drivers/staging/media/atomisp/pci/atomisp2/css2400/base/circbuf/interface/ia_css_circbuf_desc.h

   1 /*
   2  * Support for Intel Camera Imaging ISP subsystem.
   3  * Copyright (c) 2015, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14
  15 #ifndef _IA_CSS_CIRCBUF_DESC_H_
  16 #define _IA_CSS_CIRCBUF_DESC_H_
  17
  18 #include <type_support.h>
  19 #include <math_support.h>
  20 #include <storage_class.h>
  21 #include <platform_support.h>
  22 #include <sp.h>
  23 #include "ia_css_circbuf_comm.h"
  24 /****************************************************************
  25  *
  26  * Inline functions.
  27  *
  28  ****************************************************************/
  29 /**
  30  * @brief Test if the circular buffer is empty.
  31  *
  32  * @param cb_desc The pointer to the circular buffer descriptor.
  33  *
  34  * @return
  35  *      - true when it is empty.
  36  *      - false when it is not empty.
  37  */
  38 STORAGE_CLASS_INLINE bool ia_css_circbuf_desc_is_empty(
  39                 ia_css_circbuf_desc_t *cb_desc)
  40 {
  41         OP___assert(cb_desc != NULL);
  42         return (cb_desc->end == cb_desc->start);
  43 }
  44
  45 /**
  46  * @brief Test if the circular buffer descriptor is full.
  47  *
  48  * @param cb_desc       The pointer to the circular buffer
  49  *                      descriptor.
  50  *
  51  * @return
  52  *      - true when it is full.
  53  *      - false when it is not full.
  54  */
  55 STORAGE_CLASS_INLINE bool ia_css_circbuf_desc_is_full(
  56                 ia_css_circbuf_desc_t *cb_desc)
  57 {
  58         OP___assert(cb_desc != NULL);
  59         return (OP_std_modadd(cb_desc->end, 1, cb_desc->size) == cb_desc->start);
  60 }
  61
  62 /**
  63  * @brief Initialize the circular buffer descriptor
  64  *
  65  * @param cb_desc       The pointer circular buffer descriptor
  66  * @param size          The size of the circular buffer
  67  */
  68 STORAGE_CLASS_INLINE void ia_css_circbuf_desc_init(
  69         ia_css_circbuf_desc_t *cb_desc,
  70         int8_t size)
  71 {
  72         OP___assert(cb_desc != NULL);
  73         cb_desc->size = size;
  74 }
  75
  76 /**
  77  * @brief Get a position in the circular buffer descriptor.
  78  *
  79  * @param cb     The pointer to the circular buffer descriptor.
  80  * @param base   The base position.
  81  * @param offset The offset.
  82  *
  83  * @return the position in the circular buffer descriptor.
  84  */
  85 STORAGE_CLASS_INLINE uint8_t ia_css_circbuf_desc_get_pos_at_offset(
  86         ia_css_circbuf_desc_t *cb_desc,
  87         uint32_t base,
  88         int offset)
  89 {
  90         uint8_t dest;
  91         OP___assert(cb_desc != NULL);
  92         OP___assert(cb_desc->size > 0);
  93
  94         /* step 1: adjust the offset  */
  95         while (offset < 0) {
  96                 offset += cb_desc->size;
  97         }
  98
  99         /* step 2: shift and round by the upper limit */
 100         dest = OP_std_modadd(base, offset, cb_desc->size);
 101
 102         return dest;
 103 }
 104
 105 /**
 106  * @brief Get the offset between two positions in the circular buffer
 107  * descriptor.
 108  * Get the offset from the source position to the terminal position,
 109  * along the direction in which the new elements come in.
 110  *
 111  * @param cb_desc       The pointer to the circular buffer descriptor.
 112  * @param src_pos       The source position.
 113  * @param dest_pos      The terminal position.
 114  *
 115  * @return the offset.
 116  */
 117 STORAGE_CLASS_INLINE int ia_css_circbuf_desc_get_offset(
 118         ia_css_circbuf_desc_t *cb_desc,
 119         uint32_t src_pos,
 120         uint32_t dest_pos)
 121 {
 122         int offset;
 123         OP___assert(cb_desc != NULL);
 124
 125         offset = (int)(dest_pos - src_pos);
 126         offset += (offset < 0) ? cb_desc->size : 0;
 127
 128         return offset;
 129 }
 130
 131 /**
 132  * @brief Get the number of available elements.
 133  *
 134  * @param cb_desc The pointer to the circular buffer.
 135  *
 136  * @return The number of available elements.
 137  */
 138 STORAGE_CLASS_INLINE uint32_t ia_css_circbuf_desc_get_num_elems(
 139                 ia_css_circbuf_desc_t *cb_desc)
 140 {
 141         int num;
 142         OP___assert(cb_desc != NULL);
 143
 144         num = ia_css_circbuf_desc_get_offset(cb_desc,
 145                                 cb_desc->start,
 146                                 cb_desc->end);
 147
 148         return (uint32_t)num;
 149 }
 150
 151 /**
 152  * @brief Get the number of free elements.
 153  *
 154  * @param cb_desc The pointer to the circular buffer descriptor.
 155  *
 156  * @return: The number of free elements.
 157  */
 158 STORAGE_CLASS_INLINE uint32_t ia_css_circbuf_desc_get_free_elems(
 159                 ia_css_circbuf_desc_t *cb_desc)
 160 {
 161         uint32_t num;
 162         OP___assert(cb_desc != NULL);
 163
 164         num = ia_css_circbuf_desc_get_offset(cb_desc,
 165                                 cb_desc->start,
 166                                 cb_desc->end);
 167
 168         return (cb_desc->size - num);
 169 }
 170 #endif /*_IA_CSS_CIRCBUF_DESC_H_ */