/*
    * EmbeddedController.hpp
    * ACPI Embedded Controller (PNP0C09) transport
    * Copyright (c) 2026 Daniel Hammer
*/

#pragma once
#include <cstdint>

namespace Hal {
    namespace EmbeddedController {

        // ============================================================================

        // Bring-up

        // ============================================================================
        // Locate the EC in the ACPI namespace and latch its command/data ports.
        // Prefers the ECDT table when present (it is valid before the namespace
        // is loaded); otherwise walks the namespace for PNP0C09 and reads _CRS.
        // Safe to call more than once; only the first call does work.
        void Initialize(void* xsdt);

        // True once a usable command/data port pair has been found.
        bool IsAvailable();

        // Run the namespace's _REG(EmbeddedControl, 1) methods, telling firmware
        // that EC region access is live. ACPI requires this once a handler for
        // an address space is installed, and firmware leans on it hard: EC
        // methods are typically guarded by a flag that _REG sets, and until it
        // is set they return safe do-nothing answers (a battery reports itself
        // absent, a thermal zone reports no temperature). Called by Initialize.
        void RunRegMethods();

        // Log `bytes` bytes of EC address space starting at `base_`. Purely a
        // diagnostic: it is the only way to tell a broken handshake from a
        // register that genuinely reads zero.
        void DumpSpace(uint8_t base_, int bytes);

        // ============================================================================

        // Transport

        // ============================================================================
        // Read/write one byte of the EC's 256-byte address space. Both return
        // false on timeout or when no EC is present, leaving *value untouched.
        bool Read(uint8_t address, uint8_t& value);
        bool Write(uint8_t address, uint8_t value);
    };
};