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/** \addtogroup sha_module Working with SHA
 * \ingroup peripherals_module
 * The SHA driver provides the interface to configure and use the SHA
 * peripheral.
 * \n
 *
 * The Secure Hash Algorithm (SHA) module requires a padded message
 * according to FIPS180-2 specification. The first block of the
 * message must be indicated to the module by a specific command. The
 * SHA module produces a N-bit message digest each time a block is
 * written and processing period ends. N is 160 for SHA1, 224 for
 * SHA224, 256 for SHA256, 384 for SHA384, 512 for SHA512.
 *
 * To Enable a SHA encryption and decrypt,the user has to follow these
 * few steps:
 * <ul>
 * <li> Configure SHA algorithm mode, key mode, start mode and
 * operation mode by sha_configure(). </li>
 * <li> Set sha_first_block() to indicates that the next block to
 * process is the first one of a message.</li>
 * <li> Input data for encryption by sha_set_input(). </li>
 * <li> To start the encryption process with sha_start()</li>
 * <li> To get the encryption reslut by sha_get_output() </li>
 * </ul>
 *
 * For more accurate information, please look at the SHA section of the
 * Datasheet.
 *
 * Related files :\n
 * \ref sha.c\n
 * \ref sha.h\n
 */
/*@{*/
/*@}*/

/**
 * \file
 *
 * Implementation of Secure Hash Algorithm (SHA)
 *
 */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "chip.h"
#include "peripherals/sha.h"

/*----------------------------------------------------------------------------
 *        Exported functions
 *----------------------------------------------------------------------------*/

void sha_start(void)
{
	SHA->SHA_CR = SHA_CR_START;
}

void sha_soft_reset(void)
{
	SHA->SHA_CR = SHA_CR_SWRST;
}

void sha_first_block(void)
{
	SHA->SHA_CR = SHA_CR_FIRST;
}

void sha_configure(uint32_t mode)
{
	SHA->SHA_MR = mode;
}

void sha_enable_it(uint32_t sources)
{
	SHA->SHA_IER = sources;
}

void sha_disable_it(uint32_t sources)
{
	SHA->SHA_IDR = sources;
}

uint32_t sha_get_status(void)
{
	return SHA->SHA_ISR;
}

void sha_set_input(uint32_t * data, uint8_t len)
{
	uint8_t i;
	uint8_t num;
	num = len <= 16 ? len : 16;
	for (i = 0; i < num; i++)
		SHA->SHA_IDATAR[i] = (data[i]);
	num = len > 16 ? len - 16 : 0;
	for (i = 0; i < num; i++)
		SHA->SHA_IODATAR[i] = (data[i + 16]);
}

void sha_get_output(uint32_t * data)
{
	uint8_t i;
	for (i = 0; i < 16; i++)
		data[i] = SHA->SHA_IODATAR[i];
}