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
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