Ensure that i2c pins have PullUp activated

It is possible to skip this check by using `hal::I2C::i2c0_unchecked(...)` or `hal::I2C::i2c1_unchecked(...)`, but the default constructor functions now only accept pins with activated PullUp. Fixes #690.
rp-rs · Nov 17, 2023 · 6c6158d · 6c6158d
1 parent aecf366
commit 6c6158d
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diff --git a/rp2040-hal/examples/i2c.rs b/rp2040-hal/examples/i2c.rs
@@ -23,7 +23,7 @@ use hal::fugit::RateExtU32;
 // A shorter alias for the Peripheral Access Crate, which provides low-level
 // register access and a gpio related types.
 use hal::{
-    gpio::{FunctionI2C, Pin, PullUp},
+    gpio::{FunctionI2C, Pin},
     pac,
 };
 
@@ -78,8 +78,8 @@ fn main() -> ! {
     );
 
     // Configure two pins as being I²C, not GPIO
-    let sda_pin: Pin<_, FunctionI2C, PullUp> = pins.gpio18.reconfigure();
-    let scl_pin: Pin<_, FunctionI2C, PullUp> = pins.gpio19.reconfigure();
+    let sda_pin: Pin<_, FunctionI2C, _> = pins.gpio18.reconfigure();
+    let scl_pin: Pin<_, FunctionI2C, _> = pins.gpio19.reconfigure();
     // let not_an_scl_pin: Pin<_, FunctionI2C, PullUp> = pins.gpio20.reconfigure();
 
     // Create the I²C drive, using the two pre-configured pins. This will fail

diff --git a/rp2040-hal/src/i2c.rs b/rp2040-hal/src/i2c.rs
@@ -47,7 +47,7 @@ use core::{marker::PhantomData, ops::Deref};
 use fugit::HertzU32;
 
 use crate::{
-    gpio::{bank0::*, pin::pin_sealed::TypeLevelPinId, AnyPin, FunctionI2c},
+    gpio::{bank0::*, pin::pin_sealed::TypeLevelPinId, AnyPin, FunctionI2c, PullUp},
     pac::{self, i2c0::RegisterBlock as I2CBlock, I2C0, I2C1, RESETS},
     resets::SubsystemReset,
     typelevel::Sealed,
@@ -331,12 +331,32 @@ macro_rules! hal {
                     system_clock: SystemF) -> Self
                 where
                     F: Into<HertzU32>,
-                    Sda: ValidPinSda<$I2CX>,
-                    Scl: ValidPinScl<$I2CX>,
+                    Sda: ValidPinSda<$I2CX> + AnyPin<Pull = PullUp>,
+                    Scl: ValidPinScl<$I2CX> + AnyPin<Pull = PullUp>,
                     SystemF: Into<HertzU32>,
                 {
                     Self::new_controller(i2c, sda_pin, scl_pin, freq.into(), resets, system_clock.into())
                 }
+
+                $crate::paste::paste! {
+                    /// Configures the I2C peripheral to work in master mode
+                    /// This function can be called without the pull-ups on the I2C pins.
+                    pub fn [<$i2cX _unchecked>]<F, SystemF>(
+                        i2c: $I2CX,
+                        sda_pin: Sda,
+                        scl_pin: Scl,
+                        freq: F,
+                        resets: &mut RESETS,
+                        system_clock: SystemF) -> Self
+                    where
+                        F: Into<HertzU32>,
+                        Sda: ValidPinSda<$I2CX>,
+                        Scl: ValidPinScl<$I2CX>,
+                        SystemF: Into<HertzU32>,
+                    {
+                        Self::new_controller(i2c, sda_pin, scl_pin, freq.into(), resets, system_clock.into())
+                    }
+                }
             }
         )+
     }