Add minimal IQS9151 trackpad support

docs/docs/main/docs/configuration/input_device/index.md

@@ -6,6 +6,7 @@ All input devices are defined in the `[input_device]` table. Currently supported
 - [Joystick (joystick)](./joystick.md)
 - [PMW3610 Optical Mouse Sensor (pmw3610)](./pmw3610.md)
 - [Azoteq IQS5xx Trackpad (iqs5xx)](./iqs5xx.md)
+- [Azoteq IQS9151 Trackpad (iqs9151)](./iqs9151.md)
 
 Please refer to the corresponding documentation for detailed configuration settings.
 

docs/docs/main/docs/configuration/input_device/iqs9151.md

@@ -0,0 +1,89 @@
+# Azoteq IQS9151 Trackpad
+
+The Azoteq IQS9151 is an I²C capacitive trackpad controller used by some
+keyboard trackpad modules.
+
+::: note
+
+- Currently only relative cursor movement is reported. Gestures, scrolling,
+  virtual buttons, dynamic scaling, and persistent IC configuration are not
+  supported.
+- The driver performs a product-number check (`0x09bc`) and a minimal runtime
+  setup. It does not ship a panel-specific Azoteq configuration image.
+- An active-low `RDY` pin is strongly recommended. Without it, the driver falls
+  back to timed polling and may stall the I²C bus through clock-stretching if
+  it polls mid-cycle. Event mode is only enabled when `RDY` is configured.
+- Each `[[input_device.iqs9151]]` claims its own I²C peripheral. Sharing a bus
+  with another I²C device (e.g. an OLED) isn't supported yet.
+
+:::
+
+## Hardware
+
+- `SDA` / `SCL` — I²C bus, 7-bit address `0x56`.
+- `RDY` — active-low digital output used to identify the I²C communication
+  window. Connect to a GPIO that supports async level waits
+  (`embedded_hal_async::digital::Wait`).
+
+## `toml` configuration
+
+```toml
+[[input_device.iqs9151]]
+name = "trackpad0"
+id = 0 # optional 0-255. Used for debug prints. Defaults to 0.
+
+i2c.instance = "I2C0"  # RP2040: I2C0 / I2C1.  nRF52: TWISPI0 / TWISPI1 / TWISPI2.
+i2c.sda = "PIN_4"
+i2c.scl = "PIN_5"
+
+# Optional: active-low RDY pin. Strongly recommended.
+rdy = "PIN_15"
+
+# Axis tweaks applied in PointingProcessor.
+# proc_invert_x = true
+# proc_invert_y = true
+# proc_swap_xy = true
+```
+
+### Split
+
+To add the trackpad to the central or a peripheral:
+
+```toml
+[[split.central.input_device.iqs9151]]
+name = ...
+
+# resp.
+[[split.peripheral.input_device.iqs9151]]
+name = ...
+```
+
+For split keyboards the device runs on whichever side it's wired to; the
+matching `PointingProcessor` is generated on the central automatically.
+
+## Rust configuration
+
+Construct the device directly. For a split keyboard, add the device to whichever
+side (`central.rs` or `peripheral.rs`) the trackpad is physically wired to.
+
+```rust
+use embassy_rp::gpio::{Input, Pull};
+use embassy_rp::i2c::{Config, I2c};
+use rmk::input_device::iqs9151::Iqs9151;
+use rmk::input_device::pointing::{PointingProcessor, PointingProcessorConfig};
+
+let mut i2c_cfg = Config::default();
+i2c_cfg.frequency = 400_000;
+let i2c = I2c::new_async(p.I2C0, p.PIN_5, p.PIN_4, Irqs, i2c_cfg);
+let rdy = Some(Input::new(p.PIN_15, Pull::None));
+
+const POINTING_DEV_ID: u8 = 0;
+let mut trackpad = Iqs9151::new(POINTING_DEV_ID, i2c, rdy);
+
+let mut trackpad_proc = PointingProcessor::new(
+    &keymap,
+    PointingProcessorConfig::default(),
+);
+
+run_all!(trackpad, trackpad_proc, /* matrix, ... */);
+```

rmk-config/src/lib.rs

@@ -859,6 +859,7 @@ pub struct InputDeviceConfig {
     pub pmw3610: Option<Vec<Pmw3610Config>>,
     pub pmw33xx: Option<Vec<Pmw33xxConfig>>,
     pub iqs5xx: Option<Vec<Iqs5xxConfig>>,
+    pub iqs9151: Option<Vec<Iqs9151Config>>,
 }
 
 #[derive(Clone, Debug, Default, Deserialize)]
@@ -997,6 +998,43 @@ pub struct Iqs5xxI2cConfig {
     pub scl: String,
 }
 
+/// Azoteq IQS9151 trackpad configuration.
+#[derive(Clone, Debug, Default, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct Iqs9151Config {
+    /// Name of the trackpad (used for variable naming).
+    pub name: String,
+    /// RMK pointing-device id (0-255). Defaults to 0.
+    pub id: Option<u8>,
+    /// I²C bus the trackpad is connected to. The bus is dedicated to this
+    /// device — sharing with other I²C peripherals (e.g. an OLED) is not yet
+    /// supported via TOML.
+    pub i2c: Iqs9151I2cConfig,
+    /// Optional active-low `RDY` pin. Strongly recommended; without it the
+    /// driver falls back to timed polling and may stall the bus through
+    /// clock-stretching.
+    pub rdy: Option<String>,
+    /// Invert X in the PointingProcessor.
+    #[serde(default)]
+    pub proc_invert_x: bool,
+    /// Invert Y in the PointingProcessor.
+    #[serde(default)]
+    pub proc_invert_y: bool,
+    /// Swap X and Y in the PointingProcessor.
+    #[serde(default)]
+    pub proc_swap_xy: bool,
+}
+
+/// I²C bus configuration for the IQS9151. Distinct from the generic
+/// `I2cConfig` because the default IQS9151 address is fixed at `0x56`.
+#[derive(Clone, Debug, Default, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct Iqs9151I2cConfig {
+    pub instance: String,
+    pub sda: String,
+    pub scl: String,
+}
+
 #[derive(Clone, Debug, Default, Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct EncoderConfig {
@@ -1221,4 +1259,37 @@ subs = 2
         assert_eq!(config.event.layer_change.pubs, 2);
         assert_eq!(config.event.layer_change.subs, 2);
     }
+
+    #[test]
+    fn test_iqs9151_input_device_config() {
+        let user_toml = r#"
+[[input_device.iqs9151]]
+name = "trackpad"
+id = 7
+rdy = "P1_11"
+i2c.instance = "TWISPI0"
+i2c.sda = "P0_04"
+i2c.scl = "P0_05"
+proc_invert_x = true
+"#;
+        let config: KeyboardTomlConfig = Config::builder()
+            .add_source(File::from_str(user_toml, FileFormat::Toml))
+            .build()
+            .unwrap()
+            .try_deserialize()
+            .unwrap();
+
+        let iqs9151 = config.input_device.unwrap().iqs9151.unwrap();
+
+        assert_eq!(iqs9151.len(), 1);
+        assert_eq!(iqs9151[0].name, "trackpad");
+        assert_eq!(iqs9151[0].id, Some(7));
+        assert_eq!(iqs9151[0].rdy.as_deref(), Some("P1_11"));
+        assert_eq!(iqs9151[0].i2c.instance, "TWISPI0");
+        assert_eq!(iqs9151[0].i2c.sda, "P0_04");
+        assert_eq!(iqs9151[0].i2c.scl, "P0_05");
+        assert!(iqs9151[0].proc_invert_x);
+        assert!(!iqs9151[0].proc_invert_y);
+        assert!(!iqs9151[0].proc_swap_xy);
+    }
 }

rmk-config/src/resolved/hardware.rs

@@ -9,9 +9,9 @@ pub use crate::chip::{ChipModel, ChipSeries};
 pub use crate::communication::{CommunicationConfig, UsbInfo};
 pub use crate::{
     BleConfig, ChipConfig, CommunicationProtocol, DependencyConfig, DisplayConfig, DisplayDriver, EncoderConfig,
-    EncoderResolution, I2cConfig, InputDeviceConfig, Iqs5xxConfig, Iqs5xxI2cConfig, JoystickConfig, KeyInfo,
-    LightConfig, MatrixConfig, MatrixType, OutputConfig, PinConfig, Pmw33xxConfig, Pmw33xxType, Pmw3610Config,
-    PointingDeviceConfig, SerialConfig, SpiConfig, SplitBoardConfig, SplitConfig,
+    EncoderResolution, I2cConfig, InputDeviceConfig, Iqs5xxConfig, Iqs5xxI2cConfig, Iqs9151Config, Iqs9151I2cConfig,
+    JoystickConfig, KeyInfo, LightConfig, MatrixConfig, MatrixType, OutputConfig, PinConfig, Pmw33xxConfig,
+    Pmw33xxType, Pmw3610Config, PointingDeviceConfig, SerialConfig, SpiConfig, SplitBoardConfig, SplitConfig,
 };
 
 /// Resolved storage hardware config

rmk-macro/src/codegen/chip/bind_interrupt.rs

@@ -12,6 +12,7 @@ use syn::ItemMod;
 use crate::codegen::display::expand_display_interrupt;
 use crate::codegen::feature::{get_rmk_features, is_feature_enabled};
 use crate::codegen::input_device::iqs5xx::expand_iqs5xx_interrupts;
+use crate::codegen::input_device::iqs9151::expand_iqs9151_interrupts;
 
 /// Expand `bind_interrupt!` stuffs, and other code before `main` function
 pub(crate) fn expand_bind_interrupt(hardware: &Hardware, item_mod: &ItemMod) -> TokenStream2 {
@@ -92,6 +93,19 @@ pub(crate) fn bind_interrupt_default(hardware: &Hardware, item_mod: &ItemMod) ->
             .unwrap_or(Vec::new()),
     };
     let iqs5xx_interrupt = expand_iqs5xx_interrupts(&chip.series, &iqs5xx_config);
+    let iqs9151_config = match board {
+        BoardConfig::UniBody(UniBodyConfig { input_device, .. }) => {
+            input_device.clone().iqs9151.unwrap_or(Vec::new())
+        }
+        BoardConfig::Split(split_config) => split_config
+            .central
+            .input_device
+            .clone()
+            .unwrap_or(InputDeviceConfig::default())
+            .iqs9151
+            .unwrap_or(Vec::new()),
+    };
+    let iqs9151_interrupt = expand_iqs9151_interrupts(&chip.series, &iqs9151_config);
 
     match chip.series {
         rmk_config::resolved::hardware::ChipSeries::Stm32 => {
@@ -246,6 +260,7 @@ pub(crate) fn bind_interrupt_default(hardware: &Hardware, item_mod: &ItemMod) ->
                     RTC0 => ::nrf_sdc::mpsl::HighPrioInterruptHandler;
                     #pmw33xx_spi_interrupts
                     #iqs5xx_interrupt
+                    #iqs9151_interrupt
                     #display_interrupt
                     #extern_irqs
                 });
@@ -304,6 +319,7 @@ pub(crate) fn bind_interrupt_default(hardware: &Hardware, item_mod: &ItemMod) ->
                     #dma_irq_0
                     #pio0_irq_0
                     #iqs5xx_interrupt
+                    #iqs9151_interrupt
                     #display_interrupt
                 });
                 #ble_task

rmk-macro/src/codegen/input_device/iqs5xx.rs

@@ -34,6 +34,8 @@ pub(crate) fn expand_iqs5xx_device(
 
         let device_ident = format_ident!("{}_device", sensor_name);
         let i2c_ident = format_ident!("{}_i2c", sensor_name);
+        let i2c_buf_ident = format_ident!("{}_i2c_buf", sensor_name);
+        let i2c_buf_ref_ident = format_ident!("{}_i2c_buf_ref", sensor_name);
         let rdy_ident = format_ident!("{}_rdy", sensor_name);
         let processor_ident = format_ident!("{}_processor", sensor_name);
         let processor_ident_config = format_ident!("{}_config", processor_ident);
@@ -77,15 +79,15 @@ pub(crate) fn expand_iqs5xx_device(
         let device_init = match chip.series {
             ChipSeries::Nrf52 => quote! {
                 #rdy_init
-                static #i2c_ident: ::static_cell::StaticCell<[u8; 16]> = ::static_cell::StaticCell::new();
-                let #i2c_ident = #i2c_ident.init([0u8; 16]);
+                static #i2c_buf_ident: ::static_cell::StaticCell<[u8; 16]> = ::static_cell::StaticCell::new();
+                let #i2c_buf_ref_ident = #i2c_buf_ident.init([0u8; 16]);
                 let #i2c_ident = ::embassy_nrf::twim::Twim::new(
                     p.#instance_ident,
                     Irqs,
                     p.#sda_ident,
                     p.#scl_ident,
                     ::embassy_nrf::twim::Config::default(),
-                    #i2c_ident,
+                    #i2c_buf_ref_ident,
                 );
                 let mut #device_ident = ::rmk::input_device::iqs5xx::Iqs5xx::new(
                     #sensor_id,