rt-thread-official/bsp/samd21/sam_d2x_asflib/sam0/drivers/trng/trng.c

102 lines
3.3 KiB
C

/**
* \file
*
* \brief SAM True Random Number Generator (TRNG) 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>
*/
#include "trng.h"
/**
* \brief Initializes a hardware TRNG module instance.
*
* Enables the clock and initializes the TRNG module, based on the given
* configuration values.
*
* \param[in,out] module_inst Pointer to the software module instance struct
* \param[in] hw Pointer to the TRNG hardware module
* \param[in] config Pointer to the TRNG configuration options struct
*
* \return Status of the initialization procedure.
*
* \retval STATUS_OK The module was initialized successfully
*/
enum status_code trng_init(
struct trng_module *const module_inst,
Trng *const hw,
struct trng_config *const config)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(hw);
Assert(config);
/* Initialize device instance */
module_inst->hw = hw;
/* Turn on the digital interface clock */
system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBC, MCLK_APBCMASK_TRNG);
#if TRNG_CALLBACK_MODE == true
/* Initialize parameters */
for (uint8_t i = 0; i < TRNG_CALLBACK_N; i++) {
module_inst->callback[i] = NULL;
}
/* Initialize software flags*/
module_inst->register_callback_mask = 0x00;
module_inst->enable_callback_mask = 0x00;
module_inst->job_buffer = NULL;
module_inst->remaining_number = 0;
module_inst->job_status = STATUS_OK;
/* Register this instance for callbacks*/
_trng_instance = module_inst;
#endif
/* Write configuration to module */
hw->CTRLA.reg = ((uint32_t)config->run_in_standby << TRNG_CTRLA_RUNSTDBY_Pos);
return STATUS_OK;
}