Move led pins into separate struct

The main goal here is to make it easier to support the v2 board which
has completely different pin layout as the interface will still be
similar.

As an added benefit it makes the constructor for `led::Display` a bit
clearer as rather than a long list of positional arguments you
effectively provide named arguments. This is a pattern I've seen used
in the nrf-hal.

Author: robyoung

examples/led_blocking.rs

@@ -21,21 +21,21 @@ fn main() -> ! {
         let p0parts = P0Parts::new(p.GPIO);
 
         // Display
-        let row1 = p0parts.p0_13.into_push_pull_output(Level::Low);
-        let row2 = p0parts.p0_14.into_push_pull_output(Level::Low);
-        let row3 = p0parts.p0_15.into_push_pull_output(Level::Low);
-        let col1 = p0parts.p0_04.into_push_pull_output(Level::Low);
-        let col2 = p0parts.p0_05.into_push_pull_output(Level::Low);
-        let col3 = p0parts.p0_06.into_push_pull_output(Level::Low);
-        let col4 = p0parts.p0_07.into_push_pull_output(Level::Low);
-        let col5 = p0parts.p0_08.into_push_pull_output(Level::Low);
-        let col6 = p0parts.p0_09.into_push_pull_output(Level::Low);
-        let col7 = p0parts.p0_10.into_push_pull_output(Level::Low);
-        let col8 = p0parts.p0_11.into_push_pull_output(Level::Low);
-        let col9 = p0parts.p0_12.into_push_pull_output(Level::Low);
-        let mut leds = led::Display::new(
-            col1, col2, col3, col4, col5, col6, col7, col8, col9, row1, row2, row3,
-        );
+        let pins = led::Pins {
+            row1: p0parts.p0_13.into_push_pull_output(Level::Low),
+            row2: p0parts.p0_14.into_push_pull_output(Level::Low),
+            row3: p0parts.p0_15.into_push_pull_output(Level::Low),
+            col1: p0parts.p0_04.into_push_pull_output(Level::Low),
+            col2: p0parts.p0_05.into_push_pull_output(Level::Low),
+            col3: p0parts.p0_06.into_push_pull_output(Level::Low),
+            col4: p0parts.p0_07.into_push_pull_output(Level::Low),
+            col5: p0parts.p0_08.into_push_pull_output(Level::Low),
+            col6: p0parts.p0_09.into_push_pull_output(Level::Low),
+            col7: p0parts.p0_10.into_push_pull_output(Level::Low),
+            col8: p0parts.p0_11.into_push_pull_output(Level::Low),
+            col9: p0parts.p0_12.into_push_pull_output(Level::Low),
+        };
+        let mut leds = led::Display::new(pins);
 
         #[allow(non_snake_case)]
         let letter_I = [

src/led.rs

@@ -1,14 +1,16 @@
 //! On-board user LEDs
 
 use crate::hal::{
-    gpio::{p0, Output, Pin, PushPull},
+    gpio::{Output, Pin, PushPull},
     prelude::*,
 };
 
+use crate::gpio::{COL1, COL2, COL3, COL4, COL5, COL6, COL7, COL8, COL9, ROW1, ROW2, ROW3};
+
 use embedded_hal::blocking::delay::DelayUs;
 
 #[allow(clippy::upper_case_acronyms)]
-type LED = Pin<Output<PushPull>>;
+pub(crate) type LED = Pin<Output<PushPull>>;
 
 const DEFAULT_DELAY_MS: u32 = 2;
 const LED_LAYOUT: [[(usize, usize); 5]; 5] = [
@@ -19,6 +21,21 @@ const LED_LAYOUT: [[(usize, usize); 5]; 5] = [
     [(2, 2), (1, 6), (2, 0), (1, 5), (2, 1)],
 ];
 
+pub struct Pins {
+    pub col1: COL1,
+    pub col2: COL2,
+    pub col3: COL3,
+    pub col4: COL4,
+    pub col5: COL5,
+    pub col6: COL6,
+    pub col7: COL7,
+    pub col8: COL8,
+    pub col9: COL9,
+    pub row1: ROW1,
+    pub row2: ROW2,
+    pub row3: ROW3,
+}
+
 /// Array of all the LEDs in the 5x5 display on the board
 pub struct Display {
     delay_ms: u32,
@@ -29,33 +46,24 @@ pub struct Display {
 impl Display {
     /// Initializes all the user LEDs
     #[allow(clippy::too_many_arguments)]
-    pub fn new(
-        col1: p0::P0_04<Output<PushPull>>,
-        col2: p0::P0_05<Output<PushPull>>,
-        col3: p0::P0_06<Output<PushPull>>,
-        col4: p0::P0_07<Output<PushPull>>,
-        col5: p0::P0_08<Output<PushPull>>,
-        col6: p0::P0_09<Output<PushPull>>,
-        col7: p0::P0_10<Output<PushPull>>,
-        col8: p0::P0_11<Output<PushPull>>,
-        col9: p0::P0_12<Output<PushPull>>,
-        row1: p0::P0_13<Output<PushPull>>,
-        row2: p0::P0_14<Output<PushPull>>,
-        row3: p0::P0_15<Output<PushPull>>,
-    ) -> Self {
+    pub fn new(pins: Pins) -> Self {
         let mut retval = Display {
             delay_ms: DEFAULT_DELAY_MS,
-            rows: [row1.degrade(), row2.degrade(), row3.degrade()],
+            rows: [
+                pins.row1.degrade(),
+                pins.row2.degrade(),
+                pins.row3.degrade(),
+            ],
             cols: [
-                col1.degrade(),
-                col2.degrade(),
-                col3.degrade(),
-                col4.degrade(),
-                col5.degrade(),
-                col6.degrade(),
-                col7.degrade(),
-                col8.degrade(),
-                col9.degrade(),
+                pins.col1.degrade(),
+                pins.col2.degrade(),
+                pins.col3.degrade(),
+                pins.col4.degrade(),
+                pins.col5.degrade(),
+                pins.col6.degrade(),
+                pins.col7.degrade(),
+                pins.col8.degrade(),
+                pins.col9.degrade(),
             ],
         };
         // This is needed to reduce flickering on reset