/* Reflow Oven Controller
*
* Copyright (C) 2021  Mario Hüttel <mario.huettel@gmx.net>
*
* This file is part of the Reflow Oven Controller Project.
*
* The reflow oven controller is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The Reflow Oven Control Firmware 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the reflow oven controller project.
* If not, see <http://www.gnu.org/licenses/>.
*/

#include <reflow-controller/ui/shell-uart.h>
#include <reflow-controller/periph-config/shell-uart-config.h>
#include <stm-periph/stm32-gpio-macros.h>
#include <stm-periph/uart.h>
#include <helper-macros/helper-macros.h>

/**
 * @brief TX buffer for the shell's uart
 */
static char shell_uart_tx_buff[4096];

/**
 * @brief RX buffer for the shell's uart
 */
static char shell_uart_rx_buff[128];

/**
 * @brief The uart instance handling the shellmatta shell.
 */
struct stm_uart shell_uart;

void shell_uart_setup(void)
{
	struct stm_uart *uart = &shell_uart;

	uart->rx = 1;
	uart->tx = 1;
	uart->brr_val = SHELL_UART_DEFAULT_BRR_REG_VALUE;
	uart->rcc_reg = &SHELL_UART_RCC_REG;
	uart->rcc_bit_no = BITMASK_TO_BITNO(SHELL_UART_RCC_MASK);
	uart->uart_dev = SHELL_UART_PERIPH;
	uart->dma_rx_buff = shell_uart_rx_buff;
	uart->dma_tx_buff = shell_uart_tx_buff;
	uart->rx_buff_count = sizeof(shell_uart_rx_buff);
	uart->tx_buff_count = sizeof(shell_uart_tx_buff);
	uart->base_dma_num = 2;
	uart->dma_rx_stream = SHELL_UART_RECEIVE_DMA_STREAM;
	uart->dma_tx_stream = SHELL_UART_SEND_DMA_STREAM;
	uart->dma_rx_trigger_channel = SHELL_UART_RX_DMA_TRIGGER;
	uart->dma_tx_trigger_channel = SHELL_UART_TX_DMA_TRIGGER;

	uart_init(uart);
	NVIC_EnableIRQ(DMA2_Stream7_IRQn);
}

shellmatta_retCode_t shell_uart_write_callback(const char *data, uint32_t len)
{
	uart_send_array_with_dma(&shell_uart, data, len);
	return SHELLMATTA_OK;
}

int shell_uart_receive_data_with_dma(const char **data, size_t *len)
{
	return uart_receive_data_with_dma(&shell_uart, data, len);
}

int32_t shell_uart_reconfig_baud(uint32_t new_baud)
{
	uint32_t brr_val_floor;
	uint32_t brr_val_remainder;
	uint32_t error_permille;
	int64_t actual_baud;

	/* Calculate the new BRR register value */
	brr_val_floor = SHELL_UART_PERIPHERAL_CLOCK / new_baud;
	brr_val_remainder =  SHELL_UART_PERIPHERAL_CLOCK % new_baud;

	/* Round to the nearest value */
	if (brr_val_remainder > (new_baud / 2u)) {
		brr_val_floor++;
		brr_val_remainder = new_baud - brr_val_remainder;
	}

	actual_baud = (1000U *(int64_t)SHELL_UART_PERIPHERAL_CLOCK) / brr_val_floor;
	error_permille = (ABS(actual_baud - 1000U * (int64_t)new_baud)) / (int64_t)new_baud;


	if (error_permille < 20u) {
		uart_change_brr(&shell_uart, brr_val_floor);
	} else {
		return -1;
	}

	return (int32_t)error_permille;
}

uint32_t shell_uart_get_current_baudrate(void)
{
	uint32_t brr;

	brr = uart_get_brr(&shell_uart);
	if (brr == 0)
		return 0;

	return (SHELL_UART_PERIPHERAL_CLOCK) / brr;
}


/**
 * @brief Handles the TX of UART1 (Shellmatta)
 */
void DMA2_Stream7_IRQHandler(void)
{
	uint32_t hisr = DMA2->HISR & (0x3F << 22);

	DMA2->HIFCR = hisr;

	if (hisr & DMA_HISR_TCIF7)
		uart_tx_dma_complete_int_callback(&shell_uart);
}