/*
 * Android coprocessor DMA library
 *
 * Copyright 2018 Google Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef __ABC_PCIE_DMA_H
#define __ABC_PCIE_DMA_H


#include <linux/ioctl.h>
#include <linux/types.h>

#define ABC_PCIE_DMA_IOC_MAGIC 'U'

enum dma_buf_type {
	DMA_BUFFER_USER = 0,
	DMA_BUFFER_DMA_BUF
};

/* abc_dma_data_direction must match values in <linux/dma-direction.h> */
enum abc_dma_data_direction {
	ABC_DMA_TO_DEVICE = 1,
	ABC_DMA_FROM_DEVICE = 2,
};

struct abc_pcie_dma_desc_legacy {
	enum dma_buf_type local_buf_type; /* local buffer type (DMA/user) */
	union {
		void *local_buf; /* local buffer address */
		int local_dma_buf_fd; /* local DMA buffer file descriptor */
	};
	__u32 local_buf_size; /* local buffer size */

	/* TODO(alexperez):  Remove support for specifying an arbitrary AB
	 * physical address once bringup is done. b/113105230
	 *
	 * local buffer type (DMA/AB physical)
	 */
	enum dma_buf_type remote_buf_type;
	union {
		__u64 remote_buf; /* remote buffer address */
		int remote_dma_buf_fd; /* remote DMA buffer file descriptor */
	};
	enum abc_dma_data_direction dir; /* direction of the DMA transfer */
	__u8 chan; /* dma channel to be used */
};

struct abc_pcie_dma_desc {
	enum dma_buf_type local_buf_type; /* local buffer type (DMA/user) */
	union {
		void *local_buf; /* local buffer address */
		int local_dma_buf_fd; /* local DMA buffer file descriptor */
	};
	__u64 local_dma_buf_off; /* offset within dma buf to xfer from/to */

	enum dma_buf_type remote_buf_type;
	union {
		__u64 remote_buf; /* remote buffer virtual address */
		int remote_dma_buf_fd; /* remote DMA buffer file descriptor */
	};
	__u64 remote_dma_buf_off; /* offset within dma buf to xfer from/to */

	__u64 size; /* number of bytes to transfer */
	enum abc_dma_data_direction dir; /* direction of the DMA transfer */
};

struct abc_pcie_dma_desc_async {
	struct abc_pcie_dma_desc dma_desc;
	__u64 id; /* Transaction id after returning from create ioctl */
};

struct abc_pcie_dma_desc_start {
	__u64 id;
	__u32 start_id; /* ID of start if multiply re-started (out) */
};

struct abc_pcie_dma_desc_wait {
	__u64 id;
	int timeout; /* In usecs, 0:zero wait, < 0: infinite */
	int error; /* Error code if transfer state is error (out) */
	__u32 start_id; /* ID of start if multiply re-started (out) */
};

#define ABC_PCIE_DMA_IOC_POST_DMA_XFER_LEGACY				\
	_IOW(ABC_PCIE_DMA_IOC_MAGIC, 1, struct abc_pcie_dma_desc_legacy *)

#define ABC_PCIE_DMA_IOC_POST_DMA_XFER_SYNC				\
	_IOW(ABC_PCIE_DMA_IOC_MAGIC, 2, struct abc_pcie_dma_desc)

#define ABC_PCIE_DMA_IOC_POST_DMA_XFER_CREATE				\
	_IOWR(ABC_PCIE_DMA_IOC_MAGIC, 3, struct abc_pcie_dma_desc_async)

#define ABC_PCIE_DMA_IOC_POST_DMA_XFER_START				\
	_IOWR(ABC_PCIE_DMA_IOC_MAGIC, 4, struct abc_pcie_dma_desc_start)

#define ABC_PCIE_DMA_IOC_POST_DMA_XFER_WAIT				\
	_IOWR(ABC_PCIE_DMA_IOC_MAGIC, 5, struct abc_pcie_dma_desc_wait)

#define ABC_PCIE_DMA_IOC_POST_DMA_XFER_CLEAN				\
	_IOW(ABC_PCIE_DMA_IOC_MAGIC, 6, __u64)


#endif /* __ABC_PCIE_DMA_H */