va416xx-rs/va416xx-hal/src/spi.rs
Robin Mueller c53702ee74
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2024-07-07 13:48:50 +02:00

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Rust

//! API for the SPI peripheral
//!
//! ## Examples
//!
//! - [Blocking SPI example](https://egit.irs.uni-stuttgart.de/rust/va416xx-rs/src/branch/main/examples/simple/examples/spi.rs)
use core::{convert::Infallible, marker::PhantomData, ops::Deref};
use embedded_hal::spi::Mode;
use crate::{
clock::{Clocks, PeripheralSelect, SyscfgExt},
gpio::{
AltFunc1, AltFunc2, AltFunc3, Pin, PA0, PA1, PA2, PA3, PA4, PA5, PA6, PA7, PA8, PA9, PB0,
PB1, PB10, PB11, PB12, PB13, PB14, PB15, PB2, PB3, PB4, PB5, PB6, PB7, PB8, PB9, PC0, PC1,
PC10, PC11, PC7, PC8, PC9, PE10, PE11, PE12, PE13, PE14, PE15, PE5, PE6, PE7, PE8, PE9,
PF0, PF1, PF2, PF3, PF4, PF5, PF6, PF7, PG2, PG3, PG4,
},
pac,
time::Hertz,
typelevel::{NoneT, Sealed},
};
//==================================================================================================
// Defintions
//==================================================================================================
// FIFO has a depth of 16.
const FILL_DEPTH: usize = 12;
pub const DEFAULT_CLK_DIV: u16 = 2;
pub const BMSTART_BMSTOP_MASK: u32 = 1 << 31;
pub const BMSKIPDATA_MASK: u32 = 1 << 30;
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
pub enum HwChipSelectId {
Id0 = 0,
Id1 = 1,
Id2 = 2,
Id3 = 3,
Id4 = 4,
Id5 = 5,
Id6 = 6,
Id7 = 7,
Invalid = 0xff,
}
#[derive(Debug)]
pub enum SpiId {
Spi0,
Spi1,
Spi2,
Spi3,
Invalid,
}
#[derive(Debug, PartialEq, Eq, Copy, Clone)]
pub enum WordSize {
OneBit = 0x00,
FourBits = 0x03,
EightBits = 0x07,
SixteenBits = 0x0f,
}
//==================================================================================================
// Pin type definitions
//==================================================================================================
pub trait PinSck<SPI>: Sealed {}
pub trait PinMosi<SPI>: Sealed {}
pub trait PinMiso<SPI>: Sealed {}
pub trait HwCsProvider: Sealed {
const CS_ID: HwChipSelectId;
const SPI_ID: SpiId;
}
pub trait OptionalHwCs<Spi>: HwCsProvider + Sealed {}
macro_rules! hw_cs_pins {
($SPIx:path, $portId: path:
$(
($PXx:ident, $AFx:ident, $HwCsIdent:path, $typedef:ident),
)+
) => {
$(
impl HwCsProvider for Pin<$PXx, $AFx> {
const CS_ID: HwChipSelectId = $HwCsIdent;
const SPI_ID: SpiId = $portId;
}
impl OptionalHwCs<$SPIx> for Pin<$PXx, $AFx> {}
pub type $typedef = Pin<$PXx, $AFx>;
)+
};
}
impl HwCsProvider for NoneT {
const CS_ID: HwChipSelectId = HwChipSelectId::Invalid;
const SPI_ID: SpiId = SpiId::Invalid;
}
impl OptionalHwCs<pac::Spi0> for NoneT {}
impl OptionalHwCs<pac::Spi1> for NoneT {}
impl OptionalHwCs<pac::Spi2> for NoneT {}
impl OptionalHwCs<pac::Spi3> for NoneT {}
pub struct RomSpiSck;
pub struct RomSpiMiso;
pub struct RomSpiMosi;
impl Sealed for RomSpiSck {}
impl Sealed for RomSpiMosi {}
impl Sealed for RomSpiMiso {}
// SPI 0
impl PinSck<pac::Spi0> for Pin<PB15, AltFunc1> {}
impl PinMosi<pac::Spi0> for Pin<PC1, AltFunc1> {}
impl PinMiso<pac::Spi0> for Pin<PC0, AltFunc1> {}
// SPI 1
impl PinSck<pac::Spi1> for Pin<PB8, AltFunc3> {}
impl PinMosi<pac::Spi1> for Pin<PB10, AltFunc3> {}
impl PinMiso<pac::Spi1> for Pin<PB9, AltFunc3> {}
impl PinSck<pac::Spi1> for Pin<PC9, AltFunc2> {}
impl PinMosi<pac::Spi1> for Pin<PC11, AltFunc2> {}
impl PinMiso<pac::Spi1> for Pin<PC10, AltFunc2> {}
impl PinSck<pac::Spi1> for Pin<PG3, AltFunc2> {}
impl PinMiso<pac::Spi1> for Pin<PG4, AltFunc2> {}
impl PinSck<pac::Spi1> for Pin<PE13, AltFunc2> {}
impl PinMosi<pac::Spi1> for Pin<PE15, AltFunc2> {}
impl PinMiso<pac::Spi1> for Pin<PE14, AltFunc2> {}
impl PinSck<pac::Spi1> for Pin<PF3, AltFunc1> {}
impl PinMosi<pac::Spi1> for Pin<PF5, AltFunc1> {}
impl PinMiso<pac::Spi1> for Pin<PF4, AltFunc1> {}
// SPI 2
impl PinSck<pac::Spi2> for Pin<PA5, AltFunc2> {}
impl PinMosi<pac::Spi2> for Pin<PA7, AltFunc2> {}
impl PinMiso<pac::Spi2> for Pin<PA6, AltFunc2> {}
impl PinSck<pac::Spi2> for Pin<PF5, AltFunc2> {}
impl PinMosi<pac::Spi2> for Pin<PF7, AltFunc2> {}
impl PinMiso<pac::Spi2> for Pin<PF6, AltFunc2> {}
// SPI3 is shared with the ROM SPI pins and has its own dedicated pins.
//
impl PinSck<pac::Spi3> for RomSpiSck {}
impl PinMosi<pac::Spi3> for RomSpiMosi {}
impl PinMiso<pac::Spi3> for RomSpiMiso {}
// SPI 0 HW CS pins
hw_cs_pins!(
pac::Spi0, SpiId::Spi0:
(PB14, AltFunc1, HwChipSelectId::Id0, HwCs0Spi0),
(PB13, AltFunc1, HwChipSelectId::Id1, HwCs1Spi0),
(PB12, AltFunc1, HwChipSelectId::Id2, HwCs2Spi0),
(PB11, AltFunc1, HwChipSelectId::Id3, HwCs3Spi0),
);
hw_cs_pins!(
pac::Spi1, SpiId::Spi1:
(PB7, AltFunc3, HwChipSelectId::Id0, HwCs0Spi1Pb),
(PB6, AltFunc3, HwChipSelectId::Id1, HwCs1Spi1Pb),
(PB5, AltFunc3, HwChipSelectId::Id2, HwCs2Spi1Pb),
(PB4, AltFunc3, HwChipSelectId::Id3, HwCs3Spi1Pb),
(PB3, AltFunc3, HwChipSelectId::Id4, HwCs4Spi1Pb),
(PB2, AltFunc3, HwChipSelectId::Id5, HwCs5Spi1Pb),
(PB1, AltFunc3, HwChipSelectId::Id6, HwCs6Spi1Pb),
(PB0, AltFunc3, HwChipSelectId::Id7, HwCs7Spi1Pb),
(PC8, AltFunc2, HwChipSelectId::Id0, HwCs0Spi1Pc),
(PC7, AltFunc2, HwChipSelectId::Id1, HwCs1Spi1Pc),
(PE12, AltFunc2, HwChipSelectId::Id0, HwCs0Spi1Pe),
(PE11, AltFunc2, HwChipSelectId::Id1, HwCs1Spi1Pe),
(PE10, AltFunc2, HwChipSelectId::Id2, HwCs2Spi1Pe),
(PE9, AltFunc2, HwChipSelectId::Id3, HwCs3Spi1Pe),
(PE8, AltFunc2, HwChipSelectId::Id4, HwCs4Spi1Pe),
(PE7, AltFunc3, HwChipSelectId::Id5, HwCs5Spi1Pe),
(PE6, AltFunc3, HwChipSelectId::Id6, HwCs6Spi1Pe),
(PE5, AltFunc3, HwChipSelectId::Id7, HwCs7Spi1Pe),
(PF2, AltFunc1, HwChipSelectId::Id0, HwCs0Spi1Pf),
(PG2, AltFunc2, HwChipSelectId::Id0, HwCs0Spi1Pg),
);
hw_cs_pins!(
pac::Spi2, SpiId::Spi2:
(PA4, AltFunc2, HwChipSelectId::Id0, HwCs0Spi2Pa),
(PA3, AltFunc2, HwChipSelectId::Id1, HwCs1Spi2Pa),
(PA2, AltFunc2, HwChipSelectId::Id2, HwCs2Spi2Pa),
(PA1, AltFunc2, HwChipSelectId::Id3, HwCs3Spi2Pa),
(PA0, AltFunc2, HwChipSelectId::Id4, HwCs4Spi2Pa),
(PA8, AltFunc2, HwChipSelectId::Id6, HwCs6Spi2Pa),
(PA9, AltFunc2, HwChipSelectId::Id5, HwCs5Spi2Pa),
(PF0, AltFunc2, HwChipSelectId::Id4, HwCs4Spi2Pf),
(PF1, AltFunc2, HwChipSelectId::Id3, HwCs3Spi2Pf),
(PF2, AltFunc2, HwChipSelectId::Id2, HwCs2Spi2Pf),
(PF3, AltFunc2, HwChipSelectId::Id1, HwCs1Spi2Pf),
(PF4, AltFunc2, HwChipSelectId::Id0, HwCs0Spi2Pf),
);
//==================================================================================================
// Config
//==================================================================================================
pub trait TransferConfigProvider {
fn sod(&mut self, sod: bool);
fn blockmode(&mut self, blockmode: bool);
fn mode(&mut self, mode: Mode);
fn clk_div(&mut self, clk_div: u16);
fn hw_cs_id(&self) -> u8;
}
/// This struct contains all configuration parameter which are transfer specific
/// and might change for transfers to different SPI slaves
#[derive(Copy, Clone)]
pub struct TransferConfig<HwCs> {
pub clk_div: Option<u16>,
pub mode: Option<Mode>,
/// This only works if the Slave Output Disable (SOD) bit of the [`SpiConfig`] is set to
/// false
pub hw_cs: Option<HwCs>,
pub sod: bool,
/// If this is enabled, all data in the FIFO is transmitted in a single frame unless
/// the BMSTOP bit is set on a dataword. A frame is defined as CSn being active for the
/// duration of multiple data words
pub blockmode: bool,
}
/// Type erased variant of the transfer configuration. This is required to avoid generics in
/// the SPI constructor.
pub struct ErasedTransferConfig {
pub clk_div: Option<u16>,
pub mode: Option<Mode>,
pub sod: bool,
/// If this is enabled, all data in the FIFO is transmitted in a single frame unless
/// the BMSTOP bit is set on a dataword. A frame is defined as CSn being active for the
/// duration of multiple data words
pub blockmode: bool,
pub hw_cs: HwChipSelectId,
}
impl TransferConfig<NoneT> {
pub fn new_no_hw_cs(
clk_div: Option<u16>,
mode: Option<Mode>,
blockmode: bool,
sod: bool,
) -> Self {
TransferConfig {
clk_div,
mode,
hw_cs: None,
sod,
blockmode,
}
}
}
impl<HwCs: HwCsProvider> TransferConfig<HwCs> {
pub fn new(
clk_div: Option<u16>,
mode: Option<Mode>,
hw_cs: Option<HwCs>,
blockmode: bool,
sod: bool,
) -> Self {
TransferConfig {
clk_div,
mode,
hw_cs,
sod,
blockmode,
}
}
pub fn downgrade(self) -> ErasedTransferConfig {
ErasedTransferConfig {
clk_div: self.clk_div,
mode: self.mode,
sod: self.sod,
blockmode: self.blockmode,
hw_cs: HwCs::CS_ID,
}
}
}
impl<HwCs: HwCsProvider> TransferConfigProvider for TransferConfig<HwCs> {
/// Slave Output Disable
fn sod(&mut self, sod: bool) {
self.sod = sod;
}
fn blockmode(&mut self, blockmode: bool) {
self.blockmode = blockmode;
}
fn mode(&mut self, mode: Mode) {
self.mode = Some(mode);
}
fn clk_div(&mut self, clk_div: u16) {
self.clk_div = Some(clk_div);
}
fn hw_cs_id(&self) -> u8 {
HwCs::CS_ID as u8
}
}
/// Configuration options for the whole SPI bus. See Programmer Guide p.92 for more details
pub struct SpiConfig {
clk_div: u16,
/// By default, configure SPI for master mode (ms == false)
ms: bool,
/// Slave output disable. Useful if separate GPIO pins or decoders are used for CS control
pub slave_output_disable: bool,
/// Loopback mode. If you use this, don't connect MISO to MOSI, they will be tied internally
pub loopback_mode: bool,
/// Enable Master Delayer Capture Mode. See Programmers Guide p.92 for more details
pub master_delayer_capture: bool,
}
impl Default for SpiConfig {
fn default() -> Self {
Self {
clk_div: DEFAULT_CLK_DIV,
ms: Default::default(),
slave_output_disable: Default::default(),
loopback_mode: Default::default(),
master_delayer_capture: Default::default(),
}
}
}
impl SpiConfig {
pub fn loopback(mut self, enable: bool) -> Self {
self.loopback_mode = enable;
self
}
pub fn clk_div(mut self, clk_div: u16) -> Self {
self.clk_div = clk_div;
self
}
pub fn master_mode(mut self, master: bool) -> Self {
self.ms = !master;
self
}
pub fn slave_output_disable(mut self, sod: bool) -> Self {
self.slave_output_disable = sod;
self
}
}
//==================================================================================================
// Word Size
//==================================================================================================
/// Configuration trait for the Word Size used by the SPI peripheral
pub trait WordProvider: Copy + Default + Into<u32> + TryFrom<u32> + 'static {
const MASK: u32;
fn word_reg() -> u8;
}
impl WordProvider for u8 {
const MASK: u32 = 0xff;
fn word_reg() -> u8 {
0x07
}
}
impl WordProvider for u16 {
const MASK: u32 = 0xffff;
fn word_reg() -> u8 {
0x0f
}
}
pub type SpiRegBlock = pac::spi0::RegisterBlock;
/// Common trait implemented by all PAC peripheral access structures. The register block
/// format is the same for all SPI blocks.
pub trait Instance: Deref<Target = SpiRegBlock> {
const IDX: u8;
const PERIPH_SEL: PeripheralSelect;
fn ptr() -> *const SpiRegBlock;
}
impl Instance for pac::Spi0 {
const IDX: u8 = 0;
const PERIPH_SEL: PeripheralSelect = PeripheralSelect::Spi0;
#[inline(always)]
fn ptr() -> *const SpiRegBlock {
Self::ptr()
}
}
impl Instance for pac::Spi1 {
const IDX: u8 = 1;
const PERIPH_SEL: PeripheralSelect = PeripheralSelect::Spi1;
#[inline(always)]
fn ptr() -> *const SpiRegBlock {
Self::ptr()
}
}
impl Instance for pac::Spi2 {
const IDX: u8 = 2;
const PERIPH_SEL: PeripheralSelect = PeripheralSelect::Spi2;
#[inline(always)]
fn ptr() -> *const SpiRegBlock {
Self::ptr()
}
}
impl Instance for pac::Spi3 {
const IDX: u8 = 3;
const PERIPH_SEL: PeripheralSelect = PeripheralSelect::Spi3;
#[inline(always)]
fn ptr() -> *const SpiRegBlock {
Self::ptr()
}
}
//==================================================================================================
// Spi
//==================================================================================================
pub struct SpiBase<SpiInstance, Word = u8> {
spi: SpiInstance,
cfg: SpiConfig,
apb1_clk: Hertz,
/// Fill word for read-only SPI transactions.
pub fill_word: Word,
blockmode: bool,
word: PhantomData<Word>,
}
pub struct Spi<SpiInstance, Pins, Word = u8> {
inner: SpiBase<SpiInstance, Word>,
pins: Pins,
}
pub fn mode_to_cpo_cph_bit(mode: embedded_hal::spi::Mode) -> (bool, bool) {
match mode {
embedded_hal::spi::MODE_0 => (false, false),
embedded_hal::spi::MODE_1 => (false, true),
embedded_hal::spi::MODE_2 => (true, false),
embedded_hal::spi::MODE_3 => (true, true),
}
}
#[derive(Debug)]
pub struct SpiClkConfig {
prescale_val: u16,
scrdv: u8,
}
impl SpiClkConfig {
pub fn prescale_val(&self) -> u16 {
self.prescale_val
}
pub fn scrdv(&self) -> u8 {
self.scrdv
}
}
#[derive(Debug)]
pub enum SpiClkConfigError {
DivIsZero,
DivideValueNotEven,
ScrdvValueTooLarge,
}
#[inline]
pub fn spi_clk_config_from_div(mut div: u16) -> Result<SpiClkConfig, SpiClkConfigError> {
if div == 0 {
return Err(SpiClkConfigError::DivIsZero);
}
if div % 2 != 0 {
return Err(SpiClkConfigError::DivideValueNotEven);
}
let mut prescale_val = 0;
// find largest (even) prescale value that divides into div
for i in (2..=0xfe).rev().step_by(2) {
if div % i == 0 {
prescale_val = i;
break;
}
}
if prescale_val == 0 {
return Err(SpiClkConfigError::DivideValueNotEven);
}
div /= prescale_val;
if div > u8::MAX as u16 + 1 {
return Err(SpiClkConfigError::ScrdvValueTooLarge);
}
Ok(SpiClkConfig {
prescale_val,
scrdv: (div - 1) as u8,
})
}
#[inline]
pub fn clk_div_for_target_clock(spi_clk: impl Into<Hertz>, clocks: &Clocks) -> Option<u16> {
let spi_clk = spi_clk.into();
if spi_clk > clocks.apb1() {
return None;
}
// Step 1: Calculate raw divider.
let raw_div = clocks.apb1().raw() / spi_clk.raw();
let remainder = clocks.apb1().raw() % spi_clk.raw();
// Step 2: Round up if necessary.
let mut rounded_div = if remainder * 2 >= spi_clk.raw() {
raw_div + 1
} else {
raw_div
};
if rounded_div % 2 != 0 {
// Take slower clock conservatively.
rounded_div += 1;
}
if rounded_div > u16::MAX as u32 {
return None;
}
Some(rounded_div as u16)
}
impl<SpiInstance: Instance, Word: WordProvider> SpiBase<SpiInstance, Word>
where
<Word as TryFrom<u32>>::Error: core::fmt::Debug,
{
#[inline]
pub fn cfg_clock_from_div(&mut self, div: u16) -> Result<(), SpiClkConfigError> {
let val = spi_clk_config_from_div(div)?;
self.spi_instance()
.ctrl0()
.modify(|_, w| unsafe { w.scrdv().bits(val.scrdv as u8) });
self.spi_instance()
.clkprescale()
.write(|w| unsafe { w.bits(val.prescale_val as u32) });
Ok(())
}
/*
#[inline]
pub fn cfg_clock(&mut self, spi_clk: impl Into<Hertz>) {
let clk_prescale =
self.apb1_clk.raw() / (spi_clk.into().raw() * (self.cfg.ser_clock_rate_div as u32 + 1));
self.spi
.clkprescale()
.write(|w| unsafe { w.bits(clk_prescale) });
}
*/
#[inline]
pub fn cfg_mode(&mut self, mode: Mode) {
let (cpo_bit, cph_bit) = mode_to_cpo_cph_bit(mode);
self.spi.ctrl0().modify(|_, w| {
w.spo().bit(cpo_bit);
w.sph().bit(cph_bit)
});
}
#[inline]
pub fn spi_instance(&self) -> &SpiInstance {
&self.spi
}
#[inline]
pub fn clear_tx_fifo(&self) {
self.spi.fifo_clr().write(|w| w.txfifo().set_bit());
}
#[inline]
pub fn clear_rx_fifo(&self) {
self.spi.fifo_clr().write(|w| w.rxfifo().set_bit());
}
#[inline]
pub fn perid(&self) -> u32 {
self.spi.perid().read().bits()
}
#[inline]
pub fn cfg_hw_cs(&mut self, hw_cs: HwChipSelectId) {
if hw_cs == HwChipSelectId::Invalid {
return;
}
self.spi.ctrl1().modify(|_, w| {
w.sod().clear_bit();
unsafe {
w.ss().bits(hw_cs as u8);
}
w
});
}
#[inline]
pub fn cfg_hw_cs_with_pin<HwCs: OptionalHwCs<SpiInstance>>(&mut self, _: &HwCs) {
self.cfg_hw_cs(HwCs::CS_ID);
}
#[inline]
pub fn cfg_hw_cs_disable(&mut self) {
self.spi.ctrl1().modify(|_, w| {
w.sod().set_bit();
w
});
}
pub fn cfg_transfer<HwCs: OptionalHwCs<SpiInstance>>(
&mut self,
transfer_cfg: &TransferConfig<HwCs>,
) -> Result<(), SpiClkConfigError> {
if let Some(trans_clk_div) = transfer_cfg.clk_div {
self.cfg_clock_from_div(trans_clk_div)?;
}
if let Some(mode) = transfer_cfg.mode {
self.cfg_mode(mode);
}
self.blockmode = transfer_cfg.blockmode;
self.spi.ctrl1().modify(|_, w| {
if transfer_cfg.sod {
w.sod().set_bit();
} else if transfer_cfg.hw_cs.is_some() {
w.sod().clear_bit();
unsafe {
w.ss().bits(HwCs::CS_ID as u8);
}
} else {
w.sod().clear_bit();
}
if transfer_cfg.blockmode {
w.blockmode().set_bit();
} else {
w.blockmode().clear_bit();
}
w
});
Ok(())
}
/// Sends a word to the slave
#[inline(always)]
fn send_blocking(&self, word: Word) {
// TODO: Upper limit for wait cycles to avoid complete hangups?
while self.spi.status().read().tnf().bit_is_clear() {}
self.send(word)
}
#[inline(always)]
fn send(&self, word: Word) {
self.spi.data().write(|w| unsafe { w.bits(word.into()) });
}
/// Read a word from the slave. Must be preceeded by a [`send`](Self::send) call
#[inline(always)]
fn read_blocking(&self) -> Word {
// TODO: Upper limit for wait cycles to avoid complete hangups?
while self.spi.status().read().rne().bit_is_clear() {}
self.read_single_word()
}
#[inline(always)]
fn read_single_word(&self) -> Word {
(self.spi.data().read().bits() & Word::MASK)
.try_into()
.unwrap()
}
fn transfer_preparation(&self, words: &[Word]) -> Result<(), Infallible> {
if words.is_empty() {
return Ok(());
}
let mut status_reg = self.spi.status().read();
// Wait until all bytes have been transferred.
while status_reg.tfe().bit_is_clear() {
// Ignore all received read words.
if status_reg.rne().bit_is_set() {
self.clear_rx_fifo();
}
status_reg = self.spi.status().read();
}
// Ignore all received read words.
if status_reg.rne().bit_is_set() {
self.clear_rx_fifo();
}
Ok(())
}
fn initial_send_fifo_pumping(&self, words: Option<&[Word]>) -> usize {
if self.blockmode {
self.spi.ctrl1().modify(|_, w| w.mtxpause().set_bit())
}
// Fill the first half of the write FIFO
let mut current_write_idx = 0;
for _ in 0..core::cmp::min(FILL_DEPTH, words.map_or(0, |words| words.len())) {
self.send_blocking(words.map_or(self.fill_word, |words| words[current_write_idx]));
current_write_idx += 1;
}
if self.blockmode {
self.spi.ctrl1().modify(|_, w| w.mtxpause().clear_bit())
}
current_write_idx
}
}
impl<
SpiI: Instance,
Sck: PinSck<SpiI>,
Miso: PinMiso<SpiI>,
Mosi: PinMosi<SpiI>,
Word: WordProvider,
> Spi<SpiI, (Sck, Miso, Mosi), Word>
where
<Word as TryFrom<u32>>::Error: core::fmt::Debug,
{
/// Create a new SPI struct
///
/// You can delete the pin type information by calling the
/// [`downgrade`](Self::downgrade) function
///
/// ## Arguments
/// * `spi` - SPI bus to use
/// * `pins` - Pins to be used for SPI transactions. These pins are consumed
/// to ensure the pins can not be used for other purposes anymore
/// * `spi_cfg` - Configuration specific to the SPI bus
/// * `transfer_cfg` - Optional initial transfer configuration which includes
/// configuration which can change across individual SPI transfers like SPI mode
/// or SPI clock. If only one device is connected, this configuration only needs
/// to be done once.
/// * `syscfg` - Can be passed optionally to enable the peripheral clock
pub fn new(
syscfg: &mut pac::Sysconfig,
clocks: &crate::clock::Clocks,
spi: SpiI,
pins: (Sck, Miso, Mosi),
spi_cfg: SpiConfig,
transfer_cfg: Option<&ErasedTransferConfig>,
) -> Result<Self, SpiClkConfigError> {
crate::clock::enable_peripheral_clock(syscfg, SpiI::PERIPH_SEL);
// This is done in the C HAL.
syscfg.assert_periph_reset_for_two_cycles(SpiI::PERIPH_SEL);
let SpiConfig {
clk_div,
ms,
slave_output_disable,
loopback_mode,
master_delayer_capture,
} = spi_cfg;
let mut init_mode = embedded_hal::spi::MODE_0;
let mut ss = 0;
let mut init_blockmode = false;
let apb1_clk = clocks.apb1();
if let Some(transfer_cfg) = transfer_cfg {
if let Some(mode) = transfer_cfg.mode {
init_mode = mode;
}
//self.cfg_clock_from_div(transfer_cfg.clk_div);
if transfer_cfg.hw_cs != HwChipSelectId::Invalid {
ss = transfer_cfg.hw_cs as u8;
}
init_blockmode = transfer_cfg.blockmode;
}
let spi_clk_cfg = spi_clk_config_from_div(clk_div)?;
let (cpo_bit, cph_bit) = mode_to_cpo_cph_bit(init_mode);
spi.ctrl0().write(|w| {
unsafe {
w.size().bits(Word::word_reg());
w.scrdv().bits(spi_clk_cfg.scrdv);
// Clear clock phase and polarity. Will be set to correct value for each
// transfer
w.spo().bit(cpo_bit);
w.sph().bit(cph_bit)
}
});
spi.ctrl1().write(|w| {
w.lbm().bit(loopback_mode);
w.sod().bit(slave_output_disable);
w.ms().bit(ms);
w.mdlycap().bit(master_delayer_capture);
w.blockmode().bit(init_blockmode);
unsafe { w.ss().bits(ss) }
});
spi.clkprescale()
.write(|w| unsafe { w.bits(spi_clk_cfg.prescale_val as u32) });
spi.fifo_clr().write(|w| {
w.rxfifo().set_bit();
w.txfifo().set_bit()
});
// Enable the peripheral as the last step as recommended in the
// programmers guide
spi.ctrl1().modify(|_, w| w.enable().set_bit());
Ok(Spi {
inner: SpiBase {
spi,
cfg: spi_cfg,
apb1_clk,
fill_word: Default::default(),
blockmode: init_blockmode,
word: PhantomData,
},
pins,
})
}
delegate::delegate! {
to self.inner {
#[inline]
pub fn cfg_clock_from_div(&mut self, div: u16) -> Result<(), SpiClkConfigError>;
#[inline]
pub fn spi_instance(&self) -> &SpiI;
#[inline]
pub fn cfg_mode(&mut self, mode: Mode);
#[inline]
pub fn perid(&self) -> u32;
pub fn cfg_transfer<HwCs: OptionalHwCs<SpiI>>(
&mut self, transfer_cfg: &TransferConfig<HwCs>
) -> Result<(), SpiClkConfigError>;
}
}
#[inline]
pub fn set_fill_word(&mut self, fill_word: Word) {
self.inner.fill_word = fill_word;
}
#[inline]
pub fn fill_word(&self) -> Word {
self.inner.fill_word
}
/// Releases the SPI peripheral and associated pins
pub fn release(self) -> (SpiI, (Sck, Miso, Mosi), SpiConfig) {
(self.inner.spi, self.pins, self.inner.cfg)
}
pub fn downgrade(self) -> SpiBase<SpiI, Word> {
self.inner
}
}
/// Changing the word size also requires a type conversion
impl<SpiI: Instance, Sck: PinSck<SpiI>, Miso: PinMiso<SpiI>, Mosi: PinMosi<SpiI>>
From<Spi<SpiI, (Sck, Miso, Mosi), u8>> for Spi<SpiI, (Sck, Miso, Mosi), u16>
{
fn from(old_spi: Spi<SpiI, (Sck, Miso, Mosi), u8>) -> Self {
old_spi
.inner
.spi
.ctrl0()
.modify(|_, w| unsafe { w.size().bits(WordSize::SixteenBits as u8) });
Spi {
inner: SpiBase {
spi: old_spi.inner.spi,
cfg: old_spi.inner.cfg,
blockmode: old_spi.inner.blockmode,
fill_word: Default::default(),
apb1_clk: old_spi.inner.apb1_clk,
word: PhantomData,
},
pins: old_spi.pins,
}
}
}
/// Changing the word size also requires a type conversion
impl<SpiI: Instance, Sck: PinSck<SpiI>, Miso: PinMiso<SpiI>, Mosi: PinMosi<SpiI>>
From<Spi<SpiI, (Sck, Miso, Mosi), u16>> for Spi<SpiI, (Sck, Miso, Mosi), u8>
{
fn from(old_spi: Spi<SpiI, (Sck, Miso, Mosi), u16>) -> Self {
old_spi
.inner
.spi
.ctrl0()
.modify(|_, w| unsafe { w.size().bits(WordSize::EightBits as u8) });
Spi {
inner: SpiBase {
spi: old_spi.inner.spi,
cfg: old_spi.inner.cfg,
blockmode: old_spi.inner.blockmode,
apb1_clk: old_spi.inner.apb1_clk,
fill_word: Default::default(),
word: PhantomData,
},
pins: old_spi.pins,
}
}
}
impl<SpiI: Instance, Word: WordProvider> embedded_hal::spi::ErrorType for SpiBase<SpiI, Word> {
type Error = Infallible;
}
impl<SpiI: Instance, Word: WordProvider> embedded_hal::spi::SpiBus<Word> for SpiBase<SpiI, Word>
where
<Word as TryFrom<u32>>::Error: core::fmt::Debug,
{
fn read(&mut self, words: &mut [Word]) -> Result<(), Self::Error> {
self.transfer_preparation(words)?;
let mut current_read_idx = 0;
let mut current_write_idx = self.initial_send_fifo_pumping(None);
loop {
if current_write_idx < words.len() {
self.send_blocking(self.fill_word);
current_write_idx += 1;
}
if current_read_idx < words.len() {
words[current_read_idx] = self.read_blocking();
current_read_idx += 1;
}
if current_read_idx >= words.len() && current_write_idx >= words.len() {
break;
}
}
Ok(())
}
fn write(&mut self, words: &[Word]) -> Result<(), Self::Error> {
self.transfer_preparation(words)?;
let mut current_write_idx = self.initial_send_fifo_pumping(Some(words));
while current_write_idx < words.len() {
self.send_blocking(words[current_write_idx]);
current_write_idx += 1;
// Ignore received words.
if self.spi.status().read().rne().bit_is_set() {
self.clear_rx_fifo();
}
}
Ok(())
}
fn transfer(&mut self, read: &mut [Word], write: &[Word]) -> Result<(), Self::Error> {
self.transfer_preparation(write)?;
let mut current_read_idx = 0;
let mut current_write_idx = self.initial_send_fifo_pumping(Some(write));
while current_read_idx < read.len() || current_write_idx < write.len() {
if current_write_idx < write.len() {
self.send_blocking(write[current_write_idx]);
current_write_idx += 1;
}
if current_read_idx < read.len() {
read[current_read_idx] = self.read_blocking();
current_read_idx += 1;
}
}
Ok(())
}
fn transfer_in_place(&mut self, words: &mut [Word]) -> Result<(), Self::Error> {
self.transfer_preparation(words)?;
let mut current_read_idx = 0;
let mut current_write_idx = self.initial_send_fifo_pumping(Some(words));
while current_read_idx < words.len() || current_write_idx < words.len() {
if current_write_idx < words.len() {
self.send_blocking(words[current_write_idx]);
current_write_idx += 1;
}
if current_read_idx < words.len() && current_read_idx < current_write_idx {
words[current_read_idx] = self.read_blocking();
current_read_idx += 1;
}
}
Ok(())
}
fn flush(&mut self) -> Result<(), Self::Error> {
let status_reg = self.spi.status().read();
while status_reg.tfe().bit_is_clear() || status_reg.rne().bit_is_set() {
if status_reg.rne().bit_is_set() {
self.read_single_word();
}
}
Ok(())
}
}
impl<
SpiI: Instance,
Word: WordProvider,
Sck: PinSck<SpiI>,
Miso: PinMiso<SpiI>,
Mosi: PinMosi<SpiI>,
> embedded_hal::spi::ErrorType for Spi<SpiI, (Sck, Miso, Mosi), Word>
{
type Error = Infallible;
}
impl<
SpiI: Instance,
Word: WordProvider,
Sck: PinSck<SpiI>,
Miso: PinMiso<SpiI>,
Mosi: PinMosi<SpiI>,
> embedded_hal::spi::SpiBus<Word> for Spi<SpiI, (Sck, Miso, Mosi), Word>
where
<Word as TryFrom<u32>>::Error: core::fmt::Debug,
{
fn read(&mut self, words: &mut [Word]) -> Result<(), Self::Error> {
self.inner.read(words)
}
fn write(&mut self, words: &[Word]) -> Result<(), Self::Error> {
self.inner.write(words)
}
fn transfer(&mut self, read: &mut [Word], write: &[Word]) -> Result<(), Self::Error> {
self.inner.transfer(read, write)
}
fn transfer_in_place(&mut self, words: &mut [Word]) -> Result<(), Self::Error> {
self.inner.transfer_in_place(words)
}
fn flush(&mut self) -> Result<(), Self::Error> {
self.inner.flush()
}
}