/* This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
/** BusVoodoo UART mode (code)
 *  @file busvoodoo_uart.c
 *  @author King Kévin <kingkevin@cuvoodoo.info>
 *  @date 2018
 *  @note peripherals used: USART @ref busvoodoo_uart
 */
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdlib.h> // standard utilities
#include <string.h> // string utilities

/* STM32 (including CM3) libraries */
#include <libopencm3/stm32/gpio.h> // general purpose input output library
#include <libopencm3/stm32/rcc.h> // real-time control clock library
#include <libopencm3/stm32/usart.h> // USART utilities

/* own libraries */
#include "global.h" // board definitions
#include "print.h" // printing utilities
#include "menu.h" // menu definitions
#include "busvoodoo_global.h" // BusVoodoo definitions
#include "busvoodoo_oled.h" // OLED utilities
#include "busvoodoo_uart.h" // own definitions

/** @defgroup busvoodoo_uart USART peripheral used for UART communication
 *  @{
 */
#define BUSVOODOO_USART_ID 3 /**< USART peripheral */
/** @} */

/** mode setup stage */
static enum busvoodoo_uart_setting_t {
	BUSVOODOO_UART_SETTING_NONE,
	BUSVOODOO_UART_SETTING_BAUDRATE,
	BUSVOODOO_UART_SETTING_DATABITS,
	BUSVOODOO_UART_SETTING_PARITY,
	BUSVOODOO_UART_SETTING_STOPBITS,
	BUSVOODOO_UART_SETTING_DRIVE,
	BUSVOODOO_UART_SETTING_DONE,
} busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_NONE;
/** UART baud rate (in bps) */
uint32_t busvoodoo_uart_baudrate = 115200;
/** UART data bits */
uint8_t busvoodoo_uart_databits = 8;
/** UART parity setting */
char busvoodoo_uart_parity= 'n';
/** UART stop bits (multiplied by 2) */
uint8_t busvoodoo_uart_stopbits = 2;
/** pin drive mode */
char busvoodoo_uart_drive = 'p';

/** setup UART mode
 *  @param[out] prefix terminal prompt prefix
 *  @param[in] line terminal prompt line to configure mode
 *  @return if setup is complete
 */
static bool busvoodoo_uart_setup(char** prefix, const char* line)
{
	bool complete = false; // is the setup complete
	static char config[39] = {0}; // configuration string used as prefix
	if (NULL==line) { // first call
		busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_NONE; // re-start configuration
	}
	switch (busvoodoo_uart_setting) {
		case BUSVOODOO_UART_SETTING_NONE:
			snprintf(config, LENGTH(config), "baud rate in bps (1-2000000) [%u]", busvoodoo_uart_baudrate);
			*prefix = config; // ask for baud rate
			busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_BAUDRATE;
			break;
		case BUSVOODOO_UART_SETTING_BAUDRATE:
			if (NULL==line || 0==strlen(line)) { // use default setting
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DATABITS; // go to next setting
			} else { // setting provided
				uint32_t baudrate = atoi(line); // parse setting
				if (baudrate>0 && baudrate<2000000) { // check setting
					busvoodoo_uart_baudrate = baudrate; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DATABITS; // go to next setting
				}
			}
			if (BUSVOODOO_UART_SETTING_DATABITS==busvoodoo_uart_setting) { // if next setting
				snprintf(config, LENGTH(config), "data bits (8-9) [%u]", busvoodoo_uart_databits); // prepare next setting
				*prefix = config; // display next setting
			}
			break;
		case BUSVOODOO_UART_SETTING_DATABITS:
			if (NULL==line || 0==strlen(line)) { // use default setting
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_PARITY; // go to next setting
			} else { // setting provided
				uint8_t databits = atoi(line); // parse setting
				if (8==databits || 9==databits) { // check setting
					busvoodoo_uart_databits = databits; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_PARITY; // go to next setting
				}
			}
			if (BUSVOODOO_UART_SETTING_PARITY==busvoodoo_uart_setting) { // if next setting
				snprintf(config, LENGTH(config), "parity (n,e,o) [%c]", busvoodoo_uart_parity); // prepare next setting
				*prefix = config; // display next setting
			}
			break;
		case BUSVOODOO_UART_SETTING_PARITY:
			if (NULL==line || 0==strlen(line)) { // use default setting
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_STOPBITS; // go to next setting
			} else { // setting provided
				if (0==strcmp("n", line) || 0==strcmp("e", line) || 0==strcmp("o", line)) { // check setting
					busvoodoo_uart_parity = line[0]; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_STOPBITS; // go to next setting
				}
			}
			if (BUSVOODOO_UART_SETTING_STOPBITS==busvoodoo_uart_setting) { // if next setting
				snprintf(config, LENGTH(config), "stop bits (0.5-2.0) [%.1f]", busvoodoo_uart_stopbits/2.0); // prepare next setting
				*prefix = config; // display next setting
			}
			break;
		case BUSVOODOO_UART_SETTING_STOPBITS:
			if (NULL==line || 0==strlen(line)) { // use default setting
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DRIVE; // go to next setting
			} else { // setting provided
				if (0==strcmp("0.5", line) || 0==strcmp(".5", line)) { // check setting
					busvoodoo_uart_stopbits = 1; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DRIVE; // go to next setting
				} else if (0==strcmp("1", line) || 0==strcmp("1.0", line)) { // check setting
					busvoodoo_uart_stopbits = 2; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DRIVE; // go to next setting
				} else if (0==strcmp("1.5", line)) { // check setting
					busvoodoo_uart_stopbits = 3; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DRIVE; // go to next setting
				} else if (0==strcmp("2", line) || 0==strcmp("2.0", line)) { // check setting
					busvoodoo_uart_stopbits = 4; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DRIVE; // go to next setting
				}
			}
			if (BUSVOODOO_UART_SETTING_DRIVE==busvoodoo_uart_setting) { // if next setting
				printf("p) push-pull (3.3V)\n");
				printf("o) open-drain (set lV do desired voltage), with embedded pull-up (2kO)\n");
				snprintf(config, LENGTH(config), "drive mode (p,o) [%c]", busvoodoo_uart_drive); // show drive mode
				*prefix = config; // display next setting
			}
			break;
		case BUSVOODOO_UART_SETTING_DRIVE:
			if (NULL==line || 0==strlen(line)) { // use default setting
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DONE; // go to next setting
			} else { // setting provided
				if (0==strcmp("p", line) || 0==strcmp("o", line)) { // check setting
					busvoodoo_uart_drive = line[0]; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DONE; // go to next setting
				}
			}
			if (BUSVOODOO_UART_SETTING_DONE==busvoodoo_uart_setting) { // we have all settings, configure UART
				rcc_periph_clock_enable(USART_RCC(BUSVOODOO_USART_ID)); // enable clock for USART peripheral
				usart_set_baudrate(USART(BUSVOODOO_USART_ID), busvoodoo_uart_baudrate); // set baud rate
				usart_set_databits(USART(BUSVOODOO_USART_ID), busvoodoo_uart_databits); // set data bits
				switch (busvoodoo_uart_parity) { // set parity
					case 'n':
						usart_set_parity(USART(BUSVOODOO_USART_ID), USART_PARITY_NONE);
						break;
					case 'e':
						usart_set_parity(USART(BUSVOODOO_USART_ID), USART_PARITY_EVEN);
						break;
					case 'o':
						usart_set_parity(USART(BUSVOODOO_USART_ID), USART_PARITY_ODD);
						break;
					default:
						usart_set_parity(USART(BUSVOODOO_USART_ID), USART_PARITY_NONE);
						break;
				}
				switch (busvoodoo_uart_stopbits) { // set stop bits
					case 1:
						usart_set_stopbits(USART(BUSVOODOO_USART_ID), USART_STOPBITS_0_5);
						break;
					case 2:
						usart_set_stopbits(USART(BUSVOODOO_USART_ID), USART_STOPBITS_1);
						break;
					case 3:
						usart_set_stopbits(USART(BUSVOODOO_USART_ID), USART_STOPBITS_1_5);
						break;
					case 4:
						usart_set_stopbits(USART(BUSVOODOO_USART_ID), USART_STOPBITS_2);
						break;
					default:
						usart_set_stopbits(USART(BUSVOODOO_USART_ID), USART_STOPBITS_1);
						break;
				}
				usart_set_flow_control(USART(BUSVOODOO_USART_ID), USART_FLOWCONTROL_NONE); // set hardware flow control
				usart_set_mode(USART(BUSVOODOO_USART_ID), USART_MODE_TX_RX); // full-duplex communication
				switch (busvoodoo_uart_drive) { // set drive mode
					case 'p':
						busvoodoo_embedded_pullup(false); // disable embedded pull-ups
						gpio_set_mode(USART_PORT(BUSVOODOO_USART_ID), GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, USART_PIN_TX(BUSVOODOO_USART_ID)); // setup GPIO pin USART transmit
						gpio_set_mode(USART_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, USART_PIN_RX(BUSVOODOO_USART_ID)); // setup GPIO pin USART receive
						gpio_set(USART_PORT(BUSVOODOO_USART_ID), USART_PIN_RX(BUSVOODOO_USART_ID)); // pull up to avoid noise when not connected
						break;
					case 'o':
						busvoodoo_embedded_pullup(true); // enable embedded pull-ups
						gpio_set_mode(USART_PORT(BUSVOODOO_USART_ID), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, USART_PIN_TX(BUSVOODOO_USART_ID)); // setup GPIO pin USART transmit
						gpio_set_mode(USART_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_PIN_RX(BUSVOODOO_USART_ID)); // setup GPIO pin USART receive
						break;
				}
				usart_enable(USART(BUSVOODOO_USART_ID)); // enable USART
				printf("I/O pinout:\n");
				printf("+-----    -------+\n");
				printf("|xx xx RX 3V3 GND|\n");
				printf("|xx xx TX lV  5V |\n");
				printf("+----------------+\n");
				led_off(); // disable LED because there is no activity
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_NONE; // restart settings next time
				*prefix = "UART"; // display mode
				busvoodoo_oled_text_left("UART"); // set mode title on OLED display
				const char* pins[10] = {NULL, NULL, "Rx", "5V", "GND", NULL, NULL, "Tx", "lV", "3V3"}; // UART without flow control mode pinout
				busvoodoo_oled_text_pinout(pins, true); // set pinout on display
				busvoodoo_oled_update(); // update display to show text and pinout
				complete = true; // configuration is complete
			}
			break;
		default: // unknown case
			busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_NONE; // restart settings next time
			break;
	}
	return complete;
}

/** exit UART mode
 */
static void busvoodoo_uart_exit(void)
{
	usart_disable(USART(BUSVOODOO_USART_ID)); // disable USART
	rcc_periph_clock_enable(USART_RCC(BUSVOODOO_USART_ID)); // disable domain clock
	gpio_set_mode(USART_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_PIN_TX(BUSVOODOO_USART_ID)); // set pin back to floating input
	gpio_set_mode(USART_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_PIN_RX(BUSVOODOO_USART_ID)); // set pin back to floating input
	busvoodoo_embedded_pullup(false); // disable embedded pull-ups
}

// command handlers

/** command to transmit a word
 *  @param[in] argument word to transmit
 */
static void busvoodoo_uart_command_transmit(void* argument)
{
	if (NULL==argument || 0==strlen(argument)) { // nothing to transmit
		return;
	}
	uint16_t i=0;
	while (((char*)(argument))[i]) { // go through word to send
		usart_send_blocking(USART(BUSVOODOO_USART_ID), ((char*)(argument))[i++]); // send character
		busvoodoo_led_red(100); // enable red LED to show transmission
	}
}

/** command to receive data
 *  @param[in] argument no argument required
 */
static void busvoodoo_uart_command_receive(void* argument)
{
	(void)argument; // we won't use the argument
	printf("press any key to exit\n");
	while (!user_input_available) { // check for user input to exit
		if ((USART_SR(USART(BUSVOODOO_USART_ID)) & USART_SR_RXNE)) { // verify if data has been received
			char c = usart_recv(USART(BUSVOODOO_USART_ID)); // receive character
			busvoodoo_led_blue(100); // enable blue LED to show reception
			printf("%c", c); // print received character
		}
	}
	user_input_get(); // discard user input
	printf("\n"); // get to next line
}

/** command to transmit and receive data
 *  @param[in] argument no argument required
 */
static void busvoodoo_uart_command_transceive(void* argument)
{
	(void)argument; // we won't use the argument
	printf("press 5 times escape to exit\n");
	char last_c = 0; // last user character received
	uint8_t esc_count = 0; // number of times escape has press received
	while (esc_count<5) { // check for escape sequence
		if (user_input_available) { // check if user wants to transmit something
			char c = user_input_get(); // get user input
			if (0x1b==c) { // user pressed escape
				if (0x1b!=last_c) { // this is the first escape press
					esc_count = 0;
				}
				esc_count++; // increment escape count
			}
			last_c = c; // remember key press
			usart_send_blocking(USART(BUSVOODOO_USART_ID), c); // send user character
			busvoodoo_led_red(100); // enable red LED to show transmission
		}
		if ((USART_SR(USART(BUSVOODOO_USART_ID)) & USART_SR_RXNE)) { // verify if data has been received
			char c = usart_recv(USART(BUSVOODOO_USART_ID)); // receive character
			busvoodoo_led_blue(100); // enable blue LED to show reception
			printf("%c", c); // print received character
		}
	}
	printf("\n"); // get to next line
}

static const struct menu_command_t busvoodoo_uart_commands[] = {
	{
		'r',
		"receive",
		"show incoming data",
		MENU_ARGUMENT_NONE,
		NULL,
		&busvoodoo_uart_command_receive,
	},
	{
		't',
		"transmit",
		"transmit word",
		MENU_ARGUMENT_STRING,
		"word",
		&busvoodoo_uart_command_transmit,
	},
	{
		'x',
		"transceive",
		"transmit and receive data",
		MENU_ARGUMENT_NONE,
		NULL,
		&busvoodoo_uart_command_transceive,
	},
};

struct busvoodoo_mode_t busvoodoo_uart_mode = {
	"uart",
	"Universal Asynchronous Receiver-Transmitter",
	&busvoodoo_uart_setup,
	busvoodoo_uart_commands,
	LENGTH(busvoodoo_uart_commands),
	&busvoodoo_uart_exit,
};