Spi Instance

Author: burrbull

CHANGELOG.md

@@ -41,7 +41,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
-- Add `Spi::new` and deprecate `Spi:spix`, deprecate `Serial::usartx`, remove deprecated `I2c::i2cx`
+- Add `Spi::new`, `spi::Instance` and deprecate `Spi:spix`, deprecate `Serial::usartx`, remove deprecated `I2c::i2cx`
 - Deprecate `free` in favour of `release`
 - Clean features in `serial`, `spi`, `i2c`, `timer`
 - Internal implementation of GPIO Pin API changed to use Const Generics

examples/analog-stopwatch-with-spi-ssd1306.rs

@@ -98,7 +98,7 @@ fn main() -> ! {
     let miso = gpioe.pe5.into_alternate();
     let mosi = gpioe.pe6.into_alternate();
 
-    let spi = Spi::spi4(
+    let spi = Spi::new(
         dp.SPI4,
         (sck, miso, mosi),
         Mode {

src/spi.rs

@@ -374,25 +374,34 @@ pub struct Spi<SPI, PINS> {
     pins: PINS,
 }
 
-// Implemented by all I2C instances
+mod private {
+    pub trait Sealed {}
+}
+
+// Implemented by all SPI instances
+pub trait Instance: private::Sealed + Deref<Target = spi1::RegisterBlock> + Enable {
+    #[doc(hidden)]
+    fn pclk_freq(clocks: &Clocks) -> Hertz;
+}
+
+// Implemented by all SPI instances
 macro_rules! spi {
-    ($SPI:ty: ($spi:ident, $pclk:ident)) => {
+    ($SPI:ident: ($spi:ident, $pclk:ident)) => {
+        impl private::Sealed for $SPI {}
+        impl Instance for $SPI {
+            fn pclk_freq(clocks: &Clocks) -> Hertz {
+                clocks.$pclk()
+            }
+        }
+
         impl<PINS> Spi<$SPI, PINS>
         where
             PINS: Pins<$SPI>,
         {
+            #[deprecated(since = "0.10.0", note = "Please use new instead")]
             pub fn $spi(spi: $SPI, pins: PINS, mode: Mode, freq: Hertz, clocks: Clocks) -> Self {
                 Self::new(spi, pins, mode, freq, clocks)
             }
-            pub fn new(spi: $SPI, pins: PINS, mode: Mode, freq: Hertz, clocks: Clocks) -> Self {
-                unsafe {
-                    // NOTE(unsafe) this reference will only be used for atomic writes with no side effects.
-                    let rcc = &(*RCC::ptr());
-                    <$SPI>::enable(rcc);
-                }
-
-                Spi { spi, pins }.init(mode, freq, clocks.$pclk())
-            }
         }
     };
 }
@@ -414,7 +423,23 @@ spi! { SPI6: (spi6, pclk2) }
 
 impl<SPI, PINS> Spi<SPI, PINS>
 where
-    SPI: Deref<Target = spi1::RegisterBlock>,
+    SPI: Instance,
+    PINS: Pins<SPI>,
+{
+    pub fn new(spi: SPI, pins: PINS, mode: Mode, freq: Hertz, clocks: Clocks) -> Self {
+        unsafe {
+            // NOTE(unsafe) this reference will only be used for atomic writes with no side effects.
+            let rcc = &(*RCC::ptr());
+            SPI::enable(rcc);
+        }
+
+        Spi { spi, pins }.init(mode, freq, SPI::pclk_freq(&clocks))
+    }
+}
+
+impl<SPI, PINS> Spi<SPI, PINS>
+where
+    SPI: Instance,
 {
     pub fn init(self, mode: Mode, freq: Hertz, clock: Hertz) -> Self {
         // disable SS output
@@ -527,7 +552,7 @@ where
 
 impl<SPI, PINS> spi::FullDuplex<u8> for Spi<SPI, PINS>
 where
-    SPI: Deref<Target = spi1::RegisterBlock>,
+    SPI: Instance,
 {
     type Error = Error;
 
@@ -578,11 +603,11 @@ where
 }
 
 impl<SPI, PINS> embedded_hal::blocking::spi::transfer::Default<u8> for Spi<SPI, PINS> where
-    SPI: Deref<Target = spi1::RegisterBlock>
+    SPI: Instance
 {
 }
 
 impl<SPI, PINS> embedded_hal::blocking::spi::write::Default<u8> for Spi<SPI, PINS> where
-    SPI: Deref<Target = spi1::RegisterBlock>
+    SPI: Instance
 {
 }