From 52719e4be280b5dfb301da72fafe43c475376052 Mon Sep 17 00:00:00 2001
From: Richard Barnes <rlb@ipv.sx>
Date: Fri, 10 Oct 2025 15:57:32 -1000
Subject: [PATCH 1/3] Move to mipidsi

---
 ui-stm32/Cargo.toml        |   4 +-
 ui-stm32/src/board/ev13.rs | 130 ++++++++++---------------------------
 2 files changed, 36 insertions(+), 98 deletions(-)

diff --git a/ui-stm32/Cargo.toml b/ui-stm32/Cargo.toml
index 84a5b2f..8393227 100644
--- a/ui-stm32/Cargo.toml
+++ b/ui-stm32/Cargo.toml
@@ -30,11 +30,13 @@ heapless = { version = "0.9.1", features = ["defmt"] }
 embedded-io-async = "0.6.1"
 embedded-io = { version = "0.6.1", default-features = false }
 ili9341 = "0.6.0"
-display-interface = "0.5.0"
 embedded-graphics-core = { version = "0.4.0", default-features = false }
 bitmap-font = "0.3.0"
 embedded-graphics = "0.8.1"
 embedded-hal = { version = "1.0.0", default-features = false }
+mipidsi = "0.9.0"
+embassy-embedded-hal = "0.5.0"
+static_cell = "2.1.1"
 
 [profile.release]
 debug = 2
diff --git a/ui-stm32/src/board/ev13.rs b/ui-stm32/src/board/ev13.rs
index 1bb6d28..bd26389 100644
--- a/ui-stm32/src/board/ev13.rs
+++ b/ui-stm32/src/board/ev13.rs
@@ -1,5 +1,6 @@
 use super::{Button, Eeprom, Keyboard, NetTx, StatusLed};
-use display_interface::{DataFormat, DisplayError, WriteOnlyDataCommand};
+use core::cell::RefCell;
+use embassy_embedded_hal::shared_bus::blocking::spi::SpiDevice;
 use embassy_stm32::{
     bind_interrupts,
     exti::ExtiInput,
@@ -7,108 +8,37 @@ use embassy_stm32::{
     i2c::{mode::Master, I2c},
     mode::{Async, Blocking},
     peripherals,
-    spi::{Spi, Word},
+    spi::Spi,
     usart::{self, UartRx, UartTx},
 };
+use embassy_sync::blocking_mutex::{raw::NoopRawMutex, NoopMutex};
 use embassy_time::Delay;
 use embedded_graphics::{pixelcolor::Rgb565, prelude::*};
-use ili9341::{Ili9341, Orientation};
+use mipidsi::{
+    interface::SpiInterface,
+    models::ILI9341Rgb565,
+    options::{ColorOrder, Orientation},
+    Builder, Display,
+};
+use static_cell::StaticCell;
 use ui_app::{Led, Outputs};
 
-struct DisplayData {
-    // These fields are not used, but we need to keep them alive so that the chip select output is
-    // held low and the backlight output is held high.
-    _chip_select: Output<'static>,
-    _backlight: Output<'static>,
-
-    data_command: Output<'static>,
-    spi: Spi<'static, Blocking>,
-}
-
-impl DisplayData {
-    fn new(
-        mut backlight: Output<'static>,
-        mut chip_select: Output<'static>,
-        data_command: Output<'static>,
-        spi: Spi<'static, Blocking>,
-    ) -> Self {
-        backlight.set_high();
-        chip_select.set_low();
-
-        Self {
-            _backlight: backlight,
-            _chip_select: chip_select,
-            data_command,
-            spi,
-        }
-    }
-
-    fn write(&mut self, data: DataFormat<'_>) -> Result<(), DisplayError> {
-        use DataFormat::*;
-        match data {
-            U8(slice) => self.write_slice(slice),
-            U16(slice) => self.write_slice(slice),
-            U16BE(slice) => self.write_slice(slice),
-            U16LE(slice) => self.write_slice(slice),
-            U8Iter(iter) => self.write_iter(iter),
-            U16BEIter(iter) => self.write_iter(iter),
-            U16LEIter(iter) => self.write_iter(iter),
-            _ => unreachable!(),
-        }
-    }
-
-    fn write_slice<W: Word>(&mut self, data: &[W]) -> Result<(), DisplayError> {
-        self.spi.blocking_write(data).unwrap();
-        Ok(())
-    }
-
-    fn write_iter<W: Word>(
-        &mut self,
-        iter: &mut dyn Iterator<Item = W>,
-    ) -> Result<(), DisplayError> {
-        // 1kb of render buffer
-        const CHUNK_SIZE: usize = 512;
-
-        // XXX(RLB) Very C-style iteration, could probably write this in a way that would optimize
-        // better.
-        let mut data = [W::default(); CHUNK_SIZE];
-        let mut n = 0;
-        for (i, x) in iter.enumerate() {
-            data[i % CHUNK_SIZE] = x;
-            n += 1;
-
-            if n > 0 && n % CHUNK_SIZE == 0 {
-                self.spi.blocking_write(&data).unwrap();
-                n = 0;
-            }
-        }
-
-        self.spi.blocking_write(&data[..n]).unwrap();
-        Ok(())
-    }
-}
-
-impl WriteOnlyDataCommand for DisplayData {
-    fn send_commands(&mut self, cmd: DataFormat<'_>) -> Result<(), DisplayError> {
-        self.data_command.set_low();
-        self.write(cmd)
-    }
-
-    fn send_data(&mut self, buf: DataFormat<'_>) -> Result<(), DisplayError> {
-        self.data_command.set_high();
-        self.write(buf)
-    }
-}
+type DisplaySpiDevice = SpiDevice<'static, NoopRawMutex, Spi<'static, Blocking>, Output<'static>>;
+type DisplaySpiInterface = SpiInterface<'static, DisplaySpiDevice, Output<'static>>;
 
 pub struct Board {
     status_led: StatusLed,
-    screen: Ili9341<DisplayData, Output<'static>>,
+    screen: Display<DisplaySpiInterface, ILI9341Rgb565, Output<'static>>,
     net_tx: NetTx<UartTx<'static, Async>>,
     i2c: I2c<'static, Blocking, Master>,
     pub button_a: Option<Button>,
     pub button_b: Option<Button>,
     pub keyboard: Option<Keyboard>,
     pub net_rx: Option<UartRx<'static, Async>>,
+
+    // This field isn't used, but is held to keep the pin low instead of floating
+    #[allow(dead_code)]
+    backlight: Output<'static>,
 }
 
 bind_interrupts!(struct Irqs {
@@ -179,6 +109,9 @@ impl Board {
         let keyboard = Keyboard::new(cols, rows);
 
         // Screen
+        static SPI_BUS: StaticCell<NoopMutex<RefCell<Spi<'static, Blocking>>>> = StaticCell::new();
+        let display_buffer = cortex_m::singleton!(: [u8; 512] = [0; 512]).unwrap();
+
         let chip_select = Output::new(p.PB8, Level::Low, Speed::Low);
         let data_command = Output::new(p.PB9, Level::Low, Speed::Low);
         let reset = Output::new(p.PC13, Level::Low, Speed::Low);
@@ -193,15 +126,17 @@ impl Board {
             config
         };
         let spi = Spi::new_blocking_txonly(p.SPI1, p.PA5, p.PA7, config);
-
-        let screen = Ili9341::new(
-            DisplayData::new(backlight, chip_select, data_command, spi),
-            reset,
-            &mut Delay,
-            Orientation::Portrait,
-            ili9341::DisplaySize240x320,
-        )
-        .unwrap();
+        let spi_bus = NoopMutex::new(RefCell::new(spi));
+        let spi_bus = SPI_BUS.init(spi_bus);
+        let spi_dev = SpiDevice::new(spi_bus, chip_select);
+        let spi_if = SpiInterface::new(spi_dev, data_command, display_buffer);
+
+        let screen = Builder::new(ILI9341Rgb565, spi_if)
+            .reset_pin(reset)
+            .orientation(Orientation::new().flip_horizontal())
+            .color_order(ColorOrder::Bgr)
+            .init(&mut Delay)
+            .unwrap();
 
         // NET UART
         let net_uart = {
@@ -230,6 +165,7 @@ impl Board {
             button_b: Some(button_b),
             keyboard: Some(keyboard),
             net_rx: Some(net_rx),
+            backlight,
         }
     }
 }

From 2d5d053bb90b7257a345abf0ec7c5412e604ca51 Mon Sep 17 00:00:00 2001
From: Richard Barnes <rlb@ipv.sx>
Date: Fri, 10 Oct 2025 16:00:16 -1000
Subject: [PATCH 2/3] Trim dependencies

---
 ui-stm32/Cargo.toml | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/ui-stm32/Cargo.toml b/ui-stm32/Cargo.toml
index 8393227..b8fe2c7 100644
--- a/ui-stm32/Cargo.toml
+++ b/ui-stm32/Cargo.toml
@@ -19,19 +19,13 @@ defmt = "1.0.1"
 defmt-rtt = "1.0.0"
 
 embassy-executor = { version = "0.8.0", features = ["arch-cortex-m", "executor-thread", "executor-interrupt", "defmt"] }
-embassy-futures = { version = "0.1.1", features = ["defmt"] }
 embassy-stm32 = { version = "0.3.0", features = ["defmt", "stm32f405rg", "memory-x", "time-driver-tim1", "exti", "chrono"] }
 embassy-time = { version = "0.5.0", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
 panic-probe = { version = "1.0.0", features = ["print-defmt"] }
 embassy-sync = { version = "0.7.1", features = ["defmt"] }
-num_enum = { version = "0.7.4", default-features = false }
-hex = { version = "0.4.3", default-features = false }
 heapless = { version = "0.9.1", features = ["defmt"] }
 embedded-io-async = "0.6.1"
 embedded-io = { version = "0.6.1", default-features = false }
-ili9341 = "0.6.0"
-embedded-graphics-core = { version = "0.4.0", default-features = false }
-bitmap-font = "0.3.0"
 embedded-graphics = "0.8.1"
 embedded-hal = { version = "1.0.0", default-features = false }
 mipidsi = "0.9.0"
@@ -44,3 +38,7 @@ debug = 2
 [profile.dev]
 debug = 2
 opt-level = "s"
+
+# Tell `cargo machete` that these packages are needed
+[package.metadata.cargo-machete]
+ignored = ["cortex-m-rt"]

From 6768d20f9a1c75675d509742815cedfc84a9d8a1 Mon Sep 17 00:00:00 2001
From: Richard Barnes <rlb@ipv.sx>
Date: Fri, 10 Oct 2025 16:02:12 -1000
Subject: [PATCH 3/3] Backport to ev12

---
 ui-stm32/src/board/ev12.rs | 130 ++++++++++---------------------------
 1 file changed, 33 insertions(+), 97 deletions(-)

diff --git a/ui-stm32/src/board/ev12.rs b/ui-stm32/src/board/ev12.rs
index ef129d2..319da0d 100644
--- a/ui-stm32/src/board/ev12.rs
+++ b/ui-stm32/src/board/ev12.rs
@@ -1,5 +1,6 @@
 use super::{Button, Eeprom, Keyboard, NetTx, StatusLed};
-use display_interface::{DataFormat, DisplayError, WriteOnlyDataCommand};
+use core::cell::RefCell;
+use embassy_embedded_hal::shared_bus::blocking::spi::SpiDevice;
 use embassy_stm32::{
     bind_interrupts,
     exti::ExtiInput,
@@ -7,108 +8,37 @@ use embassy_stm32::{
     i2c::{mode::Master, I2c},
     mode::{Async, Blocking},
     peripherals,
-    spi::{Spi, Word},
+    spi::Spi,
     usart::{self, UartRx, UartTx},
 };
+use embassy_sync::blocking_mutex::{raw::NoopRawMutex, NoopMutex};
 use embassy_time::Delay;
 use embedded_graphics::{pixelcolor::Rgb565, prelude::*};
-use ili9341::{Ili9341, Orientation};
+use mipidsi::{
+    interface::SpiInterface,
+    models::ILI9341Rgb565,
+    options::{ColorOrder, Orientation},
+    Builder, Display,
+};
+use static_cell::StaticCell;
 use ui_app::{Led, Outputs};
 
-struct DisplayData {
-    // These fields are not used, but we need to keep them alive so that the chip select output is
-    // held low and the backlight output is held high.
-    _chip_select: Output<'static>,
-    _backlight: Output<'static>,
-
-    data_command: Output<'static>,
-    spi: Spi<'static, Blocking>,
-}
-
-impl DisplayData {
-    fn new(
-        mut backlight: Output<'static>,
-        mut chip_select: Output<'static>,
-        data_command: Output<'static>,
-        spi: Spi<'static, Blocking>,
-    ) -> Self {
-        backlight.set_high();
-        chip_select.set_low();
-
-        Self {
-            _backlight: backlight,
-            _chip_select: chip_select,
-            data_command,
-            spi,
-        }
-    }
-
-    fn write(&mut self, data: DataFormat<'_>) -> Result<(), DisplayError> {
-        use DataFormat::*;
-        match data {
-            U8(slice) => self.write_slice(slice),
-            U16(slice) => self.write_slice(slice),
-            U16BE(slice) => self.write_slice(slice),
-            U16LE(slice) => self.write_slice(slice),
-            U8Iter(iter) => self.write_iter(iter),
-            U16BEIter(iter) => self.write_iter(iter),
-            U16LEIter(iter) => self.write_iter(iter),
-            _ => unreachable!(),
-        }
-    }
-
-    fn write_slice<W: Word>(&mut self, data: &[W]) -> Result<(), DisplayError> {
-        self.spi.blocking_write(data).unwrap();
-        Ok(())
-    }
-
-    fn write_iter<W: Word>(
-        &mut self,
-        iter: &mut dyn Iterator<Item = W>,
-    ) -> Result<(), DisplayError> {
-        // 1kb of render buffer
-        const CHUNK_SIZE: usize = 512;
-
-        // XXX(RLB) Very C-style iteration, could probably write this in a way that would optimize
-        // better.
-        let mut data = [W::default(); CHUNK_SIZE];
-        let mut n = 0;
-        for (i, x) in iter.enumerate() {
-            data[i % CHUNK_SIZE] = x;
-            n += 1;
-
-            if n > 0 && n % CHUNK_SIZE == 0 {
-                self.spi.blocking_write(&data).unwrap();
-                n = 0;
-            }
-        }
-
-        self.spi.blocking_write(&data[..n]).unwrap();
-        Ok(())
-    }
-}
-
-impl WriteOnlyDataCommand for DisplayData {
-    fn send_commands(&mut self, cmd: DataFormat<'_>) -> Result<(), DisplayError> {
-        self.data_command.set_low();
-        self.write(cmd)
-    }
-
-    fn send_data(&mut self, buf: DataFormat<'_>) -> Result<(), DisplayError> {
-        self.data_command.set_high();
-        self.write(buf)
-    }
-}
+type DisplaySpiDevice = SpiDevice<'static, NoopRawMutex, Spi<'static, Blocking>, Output<'static>>;
+type DisplaySpiInterface = SpiInterface<'static, DisplaySpiDevice, Output<'static>>;
 
 pub struct Board {
     status_led: StatusLed,
-    screen: Ili9341<DisplayData, Output<'static>>,
+    screen: Display<DisplaySpiInterface, ILI9341Rgb565, Output<'static>>,
     net_tx: NetTx<UartTx<'static, Async>>,
     i2c: I2c<'static, Blocking, Master>,
     pub button_a: Option<Button>,
     pub button_b: Option<Button>,
     pub keyboard: Option<Keyboard>,
     pub net_rx: Option<UartRx<'static, Async>>,
+
+    // This field isn't used, but is held to keep the pin low instead of floating
+    #[allow(dead_code)]
+    backlight: Output<'static>,
 }
 
 bind_interrupts!(struct Irqs {
@@ -179,6 +109,9 @@ impl Board {
         let keyboard = Keyboard::new(cols, rows);
 
         // Screen
+        static SPI_BUS: StaticCell<NoopMutex<RefCell<Spi<'static, Blocking>>>> = StaticCell::new();
+        let display_buffer = cortex_m::singleton!(: [u8; 512] = [0; 512]).unwrap();
+
         let chip_select = Output::new(p.PB8, Level::Low, Speed::Low);
         let data_command = Output::new(p.PB9, Level::Low, Speed::Low);
         let reset = Output::new(p.PC13, Level::Low, Speed::Low);
@@ -193,15 +126,17 @@ impl Board {
             config
         };
         let spi = Spi::new_blocking_txonly(p.SPI1, p.PA5, p.PA7, config);
-
-        let screen = Ili9341::new(
-            DisplayData::new(backlight, chip_select, data_command, spi),
-            reset,
-            &mut Delay,
-            Orientation::Portrait,
-            ili9341::DisplaySize240x320,
-        )
-        .unwrap();
+        let spi_bus = NoopMutex::new(RefCell::new(spi));
+        let spi_bus = SPI_BUS.init(spi_bus);
+        let spi_dev = SpiDevice::new(spi_bus, chip_select);
+        let spi_if = SpiInterface::new(spi_dev, data_command, display_buffer);
+
+        let screen = Builder::new(ILI9341Rgb565, spi_if)
+            .reset_pin(reset)
+            .orientation(Orientation::new().flip_horizontal())
+            .color_order(ColorOrder::Bgr)
+            .init(&mut Delay)
+            .unwrap();
 
         // NET UART
         let net_uart = {
@@ -230,6 +165,7 @@ impl Board {
             button_b: Some(button_b),
             keyboard: Some(keyboard),
             net_rx: Some(net_rx),
+            backlight,
         }
     }
 }