stm8s_awu.c

/*
 * This file is provided under a MIT license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * MIT License
 *
 * Copyright (c) 2020 Pavel Nadein
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * 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
 * OWNER 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.
 *
 * STM8S open source driver
 *
 * Contact Information:
 * Pavel Nadein <pavelnadein@gmail.com>
 */

#include "stm8s_awu.h"

static const uint8_t apr_array[] =
	{0, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 61, 23, 23, 62};
static const uint8_t tbr_array[] =
	{0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 12, 14, 15, 15};

static void (*handler)(void);

void awu_init(enum awu_timebase_t timebase, void (*callback)(void))
{
	CLK->PCKENR2 |= CLK_PCKENR2_AWU;

	handler = callback;

	/* Enable the AWU peripheral */
	AWU->CSR |= AWU_CSR_AWUEN;
	AWU->TBR &= (u8)(~AWU_TBR_AWUTB);
	AWU->TBR |= tbr_array[(u8)timebase];

	/* Set the APR divider */
	AWU->APR &= (u8)(~AWU_APR_APR);
	AWU->APR |= apr_array[(u8)timebase];
}

INTERRUPT_HANDLER(AWU_IRQHandler, 1)
{
	handler();
	AWU->CSR;
}