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 20 struct tegra_ivc_header; 21 22 struct 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 */ 47 void *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 */ 57 int 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 */ 67 void *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 */ 77 int 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 */ 88 int 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 */ 98 void tegra_ivc_reset(struct tegra_ivc *ivc); 99 100 size_t tegra_ivc_align(size_t size); 101 unsigned tegra_ivc_total_queue_size(unsigned queue_size); 102 int 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); 107 void tegra_ivc_cleanup(struct tegra_ivc *ivc); 108 109 #endif /* __TEGRA_IVC_H */ 110