/**
* \file
*
* \brief SAM True Random Number Generator (TRNG) Driver
*
* Copyright (C) 2014-2016 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 Atmel Support
*/
#ifndef TRNG_H_INCLUDED
#define TRNG_H_INCLUDED
/**
* \defgroup asfdoc_sam0_trng_group SAM True Random Number Generator (TRNG) Driver
*
* This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration
* and management of the device's True Random Number Generator functionality.
*
* The following driver API modes are covered by this manual:
* - Polled APIs
* \if TRNG_CALLBACK_MODE
* - Callback APIs
* \endif
*
* The following peripheral is used by this module:
* - TRNG (True Random Number Generator)
*
* The following devices can use this module:
* - Atmel | SMART SAM L21/L22
*
* The outline of this documentation is as follows:
* - \ref asfdoc_sam0_trng_prerequisites
* - \ref asfdoc_sam0_trng_module_overview
* - \ref asfdoc_sam0_trng_special_considerations
* - \ref asfdoc_sam0_trng_extra_info
* - \ref asfdoc_sam0_trng_examples
* - \ref asfdoc_sam0_trng_api_overview
*
*
* \section asfdoc_sam0_trng_prerequisites Prerequisites
*
* There are no prerequisites for this module.
*
*
* \section asfdoc_sam0_trng_module_overview Module Overview
*
* This driver provides an interface for the TRNG functions on the device.
*
* As soon as the TRNG is enabled, the module provides a new 32-bit random
* data, for every 84 CLK_TRNG_APB clock cycles.
*
*
* \section asfdoc_sam0_trng_special_considerations Special Considerations
*
* There are no special considerations for this module.
*
*
* \section asfdoc_sam0_trng_extra_info Extra Information
*
* For extra information, see \ref asfdoc_sam0_trng_extra. This includes:
* - \ref asfdoc_sam0_trng_extra_acronyms
* - \ref asfdoc_sam0_trng_extra_dependencies
* - \ref asfdoc_sam0_trng_extra_errata
* - \ref asfdoc_sam0_trng_extra_history
*
*
* \section asfdoc_sam0_trng_examples Examples
*
* For a list of examples related to this driver, see
* \ref asfdoc_sam0_trng_exqsg.
*
*
* \section asfdoc_sam0_trng_api_overview API Overview
* @{
*/
#include
#include
#ifdef __cplusplus
extern "C" {
#endif
#if TRNG_CALLBACK_MODE == true
/* Forward declaration of struct */
struct trng_module;
extern struct trng_module *_trng_instance;
/** Type definition for a TRNG module callback function. */
typedef void (*trng_callback_t)(struct trng_module *const module_inst);
/** Enum for possible callback types for the TRNG module. */
enum trng_callback {
/** Callback for specific number of random data ready */
TRNG_CALLBACK_READ_BUFFER = 0,
/** Number of available callbacks */
#if !defined(__DOXYGEN__)
TRNG_CALLBACK_N,
#endif
};
#endif
/**
* \brief TRNG software device instance structure.
*
* TRNG software instance structure, used to retain software state information
* of an associated hardware module instance.
*
* \note The fields of this structure should not be altered by the user
* application; they are reserved for module-internal use only.
*/
struct trng_module {
#if !defined(__DOXYGEN__)
/** Hardware module pointer of the associated TRNG peripheral */
Trng *hw;
# if TRNG_CALLBACK_MODE == true
/** Array of callbacks */
trng_callback_t callback[TRNG_CALLBACK_N];
/** Bit mask for callbacks registered */
uint8_t register_callback_mask;
/** Bit mask for callbacks enabled */
uint8_t enable_callback_mask;
/** Holds the status of the ongoing or last read job */
volatile enum status_code job_status;
/** Pointer to buffer used for TRNG results */
volatile uint32_t *job_buffer;
/** Remaining number of TRNG results in current job */
volatile uint32_t remaining_number;
# endif
#endif
};
/**
* \brief TRNG module configuration structure.
*
* Configuration structure for a True Random Number Generator.
*/
struct trng_config {
/** If \c true, the True Random Number Generator will not be stopped in
* standby sleep mode */
bool run_in_standby;
};
/**
* \brief TRNG event enable/disable structure.
*
* Event flags for the TRNG module. This is used to enable and
* disable events via \ref trng_enable_events() and \ref trng_disable_events().
*/
struct trng_events {
/** Enable event generation on random data ready */
bool generate_event_on_data_ready;
};
/**
* \name Driver Initialization and Configuration
* @{
*/
enum status_code trng_init(
struct trng_module *const module_inst,
Trng *const hw,
struct trng_config *const config);
/**
* \brief Initializes all members of a TRNG configuration structure
* to safe defaults.
*
* Initializes all members of a given True Random Number Generator configuration
* structure to safe known default values. This function should be called on
* all new instances of these configuration structures before being modified
* by the user application.
*
* The default configuration is as follows:
* \li True Random Number Generator will not be stopped in standby sleep mode
*
* \param[out] config Configuration structure to initialize to default values
*/
static inline void trng_get_config_defaults(
struct trng_config *const config)
{
/* Sanity check arguments */
Assert(config);
/* Default configuration values */
config->run_in_standby = false;
}
/**
* \brief Enables a TRNG that was previously configured.
*
* Enables True Random Number Generator that was previously configured via a
* call to \ref trng_init().
*
* \param[in] module_inst Software instance for the True Random Number
* Generator peripheral
*/
static inline void trng_enable(
struct trng_module *const module_inst)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(module_inst->hw);
Trng *const trng_module = module_inst->hw;
/* Enable TRNG */
trng_module->CTRLA.reg |= TRNG_CTRLA_ENABLE;
}
/**
* \brief Disables a TRNG that was previously enabled.
*
* Disables True Random Number Generator that was previously started via a call
* to \ref trng_enable().
*
* \param[in] module_inst Software instance for the True Random Number
* Generator peripheral
*/
static inline void trng_disable(
struct trng_module *const module_inst)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(module_inst->hw);
Trng *const trng_module = module_inst->hw;
/* Disbale interrupt */
trng_module->INTENCLR.reg = TRNG_INTENCLR_MASK;
/* Clear interrupt flag */
trng_module->INTFLAG.reg = TRNG_INTFLAG_MASK;
/* Disable TRNG */
trng_module->CTRLA.reg &= ~TRNG_CTRLA_ENABLE;
}
/**
* \brief Enables a TRNG event output.
*
* Enables output events from the True Random Number Generator
* module. See \ref Section Struct trng_events for a list of events this module
* supports.
*
* \note Events cannot be altered while the module is enabled.
*
* \param[in] module_inst Software instance for the TRNG peripheral
* \param[in] events Struct containing flags of events to enable
*/
static inline void trng_enable_events(
struct trng_module *const module_inst,
struct trng_events *const events)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(module_inst->hw);
Trng *const trng_module = module_inst->hw;
if (events->generate_event_on_data_ready) {
/* Enable data ready event output */
trng_module->EVCTRL.reg |= TRNG_EVCTRL_DATARDYEO;
}
}
/**
* \brief Disables a TRNG event output.
*
* Disables output events from the True Random Number Generator
* module. See \ref Section Struct trng_events for a list of events
* this module supports.
*
* \note Events cannot be altered while the module is enabled.
*
* \param[in] module_inst Software instance for the TRNG peripheral
* \param[in] events Struct containing flags of events to disable
*/
static inline void trng_disable_events(
struct trng_module *const module_inst,
struct trng_events *const events)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(module_inst->hw);
Trng *const trng_module = module_inst->hw;
if (events->generate_event_on_data_ready) {
/* Disable data ready event output */
trng_module->EVCTRL.reg &= ~TRNG_EVCTRL_DATARDYEO;
}
}
/** @} */
/**
* \name Read TRNG Result
* @{
*/
/**
* \brief Read the random data result
*
* Reads the random data result.
*
* \param[in] module_inst Pointer to the TRNG software instance struct
* \param[out] result Pointer to store the result value in
*
* \return Status of the TRNG read request.
* \retval STATUS_OK The result was retrieved successfully
* \retval STATUS_BUSY A random result was not ready
*/
static inline enum status_code trng_read(
struct trng_module *const module_inst,
uint32_t *result)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(module_inst->hw);
Assert(result);
Trng *const trng_hw = module_inst->hw;
if (!(trng_hw->INTFLAG.reg & TRNG_INTFLAG_DATARDY)) {
/* Result not ready */
return STATUS_BUSY;
}
/* Get randomly generated output data (it will clear data ready flag) */
*result = trng_hw->DATA.reg;
return STATUS_OK;
}
/** @} */
#ifdef __cplusplus
}
#endif
/** @} */
/**
* \page asfdoc_sam0_trng_extra Extra Information for TRNG Driver
*
* \section asfdoc_sam0_trng_extra_acronyms Acronyms
*
*
*
*
Acronym
*
Description
*
*
*
TRNG
*
True Random Number Generator
*
*
*
*
* \section asfdoc_sam0_trng_extra_dependencies Dependencies
* This driver has no dependencies.
*
*
* \section asfdoc_sam0_trng_extra_errata Errata
* There are no errata related to this driver.
*
*
* \section asfdoc_sam0_trng_extra_history Module History
* An overview of the module history is presented in the table below, with
* details on the enhancements and fixes made to the module since its first
* release. The current version of this corresponds to the newest version in
* the table.
*
*
*
*
Changelog
*
*
*
Initial Release
*
*
*/
/**
* \page asfdoc_sam0_trng_exqsg Examples for TRNG Driver
*
* This is a list of the available Quick Start guides (QSGs) and example
* applications for \ref asfdoc_sam0_trng_group. QSGs are simple examples with
* step-by-step instructions to configure and use this driver in a selection of
* use cases. Note that QSGs can be compiled as a standalone application or be
* added to the user application.
*
* - \subpage asfdoc_sam0_trng_basic_use_case
* \if TRNG_CALLBACK_MODE
* - \subpage asfdoc_sam0_trng_basic_use_case_callback
* \endif
*
* \page asfdoc_sam0_trng_document_revision_history Document Revision History
*
*