mbed-os/features/nfc/stack/transceiver/pn512/pn512_timer.c

76 lines
2.6 KiB
C

/*
* Copyright (c) 2014-2018, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* \file pn512_timer.c
* \copyright Copyright (c) ARM Ltd 2014
* \author Donatien Garnier
*/
#include "stack/nfc_errors.h"
#include "pn512_timer.h"
#include "pn512_registers.h"
void pn512_timer_config(pn512_t *pPN512, bool autostart, uint16_t prescaler, uint16_t countdown_value)
{
pn512_timer_stop(pPN512); //just in case...
pn512_register_write(pPN512, PN512_REG_TRELOADLOW, countdown_value & 0xFF);
pn512_register_write(pPN512, PN512_REG_TRELOADHIGH, (countdown_value >> 8) & 0xFF);
pn512_register_write(pPN512, PN512_REG_TPRESCALERLOW, prescaler & 0xFF);
pn512_register_write(pPN512, PN512_REG_TMODE_TPRESCALERHIGH, (autostart ? 0x80 : 0x00) | ((prescaler >> 8) & 0x0F));
}
void pn512_timer_start(pn512_t *pPN512)
{
//The control register also contains the initiator bit that we must set correctly
switch (pPN512->framing) {
case nfc_framing_initiator_a_106:
case nfc_framing_initiator_f_212:
case nfc_framing_initiator_f_424:
pn512_register_write(pPN512, PN512_REG_CONTROL, 0x50);
break;
case nfc_framing_target_mode_detector:
case nfc_framing_target_a_106:
case nfc_framing_target_f_212:
case nfc_framing_target_f_424:
default:
pn512_register_write(pPN512, PN512_REG_CONTROL, 0x40);
break;
}
}
void pn512_timer_stop(pn512_t *pPN512)
{
//The control register also contains the initiator bit that we must set correctly
switch (pPN512->framing) {
case nfc_framing_initiator_a_106:
case nfc_framing_initiator_f_212:
case nfc_framing_initiator_f_424:
pn512_register_write(pPN512, PN512_REG_CONTROL, 0x90);
break;
case nfc_framing_target_mode_detector:
case nfc_framing_target_a_106:
case nfc_framing_target_f_212:
case nfc_framing_target_f_424:
default:
pn512_register_write(pPN512, PN512_REG_CONTROL, 0x80);
break;
}
}