acquireBuffer()

DMABuffer fl::spi::Device::acquireBuffer

(

size_t

size

)

Acquire DMA-capable buffer for zero-copy transmission.

Parameters

size	Number of bytes needed

Returns

DMABuffer (managed buffer) or error

Note

Buffer is backed by DMA-capable memory (PSRAM on ESP32)

Buffer lifetime managed by shared_ptr

Definition at line 259 of file device.cpp.hpp.

                                           {
    if (!isReady()) {
        return DMABuffer(SPIError::NOT_INITIALIZED);
    }
 
    // Get hardware controller
    if (!pImpl->hw_backend) {
        FL_WARN("SPI Device: No hardware controller available");
        return DMABuffer(SPIError::NOT_INITIALIZED);
    }
 
    // Use polymorphic interface (works for SpiHw1/2/4/8)
    SpiHwBase* hw = pImpl->hw_backend.get();
 
    // Always acquire a fresh buffer from hardware
    // Note: The hardware controller may internally cache/reuse buffers
    DMABuffer buffer = hw->acquireDMABuffer(size);
 
    if (!buffer.ok()) {
        FL_WARN("SPI Device: Failed to acquire DMA buffer from hardware");
    } else {
        FL_LOG_SPI("SPI Device: Acquired DMA buffer (" << size << " bytes)");
    }
 
    return buffer;
}

References FL_LOG_SPI, FL_WARN, isReady(), and pImpl.

Referenced by writeAsync().

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