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use core::ptr;
use core::marker::PhantomData;
use hal::serial;
use nb;
use stm32f0x0::{USART1, USART2, USART3, USART4, USART5};
use gpio::gpioa::{PA2, PA3, PA9, PA10, PA14, PA15};
use gpio::gpiob::{PB6, PB7};
use gpio::{AF0, AF1};
use rcc::{APB1, APB2, Clocks};
use time::Bps;
pub enum Event {
Rxne,
Txe,
}
#[derive(Debug)]
pub enum Error {
Framing,
Noise,
Overrun,
Parity,
#[doc(hidden)] _Extensible,
}
pub unsafe trait TxPin<USART> {}
pub unsafe trait RxPin<USART> {}
unsafe impl TxPin<USART1> for PA2<AF1> {}
unsafe impl TxPin<USART1> for PA9<AF1> {}
unsafe impl TxPin<USART1> for PA14<AF1> {}
unsafe impl TxPin<USART1> for PB6<AF0> {}
unsafe impl TxPin<USART2> for PA2<AF1> {}
unsafe impl TxPin<USART2> for PA14<AF1> {}
unsafe impl RxPin<USART1> for PA3<AF1> {}
unsafe impl RxPin<USART1> for PA10<AF1> {}
unsafe impl RxPin<USART1> for PA15<AF1> {}
unsafe impl RxPin<USART1> for PB7<AF0> {}
unsafe impl RxPin<USART2> for PA3<AF1> {}
unsafe impl RxPin<USART2> for PA15<AF1> {}
pub struct Serial<USART, PINS> {
usart: USART,
pins: PINS,
}
pub struct Rx<USART> {
_usart: PhantomData<USART>,
}
pub struct Tx<USART> {
_usart: PhantomData<USART>,
}
macro_rules! hal {
($(
$USARTX:ident: ($usartX:ident, $APB:ident, $usartXen:ident, $usartXrst:ident, $pclkX:ident),
)+) => {
$(
impl<TX, RX> Serial<$USARTX, (TX, RX)> {
pub fn $usartX(
usart: $USARTX,
pins: (TX, RX),
baud_rate: Bps,
clocks: Clocks,
apb: &mut $APB,
) -> Self
where
TX: TxPin<$USARTX>,
RX: RxPin<$USARTX>,
{
apb.enr().modify(|_, w| w.$usartXen().enabled());
apb.rstr().modify(|_, w| w.$usartXrst().set_bit());
apb.rstr().modify(|_, w| w.$usartXrst().clear_bit());
let brr = clocks.$pclkX().0 / baud_rate.0;
assert!(brr >= 16, "impossible baud rate");
usart.brr.write(|w| unsafe { w.bits(brr) });
usart
.cr1
.write(|w| w.ue().set_bit().re().set_bit().te().set_bit());
Serial { usart, pins }
}
pub fn listen(&mut self, event: Event) {
match event {
Event::Rxne => {
self.usart.cr1.modify(|_, w| w.rxneie().set_bit())
},
Event::Txe => {
self.usart.cr1.modify(|_, w| w.txeie().set_bit())
},
}
}
pub fn unlisten(&mut self, event: Event) {
match event {
Event::Rxne => {
self.usart.cr1.modify(|_, w| w.rxneie().clear_bit())
},
Event::Txe => {
self.usart.cr1.modify(|_, w| w.txeie().clear_bit())
},
}
}
pub fn split(self) -> (Tx<$USARTX>, Rx<$USARTX>) {
(
Tx {
_usart: PhantomData,
},
Rx {
_usart: PhantomData,
},
)
}
pub fn free(self) -> ($USARTX, (TX, RX)) {
(self.usart, self.pins)
}
}
impl serial::Read<u8> for Rx<$USARTX> {
type Error = Error;
fn read(&mut self) -> nb::Result<u8, Error> {
let isr = unsafe { (*$USARTX::ptr()).isr.read() };
Err(if isr.pe().bit_is_set() {
nb::Error::Other(Error::Parity)
} else if isr.fe().bit_is_set() {
nb::Error::Other(Error::Framing)
} else if isr.nf().bit_is_set() {
nb::Error::Other(Error::Noise)
} else if isr.ore().bit_is_set() {
nb::Error::Other(Error::Overrun)
} else if isr.rxne().bit_is_set() {
return Ok(unsafe {
ptr::read_volatile(&(*$USARTX::ptr()).rdr as *const _ as *const _)
});
} else {
nb::Error::WouldBlock
})
}
}
impl serial::Write<u8> for Tx<$USARTX> {
type Error = !;
fn flush(&mut self) -> nb::Result<(), !> {
let isr = unsafe { (*$USARTX::ptr()).isr.read() };
if isr.tc().bit_is_set() {
Ok(())
} else {
Err(nb::Error::WouldBlock)
}
}
fn write(&mut self, byte: u8) -> nb::Result<(), !> {
let isr = unsafe { (*$USARTX::ptr()).isr.read() };
if isr.txe().bit_is_set() {
unsafe {
ptr::write_volatile(&(*$USARTX::ptr()).tdr as *const _ as *mut _, byte)
}
Ok(())
} else {
Err(nb::Error::WouldBlock)
}
}
}
)+
}
}
hal! {
USART1: (usart1, APB2, usart1en, usart1rst, pclk1),
USART2: (usart2, APB1, usart2en, usart2rst, pclk1),
USART3: (usart3, APB1, usart3en, usart3rst, pclk1),
USART4: (usart4, APB1, usart4en, usart4rst, pclk1),
USART5: (usart5, APB1, usart5en, usart5rst, pclk1),
}