1/*
  2 * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
  3 *
  4 * This program is free software; you can redistribute it and/or modify it
  5 * under the terms and conditions of the GNU General Public License,
  6 * version 2, as published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope it will be useful, but WITHOUT
  9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 11 * more details.
 12 */
 13
 14#ifndef __TEGRA_IVC_H
 15
 16#include <linux/device.h>
 17#include <linux/dma-mapping.h>
 18#include <linux/types.h>
 19
 20struct tegra_ivc_header;
 21
 22struct tegra_ivc {
 23	struct device *peer;
 24
 25	struct {
 26		struct tegra_ivc_header *channel;
 27		unsigned int position;
 28		dma_addr_t phys;
 29	} rx, tx;
 30
 31	void (*notify)(struct tegra_ivc *ivc, void *data);
 32	void *notify_data;
 33
 34	unsigned int num_frames;
 35	size_t frame_size;
 36};
 37
 38/**
 39 * tegra_ivc_read_get_next_frame - Peek at the next frame to receive
 40 * @ivc		pointer of the IVC channel
 41 *
 42 * Peek at the next frame to be received, without removing it from
 43 * the queue.
 44 *
 45 * Returns a pointer to the frame, or an error encoded pointer.
 46 */
 47void *tegra_ivc_read_get_next_frame(struct tegra_ivc *ivc);
 48
 49/**
 50 * tegra_ivc_read_advance - Advance the read queue
 51 * @ivc		pointer of the IVC channel
 52 *
 53 * Advance the read queue
 54 *
 55 * Returns 0, or a negative error value if failed.
 56 */
 57int tegra_ivc_read_advance(struct tegra_ivc *ivc);
 58
 59/**
 60 * tegra_ivc_write_get_next_frame - Poke at the next frame to transmit
 61 * @ivc		pointer of the IVC channel
 62 *
 63 * Get access to the next frame.
 64 *
 65 * Returns a pointer to the frame, or an error encoded pointer.
 66 */
 67void *tegra_ivc_write_get_next_frame(struct tegra_ivc *ivc);
 68
 69/**
 70 * tegra_ivc_write_advance - Advance the write queue
 71 * @ivc		pointer of the IVC channel
 72 *
 73 * Advance the write queue
 74 *
 75 * Returns 0, or a negative error value if failed.
 76 */
 77int tegra_ivc_write_advance(struct tegra_ivc *ivc);
 78
 79/**
 80 * tegra_ivc_notified - handle internal messages
 81 * @ivc		pointer of the IVC channel
 82 *
 83 * This function must be called following every notification.
 84 *
 85 * Returns 0 if the channel is ready for communication, or -EAGAIN if a channel
 86 * reset is in progress.
 87 */
 88int tegra_ivc_notified(struct tegra_ivc *ivc);
 89
 90/**
 91 * tegra_ivc_reset - initiates a reset of the shared memory state
 92 * @ivc		pointer of the IVC channel
 93 *
 94 * This function must be called after a channel is reserved before it is used
 95 * for communication. The channel will be ready for use when a subsequent call
 96 * to notify the remote of the channel reset.
 97 */
 98void tegra_ivc_reset(struct tegra_ivc *ivc);
 99
100size_t tegra_ivc_align(size_t size);
101unsigned tegra_ivc_total_queue_size(unsigned queue_size);
102int tegra_ivc_init(struct tegra_ivc *ivc, struct device *peer, void *rx,
103		   dma_addr_t rx_phys, void *tx, dma_addr_t tx_phys,
104		   unsigned int num_frames, size_t frame_size,
105		   void (*notify)(struct tegra_ivc *ivc, void *data),
106		   void *data);
107void tegra_ivc_cleanup(struct tegra_ivc *ivc);
108
109#endif /* __TEGRA_IVC_H */