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 14 struct tegra_ivc_header; 15 16 struct 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 */ 41 int 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 */ 51 int 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 */ 61 int 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 */ 71 int 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 */ 82 int 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 */ 92 void tegra_ivc_reset(struct tegra_ivc *ivc); 93 94 size_t tegra_ivc_align(size_t size); 95 unsigned tegra_ivc_total_queue_size(unsigned queue_size); 96 int 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); 101 void tegra_ivc_cleanup(struct tegra_ivc *ivc); 102 103 #endif /* __TEGRA_IVC_H */ 104
