PIO support for RPi Pico

embassy-rp/src/gpio.rs

@@ -48,6 +48,21 @@ pub enum Pull {
     Down,
 }
 
+/// Drive strength of an output
+#[derive(Debug, Eq, PartialEq)]
+pub enum Drive {
+    _2mA,
+    _4mA,
+    _8mA,
+    _12mA,
+}
+/// Slew rate of an output
+#[derive(Debug, Eq, PartialEq)]
+pub enum SlewRate {
+    Fast,
+    Slow,
+}
+
 /// A GPIO bank with up to 32 pins.
 #[derive(Debug, Eq, PartialEq)]
 pub enum Bank {
@@ -459,7 +474,7 @@ impl<'d, T: Pin> Flex<'d, T> {
     #[inline]
     pub fn set_pull(&mut self, pull: Pull) {
         unsafe {
-            self.pin.pad_ctrl().write(|w| {
+            self.pin.pad_ctrl().modify(|w| {
                 w.set_ie(true);
                 match pull {
                     Pull::Up => w.set_pue(true),
@@ -470,6 +485,31 @@ impl<'d, T: Pin> Flex<'d, T> {
         }
     }
 
+    /// Set the pin's drive strength.
+    #[inline]
+    pub fn set_drive_strength(&mut self, strength: Drive) {
+        unsafe {
+            self.pin.pad_ctrl().modify(|w| {
+                w.set_drive(match strength {
+                    Drive::_2mA => pac::pads::vals::Drive::_2MA,
+                    Drive::_4mA => pac::pads::vals::Drive::_4MA,
+                    Drive::_8mA => pac::pads::vals::Drive::_8MA,
+                    Drive::_12mA => pac::pads::vals::Drive::_12MA,
+                });
+            });
+        }
+    }
+
+    // Set the pin's slew rate.
+    #[inline]
+    pub fn set_slew_rate(&mut self, slew_rate: SlewRate) {
+        unsafe {
+            self.pin.pad_ctrl().modify(|w| {
+                w.set_slewfast(slew_rate == SlewRate::Fast);
+            });
+        }
+    }
+
     /// Put the pin into input mode.
     ///
     /// The pull setting is left unchanged.

embassy-rp/src/lib.rs

@@ -12,6 +12,12 @@ pub mod dma;
 pub mod gpio;
 pub mod i2c;
 pub mod interrupt;
+
+#[cfg(feature = "pio")]
+pub mod pio;
+#[cfg(feature = "pio")]
+pub mod pio_instr_util;
+
 pub mod rom_data;
 pub mod rtc;
 pub mod spi;
@@ -102,6 +108,9 @@ embassy_hal_common::peripherals! {
     FLASH,
 
     ADC,
+
+    PIO0,
+    PIO1,
 }
 
 #[link_section = ".boot2"]

embassy-rp/src/pio_instr_util.rs

@@ -0,0 +1,90 @@
+use pio::{InSource, InstructionOperands, JmpCondition, OutDestination, SetDestination};
+
+use crate::pio::PioStateMachine;
+
+pub fn set_x<SM: PioStateMachine>(sm: &mut SM, value: u32) {
+    const OUT: u16 = InstructionOperands::OUT {
+        destination: OutDestination::X,
+        bit_count: 32,
+    }
+    .encode();
+    sm.push_tx(value);
+    sm.exec_instr(OUT);
+}
+
+pub fn get_x<SM: PioStateMachine>(sm: &mut SM) -> u32 {
+    const IN: u16 = InstructionOperands::IN {
+        source: InSource::X,
+        bit_count: 32,
+    }
+    .encode();
+    sm.exec_instr(IN);
+    sm.pull_rx()
+}
+
+pub fn set_y<SM: PioStateMachine>(sm: &mut SM, value: u32) {
+    const OUT: u16 = InstructionOperands::OUT {
+        destination: OutDestination::Y,
+        bit_count: 32,
+    }
+    .encode();
+    sm.push_tx(value);
+    sm.exec_instr(OUT);
+}
+
+pub fn get_y<SM: PioStateMachine>(sm: &mut SM) -> u32 {
+    const IN: u16 = InstructionOperands::IN {
+        source: InSource::Y,
+        bit_count: 32,
+    }
+    .encode();
+    sm.exec_instr(IN);
+
+    sm.pull_rx()
+}
+
+pub fn set_pindir<SM: PioStateMachine>(sm: &mut SM, data: u8) {
+    let set: u16 = InstructionOperands::SET {
+        destination: SetDestination::PINDIRS,
+        data,
+    }
+    .encode();
+    sm.exec_instr(set);
+}
+
+pub fn set_pin<SM: PioStateMachine>(sm: &mut SM, data: u8) {
+    let set: u16 = InstructionOperands::SET {
+        destination: SetDestination::PINS,
+        data,
+    }
+    .encode();
+    sm.exec_instr(set);
+}
+
+pub fn set_out_pin<SM: PioStateMachine>(sm: &mut SM, data: u32) {
+    const OUT: u16 = InstructionOperands::OUT {
+        destination: OutDestination::PINS,
+        bit_count: 32,
+    }
+    .encode();
+    sm.push_tx(data);
+    sm.exec_instr(OUT);
+}
+pub fn set_out_pindir<SM: PioStateMachine>(sm: &mut SM, data: u32) {
+    const OUT: u16 = InstructionOperands::OUT {
+        destination: OutDestination::PINDIRS,
+        bit_count: 32,
+    }
+    .encode();
+    sm.push_tx(data);
+    sm.exec_instr(OUT);
+}
+
+pub fn exec_jmp<SM: PioStateMachine>(sm: &mut SM, to_addr: u8) {
+    let jmp: u16 = InstructionOperands::JMP {
+        address: to_addr,
+        condition: JmpCondition::Always,
+    }
+    .encode();
+    sm.exec_instr(jmp);
+}