thermostat/src/net.rs
2020-10-30 15:03:57 +01:00

93 lines
2.9 KiB
Rust

//! As there is only one peripheral, supporting data structures are
//! declared once and globally.
use core::cell::RefCell;
use cortex_m::interrupt::{CriticalSection, Mutex};
use stm32f4xx_hal::{
rcc::Clocks,
stm32::{interrupt, Peripherals, ETHERNET_MAC, ETHERNET_DMA},
};
use smoltcp::wire::{EthernetAddress, IpCidr, Ipv4Address};
use smoltcp::iface::{NeighborCache, EthernetInterfaceBuilder, EthernetInterface};
use stm32_eth::{Eth, RingEntry, PhyAddress, RxDescriptor, TxDescriptor};
use crate::pins::EthernetPins;
/// Not on the stack so that stack can be placed in CCMRAM (which the
/// ethernet peripheral cannot access)
static mut RX_RING: Option<[RingEntry<RxDescriptor>; 8]> = None;
/// Not on the stack so that stack can be placed in CCMRAM (which the
/// ethernet peripheral cannot access)
static mut TX_RING: Option<[RingEntry<TxDescriptor>; 2]> = None;
/// Interrupt pending flag: set by the `ETH` interrupt handler, should
/// be cleared before polling the interface.
static NET_PENDING: Mutex<RefCell<bool>> = Mutex::new(RefCell::new(false));
/// Run callback `f` with ethernet driver and TCP/IP stack
pub fn run<F>(
clocks: Clocks,
ethernet_mac: ETHERNET_MAC, ethernet_dma: ETHERNET_DMA,
eth_pins: EthernetPins,
ethernet_addr: EthernetAddress,
local_addr: Ipv4Address,
f: F
) where
F: FnOnce(EthernetInterface<&mut stm32_eth::Eth<'static, 'static>>),
{
let rx_ring = unsafe {
RX_RING.get_or_insert(Default::default())
};
let tx_ring = unsafe {
TX_RING.get_or_insert(Default::default())
};
// Ethernet driver
let mut eth_dev = Eth::new(
ethernet_mac, ethernet_dma,
&mut rx_ring[..], &mut tx_ring[..],
PhyAddress::_0,
clocks,
eth_pins,
).unwrap();
eth_dev.enable_interrupt();
// IP stack
// Netmask 0 means we expect any IP address on the local segment.
// No routing.
let mut ip_addrs = [IpCidr::new(local_addr.into(), 0)];
let mut neighbor_storage = [None; 16];
let neighbor_cache = NeighborCache::new(&mut neighbor_storage[..]);
let iface = EthernetInterfaceBuilder::new(&mut eth_dev)
.ethernet_addr(ethernet_addr)
.ip_addrs(&mut ip_addrs[..])
.neighbor_cache(neighbor_cache)
.finalize();
f(iface);
}
/// Potentially wake up from `wfi()`, set the interrupt pending flag,
/// clear interrupt flags.
#[interrupt]
fn ETH() {
cortex_m::interrupt::free(|cs| {
*NET_PENDING.borrow(cs)
.borrow_mut() = true;
});
let p = unsafe { Peripherals::steal() };
stm32_eth::eth_interrupt_handler(&p.ETHERNET_DMA);
}
/// Has an interrupt occurred since last call to `clear_pending()`?
pub fn is_pending(cs: &CriticalSection) -> bool {
*NET_PENDING.borrow(cs)
.borrow()
}
/// Clear the interrupt pending flag before polling the interface for
/// data.
pub fn clear_pending(cs: &CriticalSection) {
*NET_PENDING.borrow(cs)
.borrow_mut() = false;
}