PIO support for RPi Pico

2 files changed, 172 insertions, 0 deletions

diff --git a/examples/rp/src/bin/pio_async.rs b/examples/rp/src/bin/pio_async.rs
new file mode 100644
index 000000000..e9211db3b
--- /dev/null
+++ b/examples/rp/src/bin/pio_async.rs
@@ -0,0 +1,105 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+use defmt::info;
+use embassy_executor::Spawner;
+use embassy_rp::gpio::{AnyPin, Pin};
+use embassy_rp::pio::{Pio0, PioPeripherial, PioStateMachine, PioStateMachineInstance, ShiftDirection, Sm0, Sm1, Sm2};
+use embassy_rp::pio_instr_util;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::task]
+async fn pio_task_sm0(mut sm: PioStateMachineInstance<Pio0, Sm0>, pin: AnyPin) {
+    // Setup sm0
+
+    // Send data serially to pin
+    let prg = pio_proc::pio_asm!(
+        ".origin 16",
+        "set pindirs, 1",
+        ".wrap_target",
+        "out pins,1 [19]",
+        ".wrap",
+    );
+
+    let origin = prg.program.origin.unwrap_or(0);
+    let out_pin = sm.make_pio_pin(pin);
+    let pio_pins = [&out_pin];
+    sm.set_out_pins(&pio_pins);
+    sm.write_instr(origin as usize, &prg.program.code);
+    pio_instr_util::exec_jmp(&mut sm, origin);
+    sm.set_clkdiv((125e6 / 20.0 / 2e2 * 256.0) as u32);
+    sm.set_set_range(0, 1);
+    sm.set_wrap(prg.program.wrap.source + origin, prg.program.wrap.target + origin);
+    sm.set_autopull(true);
+    sm.set_out_shift_dir(ShiftDirection::Left);
+
+    sm.set_enable(true);
+
+    let mut v = 0x0f0caffa;
+    loop {
+        sm.wait_push(v).await;
+        v ^= 0xffff;
+        info!("Pushed {:032b} to FIFO", v);
+    }
+}
+
+#[embassy_executor::task]
+async fn pio_task_sm1(mut sm: PioStateMachineInstance<Pio0, Sm1>) {
+    // Setupm sm1
+
+    // Read 0b10101 repeatedly until ISR is full
+    let prg = pio_proc::pio_asm!(".origin 8", "set x, 0x15", ".wrap_target", "in x, 5 [31]", ".wrap",);
+
+    let origin = prg.program.origin.unwrap_or(0);
+    sm.write_instr(origin as usize, &prg.program.code);
+    pio_instr_util::exec_jmp(&mut sm, origin);
+    sm.set_clkdiv((125e6 / 2e3 * 256.0) as u32);
+    sm.set_set_range(0, 0);
+    sm.set_wrap(prg.program.wrap.source + origin, prg.program.wrap.target + origin);
+    sm.set_autopush(true);
+    sm.set_in_shift_dir(ShiftDirection::Right);
+    sm.set_enable(true);
+    loop {
+        let rx = sm.wait_pull().await;
+        info!("Pulled {:032b} from FIFO", rx);
+    }
+}
+
+#[embassy_executor::task]
+async fn pio_task_sm2(mut sm: PioStateMachineInstance<Pio0, Sm2>) {
+    // Setup sm2
+
+    // Repeatedly trigger IRQ 3
+    let prg = pio_proc::pio_asm!(
+        ".origin 0",
+        ".wrap_target",
+        "set x,10",
+        "delay:",
+        "jmp x-- delay [15]",
+        "irq 3 [15]",
+        ".wrap",
+    );
+    let origin = prg.program.origin.unwrap_or(0);
+
+    sm.write_instr(origin as usize, &prg.program.code);
+    sm.set_wrap(prg.program.wrap.source + origin, prg.program.wrap.target + origin);
+    pio_instr_util::exec_jmp(&mut sm, origin);
+    sm.set_clkdiv((125e6 / 2e3 * 256.0) as u32);
+    sm.set_enable(true);
+    loop {
+        sm.wait_irq(3).await;
+        info!("IRQ trigged");
+    }
+}
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_rp::init(Default::default());
+    let pio = p.PIO0;
+
+    let (_, sm0, sm1, sm2, ..) = pio.split();
+
+    spawner.spawn(pio_task_sm0(sm0, p.PIN_0.degrade())).unwrap();
+    spawner.spawn(pio_task_sm1(sm1)).unwrap();
+    spawner.spawn(pio_task_sm2(sm2)).unwrap();
+}
diff --git a/examples/rp/src/bin/pio_dma.rs b/examples/rp/src/bin/pio_dma.rs
new file mode 100644
index 000000000..bdcdf200c
--- /dev/null
+++ b/examples/rp/src/bin/pio_dma.rs
@@ -0,0 +1,67 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+use defmt::info;
+use embassy_executor::Spawner;
+use embassy_futures::join::join;
+use embassy_rp::pio::{PioPeripherial, PioStateMachine, ShiftDirection};
+use embassy_rp::{pio_instr_util, Peripheral};
+use {defmt_rtt as _, panic_probe as _};
+
+fn swap_nibbles(v: u32) -> u32 {
+    let v = (v & 0x0f0f_0f0f) << 4 | (v & 0xf0f0_f0f0) >> 4;
+    let v = (v & 0x00ff_00ff) << 8 | (v & 0xff00_ff00) >> 8;
+    (v & 0x0000_ffff) << 16 | (v & 0xffff_0000) >> 16
+}
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = embassy_rp::init(Default::default());
+    let pio = p.PIO0;
+    let (_, mut sm, ..) = pio.split();
+
+    let prg = pio_proc::pio_asm!(
+        ".origin 0",
+        "set pindirs,1",
+        ".wrap_target",
+        "set y,7",
+        "loop:",
+        "out x,4",
+        "in x,4",
+        "jmp y--, loop",
+        ".wrap",
+    );
+
+    let origin = prg.program.origin.unwrap_or(0);
+    sm.write_instr(origin as usize, &prg.program.code);
+    pio_instr_util::exec_jmp(&mut sm, origin);
+    sm.set_clkdiv((125e6 / 10e3 * 256.0) as u32);
+    sm.set_wrap(prg.program.wrap.source + origin, prg.program.wrap.target + origin);
+    sm.set_autopull(true);
+    sm.set_autopush(true);
+    sm.set_pull_threshold(32);
+    sm.set_push_threshold(32);
+    sm.set_out_shift_dir(ShiftDirection::Right);
+    sm.set_in_shift_dir(ShiftDirection::Left);
+
+    sm.set_enable(true);
+
+    let mut dma_out_ref = p.DMA_CH0.into_ref();
+    let mut dma_in_ref = p.DMA_CH1.into_ref();
+    let mut dout = [0x12345678u32; 29];
+    for i in 1..dout.len() {
+        dout[i] = (dout[i - 1] & 0x0fff_ffff) * 13 + 7;
+    }
+    let mut din = [0u32; 29];
+    loop {
+        join(
+            sm.dma_push(dma_out_ref.reborrow(), &dout),
+            sm.dma_pull(dma_in_ref.reborrow(), &mut din),
+        )
+        .await;
+        for i in 0..din.len() {
+            assert_eq!(din[i], swap_nibbles(dout[i]));
+        }
+        info!("Swapped {} words", dout.len());
+    }
+}