diff options
Diffstat (limited to 'ble/src/logger.rs')
-rw-r--r-- | ble/src/logger.rs | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/ble/src/logger.rs b/ble/src/logger.rs new file mode 100644 index 0000000..f102b74 --- /dev/null +++ b/ble/src/logger.rs @@ -0,0 +1,127 @@ +use crate::rtc; + +use core::cell::UnsafeCell; +use core::fmt::{self, Write}; +use log::{Metadata, Record}; +use nrf52840_hal::{target::UARTE0, uarte, Uarte}; +use starb::{Reader, RingBuffer, Writer}; + +static mut UARTE0: usize = 0; + +struct JoinedRingBuffer<'a> { + lbr: Reader<'a, u8>, + lbw: Writer<'a, u8>, +} + +impl<'a> JoinedRingBuffer<'a> { + const fn new(rb: &'a RingBuffer<u8>) -> Self { + let (lbr, lbw) = rb.split(); + Self { lbr: lbr, lbw: lbw } + } +} + +impl fmt::Write for JoinedRingBuffer<'_> { + fn write_str(&mut self, s: &str) -> Result<(), fmt::Error> { + for b in s.bytes() { + if let Err(_) = self.lbw.unshift(b) { + // Ignore buffer full errors for logging. + return Ok(()); + } + } + Ok(()) + } +} + +static mut LB: RingBuffer<u8> = RingBuffer::<u8>::new(0); +static mut JRB: JoinedRingBuffer = unsafe { JoinedRingBuffer::new(&LB) }; + +// The UART isn't necessarily Sync, so wrap it in something that +// is. As long as flush() is only called from one thread, we're fine, +// but this is a guarantee that the logger module doesn't make. +pub struct WriteWrapper<W> { + w: W, +} +impl<W> WriteWrapper<W> { + pub fn new(writer: W) -> Self { + Self { w: writer } + } +} +unsafe impl<W> Sync for WriteWrapper<W> {} + +pub struct SerialLogger<W> { + writer: UnsafeCell<WriteWrapper<Uarte<W>>>, +} + +impl<W> SerialLogger<W> +where + W: uarte::Instance, +{ + pub fn new(writer: WriteWrapper<Uarte<W>>) -> Self { + // Stash this for unsafe usage in case there's an issue with + // the rest of the logging. + unsafe { UARTE0 = core::mem::transmute(&writer.w) }; + Self { + writer: UnsafeCell::new(writer), + } + } +} +unsafe impl<W> Send for SerialLogger<W> {} +unsafe impl<W> Sync for SerialLogger<W> {} + +impl<W> log::Log for SerialLogger<W> +where + W: uarte::Instance, +{ + fn enabled(&self, metadata: &Metadata) -> bool { + metadata.level() <= log::max_level() + } + + fn log(&self, record: &Record) { + if !self.enabled(record.metadata()) { + return; + } + + let jrb = unsafe { &mut JRB }; + write!( + jrb, + "[{}] {} {} -- {}\r\n", + rtc::millis(), + record.level(), + record.target(), + record.args() + ) + .ok(); + } + + fn flush(&self) { + // Unsafe due to mutable static. We can only deal with the + // tail position of the buffer here to keep things safe. + let jrb = unsafe { &mut JRB }; + if jrb.lbr.is_empty() { + return; + } + + let writer = unsafe { &mut (*self.writer.get()) }; + while let Some(b) = jrb.lbr.shift() { + // TODO: The UARTE peripheral uses DMA to send a bunch of + // stuff at speed, in hardware. It would be nice to use + // it, but we can't just take a slice of the ring buffer, + // since we don't know about its internal structure here. + writer.w.write(&[b]).expect("writing log"); + } + } +} + +// Write to the UART right now, instead of putting it on a ring +// buffer. This function is a huge hack, and only useful for debugging +// either before the main loop starts or if the ring buffer is broken. +pub unsafe fn write_fmt_now(args: fmt::Arguments, nl: bool) { + if UARTE0 == 0 { + return; + } + let uart: &mut Uarte<UARTE0> = core::mem::transmute(UARTE0); + fmt::write(uart, args).expect("writing fmt now to uart"); + if nl { + uart.write_str("\r\n").expect("writing nl now to uart"); + } +} |