usbtest/libopencm3/lib/stm32/common/timer_common_f0234.c

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/** @addtogroup timer_file
*/
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2010 Edward Cheeseman <evbuilder@users.sourceforge.org>
* Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
/**@{*/
#include <libopencm3/stm32/timer.h>
/*---------------------------------------------------------------------------*/
/** @brief Set Input Polarity
The timer channel must be set to input capture mode.
@param[in] timer_peripheral Unsigned int32. Timer register address base
@param[in] ic ::tim_ic_id. Input Capture channel designator.
@param[in] pol ::tim_ic_pol. Input Capture polarity control.
*/
void timer_ic_set_polarity(uint32_t timer_peripheral, enum tim_ic_id ic,
enum tim_ic_pol pol)
{
/* Clear CCxP and CCxNP to zero. For both edge trigger both fields are
* set. Case 10 is invalid.
*/
TIM_CCER(timer_peripheral) &= ~(0xa << (ic * 4));
switch (pol) {
case TIM_IC_RISING: /* 00 */
break;
case TIM_IC_BOTH: /* 11 */
TIM_CCER(timer_peripheral) |= (0xa << (ic * 4));
break;
case TIM_IC_FALLING: /* 01 */
TIM_CCER(timer_peripheral) |= (0x2 << (ic * 4));
}
}
/**@}*/