/*
 * MIT License
 *
 * Copyright (c) 2020 Joey Castillo
 *
 * 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.
 */

 /*
 * UART methods are Copyright (c) 2014-2017, Alex Taradov <alex@taradov.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. The name of the author may not 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.
 */

#include "watch_uart.h"
#include "peripheral_clk_config.h"

void watch_enable_debug_uart(uint32_t baud) {
    uint64_t br = (uint64_t)65536 * ((CONF_CPU_FREQUENCY * 4) - 16 * baud) / (CONF_CPU_FREQUENCY * 4);

    gpio_set_pin_direction(D1, GPIO_DIRECTION_IN);
    gpio_set_pin_function(D1, PINMUX_PB00C_SERCOM3_PAD2);

    MCLK->APBCMASK.reg |= MCLK_APBCMASK_SERCOM3;

    GCLK->PCHCTRL[SERCOM3_GCLK_ID_CORE].reg = GCLK_PCHCTRL_GEN(0) | GCLK_PCHCTRL_CHEN;
    while (0 == (GCLK->PCHCTRL[SERCOM3_GCLK_ID_CORE].reg & GCLK_PCHCTRL_CHEN));

    SERCOM3->USART.CTRLA.reg =
        SERCOM_USART_CTRLA_DORD | SERCOM_USART_CTRLA_MODE(1/*USART_INT_CLK*/) |
        SERCOM_USART_CTRLA_RXPO(0/*PAD0*/) | SERCOM_USART_CTRLA_TXPO(1/*PAD2*/);

    SERCOM3->USART.CTRLB.reg = SERCOM_USART_CTRLB_RXEN | SERCOM_USART_CTRLB_TXEN |
        SERCOM_USART_CTRLB_CHSIZE(0/*8 bits*/);

    SERCOM3->USART.BAUD.reg = (uint16_t)br;

    SERCOM3->USART.CTRLA.reg |= SERCOM_USART_CTRLA_ENABLE;
}

void watch_debug_putc(char c) {
    while (!(SERCOM3->USART.INTFLAG.reg & SERCOM_USART_INTFLAG_DRE));
    SERCOM3->USART.DATA.reg = c;
}

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
void watch_debug_puts(char *s) {
    while (*s) watch_debug_putc(*s++);
}
#pragma GCC diagnostic pop