/*
 * FeatherHAB
 *
 * This file is part of FeatherHAB.
 *
 * FeatherHab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * FeatherHab 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with FeatherHAB. If not, see <http://www.gnu.org/licenses/>.
 *
 * Ethan Zonca
 *
 */

#include "stm32f0xx_hal.h"
#include "system/adc.h"

ADC_HandleTypeDef hadc;
DMA_HandleTypeDef hdma_adc;

#define ADC_BUF_LEN 1
uint16_t adc_buffer[ADC_BUF_LEN];


void adc_init(void)
{

    __ADC1_CLK_ENABLE();

	GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_InitStruct.Pin = GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);


	ADC_ChannelConfTypeDef sConfig;
	hadc.Instance = ADC1;
	hadc.Init.ClockPrescaler = ADC_CLOCK_ASYNC;
	hadc.Init.Resolution = ADC_RESOLUTION12b;
	hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
	hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;
	hadc.Init.EOCSelection = EOC_SEQ_CONV;
	hadc.Init.LowPowerAutoWait = DISABLE;
	hadc.Init.LowPowerAutoPowerOff = DISABLE;
	hadc.Init.ContinuousConvMode = ENABLE;
	hadc.Init.DiscontinuousConvMode = DISABLE;
	hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
	hadc.Init.DMAContinuousRequests = ENABLE;
	hadc.Init.Overrun = OVR_DATA_OVERWRITTEN;
	HAL_ADC_Init(&hadc);

	sConfig.Channel = ADC_CHANNEL_6;
	sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
	sConfig.SamplingTime = ADC_SAMPLETIME_239CYCLES_5;
	HAL_ADC_ConfigChannel(&hadc, &sConfig);


	__DMA1_CLK_ENABLE();
		HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 0, 0);
	HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);

    hdma_adc.Instance = DMA1_Channel1;
    hdma_adc.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_adc.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_adc.Init.MemInc = DMA_MINC_ENABLE;
    hdma_adc.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
    hdma_adc.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
    hdma_adc.Init.Mode = DMA_CIRCULAR;
    hdma_adc.Init.Priority = DMA_PRIORITY_LOW;
    HAL_DMA_Init(&hdma_adc);

    __HAL_LINKDMA(&hadc,DMA_Handle,hdma_adc);


    HAL_ADC_Start_DMA(&hadc, adc_buffer, ADC_BUF_LEN);


}

uint8_t adc_get_vbatt(void)
{
	return adc_buffer[0] / 62.5; // tenths of volts ish
}

DMA_HandleTypeDef* adc__hdma_gethandle(void)
{
	return &hdma_adc;
}