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Use statically typed time consistently #231

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114 changes: 75 additions & 39 deletions src/i2c.rs
Original file line number Diff line number Diff line change
@@ -1,16 +1,17 @@
//! Inter-Integrated Circuit (I2C) bus
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What's the reason for the comment style change? C++ comments are not so typical in the Rust world.

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Oops, I think I started adding a larger doc chunk, but then changed my mind about what I wanted to do. I'll revert it until I get around to adding i2c docs

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Even then it should be possible to use Rust style comments. ;)

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Sure, but I kind of dislike that for large blocks, especially inserting new lines


/**
Inter-Integrated Circuit (I2C) bus
*/
// This document describes a correct i2c implementation and is what
// parts of this code is based on
// https://www.st.com/content/ccc/resource/technical/document/application_note/5d/ae/a3/6f/08/69/4e/9b/CD00209826.pdf/files/CD00209826.pdf/jcr:content/translations/en.CD00209826.pdf

use crate::afio::MAPR;
use crate::gpio::gpiob::{PB10, PB11, PB6, PB7, PB8, PB9};
use crate::gpio::{Alternate, OpenDrain};
use crate::hal::blocking::i2c::{Read, Write, WriteRead};
use crate::pac::{DWT, I2C1, I2C2};
use crate::prelude::*;
use crate::rcc::{sealed::RccBus, Clocks, Enable, GetBusFreq, Reset};
use crate::time::Hertz;
use crate::time::{Hertz, Microseconds};
use nb::Error::{Other, WouldBlock};
use nb::{Error as NbError, Result as NbResult};

Expand Down Expand Up @@ -100,7 +101,7 @@ pub struct I2c<I2C, PINS> {
pub struct BlockingI2c<I2C, PINS> {
nb: I2c<I2C, PINS>,
start_timeout: u32,
start_retries: u8,
start_attempts: u8,
addr_timeout: u32,
data_timeout: u32,
}
Expand All @@ -123,19 +124,57 @@ impl<PINS> I2c<I2C1, PINS> {
}
}

/// Timeouts for different stages of the communication
pub struct BlockingTimeouts {
/// How many times to attempt starting the transmission before giving up
pub start_attempts: u8,
pub start: Microseconds,
pub addr: Microseconds,
pub data: Microseconds,
}

impl Default for BlockingTimeouts {
// TODO: Are these sane defaults
/// Default timeouts, waits 1 ms for all stages, and does not make multiple
/// attempts to start the transmission
fn default() -> Self {
Self {
start_attempts: 1,
start: 1000.us(),
addr: 1000.us(),
data: 1000.us(),
}
}
}

impl BlockingTimeouts {
pub fn start_timeout(self, start: Microseconds) -> Self {
Self { start, ..self }
}
pub fn addr_timeout(self, addr: Microseconds) -> Self {
Self { addr, ..self }
}
pub fn data_timeout(self, data: Microseconds) -> Self {
Self { data, ..self }
}
pub fn start_attempts(self, start_attempts: u8) -> Self {
Self {
start_attempts,
..self
}
}
}

impl<PINS> BlockingI2c<I2C1, PINS> {
/// Creates a blocking I2C1 object on pins PB6 and PB7 or PB8 and PB9 using the embedded-hal `BlockingI2c` trait.
pub fn i2c1(
i2c: I2C1,
pins: PINS,
mapr: &mut MAPR,
mode: Mode,
clocks: Clocks,
timeouts: BlockingTimeouts,
mapr: &mut MAPR,
apb: &mut <I2C1 as RccBus>::Bus,
start_timeout_us: u32,
start_retries: u8,
addr_timeout_us: u32,
data_timeout_us: u32,
) -> Self
where
PINS: Pins<I2C1>,
Expand All @@ -147,10 +186,10 @@ impl<PINS> BlockingI2c<I2C1, PINS> {
mode,
clocks,
apb,
start_timeout_us,
start_retries,
addr_timeout_us,
data_timeout_us,
timeouts.start,
timeouts.start_attempts,
timeouts.addr,
timeouts.data,
)
}
}
Expand Down Expand Up @@ -178,11 +217,8 @@ impl<PINS> BlockingI2c<I2C2, PINS> {
pins: PINS,
mode: Mode,
clocks: Clocks,
timeouts: BlockingTimeouts,
apb: &mut <I2C2 as RccBus>::Bus,
start_timeout_us: u32,
start_retries: u8,
addr_timeout_us: u32,
data_timeout_us: u32,
) -> Self
where
PINS: Pins<I2C2>,
Expand All @@ -193,10 +229,10 @@ impl<PINS> BlockingI2c<I2C2, PINS> {
mode,
clocks,
apb,
start_timeout_us,
start_retries,
addr_timeout_us,
data_timeout_us,
timeouts.start,
timeouts.start_attempts,
timeouts.addr,
timeouts.data,
)
}
}
Expand All @@ -205,18 +241,18 @@ impl<PINS> BlockingI2c<I2C2, PINS> {
fn blocking_i2c<I2C, PINS>(
i2c: I2c<I2C, PINS>,
clocks: Clocks,
start_timeout_us: u32,
start_retries: u8,
addr_timeout_us: u32,
data_timeout_us: u32,
start_timeout: Microseconds,
start_attempts: u8,
addr_timeout: Microseconds,
data_timeout: Microseconds,
) -> BlockingI2c<I2C, PINS> {
let sysclk_mhz = clocks.sysclk().0 / 1_000_000;
BlockingI2c {
nb: i2c,
start_timeout: start_timeout_us * sysclk_mhz,
start_retries,
addr_timeout: addr_timeout_us * sysclk_mhz,
data_timeout: data_timeout_us * sysclk_mhz,
start_timeout: start_timeout.0 * sysclk_mhz,
start_attempts,
addr_timeout: addr_timeout.0 * sysclk_mhz,
data_timeout: data_timeout.0 * sysclk_mhz,
}
}

Expand Down Expand Up @@ -385,30 +421,30 @@ macro_rules! hal {
mode: Mode,
clocks: Clocks,
apb: &mut <$I2CX as RccBus>::Bus,
start_timeout_us: u32,
start_retries: u8,
addr_timeout_us: u32,
data_timeout_us: u32
start_timeout: Microseconds,
start_attempts: u8,
addr_timeout: Microseconds,
data_timeout: Microseconds
) -> Self {
blocking_i2c(I2c::$i2cX(i2c, pins, mode, clocks, apb),
clocks, start_timeout_us, start_retries,
addr_timeout_us, data_timeout_us)
clocks, start_timeout, start_attempts,
addr_timeout, data_timeout)
}

fn send_start_and_wait(&mut self) -> NbResult<(), Error> {
// According to http://www.st.com/content/ccc/resource/technical/document/errata_sheet/f5/50/c9/46/56/db/4a/f6/CD00197763.pdf/files/CD00197763.pdf/jcr:content/translations/en.CD00197763.pdf
// 2.14.4 Wrong behavior of I2C peripheral in master mode after a misplaced STOP
let mut retries_left = self.start_retries;
let mut attempts_left = self.start_attempts;
let mut last_ret: NbResult<(), Error> = Err(WouldBlock);
while retries_left > 0 {
while attempts_left > 0 {
self.nb.send_start();
last_ret = busy_wait_cycles!(self.nb.wait_after_sent_start(), self.start_timeout);
if last_ret.is_err() {
self.nb.reset();
} else {
break;
}
retries_left -= 1;
attempts_left -= 1;
}
last_ret
}
Expand Down
24 changes: 12 additions & 12 deletions src/time.rs
Original file line number Diff line number Diff line change
Expand Up @@ -100,10 +100,10 @@ pub struct MegaHertz(pub u32);

/// Time unit
#[derive(PartialEq, PartialOrd, Clone, Copy)]
pub struct MilliSeconds(pub u32);
pub struct Milliseconds(pub u32);

#[derive(PartialEq, PartialOrd, Clone, Copy)]
pub struct MicroSeconds(pub u32);
pub struct Microseconds(pub u32);

/// Extension trait that adds convenience methods to the `u32` type
pub trait U32Ext {
Expand All @@ -119,11 +119,11 @@ pub trait U32Ext {
/// Wrap in `MegaHertz`
fn mhz(self) -> MegaHertz;

/// Wrap in `MilliSeconds`
fn ms(self) -> MilliSeconds;
/// Wrap in `Milliseconds`
fn ms(self) -> Milliseconds;

/// Wrap in `MicroSeconds`
fn us(self) -> MicroSeconds;
/// Wrap in `Microseconds`
fn us(self) -> Microseconds;
}

impl U32Ext for u32 {
Expand All @@ -143,12 +143,12 @@ impl U32Ext for u32 {
MegaHertz(self)
}

fn ms(self) -> MilliSeconds {
MilliSeconds(self)
fn ms(self) -> Milliseconds {
Milliseconds(self)
}

fn us(self) -> MicroSeconds {
MicroSeconds(self)
fn us(self) -> Microseconds {
Microseconds(self)
}
}

Expand All @@ -170,13 +170,13 @@ impl From<MegaHertz> for KiloHertz {
}
}

impl Into<Hertz> for MilliSeconds {
impl Into<Hertz> for Milliseconds {
fn into(self) -> Hertz {
Hertz(1_000 / self.0)
}
}

impl Into<Hertz> for MicroSeconds {
impl Into<Hertz> for Microseconds {
fn into(self) -> Hertz {
Hertz(1_000_000 / self.0)
}
Expand Down
16 changes: 8 additions & 8 deletions src/watchdog.rs
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@
use crate::{
hal::watchdog::{Watchdog, WatchdogEnable},
pac::{DBGMCU as DBG, IWDG},
time::MilliSeconds,
time::Milliseconds,
};

/// Wraps the Independent Watchdog (IWDG) peripheral
Expand All @@ -29,15 +29,15 @@ impl IndependentWatchdog {
dbg.cr.modify(|_, w| w.dbg_iwdg_stop().bit(stop));
}

fn setup(&self, timeout_ms: u32) {
fn setup(&self, timeout: Milliseconds) {
let mut pr = 0;
while pr < MAX_PR && Self::timeout_period(pr, MAX_RL) < timeout_ms {
while pr < MAX_PR && Self::timeout_period(pr, MAX_RL) < timeout.0 {
pr += 1;
}

let max_period = Self::timeout_period(pr, MAX_RL);
let max_rl = u32::from(MAX_RL);
let rl = (timeout_ms * max_rl / max_period).min(max_rl) as u16;
let rl = (timeout.0 * max_rl / max_period).min(max_rl) as u16;

self.access_registers(|iwdg| {
iwdg.pr.modify(|_, w| w.pr().bits(pr));
Expand All @@ -50,13 +50,13 @@ impl IndependentWatchdog {
}

/// Returns the interval in ms
pub fn interval(&self) -> MilliSeconds {
pub fn interval(&self) -> Milliseconds {
while self.is_pr_updating() {}

let pr = self.iwdg.pr.read().pr().bits();
let rl = self.iwdg.rlr.read().rl().bits();
let ms = Self::timeout_period(pr, rl);
MilliSeconds(ms)
Milliseconds(ms)
}

/// pr: Prescaler divider bits, rl: reload value
Expand Down Expand Up @@ -89,10 +89,10 @@ impl IndependentWatchdog {
}

impl WatchdogEnable for IndependentWatchdog {
type Time = MilliSeconds;
type Time = Milliseconds;

fn start<T: Into<Self::Time>>(&mut self, period: T) {
self.setup(period.into().0);
self.setup(period.into());

self.iwdg.kr.write(|w| unsafe { w.key().bits(KR_START) });
}
Expand Down