1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
  4 */
  5
  6#ifndef __TEGRA_IVC_H
  7#define __TEGRA_IVC_H
  8
  9#include <linux/device.h>
 10#include <linux/dma-mapping.h>
 11#include <linux/iosys-map.h>
 12#include <linux/types.h>
 13
 14struct tegra_ivc_header;
 15
 16struct tegra_ivc {
 17	struct device *peer;
 18
 19	struct {
 20		struct iosys_map map;
 21		unsigned int position;
 22		dma_addr_t phys;
 23	} rx, tx;
 24
 25	void (*notify)(struct tegra_ivc *ivc, void *data);
 26	void *notify_data;
 27
 28	unsigned int num_frames;
 29	size_t frame_size;
 30};
 31
 32/**
 33 * tegra_ivc_read_get_next_frame - Peek at the next frame to receive
 34 * @ivc		pointer of the IVC channel
 35 *
 36 * Peek at the next frame to be received, without removing it from
 37 * the queue.
 38 *
 39 * Returns a pointer to the frame, or an error encoded pointer.
 40 */
 41int tegra_ivc_read_get_next_frame(struct tegra_ivc *ivc, struct iosys_map *map);
 42
 43/**
 44 * tegra_ivc_read_advance - Advance the read queue
 45 * @ivc		pointer of the IVC channel
 46 *
 47 * Advance the read queue
 48 *
 49 * Returns 0, or a negative error value if failed.
 50 */
 51int tegra_ivc_read_advance(struct tegra_ivc *ivc);
 52
 53/**
 54 * tegra_ivc_write_get_next_frame - Poke at the next frame to transmit
 55 * @ivc		pointer of the IVC channel
 56 *
 57 * Get access to the next frame.
 58 *
 59 * Returns a pointer to the frame, or an error encoded pointer.
 60 */
 61int tegra_ivc_write_get_next_frame(struct tegra_ivc *ivc, struct iosys_map *map);
 62
 63/**
 64 * tegra_ivc_write_advance - Advance the write queue
 65 * @ivc		pointer of the IVC channel
 66 *
 67 * Advance the write queue
 68 *
 69 * Returns 0, or a negative error value if failed.
 70 */
 71int tegra_ivc_write_advance(struct tegra_ivc *ivc);
 72
 73/**
 74 * tegra_ivc_notified - handle internal messages
 75 * @ivc		pointer of the IVC channel
 76 *
 77 * This function must be called following every notification.
 78 *
 79 * Returns 0 if the channel is ready for communication, or -EAGAIN if a channel
 80 * reset is in progress.
 81 */
 82int tegra_ivc_notified(struct tegra_ivc *ivc);
 83
 84/**
 85 * tegra_ivc_reset - initiates a reset of the shared memory state
 86 * @ivc		pointer of the IVC channel
 87 *
 88 * This function must be called after a channel is reserved before it is used
 89 * for communication. The channel will be ready for use when a subsequent call
 90 * to notify the remote of the channel reset.
 91 */
 92void tegra_ivc_reset(struct tegra_ivc *ivc);
 93
 94size_t tegra_ivc_align(size_t size);
 95unsigned tegra_ivc_total_queue_size(unsigned queue_size);
 96int tegra_ivc_init(struct tegra_ivc *ivc, struct device *peer, const struct iosys_map *rx,
 97		   dma_addr_t rx_phys, const struct iosys_map *tx, dma_addr_t tx_phys,
 98		   unsigned int num_frames, size_t frame_size,
 99		   void (*notify)(struct tegra_ivc *ivc, void *data),
100		   void *data);
101void tegra_ivc_cleanup(struct tegra_ivc *ivc);
102
103#endif /* __TEGRA_IVC_H */