include/soc/tegra/ivc.h

   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 */