From 83066b10134e177b3e950789f9fa04e1cc70d0ad Mon Sep 17 00:00:00 2001
From: Felix Wittwer <dev@felixwittwer.de>
Date: Sun, 31 Jul 2022 21:13:01 +0200
Subject: [PATCH] Remove Chip Select Pin

---
 examples/raspberry_pi_inky_phat.rs | 12 ++++++------
 src/interface.rs                   | 18 ++++--------------
 2 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/examples/raspberry_pi_inky_phat.rs b/examples/raspberry_pi_inky_phat.rs
index 6830b1d..ada528d 100644
--- a/examples/raspberry_pi_inky_phat.rs
+++ b/examples/raspberry_pi_inky_phat.rs
@@ -63,11 +63,11 @@ fn main() -> Result<(), std::io::Error> {
 
     // https://pinout.xyz/pinout/inky_phat
     // Configure Digital I/O Pins
-    let cs = Pin::new(8); // BCM8
-    cs.export().expect("cs export");
-    while !cs.is_exported() {}
-    cs.set_direction(Direction::Out).expect("CS Direction");
-    cs.set_value(1).expect("CS Value set to 1");
+    //let cs = Pin::new(8); // BCM8
+    //cs.export().expect("cs export");
+    //while !cs.is_exported() {}
+    //cs.set_direction(Direction::Out).expect("CS Direction");
+    //cs.set_value(1).expect("CS Value set to 1");
 
     let busy = Pin::new(17); // BCM17
     busy.export().expect("busy export");
@@ -92,7 +92,7 @@ fn main() -> Result<(), std::io::Error> {
     // Initialise display controller
     let mut delay = Delay {};
 
-    let controller = ssd1675::Interface::new(spi, cs, busy, dc, reset);
+    let controller = ssd1675::Interface::new(spi, busy, dc, reset);
 
     let mut black_buffer = [0u8; ROWS as usize * COLS as usize / 8];
     let mut red_buffer = [0u8; ROWS as usize * COLS as usize / 8];
diff --git a/src/interface.rs b/src/interface.rs
index 433f0cf..88d32c5 100644
--- a/src/interface.rs
+++ b/src/interface.rs
@@ -80,12 +80,9 @@ pub trait DisplayInterface {
 /// // Build the interface from the pins and SPI device
 /// let controller = ssd1675::Interface::new(spi, cs, busy, dc, reset);
 
-#[allow(dead_code)] // Prevent warning about CS being unused
-pub struct Interface<SPI, CS, BUSY, DC, RESET> {
+pub struct Interface<SPI, BUSY, DC, RESET> {
     /// SPI interface
     spi: SPI,
-    /// CS (chip select) for SPI (output)
-    cs: CS,
     /// Active low busy pin (input)
     busy: BUSY,
     /// Data/Command Control Pin (High for data, Low for command) (output)
@@ -94,19 +91,17 @@ pub struct Interface<SPI, CS, BUSY, DC, RESET> {
     reset: RESET,
 }
 
-impl<SPI, CS, BUSY, DC, RESET> Interface<SPI, CS, BUSY, DC, RESET>
+impl<SPI, BUSY, DC, RESET> Interface<SPI, BUSY, DC, RESET>
 where
     SPI: hal::blocking::spi::Write<u8>,
-    CS: hal::digital::v2::OutputPin,
     BUSY: hal::digital::v2::InputPin,
     DC: hal::digital::v2::OutputPin,
     RESET: hal::digital::v2::OutputPin,
 {
     /// Create a new Interface from embedded hal traits.
-    pub fn new(spi: SPI, cs: CS, busy: BUSY, dc: DC, reset: RESET) -> Self {
+    pub fn new(spi: SPI, busy: BUSY, dc: DC, reset: RESET) -> Self {
         Self {
             spi,
-            cs,
             busy,
             dc,
             reset,
@@ -114,9 +109,6 @@ where
     }
 
     fn write(&mut self, data: &[u8]) -> Result<(), SPI::Error> {
-        // Select the controller with chip select (CS)
-        // self.cs.set_low();
-
         // Linux has a default limit of 4096 bytes per SPI transfer
         // https://github.com/torvalds/linux/blob/ccda4af0f4b92f7b4c308d3acc262f4a7e3affad/drivers/spi/spidev.c#L93
         if cfg!(target_os = "linux") {
@@ -134,11 +126,9 @@ where
     }
 }
 
-impl<SPI, CS, BUSY, DC, RESET> DisplayInterface for Interface<SPI, CS, BUSY, DC, RESET>
+impl<SPI, BUSY, DC, RESET> DisplayInterface for Interface<SPI, BUSY, DC, RESET>
 where
     SPI: hal::blocking::spi::Write<u8>,
-    CS: hal::digital::v2::OutputPin,
-    CS::Error: Debug,
     BUSY: hal::digital::v2::InputPin,
     DC: hal::digital::v2::OutputPin,
     DC::Error: Debug,