4 files changed, 262 insertions, 33 deletions

diff --git a/examples/rpi-pico-w/Cargo.toml b/examples/rpi-pico-w/Cargo.toml
index 99b82ca31..0d789a932 100644
--- a/examples/rpi-pico-w/Cargo.toml
+++ b/examples/rpi-pico-w/Cargo.toml
@@ -5,11 +5,31 @@ edition = "2021"
 
 
 [dependencies]
-cyw43 = { path = "../../", features = ["defmt", "firmware-logs"]}
-embassy-executor = { version = "0.1.0",  features = ["defmt", "integrated-timers"] }
-embassy-time = { version = "0.1.0",  features = ["defmt", "defmt-timestamp-uptime"] }
-embassy-rp = { version = "0.1.0",  features = ["defmt", "unstable-traits", "nightly", "unstable-pac", "time-driver"] }
-embassy-net = { version = "0.1.0", features = ["defmt", "tcp", "dhcpv4", "medium-ethernet", "unstable-traits", "nightly"] }
+cyw43 = { path = "../../", features = ["defmt", "firmware-logs"] }
+embassy-executor = { version = "0.1.0", features = [
+    "defmt",
+    "integrated-timers",
+] }
+embassy-time = { version = "0.1.0", features = [
+    "defmt",
+    "defmt-timestamp-uptime",
+] }
+embassy-rp = { version = "0.1.0", features = [
+    "defmt",
+    "unstable-traits",
+    "nightly",
+    "unstable-pac",
+    "pio",
+    "time-driver",
+] }
+embassy-net = { version = "0.1.0", features = [
+    "defmt",
+    "tcp",
+    "dhcpv4",
+    "medium-ethernet",
+    "unstable-traits",
+    "nightly",
+] }
 atomic-polyfill = "0.1.5"
 static_cell = "1.0"
 
@@ -17,9 +37,15 @@ defmt = "0.3"
 defmt-rtt = "0.3"
 panic-probe = { version = "0.3", features = ["print-defmt"] }
 
-cortex-m = { version = "0.7.6", features = ["critical-section-single-core"]}
+cortex-m = { version = "0.7.6", features = ["critical-section-single-core"] }
 cortex-m-rt = "0.7.0"
-futures = { version = "0.3.17", default-features = false, features = ["async-await", "cfg-target-has-atomic", "unstable"] }
+futures = { version = "0.3.17", default-features = false, features = [
+    "async-await",
+    "cfg-target-has-atomic",
+    "unstable",
+] }
+pio-proc = "0.2"
+pio = "0.2.1"
 
 embedded-hal-1 = { package = "embedded-hal", version = "1.0.0-alpha.9" }
 embedded-hal-async = { version = "0.2.0-alpha.0" }
diff --git a/examples/rpi-pico-w/build.rs b/examples/rpi-pico-w/build.rs
index d4c3ec89d..3f915f931 100644
--- a/examples/rpi-pico-w/build.rs
+++ b/examples/rpi-pico-w/build.rs
@@ -14,23 +14,23 @@ use std::io::Write;
 use std::path::PathBuf;
 
 fn main() {
-    // // Put `memory.x` in our output directory and ensure it's
-    // // on the linker search path.
-    // let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
-    // File::create(out.join("memory.x"))
-    //     .unwrap()
-    //     .write_all(include_bytes!("memory.x"))
-    //     .unwrap();
-    // println!("cargo:rustc-link-search={}", out.display());
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
 
-    // // By default, Cargo will re-run a build script whenever
-    // // any file in the project changes. By specifying `memory.x`
-    // // here, we ensure the build script is only re-run when
-    // // `memory.x` is changed.
-    // println!("cargo:rerun-if-changed=memory.x");
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
 
-    // println!("cargo:rustc-link-arg-bins=--nmagic");
-    // println!("cargo:rustc-link-arg-bins=-Tlink.x");
-    // println!("cargo:rustc-link-arg-bins=-Tlink-rp.x");
-    // println!("cargo:rustc-link-arg-bins=-Tdefmt.x");
+    println!("cargo:rustc-link-arg-bins=--nmagic");
+    println!("cargo:rustc-link-arg-bins=-Tlink.x");
+    println!("cargo:rustc-link-arg-bins=-Tlink-rp.x");
+    println!("cargo:rustc-link-arg-bins=-Tdefmt.x");
 }
diff --git a/examples/rpi-pico-w/src/main.rs b/examples/rpi-pico-w/src/main.rs
index f768af193..3563d165a 100644
--- a/examples/rpi-pico-w/src/main.rs
+++ b/examples/rpi-pico-w/src/main.rs
@@ -4,21 +4,25 @@
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
 
+mod pio;
+
 use core::convert::Infallible;
+use core::str::from_utf8;
 
 use defmt::*;
 use embassy_executor::Spawner;
 use embassy_net::tcp::TcpSocket;
 use embassy_net::{Config, Stack, StackResources};
 use embassy_rp::gpio::{Flex, Level, Output};
-use embassy_rp::peripherals::{PIN_23, PIN_24, PIN_25, PIN_29};
+use embassy_rp::peripherals::{DMA_CH0, PIN_23, PIN_24, PIN_25, PIN_29};
+use embassy_rp::pio::{Pio0, PioPeripherial, PioStateMachineInstance, Sm0};
 use embedded_hal_1::spi::ErrorType;
 use embedded_hal_async::spi::{ExclusiveDevice, SpiBusFlush, SpiBusRead, SpiBusWrite};
 use embedded_io::asynch::Write;
 use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
 
-use core::str::from_utf8;
+use crate::pio::PioSpi;
 
 macro_rules! singleton {
     ($val:expr) => {{
@@ -30,7 +34,11 @@ macro_rules! singleton {
 
 #[embassy_executor::task]
 async fn wifi_task(
-    runner: cyw43::Runner<'static, Output<'static, PIN_23>, ExclusiveDevice<MySpi, Output<'static, PIN_25>>>,
+    runner: cyw43::Runner<
+        'static,
+        Output<'static, PIN_23>,
+        ExclusiveDevice<PioSpi<PioStateMachineInstance<Pio0, Sm0>, DMA_CH0>, Output<'static, PIN_25>>,
+    >,
 ) -> ! {
     runner.run().await
 }
@@ -59,12 +67,15 @@ async fn main(spawner: Spawner) {
 
     let pwr = Output::new(p.PIN_23, Level::Low);
     let cs = Output::new(p.PIN_25, Level::High);
-    let clk = Output::new(p.PIN_29, Level::Low);
-    let mut dio = Flex::new(p.PIN_24);
-    dio.set_low();
-    dio.set_as_output();
-
-    let bus = MySpi { clk, dio };
+    // let clk = Output::new(p.PIN_29, Level::Low);
+    // let mut dio = Flex::new(p.PIN_24);
+    // dio.set_low();
+    // dio.set_as_output();
+    // // let bus = MySpi { clk, dio };
+
+    let (_, sm, _, _, _) = p.PIO0.split();
+    let dma = p.DMA_CH0;
+    let bus = PioSpi::new(sm, p.PIN_24, p.PIN_29, dma);
     let spi = ExclusiveDevice::new(bus, cs);
 
     let state = singleton!(cyw43::State::new());
@@ -110,6 +121,7 @@ async fn main(spawner: Spawner) {
         let mut socket = TcpSocket::new(stack, &mut rx_buffer, &mut tx_buffer);
         socket.set_timeout(Some(embassy_net::SmolDuration::from_secs(10)));
 
+        control.gpio_set(0, false).await;
         info!("Listening on TCP:1234...");
         if let Err(e) = socket.accept(1234).await {
             warn!("accept error: {:?}", e);
@@ -117,6 +129,7 @@ async fn main(spawner: Spawner) {
         }
 
         info!("Received connection from {:?}", socket.remote_endpoint());
+        control.gpio_set(0, true).await;
 
         loop {
             let n = match socket.read(&mut buf).await {
diff --git a/examples/rpi-pico-w/src/pio.rs b/examples/rpi-pico-w/src/pio.rs
new file mode 100644
index 000000000..abb71b5de
--- /dev/null
+++ b/examples/rpi-pico-w/src/pio.rs
@@ -0,0 +1,190 @@
+use core::slice;
+
+use cyw43::SpiBusCyw43;
+use embassy_rp::dma::Channel;
+use embassy_rp::gpio::{Pin, Pull};
+use embassy_rp::pio::{PioStateMachine, ShiftDirection};
+use embassy_rp::relocate::RelocatedProgram;
+use embassy_rp::{pio_instr_util, Peripheral};
+use embedded_hal_1::spi::ErrorType;
+use embedded_hal_async::spi::SpiBusFlush;
+use pio::Wrap;
+use pio_proc::pio_asm;
+
+pub struct PioSpi<SM, DMA> {
+    // cs: Output<'static, AnyPin>,
+    sm: SM,
+    dma: DMA,
+    wrap_target: u8,
+}
+
+impl<SM, DMA> PioSpi<SM, DMA>
+where
+    SM: PioStateMachine,
+    DMA: Channel,
+{
+    pub fn new<DIO, CLK>(
+        mut sm: SM,
+        // cs: AnyPin,
+        dio: DIO,
+        clk: CLK,
+        dma: DMA,
+    ) -> Self
+    where
+        DIO: Pin,
+        CLK: Pin,
+    {
+        let program = pio_asm!(
+            ".side_set 1"
+            // "set pindirs, 1 side 0"
+            // "set pins, 0    side 0"
+            ".wrap_target"
+            "lp:",
+            "out pins, 1    side 0"
+            "jmp x-- lp     side 1"
+            "set pindirs, 0 side 0"
+            // "nop            side 1"
+            "lp2:"
+            "in pins, 1     side 0"
+            "jmp y-- lp2    side 1"
+            ".wrap"
+        );
+
+        let relocated = RelocatedProgram::new(&program.program);
+
+        let mut pin_io = sm.make_pio_pin(dio);
+        pin_io.set_pull(Pull::Down);
+        pin_io.set_schmitt(true);
+        let pin_clk = sm.make_pio_pin(clk);
+
+        sm.write_instr(relocated.origin() as usize, relocated.code());
+
+        // 16 Mhz
+        sm.set_clkdiv(0x07d0);
+
+        // 8Mhz
+        sm.set_clkdiv(0x0a_00);
+
+        // 1Mhz
+        // sm.set_clkdiv(0x7d_00);
+
+        // slowest possible
+        // sm.set_clkdiv(0xffff_00);
+
+        sm.set_autopull(true);
+        // sm.set_pull_threshold(32);
+        sm.set_autopush(true);
+        // sm.set_push_threshold(32);
+
+        sm.set_out_pins(&[&pin_io]);
+        sm.set_in_base_pin(&pin_io);
+
+        sm.set_set_pins(&[&pin_clk]);
+        pio_instr_util::set_pindir(&mut sm, 0b1);
+        sm.set_set_pins(&[&pin_io]);
+        pio_instr_util::set_pindir(&mut sm, 0b1);
+
+        sm.set_sideset_base_pin(&pin_clk);
+        sm.set_sideset_count(1);
+
+        sm.set_out_shift_dir(ShiftDirection::Left);
+        sm.set_in_shift_dir(ShiftDirection::Left);
+
+        let Wrap { source, target } = relocated.wrap();
+        sm.set_wrap(source, target);
+
+        // pull low for startup
+        pio_instr_util::set_pin(&mut sm, 0);
+
+        Self {
+            // cs: Output::new(cs, Level::High),
+            sm,
+            dma,
+            wrap_target: target,
+        }
+    }
+
+    pub async fn write(&mut self, write: &[u32]) {
+        let write_bits = write.len() * 32 - 1;
+        let read_bits = 31;
+
+        defmt::trace!("write={} read={}", write_bits, read_bits);
+
+        let mut dma = Peripheral::into_ref(&mut self.dma);
+        pio_instr_util::set_x(&mut self.sm, write_bits as u32);
+        pio_instr_util::set_y(&mut self.sm, read_bits as u32);
+        pio_instr_util::set_pindir(&mut self.sm, 0b1);
+        pio_instr_util::exec_jmp(&mut self.sm, self.wrap_target);
+
+        self.sm.set_enable(true);
+
+        self.sm.dma_push(dma.reborrow(), write).await;
+
+        let mut status = 0;
+        self.sm.dma_pull(dma, slice::from_mut(&mut status)).await;
+        defmt::trace!("{:#08x}", status);
+
+        self.sm.set_enable(false);
+    }
+
+    pub async fn cmd_read(&mut self, cmd: u32, read: &mut [u32]) {
+        let write_bits = 31;
+        let read_bits = read.len() * 32 - 1;
+
+        defmt::trace!("write={} read={}", write_bits, read_bits);
+
+        let mut dma = Peripheral::into_ref(&mut self.dma);
+        pio_instr_util::set_y(&mut self.sm, read_bits as u32);
+        pio_instr_util::set_x(&mut self.sm, write_bits as u32);
+        pio_instr_util::set_pindir(&mut self.sm, 0b1);
+        pio_instr_util::exec_jmp(&mut self.sm, self.wrap_target);
+        // self.cs.set_low();
+        self.sm.set_enable(true);
+
+        self.sm.dma_push(dma.reborrow(), slice::from_ref(&cmd)).await;
+        self.sm.dma_pull(dma, read).await;
+
+        self.sm.set_enable(false);
+    }
+}
+
+#[derive(Debug)]
+pub enum PioError {}
+
+impl embedded_hal_async::spi::Error for PioError {
+    fn kind(&self) -> embedded_hal_1::spi::ErrorKind {
+        embedded_hal_1::spi::ErrorKind::Other
+    }
+}
+
+impl<SM, DMA> ErrorType for PioSpi<SM, DMA>
+where
+    SM: PioStateMachine,
+{
+    type Error = PioError;
+}
+
+impl<SM, DMA> SpiBusFlush for PioSpi<SM, DMA>
+where
+    SM: PioStateMachine,
+{
+    async fn flush(&mut self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+impl<SM, DMA> SpiBusCyw43<u32> for PioSpi<SM, DMA>
+where
+    SM: PioStateMachine,
+    DMA: Channel,
+{
+    async fn cmd_write<'a>(&'a mut self, write: &'a [u32]) -> Result<(), Self::Error> {
+        self.write(write).await;
+        Ok(())
+    }
+
+    async fn cmd_read<'a>(&'a mut self, write: &'a [u32], read: &'a mut [u32]) -> Result<(), Self::Error> {
+        self.cmd_read(write[0], read).await;
+        Ok(())
+    }
+}