OpenRTX/lib/miosix-kernel/miosix/arch/common/drivers/stm32_hardware_rng.h

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3.5 KiB
C++

/***************************************************************************
* Copyright (C) 2013 by Terraneo Federico *
* *
* This program 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 2 of the License, or *
* (at your option) any later version. *
* *
* This program 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. *
* *
* As a special exception, if other files instantiate templates or use *
* macros or inline functions from this file, or you compile this file *
* and link it with other works to produce a work based on this file, *
* this file does not by itself cause the resulting work to be covered *
* by the GNU General Public License. However the source code for this *
* file must still be made available in accordance with the GNU General *
* Public License. This exception does not invalidate any other reasons *
* why a work based on this file might be covered by the GNU General *
* Public License. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef RNG_H
#define RNG_H
#include "interfaces/arch_registers.h"
#include "kernel/sync.h"
namespace miosix {
/**
* Class to access the hardware random number generator in Miosix
* Works with the hardware RNG in stm32f2 and stm32f4
*/
class HardwareRng
{
public:
/**
* \return an instance of this class (singleton)
*/
static HardwareRng& instance();
/**
* \return a 32 bit random number
* \throws runtime_error if the self test is not passed
*/
unsigned int get();
/**
* Fill a buffer with random data
* \param buf buffer to be filled
* \param size buffer size
* \throws runtime_error if the self test is not passed
*/
void get(void *buf, unsigned int size);
private:
HardwareRng(const HardwareRng&);
HardwareRng& operator=(const HardwareRng&);
/**
* Constructor
*/
HardwareRng() : old(0)
{
miosix::FastInterruptDisableLock dLock;
RCC->AHB2ENR |= RCC_AHB2ENR_RNGEN;
RCC_SYNC();
}
/**
* \return a 32 bit random number
* \throws runtime_error if the self test is not passed
*/
unsigned int getImpl();
/**
* To save power, enable the peripheral ony when requested
*/
class PeripheralEnable
{
public:
PeripheralEnable() { RNG->CR=RNG_CR_RNGEN; }
~PeripheralEnable() { RNG->CR=0; }
};
miosix::FastMutex mutex; ///< To protect against concurrent access
unsigned int old; ///< Previously read value
};
} //namespace miosix
#endif //RNG_H