/* * 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; } }