esp-idf/components/soc/include/soc/lldesc.h
2022-01-19 11:08:57 +08:00

91 lines
3.5 KiB
C

/*
* SPDX-FileCopyrightText: 2010-2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#include <stdbool.h>
#include "sdkconfig.h"
#if CONFIG_IDF_TARGET_ESP32
#include "esp32/rom/lldesc.h"
#elif CONFIG_IDF_TARGET_ESP32S2
#include "esp32s2/rom/lldesc.h"
#elif CONFIG_IDF_TARGET_ESP32S3
#include "esp32s3/rom/lldesc.h"
#elif CONFIG_IDF_TARGET_ESP32C3
#include "esp32c3/rom/lldesc.h"
#elif CONFIG_IDF_TARGET_ESP32H2
#include "esp32h2/rom/lldesc.h"
#elif CONFIG_IDF_TARGET_ESP32C2
#include "esp32c2/rom/lldesc.h"
#endif
//the size field has 12 bits, but 0 not for 4096.
//to avoid possible problem when the size is not word-aligned, we only use 4096-4 per desc.
/** Maximum size of data in the buffer that a DMA descriptor can hold. */
#define LLDESC_MAX_NUM_PER_DESC (4096-4)
// Some DMA operations might impose certain alignment restrictions on the length
#define LLDESC_MAX_NUM_PER_DESC_16B_ALIGNED (4096 - 16)
#define LLDESC_MAX_NUM_PER_DESC_32B_ALIGNED (4096 - 32)
/**
* Generate a linked list pointing to a (huge) buffer in an descriptor array.
*
* The caller should ensure there is enough size to hold the array, by calling
* ``lldesc_get_required_num_constrained`` with the same max_desc_size argument.
*
* @param[out] out_desc_array Output of a descriptor array, the head should be fed to the DMA.
* @param buffer Buffer for the descriptors to point to.
* @param size Size (or length for TX) of the buffer
* @param max_desc_size Maximum length of each descriptor
* @param isrx The RX DMA may require the buffer to be word-aligned, set to true for a RX link, otherwise false.
*/
void lldesc_setup_link_constrained(lldesc_t *out_desc_array, const void *buffer, int size, int max_desc_size, bool isrx);
/**
* Generate a linked list pointing to a (huge) buffer in an descriptor array.
*
* The caller should ensure there is enough size to hold the array, by calling
* ``lldesc_get_required_num``.
*
* @param[out] out_desc_array Output of a descriptor array, the head should be fed to the DMA.
* @param buffer Buffer for the descriptors to point to.
* @param size Size (or length for TX) of the buffer
* @param isrx The RX DMA may require the buffer to be word-aligned, set to true for a RX link, otherwise false.
*/
#define lldesc_setup_link(out_desc_array, buffer, size, isrx) lldesc_setup_link_constrained(out_desc_array, buffer, size, LLDESC_MAX_NUM_PER_DESC, isrx)
/**
* @brief Get the received length of a linked list, until end of the link or eof.
*
* @param head The head of the linked list.
* @param[out] out_next Output of the next descriptor of the EOF descriptor. Return NULL if there's no
* EOF. Can be set to NULL if next descriptor is not needed.
* @return The accumulation of the `len` field of all descriptors until EOF or the end of the link.
*/
int lldesc_get_received_len(lldesc_t* head, lldesc_t** out_next);
/**
* Get the number of descriptors required for a given buffer size.
*
* @param data_size Size to check descriptor num.
*
* @return Numbers required.
*/
static inline int lldesc_get_required_num_constrained(int data_size, int max_desc_size)
{
return (data_size + max_desc_size - 1) / max_desc_size;
}
/**
* Get the number of descriptors required for a given buffer size.
*
* @param data_size Size to check descriptor num.
* @param max_desc_size Maximum length of each descriptor
* @return Numbers required.
*/
#define lldesc_get_required_num(data_size) lldesc_get_required_num_constrained(data_size, LLDESC_MAX_NUM_PER_DESC)