231 lines
6.1 KiB
C

/**
* \file
*
* \brief SAM DMA cyclic redundancy check (CRC) Driver
*
* Copyright (C) 2014-2015 Atmel Corporation. All rights reserved.
*
* \asf_license_start
*
* \page License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The name of Atmel may not be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 4. This software may only be redistributed and used in connection with an
* Atmel microcontroller product.
*
* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* \asf_license_stop
*
*/
/*
* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
*/
#ifndef DMA_CRC_H_INCLUDED
#define DMA_CRC_H_INCLUDED
#include <compiler.h>
#ifdef __cplusplus
extern "C" {
#endif
/** DMA channel n offset. */
#define DMA_CRC_CHANNEL_N_OFFSET 0x20
/** CRC Polynomial Type. */
enum crc_polynomial_type {
/** CRC16 (CRC-CCITT). */
CRC_TYPE_16,
/** CRC32 (IEEE 802.3). */
CRC_TYPE_32,
};
/** CRC Beat Type. */
enum crc_beat_size {
/** Byte bus access. */
CRC_BEAT_SIZE_BYTE,
/** Half-word bus access. */
CRC_BEAT_SIZE_HWORD,
/** Word bus access. */
CRC_BEAT_SIZE_WORD,
};
/** Configurations for CRC calculation. */
struct dma_crc_config {
/** CRC polynomial type. */
enum crc_polynomial_type type;
/** CRC beat size. */
enum crc_beat_size size;
};
/**
* \brief Get DMA CRC default configurations.
*
* The default configuration is as follows:
* \li Polynomial type is set to CRC-16(CRC-CCITT)
* \li CRC Beat size: BYTE
*
* \param[in] config default configurations
*/
static inline void dma_crc_get_config_defaults(struct dma_crc_config *config)
{
Assert(config);
config->type = CRC_TYPE_16;
config->size = CRC_BEAT_SIZE_BYTE;
}
/**
* \brief Enable DMA CRC module with an DMA channel.
*
* This function enables a CRC calculation with an allocated DMA channel. This channel ID
* can be gotten from a successful \ref dma_allocate.
*
* \param[in] channel_id DMA channel expected with CRC calculation
* \param[in] config CRC calculation configurations
*
* \return Status of the DMC CRC.
* \retval STATUS_OK Get the DMA CRC module
* \retval STATUS_BUSY DMA CRC module is already taken and not ready yet
*/
static inline enum status_code dma_crc_channel_enable(uint32_t channel_id,
struct dma_crc_config *config)
{
if (DMAC->CRCSTATUS.reg & DMAC_CRCSTATUS_CRCBUSY) {
return STATUS_BUSY;
}
DMAC->CRCCTRL.reg = DMAC_CRCCTRL_CRCBEATSIZE(config->size) |
DMAC_CRCCTRL_CRCPOLY(config->type) |
DMAC_CRCCTRL_CRCSRC(channel_id+DMA_CRC_CHANNEL_N_OFFSET);
DMAC->CTRL.reg |= DMAC_CTRL_CRCENABLE;
return STATUS_OK;
}
/**
* \brief Disable DMA CRC module.
*
*/
static inline void dma_crc_disable(void)
{
DMAC->CTRL.reg &= ~DMAC_CTRL_CRCENABLE;
DMAC->CRCCTRL.reg = 0;
}
/**
* \brief Get DMA CRC checksum value.
*
* \return Calculated CRC checksum.
*/
static inline uint32_t dma_crc_get_checksum(void)
{
if (DMAC->CRCCTRL.bit.CRCSRC == DMAC_CRCCTRL_CRCSRC_IO_Val) {
DMAC->CRCSTATUS.reg = DMAC_CRCSTATUS_CRCBUSY;
}
return DMAC->CRCCHKSUM.reg;
}
/**
* \brief Enable DMA CRC module with I/O.
*
* This function enables a CRC calculation with I/O mode.
*
* \param[in] config CRC calculation configurations.
*
* \return Status of the DMC CRC.
* \retval STATUS_OK Get the DMA CRC module
* \retval STATUS_BUSY DMA CRC module is already taken and not ready yet
*/
static inline enum status_code dma_crc_io_enable(
struct dma_crc_config *config)
{
if (DMAC->CRCSTATUS.reg & DMAC_CRCSTATUS_CRCBUSY) {
return STATUS_BUSY;
}
if (DMAC->CTRL.reg & DMAC_CTRL_CRCENABLE) {
return STATUS_BUSY;
}
DMAC->CRCCTRL.reg = DMAC_CRCCTRL_CRCBEATSIZE(config->size) |
DMAC_CRCCTRL_CRCPOLY(config->type) |
DMAC_CRCCTRL_CRCSRC_IO;
if (config->type == CRC_TYPE_32) {
DMAC->CRCCHKSUM.reg = 0xFFFFFFFF;
}
DMAC->CTRL.reg |= DMAC_CTRL_CRCENABLE;
return STATUS_OK;
}
/**
* \brief Calculate CRC with I/O.
*
* This function calculate the CRC of the input data buffer.
*
* \param[in] buffer CRC Pointer to calculation buffer
* \param[in] total_beat_size Total beat size to be calculated
*
* \return Calculated CRC checksum value.
*/
static inline void dma_crc_io_calculation(void *buffer,
uint32_t total_beat_size)
{
uint32_t counter = total_beat_size;
uint8_t *buffer_8;
uint16_t *buffer_16;
uint32_t *buffer_32;
for (counter=0; counter<total_beat_size; counter++) {
if (DMAC->CRCCTRL.bit.CRCBEATSIZE == CRC_BEAT_SIZE_BYTE) {
buffer_8 = buffer;
DMAC->CRCDATAIN.reg = buffer_8[counter];
} else if (DMAC->CRCCTRL.bit.CRCBEATSIZE == CRC_BEAT_SIZE_HWORD) {
buffer_16 = buffer;
DMAC->CRCDATAIN.reg = buffer_16[counter];
} else if (DMAC->CRCCTRL.bit.CRCBEATSIZE == CRC_BEAT_SIZE_WORD) {
buffer_32 = buffer;
DMAC->CRCDATAIN.reg = buffer_32[counter];
}
/* Wait several cycle to make sure CRC complete */
nop();
nop();
nop();
nop();
}
}
#ifdef __cplusplus
}
#endif
#endif /* DMA_CRC_H_INCLUDED */