Add Pins struct owning pins, add try_acquire, add docs, cleanup

Author: kalkyl

CHANGELOG.md

@@ -11,6 +11,7 @@
 - TWIS module ([#196]).
 - PWM module ([#200]).
 - I2S module ([#201]).
+- SPIS module ([#226]).
 
 ### Fixes
 
@@ -95,6 +96,5 @@ None
 [#168]: https://github.com/nrf-rs/nrf-hal/pull/168
 [#167]: https://github.com/nrf-rs/nrf-hal/pull/167
 [#172]: https://github.com/nrf-rs/nrf-hal/pull/172
-
 [0.11.0]: https://github.com/nrf-rs/nrf-hal/releases/tag/v0.11.0
 [0.11.1]: https://github.com/nrf-rs/nrf-hal/releases/tag/v0.11.1

examples/spis-demo/src/main.rs

@@ -38,10 +38,12 @@ const APP: () = {
 
         let spis = Spis::new(
             ctx.device.SPIS0,
-            &sck_pin,
-            &cs_pin,
-            Some(&copi_pin),
-            Some(&cipo_pin),
+            Pins {
+                sck: sck_pin,
+                cs: cs_pin,
+                copi: Some(copi_pin),
+                cipo: Some(cipo_pin),
+            },
         );
         spis.enable_interrupt(SpisEvent::End);