io.cxxm

/// SPDX-License-Identifier: Apache-2.0
/// @file arch/s390x/io/ccw_io.cxxm
/// @brief CCW I/O engine — synchronous I/O, SENSE ID, and device probing.
 
export module arch.s390x.io.ccw.core;
import arch.s390x.io.types;
import zxfoundation.base.types;
import lib.error;
import std;
 
export {
 
namespace arch::s390x::io::ccw {
 
    /// @brief Execute a CCW chain synchronously (polling mode).
    /// @param sch_index  Index into the subchannel table.
    /// @param ccw_chain  Pointer to CCW chain in DMA31-addressable memory.
    /// @param ccw_count  Number of CCWs in the chain (logging only).
    /// @param key        Storage key for the ORB (default 0 = nucleus).
    /// @param timeout_us Timeout in microseconds (default 5 s).
    /// @return The IRB captured by the interrupt handler on success,
    ///         kernel_error on timeout or I/O failure.
    [[nodiscard]] auto sync(
        u32 sch_index,
        const ccw1* ccw_chain,
        [[maybe_unused]] u32 ccw_count,
        u8 key = 0,
        u64 timeout_us = 5'000'000
    ) noexcept -> ::std::expected<irb, ::lib::kernel_error>;
 
    /// @brief Issue SENSE ID on a subchannel to identify the attached device.
    /// @param sch_index Index into the subchannel table.
    /// @return senseid_data on success, kernel_error on failure.
    [[nodiscard]] auto sense_id(u32 sch_index) noexcept
        -> ::std::expected<senseid_data, ::lib::kernel_error>;
 
    /// @brief Run SENSE ID on all probed subchannels to populate device type info.
    auto probe_devices() noexcept -> void;
 
} // namespace arch::s390x::io::ccw
 
} // end export