spi: Replace delay_ns func pointer with delay on cortex-m

* SPI NSS nanosecond delays now only takes place on Cortex-M CPUs
This commit is contained in:
Harry Ho 2021-06-03 15:03:43 +08:00
parent 9de8d77a24
commit 999ca5f08a
3 changed files with 37 additions and 25 deletions

View File

@ -32,6 +32,7 @@ nal = [
"embedded-time", "embedded-nal", "heapless",
"smoltcp-phy", "smoltcp/socket-tcp", "smoltcp/ethernet"
]
cortex-m-cpu = ["cortex-m"]
# Example-based features
smoltcp-examples = [
"smoltcp-phy", "smoltcp/socket-tcp", "smoltcp/ethernet"

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@ -44,24 +44,28 @@ impl From<spi::Error> for Error {
/// ENC424J600 controller in SPI mode
pub struct Enc424j600<SPI: Transfer<u8>,
NSS: OutputPin,
F: FnMut(u32) -> ()> {
spi_port: spi::SpiPort<SPI, NSS, F>,
NSS: OutputPin> {
spi_port: spi::SpiPort<SPI, NSS>,
rx_buf: rx::RxBuffer,
tx_buf: tx::TxBuffer
tx_buf: tx::TxBuffer,
}
impl <SPI: Transfer<u8>,
NSS: OutputPin,
F: FnMut(u32) -> ()> Enc424j600<SPI, NSS, F> {
pub fn new(spi: SPI, nss: NSS, delay_ns: F) -> Self {
NSS: OutputPin> Enc424j600<SPI, NSS> {
pub fn new(spi: SPI, nss: NSS) -> Self {
Enc424j600 {
spi_port: spi::SpiPort::new(spi, nss, delay_ns),
spi_port: spi::SpiPort::new(spi, nss),
rx_buf: rx::RxBuffer::new(),
tx_buf: tx::TxBuffer::new()
tx_buf: tx::TxBuffer::new(),
}
}
#[cfg(feature = "cortex-m-cpu")]
pub fn cpu_freq_mhz(mut self, freq: u32) -> Self {
self.spi_port = self.spi_port.cpu_freq_mhz(freq);
self
}
pub fn init(&mut self, delay: &mut impl DelayUs<u16>) -> Result<(), Error> {
self.reset(delay)?;
self.init_rxbuf()?;
@ -145,8 +149,7 @@ impl <SPI: Transfer<u8>,
}
impl <SPI: Transfer<u8>,
NSS: OutputPin,
F: FnMut(u32) -> ()> EthPhy for Enc424j600<SPI, NSS, F> {
NSS: OutputPin> EthPhy for Enc424j600<SPI, NSS> {
/// Receive the next packet and return it
/// Set is_poll to true for returning until PKTIF is set;
/// Set is_poll to false for returning Err when PKTIF is not set

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@ -62,11 +62,11 @@ pub mod addrs {
/// Struct for SPI I/O interface on ENC424J600
/// Note: stm32f4xx_hal::spi's pins include: SCK, MISO, MOSI
pub struct SpiPort<SPI: Transfer<u8>,
NSS: OutputPin,
F: FnMut(u32) -> ()> {
NSS: OutputPin> {
spi: SPI,
nss: NSS,
delay_ns: F,
#[cfg(feature = "cortex-m-cpu")]
cpu_freq_mhz: f32,
}
pub enum Error {
@ -76,19 +76,25 @@ pub enum Error {
#[allow(unused_must_use)]
impl <SPI: Transfer<u8>,
NSS: OutputPin,
F: FnMut(u32) -> ()> SpiPort<SPI, NSS, F> {
NSS: OutputPin> SpiPort<SPI, NSS> {
// TODO: return as Result()
pub fn new(spi: SPI, mut nss: NSS, delay_ns: F) -> Self {
pub fn new(spi: SPI, mut nss: NSS) -> Self {
nss.set_high();
SpiPort {
spi,
nss,
delay_ns,
#[cfg(feature = "cortex-m-cpu")]
cpu_freq_mhz: 0.,
}
}
#[cfg(feature = "cortex-m-cpu")]
pub fn cpu_freq_mhz(mut self, freq: u32) -> Self {
self.cpu_freq_mhz = freq as f32;
self
}
pub fn read_reg_8b(&mut self, addr: u8) -> Result<u8, Error> {
// Using RCRU instruction to read using unbanked (full) address
let mut buf: [u8; 4] = [0; 4];
@ -180,10 +186,6 @@ impl <SPI: Transfer<u8>,
}
}
pub fn delay_us(&mut self, duration: u32) {
(self.delay_ns)(duration * 1000)
}
// TODO: Actual data should start from buf[0], not buf[1]
// Completes an SPI transfer for reading data to the given buffer,
// or writing data from the buffer.
@ -195,10 +197,12 @@ impl <SPI: Transfer<u8>,
assert!(buf.len() > data_length);
// Enable chip select
self.nss.set_low();
// >=50ns min. CS_n setup time
#[cfg(feature = "cortex-m-cpu")]
match opcode {
opcodes::RCRU | opcodes::WCRU |
opcodes::RRXDATA | opcodes::WGPDATA => {
(self.delay_ns)(50); // >=50ns min. CS_n setup time
cortex_m::asm::delay((0.05*(self.cpu_freq_mhz+1.)) as u32);
}
_ => { }
}
@ -209,9 +213,13 @@ impl <SPI: Transfer<u8>,
opcodes::RCRU | opcodes::WCRU |
opcodes::RRXDATA | opcodes::WGPDATA => {
// Disable chip select
(self.delay_ns)(50); // >=50ns min. CS_n hold time
// >=50ns min. CS_n hold time
#[cfg(feature = "cortex-m-cpu")]
cortex_m::asm::delay((0.05*(self.cpu_freq_mhz+1.)) as u32);
self.nss.set_high();
(self.delay_ns)(20); // >=20ns min. CS_n disable time
// >=20ns min. CS_n disable time
#[cfg(feature = "cortex-m-cpu")]
cortex_m::asm::delay((0.02*(self.cpu_freq_mhz+1.)) as u32);
}
_ => { }
}