Initial LCD support. (#568)

* Initial LCD support.

The esp32p4 supports LCDs through DSI. This is the initial LCD support
for esp32p4.

* Rename peripheral to DSI, embedded_graphics support.

* Delete lcd.rs.

* Rename dsi.rs back to lcd.rs.

Author: mdwn

CHANGELOG.md

@@ -39,6 +39,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Removed the modem peripheral for esp32p4
 - LDO support for esp32p4
 - Support for `PLL_F48M` UART clock source on ESP32-H2
+- LCD driver support; DSI peripheral support with the LCD driver for esp32p4
 
 ### Fixed
 - Fix pcnt_rotary_encoder example for esp32

Cargo.toml

@@ -53,6 +53,7 @@ pcnt-legacy = []
 # - When enabled, the code for the legacy driver will be compiled.
 # - When disabled the code for the new driver will be compiled.
 timer-legacy = []
+embedded-graphics = ["dep:embedded-graphics-core"]
 
 [dependencies]
 nb = "1"
@@ -70,6 +71,7 @@ enumset = { version = "1.1.4", default-features = false }
 log = { version = "0.4", default-features = false }
 atomic-waker = { version = "1.1.1", default-features = false }
 embassy-sync = "0.7"
+embedded-graphics-core = { version = "0.4", optional = true }
 
 [build-dependencies]
 embuild = "0.33"

examples/lcd_dsi_basic.rs

@@ -0,0 +1,127 @@
+//! Basic LCD DSI example for ESP32-P4
+//!
+//! This example shows how to:
+//! - Configure the LCD peripheral for a DSI panel
+//! - Create a vendor-specific control panel (ILI9881C over DBI)
+//! - Initialize the panel
+//! - Create a DPI panel for frame updates
+//! - Draw a simple bitmap
+//!
+//! Requirements:
+//! - Target: ESP32-P4 (`ESP_IDF_TARGET=esp32p4`)
+//! - ESP-IDF must have the ILI9881C DSI panel component enabled
+//! - A compatible 1024×600 MIPI-DSI display connected to the LCD peripheral
+
+#![allow(unknown_lints)]
+#![allow(unexpected_cfgs)]
+
+#[cfg(esp32p4)]
+mod example {
+    use std::time::Duration;
+
+    use esp_idf_hal::lcd::*;
+    use esp_idf_hal::ldo::*;
+    use esp_idf_hal::peripherals::Peripherals;
+
+    use esp_idf_sys::*;
+
+    pub fn run() -> anyhow::Result<()> {
+        // Link ESP-IDF patches (required for examples)
+        esp_idf_hal::sys::link_patches();
+
+        let peripherals = Peripherals::take()?;
+
+        // Configure LDO3 for MIPI D-PHY supply (typically 2.5 V).
+        //
+        // NOTE: Adjust the voltage to match your board's design and panel
+        // requirements. 2.5 V is a common value for the DSI PHY supply.
+        let ldo_cfg = LdoChannelConfig::new(2500);
+        let _ldo3 = LdoChannel::new(&peripherals.ldo3, &ldo_cfg)?;
+
+        // Give the LDO some time to stabilize before enabling the panel.
+        std::thread::sleep(Duration::from_millis(20));
+
+        // Configure video timing for a 1024×600 panel.
+        // Adjust these values to match your panel's datasheet.
+        let video_timing = VideoTiming::new(1024, 600)
+            .hsync_back_porch(100)
+            .hsync_pulse_width(100)
+            .hsync_front_porch(100)
+            .vsync_back_porch(10)
+            .vsync_pulse_width(10)
+            .vsync_front_porch(10);
+
+        // High-level LCD configuration:
+        // - 2 DSI data lanes at 1250 Mbps
+        // - RGB888 pixel format
+        // - DPI clock at 48 MHz
+        let config = LcdConfig::new(
+            video_timing,
+            2,    // num_data_lanes
+            1250, // lane_bit_rate_mbps
+            48,   // dpi_clock_freq_mhz
+            PixelFormat::Rgb888,
+        );
+
+        // Create driver with DSI bus and DBI IO
+        let mut lcd = LcdDriver::new(peripherals.dsi, &config)?;
+
+        // Create vendor control panel (e.g., ILI9881C) over DBI.
+        //
+        // Note: This requires the corresponding ESP-IDF component
+        // (e.g., ILI9881C DSI panel driver) to be enabled.
+        let mut dev_config: esp_lcd_panel_dev_config_t = lcd.config().into();
+
+        // Configure reset GPIO if your panel uses one (adjust as needed).
+        // Use -1 for no reset GPIO.
+        dev_config.reset_gpio_num = -1;
+
+        let mut control_panel: PanelHandle = core::ptr::null_mut();
+        unsafe {
+            // Replace `esp_lcd_new_panel_ili9881c` with the appropriate
+            // vendor-specific constructor for your panel if needed.
+            esp!(esp_lcd_new_panel_ili9881c(
+                lcd.dbi_io_handle(),
+                &dev_config,
+                &mut control_panel
+            ))?;
+        }
+        lcd.set_control_panel(control_panel)?;
+
+        // Initialize the control panel
+        lcd.reset()?;
+        lcd.init()?;
+        lcd.set_display_on(true)?;
+
+        // Create the DPI panel for pixel data transfers.
+        // This consumes the NoDpiPanel driver and returns a WithDpiPanel driver.
+        let lcd = lcd.create_dpi_panel()?;
+
+        // Simple test bitmap: clear screen to black.
+        //
+        // NOTE:
+        // - draw_bitmap uses half-open intervals [x1, x2) × [y1, y2)
+        // - For a 1024×600 display, use x2=1024, y2=600 (NOT 1023, 599)
+        // - For RGB888, 3 bytes per pixel
+        let bitmap = vec![0u8; 1024 * 600 * 3];
+
+        lcd.draw_bitmap(0, 0, 1024, 600, &bitmap)?;
+
+        // Keep the application alive so the display remains on
+        loop {
+            std::thread::sleep(Duration::from_secs(1));
+        }
+    }
+}
+
+#[cfg(not(esp32p4))]
+mod example {
+    pub fn run() -> anyhow::Result<()> {
+        println!("This example is not supported on this target");
+        Ok(())
+    }
+}
+
+fn main() -> anyhow::Result<()> {
+    example::run()
+}