6 +153,11 @@ pub(crate) fn set_function<P: PinId>(pin: &P, function: DynFunction) {
         DynFunction::Usb => FUNCSEL_A::USB,
         DynFunction::Null => FUNCSEL_A::NULL,
     };
+    if funcsel != FUNCSEL_A::NULL {
+        pin.pad_ctrl().modify(|_, w| w.ie().set_bit());
+    } else {
+        pin.pad_ctrl().modify(|_, w| w.ie().clear_bit());
+    }
 
     pin.io_ctrl().modify(|_, w| w.funcsel().variant(funcsel));
 }