embassy/cyw43/src/bus.rs

329 lines
11 KiB
Rust

use embassy_futures::yield_now;
use embassy_time::Timer;
use embedded_hal_1::digital::OutputPin;
use futures::FutureExt;
use crate::consts::*;
use crate::slice8_mut;
/// Custom Spi Trait that _only_ supports the bus operation of the cyw43
/// Implementors are expected to hold the CS pin low during an operation.
pub trait SpiBusCyw43 {
/// Issues a write command on the bus
/// First 32 bits of `word` are expected to be a cmd word
async fn cmd_write(&mut self, write: &[u32]) -> u32;
/// Issues a read command on the bus
/// `write` is expected to be a 32 bit cmd word
/// `read` will contain the response of the device
/// Backplane reads have a response delay that produces one extra unspecified word at the beginning of `read`.
/// Callers that want to read `n` word from the backplane, have to provide a slice that is `n+1` words long.
async fn cmd_read(&mut self, write: u32, read: &mut [u32]) -> u32;
/// Wait for events from the Device. A typical implementation would wait for the IRQ pin to be high.
/// The default implementation always reports ready, resulting in active polling of the device.
async fn wait_for_event(&mut self) {
yield_now().await;
}
}
pub(crate) struct Bus<PWR, SPI> {
backplane_window: u32,
pwr: PWR,
spi: SPI,
status: u32,
}
impl<PWR, SPI> Bus<PWR, SPI>
where
PWR: OutputPin,
SPI: SpiBusCyw43,
{
pub(crate) fn new(pwr: PWR, spi: SPI) -> Self {
Self {
backplane_window: 0xAAAA_AAAA,
pwr,
spi,
status: 0,
}
}
pub async fn init(&mut self) {
// Reset
self.pwr.set_low().unwrap();
Timer::after_millis(20).await;
self.pwr.set_high().unwrap();
Timer::after_millis(250).await;
while self
.read32_swapped(REG_BUS_TEST_RO)
.inspect(|v| trace!("{:#x}", v))
.await
!= FEEDBEAD
{}
self.write32_swapped(REG_BUS_TEST_RW, TEST_PATTERN).await;
let val = self.read32_swapped(REG_BUS_TEST_RW).await;
trace!("{:#x}", val);
assert_eq!(val, TEST_PATTERN);
let val = self.read32_swapped(REG_BUS_CTRL).await;
trace!("{:#010b}", (val & 0xff));
// 32-bit word length, little endian (which is the default endianess).
self.write32_swapped(
REG_BUS_CTRL,
WORD_LENGTH_32 | HIGH_SPEED | INTERRUPT_HIGH | WAKE_UP | STATUS_ENABLE | INTERRUPT_WITH_STATUS,
)
.await;
let val = self.read8(FUNC_BUS, REG_BUS_CTRL).await;
trace!("{:#b}", val);
let val = self.read32(FUNC_BUS, REG_BUS_TEST_RO).await;
trace!("{:#x}", val);
assert_eq!(val, FEEDBEAD);
let val = self.read32(FUNC_BUS, REG_BUS_TEST_RW).await;
trace!("{:#x}", val);
assert_eq!(val, TEST_PATTERN);
}
pub async fn wlan_read(&mut self, buf: &mut [u32], len_in_u8: u32) {
let cmd = cmd_word(READ, INC_ADDR, FUNC_WLAN, 0, len_in_u8);
let len_in_u32 = (len_in_u8 as usize + 3) / 4;
self.status = self.spi.cmd_read(cmd, &mut buf[..len_in_u32]).await;
}
pub async fn wlan_write(&mut self, buf: &[u32]) {
let cmd = cmd_word(WRITE, INC_ADDR, FUNC_WLAN, 0, buf.len() as u32 * 4);
//TODO try to remove copy?
let mut cmd_buf = [0_u32; 513];
cmd_buf[0] = cmd;
cmd_buf[1..][..buf.len()].copy_from_slice(buf);
self.status = self.spi.cmd_write(&cmd_buf[..buf.len() + 1]).await;
}
#[allow(unused)]
pub async fn bp_read(&mut self, mut addr: u32, mut data: &mut [u8]) {
// It seems the HW force-aligns the addr
// to 2 if data.len() >= 2
// to 4 if data.len() >= 4
// To simplify, enforce 4-align for now.
assert!(addr % 4 == 0);
// Backplane read buffer has one extra word for the response delay.
let mut buf = [0u32; BACKPLANE_MAX_TRANSFER_SIZE / 4 + 1];
while !data.is_empty() {
// Ensure transfer doesn't cross a window boundary.
let window_offs = addr & BACKPLANE_ADDRESS_MASK;
let window_remaining = BACKPLANE_WINDOW_SIZE - window_offs as usize;
let len = data.len().min(BACKPLANE_MAX_TRANSFER_SIZE).min(window_remaining);
self.backplane_set_window(addr).await;
let cmd = cmd_word(READ, INC_ADDR, FUNC_BACKPLANE, window_offs, len as u32);
// round `buf` to word boundary, add one extra word for the response delay
self.status = self.spi.cmd_read(cmd, &mut buf[..(len + 3) / 4 + 1]).await;
// when writing out the data, we skip the response-delay byte
data[..len].copy_from_slice(&slice8_mut(&mut buf[1..])[..len]);
// Advance ptr.
addr += len as u32;
data = &mut data[len..];
}
}
pub async fn bp_write(&mut self, mut addr: u32, mut data: &[u8]) {
// It seems the HW force-aligns the addr
// to 2 if data.len() >= 2
// to 4 if data.len() >= 4
// To simplify, enforce 4-align for now.
assert!(addr % 4 == 0);
let mut buf = [0u32; BACKPLANE_MAX_TRANSFER_SIZE / 4 + 1];
while !data.is_empty() {
// Ensure transfer doesn't cross a window boundary.
let window_offs = addr & BACKPLANE_ADDRESS_MASK;
let window_remaining = BACKPLANE_WINDOW_SIZE - window_offs as usize;
let len = data.len().min(BACKPLANE_MAX_TRANSFER_SIZE).min(window_remaining);
slice8_mut(&mut buf[1..])[..len].copy_from_slice(&data[..len]);
self.backplane_set_window(addr).await;
let cmd = cmd_word(WRITE, INC_ADDR, FUNC_BACKPLANE, window_offs, len as u32);
buf[0] = cmd;
self.status = self.spi.cmd_write(&buf[..(len + 3) / 4 + 1]).await;
// Advance ptr.
addr += len as u32;
data = &data[len..];
}
}
pub async fn bp_read8(&mut self, addr: u32) -> u8 {
self.backplane_readn(addr, 1).await as u8
}
pub async fn bp_write8(&mut self, addr: u32, val: u8) {
self.backplane_writen(addr, val as u32, 1).await
}
pub async fn bp_read16(&mut self, addr: u32) -> u16 {
self.backplane_readn(addr, 2).await as u16
}
#[allow(unused)]
pub async fn bp_write16(&mut self, addr: u32, val: u16) {
self.backplane_writen(addr, val as u32, 2).await
}
#[allow(unused)]
pub async fn bp_read32(&mut self, addr: u32) -> u32 {
self.backplane_readn(addr, 4).await
}
pub async fn bp_write32(&mut self, addr: u32, val: u32) {
self.backplane_writen(addr, val, 4).await
}
async fn backplane_readn(&mut self, addr: u32, len: u32) -> u32 {
self.backplane_set_window(addr).await;
let mut bus_addr = addr & BACKPLANE_ADDRESS_MASK;
if len == 4 {
bus_addr |= BACKPLANE_ADDRESS_32BIT_FLAG
}
self.readn(FUNC_BACKPLANE, bus_addr, len).await
}
async fn backplane_writen(&mut self, addr: u32, val: u32, len: u32) {
self.backplane_set_window(addr).await;
let mut bus_addr = addr & BACKPLANE_ADDRESS_MASK;
if len == 4 {
bus_addr |= BACKPLANE_ADDRESS_32BIT_FLAG
}
self.writen(FUNC_BACKPLANE, bus_addr, val, len).await
}
async fn backplane_set_window(&mut self, addr: u32) {
let new_window = addr & !BACKPLANE_ADDRESS_MASK;
if (new_window >> 24) as u8 != (self.backplane_window >> 24) as u8 {
self.write8(
FUNC_BACKPLANE,
REG_BACKPLANE_BACKPLANE_ADDRESS_HIGH,
(new_window >> 24) as u8,
)
.await;
}
if (new_window >> 16) as u8 != (self.backplane_window >> 16) as u8 {
self.write8(
FUNC_BACKPLANE,
REG_BACKPLANE_BACKPLANE_ADDRESS_MID,
(new_window >> 16) as u8,
)
.await;
}
if (new_window >> 8) as u8 != (self.backplane_window >> 8) as u8 {
self.write8(
FUNC_BACKPLANE,
REG_BACKPLANE_BACKPLANE_ADDRESS_LOW,
(new_window >> 8) as u8,
)
.await;
}
self.backplane_window = new_window;
}
pub async fn read8(&mut self, func: u32, addr: u32) -> u8 {
self.readn(func, addr, 1).await as u8
}
pub async fn write8(&mut self, func: u32, addr: u32, val: u8) {
self.writen(func, addr, val as u32, 1).await
}
pub async fn read16(&mut self, func: u32, addr: u32) -> u16 {
self.readn(func, addr, 2).await as u16
}
#[allow(unused)]
pub async fn write16(&mut self, func: u32, addr: u32, val: u16) {
self.writen(func, addr, val as u32, 2).await
}
pub async fn read32(&mut self, func: u32, addr: u32) -> u32 {
self.readn(func, addr, 4).await
}
#[allow(unused)]
pub async fn write32(&mut self, func: u32, addr: u32, val: u32) {
self.writen(func, addr, val, 4).await
}
async fn readn(&mut self, func: u32, addr: u32, len: u32) -> u32 {
let cmd = cmd_word(READ, INC_ADDR, func, addr, len);
let mut buf = [0; 2];
// if we are reading from the backplane, we need an extra word for the response delay
let len = if func == FUNC_BACKPLANE { 2 } else { 1 };
self.status = self.spi.cmd_read(cmd, &mut buf[..len]).await;
// if we read from the backplane, the result is in the second word, after the response delay
if func == FUNC_BACKPLANE {
buf[1]
} else {
buf[0]
}
}
async fn writen(&mut self, func: u32, addr: u32, val: u32, len: u32) {
let cmd = cmd_word(WRITE, INC_ADDR, func, addr, len);
self.status = self.spi.cmd_write(&[cmd, val]).await;
}
async fn read32_swapped(&mut self, addr: u32) -> u32 {
let cmd = cmd_word(READ, INC_ADDR, FUNC_BUS, addr, 4);
let cmd = swap16(cmd);
let mut buf = [0; 1];
self.status = self.spi.cmd_read(cmd, &mut buf).await;
swap16(buf[0])
}
async fn write32_swapped(&mut self, addr: u32, val: u32) {
let cmd = cmd_word(WRITE, INC_ADDR, FUNC_BUS, addr, 4);
let buf = [swap16(cmd), swap16(val)];
self.status = self.spi.cmd_write(&buf).await;
}
pub async fn wait_for_event(&mut self) {
self.spi.wait_for_event().await;
}
pub fn status(&self) -> u32 {
self.status
}
}
fn swap16(x: u32) -> u32 {
x.rotate_left(16)
}
fn cmd_word(write: bool, incr: bool, func: u32, addr: u32, len: u32) -> u32 {
(write as u32) << 31 | (incr as u32) << 30 | (func & 0b11) << 28 | (addr & 0x1FFFF) << 11 | (len & 0x7FF)
}