nes-proj/cpu/cc2538/dev/crypto.c
Benoît Thébaudeau b92a5afcc4 cc2538: ccm: Make it possible to use the interrupt
Using the AES interrupt allows the user process not to waste time
polling for the completion of the operation. This time can be used by
the user process to do something else, or to let the system enter PM0.

Since the system is now free to perform various operations during a
crypto operation, a protection of the crypto resource is added, and PM1+
is prohibited in order not to stall crypto operations.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
2015-06-02 21:41:07 +02:00

121 lines
3.9 KiB
C

/*
* Copyright (c) 2013, ADVANSEE - http://www.advansee.com/
* All rights reserved.
*
* 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. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS 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.
*/
/**
* \addtogroup cc2538-crypto
* @{
*
* \file
* Implementation of the cc2538 AES/SHA cryptoprocessor driver
*/
#include "contiki.h"
#include "sys/energest.h"
#include "dev/sys-ctrl.h"
#include "dev/nvic.h"
#include "dev/crypto.h"
#include "dev/aes.h"
#include "reg.h"
#include "lpm.h"
#include <stdbool.h>
/*---------------------------------------------------------------------------*/
static volatile struct process *notification_process = NULL;
/*---------------------------------------------------------------------------*/
/** \brief The AES/SHA cryptoprocessor ISR
*
* This is the interrupt service routine for the AES/SHA
* cryptoprocessor.
*
* This ISR is called at worst from PM0, so lpm_exit() does not need
* to be called.
*/
void
crypto_isr(void)
{
ENERGEST_ON(ENERGEST_TYPE_IRQ);
nvic_interrupt_unpend(NVIC_INT_AES);
nvic_interrupt_disable(NVIC_INT_AES);
if(notification_process != NULL) {
process_poll((struct process *)notification_process);
notification_process = NULL;
}
ENERGEST_OFF(ENERGEST_TYPE_IRQ);
}
/*---------------------------------------------------------------------------*/
static bool
permit_pm1(void)
{
return REG(AES_CTRL_ALG_SEL) == 0;
}
/*---------------------------------------------------------------------------*/
void
crypto_init(void)
{
volatile int i;
lpm_register_peripheral(permit_pm1);
crypto_enable();
/* Reset the AES/SHA cryptoprocessor */
REG(SYS_CTRL_SRSEC) |= SYS_CTRL_SRSEC_AES;
for(i = 0; i < 16; i++);
REG(SYS_CTRL_SRSEC) &= ~SYS_CTRL_SRSEC_AES;
}
/*---------------------------------------------------------------------------*/
void
crypto_enable(void)
{
/* Enable the clock for the AES/SHA cryptoprocessor */
REG(SYS_CTRL_RCGCSEC) |= SYS_CTRL_RCGCSEC_AES;
REG(SYS_CTRL_SCGCSEC) |= SYS_CTRL_SCGCSEC_AES;
REG(SYS_CTRL_DCGCSEC) |= SYS_CTRL_DCGCSEC_AES;
}
/*---------------------------------------------------------------------------*/
void
crypto_disable(void)
{
/* Gate the clock for the AES/SHA cryptoprocessor */
REG(SYS_CTRL_RCGCSEC) &= ~SYS_CTRL_RCGCSEC_AES;
REG(SYS_CTRL_SCGCSEC) &= ~SYS_CTRL_SCGCSEC_AES;
REG(SYS_CTRL_DCGCSEC) &= ~SYS_CTRL_DCGCSEC_AES;
}
/*---------------------------------------------------------------------------*/
void
crypto_register_process_notification(struct process *p)
{
notification_process = p;
}
/** @} */