Add FlexCAN pin trait, FlexCAN1 and 2 1060 impls

1060 pins implementations checked against section 44.3 in the 1060
reference manual. See imxrt-rs/imxrt-hal#122 for a related FlexCAN
driver.

src/can.rs

@@ -0,0 +1,54 @@
+//! Can pad configurations
+
+/// A Can signal
+pub trait Signal: private::Sealed {}
+
+/// A tag that indicates a Can TX pad
+pub enum Tx {}
+/// A tag that indicates a Can Rx pad
+pub enum Rx {}
+
+impl Signal for Tx {}
+impl Signal for Rx {}
+mod private {
+    pub trait Sealed {}
+    impl Sealed for super::Tx {}
+    impl Sealed for super::Rx {}
+}
+
+/// A Can pin
+pub trait Pin: super::IOMUX {
+    /// Alternate value for this pin
+    const ALT: u32;
+    /// Daisy register
+    const DAISY: Option<super::Daisy>;
+    /// CAN signal
+    type Signal: Signal;
+    /// CAN module; `U1` for `CAN1`
+    type Module: super::consts::Unsigned;
+}
+
+/// Prepare a Can pin
+///
+/// # Safety
+///
+/// `prepare()` inherits all the unsafety that comes from the `IOMUX` supertrait.
+pub fn prepare<P: Pin>(pin: &mut P) {
+    super::alternate(pin, P::ALT);
+    super::set_sion(pin);
+    if let Some(daisy) = P::DAISY {
+        unsafe { daisy.write() };
+    }
+}
+
+#[allow(unused)] // Used in chip-specific modules...
+macro_rules! can {
+    (module: $module:ty, alt: $alt:expr, pad: $pad:ty, signal: $signal:ty, daisy: $daisy:expr) => {
+        impl Pin for $pad {
+            const ALT: u32 = $alt;
+            const DAISY: Option<Daisy> = $daisy;
+            type Signal = $signal;
+            type Module = $module;
+        }
+    };
+}

src/imxrt106x/can.rs

@@ -0,0 +1,52 @@
+//! Can pin implementation
+
+use super::pads::{ad_b0::*, ad_b1::*, b0::*, b1::*, emc::*, sd_b1::*};
+
+use crate::{
+    can::{Pin, Rx, Tx},
+    consts::*,
+    Daisy,
+};
+
+//
+// CAN1
+//
+can!(module: U1, alt: 2, pad: AD_B1_08, signal: Tx, daisy: None);
+can!(module: U1, alt: 2, pad: B0_02, signal: Tx, daisy: None);
+can!(module: U1, alt: 3, pad: EMC_17, signal: Tx, daisy: None);
+can!(module: U1, alt: 4, pad: SD_B1_02, signal: Tx, daisy: None);
+can!(module: U1, alt: 2, pad: AD_B1_09, signal: Rx, daisy: Some(DAISY_CAN1_RX_GPIO_AD_B1_09));
+can!(module: U1, alt: 2, pad: B0_03, signal: Rx, daisy: Some(DAISY_CAN1_RX_GPIO_B0_03));
+can!(module: U1, alt: 3, pad: EMC_18, signal: Rx, daisy: Some(DAISY_CAN1_RX_GPIO_EMC_18));
+can!(module: U1, alt: 4, pad: SD_B1_03, signal: Rx, daisy: Some(DAISY_CAN1_RX_GPIO_SD_B1_03));
+
+//
+// CAN2
+//
+can!(module: U2, alt: 0, pad: AD_B0_02, signal: Tx, daisy: None);
+can!(module: U2, alt: 3, pad: EMC_09, signal: Tx, daisy: None);
+can!(module: U2, alt: 6, pad: B1_08, signal: Tx, daisy: None);
+can!(module: U2, alt: 6, pad: AD_B0_14, signal: Tx, daisy: None);
+can!(module: U2, alt: 0, pad: AD_B0_03, signal: Rx, daisy: Some(DAISY_CAN2_RX_GPIO_AD_B0_03));
+can!(module: U2, alt: 3, pad: EMC_10, signal: Rx, daisy: Some(DAISY_CAN2_RX_GPIO_EMC_10));
+can!(module: U2, alt: 6, pad: AD_B0_15, signal: Rx, daisy: Some(DAISY_CAN2_RX_GPIO_AD_B0_15));
+can!(module: U2, alt: 6, pad: B1_09, signal: Rx, daisy: Some(DAISY_CAN2_RX_GPIO_B1_09));
+
+/// Auto-generated DAISY values
+mod daisy {
+    #![allow(unused)]
+
+    use super::Daisy;
+
+    pub const DAISY_CAN1_RX_GPIO_SD_B1_03: Daisy = Daisy::new(0x401F_844C as *mut u32, 0);
+    pub const DAISY_CAN1_RX_GPIO_EMC_18: Daisy = Daisy::new(0x401F_844C as *mut u32, 1);
+    pub const DAISY_CAN1_RX_GPIO_AD_B1_09: Daisy = Daisy::new(0x401F_844C as *mut u32, 2);
+    pub const DAISY_CAN1_RX_GPIO_B0_03: Daisy = Daisy::new(0x401F_844C as *mut u32, 3);
+
+    pub const DAISY_CAN2_RX_GPIO_EMC_10: Daisy = Daisy::new(0x401F_8450 as *mut u32, 0);
+    pub const DAISY_CAN2_RX_GPIO_AD_B0_03: Daisy = Daisy::new(0x401F_8450 as *mut u32, 1);
+    pub const DAISY_CAN2_RX_GPIO_AD_B0_15: Daisy = Daisy::new(0x401F_8450 as *mut u32, 2);
+    pub const DAISY_CAN2_RX_GPIO_B1_09: Daisy = Daisy::new(0x401F_8450 as *mut u32, 3);
+}
+
+use daisy::*;

src/imxrt106x/mod.rs

@@ -89,6 +89,7 @@
 //! ```
 
 mod adc;
+mod can;
 mod i2c;
 mod pwm;
 mod sai;

src/lib.rs

@@ -87,6 +87,8 @@
 
 #[macro_use]
 pub mod adc;
+#[macro_use]
+pub mod can;
 mod config;
 #[macro_use]
 pub mod i2c;