examples: add dma example for lpc55s28-evk

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2026-05-14 01:51:40 -07:00
parent a918ebc554
commit e2edb1d468
8 changed files with 2052 additions and 0 deletions
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//! Contains hardware setup unrelated to Usb Audio Class implementation
use crate::hal;
use core::cell::{OnceCell, UnsafeCell};
use core::mem::MaybeUninit;
use core::ptr::null_mut;
use crate::Syscon;
use crate::{MCLK_FREQ, SAMPLE_RATE, pac};
use defmt::debug;
use hal::{
Iocon, Pin,
drivers::pins,
prelude::*,
traits::wg::digital::v2::{OutputPin, ToggleableOutputPin},
typestates::pin::{gpio::direction::Output, state::Gpio},
};
use lpc55_hal::Enabled;
use static_cell::StaticCell;
pub(crate) struct PllConstants {
pub m: u16, // 1-65535
pub n: u8, // 1-255
pub p: u8, // 1-31
pub selp: u8, // 5 bits
pub seli: u8, // 6 bits
}
impl PllConstants {
pub(crate) const fn new(n: u8, m: u16, p: u8) -> Self {
assert!(n != 0, "1 <= N <= 255");
assert!(m != 0, "1 <= M <= 65535");
assert!(p != 0 && p <= 31, "1 <= P <= 31");
// Following ripped from lpc55-hal and made const
// UM 4.6.6.3.2
let selp = {
let v = (m >> 2) + 1;
if v < 31 { v } else { 31 }
} as u8;
let seli = {
let v = match m {
m if m >= 8000 => 1,
m if m >= 122 => 8000 / m,
_ => 2 * (m >> 2) + 3,
};
if v < 63 { v } else { 63 }
} as u8;
// let seli = min(2*(m >> 2) + 3, 63);
Self {
n,
m,
p,
selp,
seli,
}
}
}
impl defmt::Format for PllConstants {
fn format(&self, fmt: defmt::Formatter) {
let factor = f32::from(self.m) / (f32::from(self.n) * 2.0 * f32::from(self.p));
defmt::write!(
fmt,
"m: {} n: {} p: {} selp: {} seli: {} fout: fin * {}",
self.m,
self.n,
self.p,
self.selp,
self.seli,
factor
);
}
}
// Fo = M/(N*2*P) * Fin
// Fo = 3072/(125*2*8) * 16MHz = 24.576MHz
const AUDIO_PLL: PllConstants = PllConstants::new(125, 3072, 8);
// Set PLL0 to 24.576MHz, start, and wait for lock
// This is not exposed by lpc55-hal, unfortunately. Copy their implementation here.
pub(crate) fn init_audio_pll() {
let syscon = unsafe { &*pac::SYSCON::ptr() };
let pmc = unsafe { &*pac::PMC::ptr() };
let anactrl = unsafe { &*pac::ANACTRL::ptr() };
debug!("start clk_in");
pmc.pdruncfg0
.modify(|_, w| w.pden_xtal32m().poweredon().pden_ldoxo32m().poweredon());
syscon.clock_ctrl.modify(|_, w| w.clkin_ena().enable());
anactrl
.xo32m_ctrl
.modify(|_, w| w.enable_system_clk_out().enable());
debug!("init pll0: {}", AUDIO_PLL);
pmc.pdruncfg0
.modify(|_, w| w.pden_pll0().poweredoff().pden_pll0_sscg().poweredoff());
syscon.pll0clksel.write(|w| w.sel().enum_0x1()); // clk_in
syscon.pll0ctrl.write(|w| unsafe {
w.clken()
.enable()
.seli()
.bits(AUDIO_PLL.seli)
.selp()
.bits(AUDIO_PLL.selp)
});
syscon
.pll0ndec
.write(|w| unsafe { w.ndiv().bits(AUDIO_PLL.n) });
syscon.pll0ndec.write(|w| unsafe {
w.ndiv().bits(AUDIO_PLL.n).nreq().set_bit() // latch
});
syscon
.pll0pdec
.write(|w| unsafe { w.pdiv().bits(AUDIO_PLL.p) });
syscon.pll0pdec.write(|w| unsafe {
w.pdiv().bits(AUDIO_PLL.p).preq().set_bit() // latch
});
syscon.pll0sscg0.write(|w| unsafe { w.md_lbs().bits(0) });
syscon
.pll0sscg1
.write(|w| unsafe { w.mdiv_ext().bits(AUDIO_PLL.m).sel_ext().set_bit() });
syscon.pll0sscg1.write(|w| unsafe {
w.mdiv_ext()
.bits(AUDIO_PLL.m)
.sel_ext()
.set_bit()
.mreq()
.set_bit() // latch
.md_req()
.set_bit() // latch
});
pmc.pdruncfg0
.modify(|_, w| w.pden_pll0().poweredon().pden_pll0_sscg().poweredon());
debug!("pll0 wait for lock");
let mut i = 0usize;
while syscon.pll0stat.read().lock().bit_is_clear() {
i += 1;
}
debug!("pll0 locked after {} tries", i);
}
const SYS_PLL: PllConstants = PllConstants::new(4, 75, 1); // 150MHz
pub(crate) fn init_sys_pll1() {
let syscon = unsafe { &*pac::SYSCON::ptr() };
let pmc = unsafe { &*pac::PMC::ptr() };
let anactrl = unsafe { &*pac::ANACTRL::ptr() };
debug!("start clk_in");
pmc.pdruncfg0
.modify(|_, w| w.pden_xtal32m().poweredon().pden_ldoxo32m().poweredon());
syscon.clock_ctrl.modify(|_, w| w.clkin_ena().enable());
anactrl
.xo32m_ctrl
.modify(|_, w| w.enable_system_clk_out().enable());
debug!("init pll1: {}", SYS_PLL);
pmc.pdruncfg0.modify(|_, w| w.pden_pll1().poweredoff());
syscon.pll1clksel.write(|w| w.sel().enum_0x1()); // clk_in
syscon.pll1ctrl.write(|w| unsafe {
w.clken()
.enable()
.seli()
.bits(SYS_PLL.seli)
.selp()
.bits(SYS_PLL.selp)
});
syscon
.pll1ndec
.write(|w| unsafe { w.ndiv().bits(SYS_PLL.n) });
syscon.pll1ndec.write(|w| unsafe {
w.ndiv().bits(SYS_PLL.n).nreq().set_bit() // latch
});
syscon
.pll1mdec
.write(|w| unsafe { w.mdiv().bits(SYS_PLL.m) });
syscon
.pll1pdec
.write(|w| unsafe { w.pdiv().bits(SYS_PLL.p) });
syscon.pll1pdec.write(|w| unsafe {
w.pdiv().bits(SYS_PLL.p).preq().set_bit() // latch
});
pmc.pdruncfg0.modify(|_, w| w.pden_pll1().poweredon());
debug!("pll1 wait for lock");
let mut i = 0usize;
while syscon.pll1stat.read().lock().bit_is_clear() {
i += 1;
}
debug!("pll1 locked after {} tries", i);
// switch system clock to pll1
syscon.fmccr.modify(|_, w| w.flashtim().flashtim11());
syscon.mainclkselb.modify(|_, w| w.sel().enum_0x2()); // pll1
}
pub struct I2sTx {
pub i2s: pac::I2S7,
}
pub fn init_i2s(mut fc7: pac::FLEXCOMM7, i2s7: pac::I2S7, syscon: &mut Syscon) -> I2sTx {
defmt::debug!("init i2s");
// Enable BOTH
syscon.reset(&mut fc7);
syscon.enable_clock(&mut fc7);
unsafe {
pac::IOCON::ptr().as_ref().unwrap().pio1_31.modify(|_, w| {
w.func()
.alt1()
.mode()
.inactive()
.slew()
.fast()
.invert()
.disabled()
.digimode()
.digital()
.od()
.normal()
});
pac::SYSCON::ptr()
.as_ref()
.unwrap()
.fcclksel7()
.modify(|_, w| w.sel().enum_0x5()); // MCLK
pac::SYSCON::ptr()
.as_ref()
.unwrap()
.mclkclksel
.modify(|_, w| w.sel().enum_0x1()); // PLL0
pac::SYSCON::ptr()
.as_ref()
.unwrap()
.mclkdiv
.modify(|_, w| w.div().bits(1).halt().run().reset().released()); // div by 2 = PLL0 fout / 2 = 12.288MHz, max for WM8904 @ 96k
pac::SYSCON::ptr()
.as_ref()
.unwrap()
.mclkio
.modify(|_, w| w.mclkio().output());
};
// Select I2S TX function
fc7.pselid.write(|w| w.persel().i2s_transmit());
let regs = i2s7;
// Enable TX FIFO only
regs.fifocfg.modify(|_, w| {
w.enabletx()
.enabled()
.enablerx()
.disabled()
.dmatx()
.disabled()
.txi2se0()
.zero()
});
regs.fifotrig.modify(|_, w| unsafe { w.txlvl().bits(6) });
// Flush
regs.fifocfg.modify(|_, w| w.emptytx().set_bit());
regs.cfg2
.modify(|_, w| unsafe { w.position().bits(0).framelen().bits(63) }); // framelen = 64
let bclk_div = (MCLK_FREQ / SAMPLE_RATE / 64) as u16;
regs.div
.modify(|_, w| unsafe { w.div().bits(bclk_div - 1) }); // Clock source is MCLK (12.288MHz) / 4 = 3MHz
// Config
regs.cfg1.modify(|_, w| unsafe {
w.mstslvcfg()
.normal_master()
.onechannel()
.dual_channel()
.datalen()
.bits(31)
.mainenable()
.enabled()
.mode()
.classic_mode()
.datapause()
.normal()
});
I2sTx { i2s: regs }
}
pub struct SharedLed<T: OutputPin> {
inner: UnsafeCell<T>,
}
unsafe impl<T: OutputPin> Sync for SharedLed<T> {}
impl<T: OutputPin> SharedLed<T> {
pub fn new(inner: T) -> Self {
Self {
inner: UnsafeCell::new(inner),
}
}
pub fn on(&self) {
unsafe {
(*self.inner.get()).set_low().ok();
}
}
pub fn off(&self) {
unsafe {
(*self.inner.get()).set_high().ok();
}
}
}
impl<T: OutputPin + ToggleableOutputPin> SharedLed<T> {
pub fn toggle(&self) {
unsafe {
(*self.inner.get()).toggle().ok();
}
}
}
type RedLed = Pin<pins::Pio1_6, Gpio<Output>>;
type GreenLed = Pin<pins::Pio1_7, Gpio<Output>>;
type BlueLed = Pin<pins::Pio1_4, Gpio<Output>>;
pub static RED_LED: MaybeUninit<SharedLed<RedLed>> = MaybeUninit::uninit();
pub static GREEN_LED: MaybeUninit<SharedLed<GreenLed>> = MaybeUninit::uninit();
pub static BLUE_LED: MaybeUninit<SharedLed<BlueLed>> = MaybeUninit::uninit();
pub fn init_leds(iocon: &mut Iocon<Enabled>, gpio: &mut hal::Gpio<Enabled>) {
let red_led = SharedLed::new(
pins::Pio1_6::take()
.unwrap()
.into_gpio_pin(iocon, gpio)
.into_output_low(),
);
let green_led = SharedLed::new(
pins::Pio1_7::take()
.unwrap()
.into_gpio_pin(iocon, gpio)
.into_output_low(),
);
let blue_led = SharedLed::new(
pins::Pio1_4::take()
.unwrap()
.into_gpio_pin(iocon, gpio)
.into_output_low(),
);
unsafe {
core::ptr::write(RED_LED.as_ptr() as *mut SharedLed<RedLed>, red_led);
core::ptr::write(GREEN_LED.as_ptr() as *mut SharedLed<GreenLed>, green_led);
core::ptr::write(BLUE_LED.as_ptr() as *mut SharedLed<BlueLed>, blue_led);
}
}
pub fn red_led() -> &'static SharedLed<RedLed> {
unsafe { &*RED_LED.as_ptr() }
}
pub fn green_led() -> &'static SharedLed<GreenLed> {
unsafe { &*GREEN_LED.as_ptr() }
}
pub fn blue_led() -> &'static SharedLed<BlueLed> {
unsafe { &*BLUE_LED.as_ptr() }
}