/* SPDX-License-Identifier: GPL-2.0 */
/*
 * IMPORTANT: The following constants must match the ones used and defined in
 * external/qemu/include/hw/misc/goldfish_pipe.h
 */

#ifndef GOLDFISH_PIPE_QEMU_H
#define GOLDFISH_PIPE_QEMU_H

/* List of bitflags returned in status of CMD_POLL command */
enum PipePollFlags {
        PIPE_POLL_IN    = 1 << 0,
        PIPE_POLL_OUT   = 1 << 1,
        PIPE_POLL_HUP   = 1 << 2
};

/* Possible status values used to signal errors */
enum PipeErrors {
        PIPE_ERROR_INVAL        = -1,
        PIPE_ERROR_AGAIN        = -2,
        PIPE_ERROR_NOMEM        = -3,
        PIPE_ERROR_IO           = -4
};

/* Bit-flags used to signal events from the emulator */
enum PipeWakeFlags {
        /* emulator closed pipe */
        PIPE_WAKE_CLOSED                = 1 << 0,

        /* pipe can now be read from */
        PIPE_WAKE_READ                  = 1 << 1,

        /* pipe can now be written to */
        PIPE_WAKE_WRITE                 = 1 << 2,

        /* unlock this pipe's DMA buffer */
        PIPE_WAKE_UNLOCK_DMA            = 1 << 3,

        /* unlock DMA buffer of the pipe shared to this pipe */
        PIPE_WAKE_UNLOCK_DMA_SHARED     = 1 << 4,
};

/* Possible pipe closing reasons */
enum PipeCloseReason {
        /* guest sent a close command */
        PIPE_CLOSE_GRACEFUL             = 0,

        /* guest rebooted, we're closing the pipes */
        PIPE_CLOSE_REBOOT               = 1,

        /* close old pipes on snapshot load */
        PIPE_CLOSE_LOAD_SNAPSHOT        = 2,

        /* some unrecoverable error on the pipe */
        PIPE_CLOSE_ERROR                = 3,
};

/* Bit flags for the 'flags' field */
enum PipeFlagsBits {
        BIT_CLOSED_ON_HOST = 0,  /* pipe closed by host */
        BIT_WAKE_ON_WRITE  = 1,  /* want to be woken on writes */
        BIT_WAKE_ON_READ   = 2,  /* want to be woken on reads */
};

enum PipeRegs {
        PIPE_REG_CMD = 0,

        PIPE_REG_SIGNAL_BUFFER_HIGH = 4,
        PIPE_REG_SIGNAL_BUFFER = 8,
        PIPE_REG_SIGNAL_BUFFER_COUNT = 12,

        PIPE_REG_OPEN_BUFFER_HIGH = 20,
        PIPE_REG_OPEN_BUFFER = 24,

        PIPE_REG_VERSION = 36,

        PIPE_REG_GET_SIGNALLED = 48,
};

enum PipeCmdCode {
        /* to be used by the pipe device itself */
        PIPE_CMD_OPEN           = 1,

        PIPE_CMD_CLOSE,
        PIPE_CMD_POLL,
        PIPE_CMD_WRITE,
        PIPE_CMD_WAKE_ON_WRITE,
        PIPE_CMD_READ,
        PIPE_CMD_WAKE_ON_READ,

        /*
         * TODO(zyy): implement a deferred read/write execution to allow
         * parallel processing of pipe operations on the host.
         */
        PIPE_CMD_WAKE_ON_DONE_IO,
};

#endif /* GOLDFISH_PIPE_QEMU_H */