esp-idf/components/esp_rom/include/esp_rom_lldesc.h

46 lines
1.3 KiB
C

/*
* SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#include <stdint.h>
#include "sys/queue.h"
#ifdef __cplusplus
extern "C" {
#endif
/*
* SLC2 DMA Desc struct, aka lldesc_t
*
* --------------------------------------------------------------
* | own | EoF | sub_sof | 5'b0 | length [11:0] | size [11:0] |
* --------------------------------------------------------------
* | buf_ptr [31:0] |
* --------------------------------------------------------------
* | next_desc_ptr [31:0] |
* --------------------------------------------------------------
*/
/* this bitfield is start from the LSB!!! */
typedef struct lldesc_s {
volatile uint32_t size : 12,
length: 12,
offset: 5, /* h/w reserved 5bit, s/w use it as offset in buffer */
sosf : 1, /* start of sub-frame */
eof : 1, /* end of frame */
owner : 1; /* hw or sw */
volatile const uint8_t *buf; /* point to buffer data */
union {
volatile uint32_t empty;
STAILQ_ENTRY(lldesc_s) qe; /* pointing to the next desc */
};
} lldesc_t;
#ifdef __cplusplus
}
#endif