ardupilot/libraries/AP_HAL_ChibiOS/hwdef/common/bouncebuffer.c

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/*
* This file is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This file is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
bouncebuffer code for DMA safe memory operations
*/
#include "stm32_util.h"
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include "bouncebuffer.h"
#if defined(STM32F7) && STM32_DMA_CACHE_HANDLING == TRUE
// on F7 we check we are in the DTCM region, and 16 bit aligned
#define IS_DMA_SAFE(addr) ((((uint32_t)(addr)) & ((0xFFFFFFFF & ~(DTCM_RAM_SIZE_KB*1024U-1)) | 1U)) == 0x20000000)
#else
// this checks an address is in main memory and 16 bit aligned
#define IS_DMA_SAFE(addr) ((((uint32_t)(addr)) & 0xF0000001) == 0x20000000)
#endif
/*
initialise a bouncebuffer
*/
void bouncebuffer_init(struct bouncebuffer_t **bouncebuffer, uint32_t prealloc_bytes)
{
(*bouncebuffer) = calloc(1, sizeof(struct bouncebuffer_t));
osalDbgAssert(((*bouncebuffer) != NULL), "bouncebuffer init");
if (prealloc_bytes) {
(*bouncebuffer)->dma_buf = malloc_dma(prealloc_bytes);
osalDbgAssert(((*bouncebuffer)->dma_buf != NULL), "bouncebuffer preallocate");
(*bouncebuffer)->size = prealloc_bytes;
}
}
/*
setup for reading from a device into memory, allocating a bouncebuffer if needed
*/
void bouncebuffer_setup_read(struct bouncebuffer_t *bouncebuffer, uint8_t **buf, uint32_t size)
{
if (!bouncebuffer || IS_DMA_SAFE(*buf)) {
// nothing needs to be done
return;
}
osalDbgAssert((bouncebuffer->busy == false), "bouncebuffer read");
bouncebuffer->orig_buf = *buf;
if (bouncebuffer->size < size) {
if (bouncebuffer->size > 0) {
free(bouncebuffer->dma_buf);
}
bouncebuffer->dma_buf = malloc_dma(size);
osalDbgAssert((bouncebuffer->dma_buf != NULL), "bouncebuffer read allocate");
bouncebuffer->size = size;
}
*buf = bouncebuffer->dma_buf;
bouncebuffer->busy = true;
}
/*
finish a read operation
*/
void bouncebuffer_finish_read(struct bouncebuffer_t *bouncebuffer, const uint8_t *buf, uint32_t size)
{
if (bouncebuffer && buf == bouncebuffer->dma_buf) {
osalDbgAssert((bouncebuffer->busy == true), "bouncebuffer finish_read");
memcpy(bouncebuffer->orig_buf, buf, size);
bouncebuffer->busy = false;
}
}
/*
setup for reading from memory to a device, allocating a bouncebuffer if needed
*/
void bouncebuffer_setup_write(struct bouncebuffer_t *bouncebuffer, const uint8_t **buf, uint32_t size)
{
if (!bouncebuffer || IS_DMA_SAFE(*buf)) {
// nothing needs to be done
return;
}
osalDbgAssert((bouncebuffer->busy == false), "bouncebuffer write");
if (bouncebuffer->size < size) {
if (bouncebuffer->size > 0) {
free(bouncebuffer->dma_buf);
}
bouncebuffer->dma_buf = malloc_dma(size);
osalDbgAssert((bouncebuffer->dma_buf != NULL), "bouncebuffer write allocate");
bouncebuffer->size = size;
}
memcpy(bouncebuffer->dma_buf, *buf, size);
*buf = bouncebuffer->dma_buf;
bouncebuffer->busy = true;
}
/*
finish a write operation
*/
void bouncebuffer_finish_write(struct bouncebuffer_t *bouncebuffer, const uint8_t *buf)
{
if (bouncebuffer && buf == bouncebuffer->dma_buf) {
osalDbgAssert((bouncebuffer->busy == true), "bouncebuffer finish_wite");
bouncebuffer->busy = false;
}
}