oxigdal-embedded 0.1.4

//! ESP32 specific optimizations and support
//!
//! Provides implementations for ESP32, ESP32-S2, ESP32-S3, ESP32-C3, and ESP32-C6

use super::{TargetArch, TargetCapabilities};
use core::sync::atomic::{Ordering, fence};

/// ESP32 variant
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Esp32Variant {
    /// ESP32 (Xtensa LX6)
    Esp32,
    /// ESP32-S2 (Xtensa LX7)
    Esp32S2,
    /// ESP32-S3 (Xtensa LX7, dual-core)
    Esp32S3,
    /// ESP32-C3 (RISC-V)
    Esp32C3,
    /// ESP32-C6 (RISC-V)
    Esp32C6,
    /// ESP32-H2 (RISC-V)
    Esp32H2,
}

/// ESP32 target implementation
pub struct Esp32Target {
    variant: Esp32Variant,
}

impl Esp32Target {
    /// Create a new ESP32 target
    pub const fn new(variant: Esp32Variant) -> Self {
        Self { variant }
    }

    /// Get the ESP32 variant
    pub const fn variant(&self) -> Esp32Variant {
        self.variant
    }

    /// Check if this is an Xtensa-based ESP32
    pub const fn is_xtensa(&self) -> bool {
        matches!(
            self.variant,
            Esp32Variant::Esp32 | Esp32Variant::Esp32S2 | Esp32Variant::Esp32S3
        )
    }

    /// Check if this is a RISC-V based ESP32
    pub const fn is_riscv(&self) -> bool {
        matches!(
            self.variant,
            Esp32Variant::Esp32C3 | Esp32Variant::Esp32C6 | Esp32Variant::Esp32H2
        )
    }
}

impl TargetArch for Esp32Target {
    fn name(&self) -> &'static str {
        match self.variant {
            Esp32Variant::Esp32 => "ESP32",
            Esp32Variant::Esp32S2 => "ESP32-S2",
            Esp32Variant::Esp32S3 => "ESP32-S3",
            Esp32Variant::Esp32C3 => "ESP32-C3",
            Esp32Variant::Esp32C6 => "ESP32-C6",
            Esp32Variant::Esp32H2 => "ESP32-H2",
        }
    }

    fn pointer_size(&self) -> usize {
        4 // All ESP32 variants are 32-bit
    }

    fn native_alignment(&self) -> usize {
        4 // 32-bit alignment
    }

    fn supports_unaligned_access(&self) -> bool {
        // Xtensa supports unaligned access with performance penalty
        // RISC-V variants do not
        self.is_xtensa()
    }

    fn memory_barrier(&self) {
        memory_barrier();
    }

    fn cycle_count(&self) -> Option<u64> {
        cycle_count(self.variant)
    }
}

/// Get ESP32 target capabilities
pub fn get_capabilities() -> TargetCapabilities {
    let variant = detect_variant();

    TargetCapabilities {
        has_fpu: true, // All ESP32 variants have FPU
        has_simd: false,
        has_aes: matches!(
            variant,
            Esp32Variant::Esp32 | Esp32Variant::Esp32S3 | Esp32Variant::Esp32C6
        ),
        has_crc: false,
        cache_line_size: 32, // ESP32 cache line size
        num_cores: match variant {
            Esp32Variant::Esp32 | Esp32Variant::Esp32S3 => 2,
            _ => 1,
        },
    }
}

/// Detect ESP32 variant at compile time
pub const fn detect_variant() -> Esp32Variant {
    #[cfg(all(target_arch = "xtensa", esp32))]
    {
        Esp32Variant::Esp32
    }

    #[cfg(all(target_arch = "xtensa", esp32s2))]
    {
        Esp32Variant::Esp32S2
    }

    #[cfg(all(target_arch = "xtensa", esp32s3))]
    {
        Esp32Variant::Esp32S3
    }

    #[cfg(all(target_arch = "riscv32", esp32c3))]
    {
        Esp32Variant::Esp32C3
    }

    #[cfg(all(target_arch = "riscv32", esp32c6))]
    {
        Esp32Variant::Esp32C6
    }

    #[cfg(all(target_arch = "riscv32", esp32h2))]
    {
        Esp32Variant::Esp32H2
    }

    #[cfg(not(any(esp32, esp32s2, esp32s3, esp32c3, esp32c6, esp32h2)))]
    {
        Esp32Variant::Esp32 // Default fallback
    }
}

/// ESP32 memory barrier
#[inline]
pub fn memory_barrier() {
    fence(Ordering::SeqCst);

    #[cfg(target_arch = "xtensa")]
    {
        unsafe {
            // MEMW instruction for Xtensa
            core::arch::asm!("memw", options(nostack, nomem));
        }
    }

    #[cfg(all(target_arch = "riscv32", any(esp32c3, esp32c6, esp32h2)))]
    {
        unsafe {
            core::arch::asm!("fence rw, rw", options(nostack, nomem));
        }
    }
}

/// Get cycle count from ESP32
#[inline]
pub fn cycle_count(variant: Esp32Variant) -> Option<u64> {
    match variant {
        Esp32Variant::Esp32 | Esp32Variant::Esp32S2 | Esp32Variant::Esp32S3 => {
            #[cfg(target_arch = "xtensa")]
            {
                let count: u32;
                unsafe {
                    // CCOUNT special register
                    core::arch::asm!(
                        "rsr.ccount {0}",
                        out(reg) count,
                        options(nostack, nomem, preserves_flags)
                    );
                }
                Some(count as u64)
            }

            #[cfg(not(target_arch = "xtensa"))]
            {
                None
            }
        }
        Esp32Variant::Esp32C3 | Esp32Variant::Esp32C6 | Esp32Variant::Esp32H2 => {
            // Use RISC-V cycle counter
            #[cfg(target_arch = "riscv32")]
            {
                let low: u32;
                let high1: u32;
                let high2: u32;

                unsafe {
                    loop {
                        core::arch::asm!(
                            "rdcycleh {high}",
                            "rdcycle {low}",
                            "rdcycleh {high2}",
                            high = out(reg) high1,
                            low = out(reg) low,
                            high2 = out(reg) high2,
                            options(nostack, nomem, preserves_flags)
                        );

                        if high1 == high2 {
                            break;
                        }
                    }
                }

                Some(((high1 as u64) << 32) | (low as u64))
            }

            #[cfg(not(target_arch = "riscv32"))]
            {
                None
            }
        }
    }
}

/// ESP32 WiFi and wireless support
pub mod wireless {
    use crate::error::Result;

    /// WiFi power mode
    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
    pub enum WifiPowerMode {
        /// Full power
        Active,
        /// Modem sleep
        ModemSleep,
        /// Light sleep
        LightSleep,
    }

    /// Set WiFi power mode (placeholder for actual implementation)
    pub fn set_wifi_power_mode(_mode: WifiPowerMode) -> Result<()> {
        // This would interface with ESP-IDF or esp-hal
        Ok(())
    }
}

/// ESP32 RTC and sleep modes
pub mod sleep {
    use crate::error::Result;

    /// Deep sleep wakeup source
    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
    pub enum WakeupSource {
        /// Timer wakeup
        Timer,
        /// GPIO wakeup
        Gpio,
        /// Touch pad wakeup
        Touchpad,
        /// ULP coprocessor wakeup
        Ulp,
    }

    /// Enter deep sleep mode
    pub fn deep_sleep(_duration_us: u64, _sources: &[WakeupSource]) -> Result<()> {
        // This would interface with ESP-IDF or esp-hal
        Ok(())
    }

    /// Enter light sleep mode
    pub fn light_sleep(_duration_us: u64) -> Result<()> {
        // This would interface with ESP-IDF or esp-hal
        Ok(())
    }
}

/// ESP32 flash operations
pub mod flash {
    use crate::error::{EmbeddedError, Result};

    /// Read from flash memory
    ///
    /// # Safety
    ///
    /// addr must be a valid flash address
    pub unsafe fn read(_addr: u32, _buffer: &mut [u8]) -> Result<usize> {
        // This would interface with ESP flash driver
        Err(EmbeddedError::UnsupportedOperation)
    }

    /// Write to flash memory
    ///
    /// # Safety
    ///
    /// addr must be a valid flash address and sector must be erased
    pub unsafe fn write(_addr: u32, _data: &[u8]) -> Result<usize> {
        // This would interface with ESP flash driver
        Err(EmbeddedError::UnsupportedOperation)
    }

    /// Erase flash sector
    ///
    /// # Safety
    ///
    /// addr must be a valid flash address aligned to sector boundary
    pub unsafe fn erase_sector(_addr: u32) -> Result<()> {
        // This would interface with ESP flash driver
        Err(EmbeddedError::UnsupportedOperation)
    }
}

/// ESP32 hardware crypto acceleration
#[cfg(any(esp32, esp32s3, esp32c6))]
pub mod crypto {
    use crate::error::{EmbeddedError, Result};

    /// AES encryption mode
    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
    pub enum AesMode {
        /// ECB mode
        Ecb,
        /// CBC mode
        Cbc,
        /// CTR mode
        Ctr,
    }

    /// AES key size
    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
    pub enum AesKeySize {
        /// 128-bit key
        Aes128,
        /// 192-bit key
        Aes192,
        /// 256-bit key
        Aes256,
    }

    /// Encrypt data using hardware AES
    pub fn aes_encrypt(
        _mode: AesMode,
        _key_size: AesKeySize,
        _key: &[u8],
        _iv: Option<&[u8]>,
        _input: &[u8],
        _output: &mut [u8],
    ) -> Result<()> {
        // This would interface with ESP-IDF crypto driver
        Err(EmbeddedError::UnsupportedOperation)
    }

    /// Decrypt data using hardware AES
    pub fn aes_decrypt(
        _mode: AesMode,
        _key_size: AesKeySize,
        _key: &[u8],
        _iv: Option<&[u8]>,
        _input: &[u8],
        _output: &mut [u8],
    ) -> Result<()> {
        // This would interface with ESP-IDF crypto driver
        Err(EmbeddedError::UnsupportedOperation)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_esp32_target() {
        let target = Esp32Target::new(Esp32Variant::Esp32);
        assert_eq!(target.name(), "ESP32");
        assert_eq!(target.pointer_size(), 4);
        assert_eq!(target.native_alignment(), 4);
    }

    #[test]
    fn test_variant_detection() {
        let variant = detect_variant();
        // Should compile without panic
        let _ = variant;
    }

    #[test]
    fn test_capabilities() {
        let caps = get_capabilities();
        assert!(caps.cache_line_size > 0);
        assert!(caps.num_cores > 0);
    }
}