2fcdfc4876
It was intended to allow changing baudrate on shared spi/i2c. There's no advantage in using it for PWM or PIO, and makes it less usable because you have to have `embassy-embedded-hal` as a dep to use it.
80 lines
2.1 KiB
Rust
80 lines
2.1 KiB
Rust
#![no_std]
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#![no_main]
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#![feature(type_alias_impl_trait)]
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use defmt::info;
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use embassy_executor::Spawner;
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use embassy_futures::join::join;
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use embassy_rp::pio::{Config, Pio, ShiftConfig, ShiftDirection};
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use embassy_rp::relocate::RelocatedProgram;
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use embassy_rp::Peripheral;
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use fixed::traits::ToFixed;
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use fixed_macro::types::U56F8;
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use {defmt_rtt as _, panic_probe as _};
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fn swap_nibbles(v: u32) -> u32 {
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let v = (v & 0x0f0f_0f0f) << 4 | (v & 0xf0f0_f0f0) >> 4;
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let v = (v & 0x00ff_00ff) << 8 | (v & 0xff00_ff00) >> 8;
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(v & 0x0000_ffff) << 16 | (v & 0xffff_0000) >> 16
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}
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#[embassy_executor::main]
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async fn main(_spawner: Spawner) {
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let p = embassy_rp::init(Default::default());
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let pio = p.PIO0;
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let Pio {
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mut common,
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sm0: mut sm,
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..
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} = Pio::new(pio);
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let prg = pio_proc::pio_asm!(
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".origin 0",
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"set pindirs,1",
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".wrap_target",
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"set y,7",
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"loop:",
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"out x,4",
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"in x,4",
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"jmp y--, loop",
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".wrap",
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);
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let relocated = RelocatedProgram::new(&prg.program);
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let mut cfg = Config::default();
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cfg.use_program(&common.load_program(&relocated), &[]);
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cfg.clock_divider = (U56F8!(125_000_000) / U56F8!(10_000)).to_fixed();
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cfg.shift_in = ShiftConfig {
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auto_fill: true,
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threshold: 32,
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direction: ShiftDirection::Left,
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};
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cfg.shift_out = ShiftConfig {
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auto_fill: true,
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threshold: 32,
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direction: ShiftDirection::Right,
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};
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sm.set_config(&cfg);
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sm.set_enable(true);
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let mut dma_out_ref = p.DMA_CH0.into_ref();
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let mut dma_in_ref = p.DMA_CH1.into_ref();
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let mut dout = [0x12345678u32; 29];
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for i in 1..dout.len() {
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dout[i] = (dout[i - 1] & 0x0fff_ffff) * 13 + 7;
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}
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let mut din = [0u32; 29];
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loop {
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let (rx, tx) = sm.rx_tx();
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join(
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tx.dma_push(dma_out_ref.reborrow(), &dout),
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rx.dma_pull(dma_in_ref.reborrow(), &mut din),
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)
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.await;
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for i in 0..din.len() {
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assert_eq!(din[i], swap_nibbles(dout[i]));
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}
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info!("Swapped {} words", dout.len());
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}
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}
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