stm32f1/lib/busvoodoo_uart.c

/* 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_HWFLOWCTL,
	BUSVOODOO_UART_SETTING_DRIVE,
	BUSVOODOO_UART_SETTING_DONE,
} busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_NONE; /**< current mode setup stage */
/** UART baud rate (in bps) */
static uint32_t busvoodoo_uart_baudrate = 115200;
/** UART data bits */
static uint8_t busvoodoo_uart_databits = 8;
/** UART parity setting */
static uint32_t busvoodoo_uart_parity = USART_PARITY_NONE;
/** UART stop bits setting */
static uint32_t busvoodoo_uart_stopbits = USART_STOPBITS_1;
/** UART hardware flow control setting (true = with hardware flow control, false = without hardware flow control */
static bool busvoodoo_uart_hwflowctl = false;
/** pin drive mode (true = push-pull, false = open-drain) */
static bool busvoodoo_uart_drive = true;
/** if embedded pull-up resistors are used */
static bool busvoodoo_uart_pullup = false;

/** 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
	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(busvoodoo_global_string, LENGTH(busvoodoo_global_string), "baud rate in bps (1-2000000) [%u]", busvoodoo_uart_baudrate);
			*prefix = busvoodoo_global_string; // 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(busvoodoo_global_string, LENGTH(busvoodoo_global_string), "data bits (8-9) [%u]", busvoodoo_uart_databits); // prepare next setting
				*prefix = busvoodoo_global_string; // 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
				printf("1) none\n");
				printf("2) even\n");
				printf("3) odd\n");
				snprintf(busvoodoo_global_string, LENGTH(busvoodoo_global_string), "parity (1,2,3) [%c]", USART_PARITY_NONE==busvoodoo_uart_parity ? '1' : (USART_PARITY_EVEN==busvoodoo_uart_parity ? '2' : '3')); // prepare next setting
				*prefix = busvoodoo_global_string; // 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 if (1==strlen(line)) { // setting provided
				if ('1'==line[0]) { // no parity
					busvoodoo_uart_parity = USART_PARITY_NONE;
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_STOPBITS; // go to next setting
				} else if ('2'==line[0]) { // even parity
					busvoodoo_uart_parity = USART_PARITY_EVEN;
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_STOPBITS; // go to next setting
				} else if ('3'==line[0]) { // odd parity
					busvoodoo_uart_parity = USART_PARITY_ODD;
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_STOPBITS; // go to next setting
				}
			}
			if (BUSVOODOO_UART_SETTING_STOPBITS==busvoodoo_uart_setting) { // if next setting
				printf("1) 0.5\n");
				printf("2) 1\n");
				printf("3) 1.5\n");
				printf("4) 2\n");
				snprintf(busvoodoo_global_string, LENGTH(busvoodoo_global_string), "stop bits (1,2,3,4) [%s]", USART_STOPBITS_0_5==busvoodoo_uart_stopbits ? "0.5" : (USART_STOPBITS_1==busvoodoo_uart_stopbits ? "1" : (USART_STOPBITS_1_5==busvoodoo_uart_stopbits ? "1.5" : "2.0"))); // prepare next setting
				*prefix = busvoodoo_global_string; // display next setting
			}
			break;
		case BUSVOODOO_UART_SETTING_STOPBITS:
			if (NULL==line || 0==strlen(line)) { // use default setting
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_HWFLOWCTL; // go to next setting
			} else if (1==strlen(line)) { // setting provided
				if ('1'==line[0]) { // 0.5 stop bits
					busvoodoo_uart_stopbits = USART_STOPBITS_0_5; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_HWFLOWCTL; // go to next setting
				} else if ('2'==line[0]) { // 1 stop bits
					busvoodoo_uart_stopbits = USART_STOPBITS_1; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_HWFLOWCTL; // go to next setting
				} else if ('3'==line[0]) { // 1.5 stop bits
					busvoodoo_uart_stopbits = USART_STOPBITS_1_5; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_HWFLOWCTL; // go to next setting
				} else if ('4'==line[0]) { // 2 stop bits
					busvoodoo_uart_stopbits = USART_STOPBITS_2; // remember setting
					busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_HWFLOWCTL; // go to next setting
				}
			}
			if (BUSVOODOO_UART_SETTING_HWFLOWCTL==busvoodoo_uart_setting) { // if next setting
				printf("1) no flow control\n");
				printf("2) RTS/CTS hardware flow control\n");
				snprintf(busvoodoo_global_string, LENGTH(busvoodoo_global_string), "flow control (1,2) [%c]", busvoodoo_uart_hwflowctl ? '2' : '1'); // prepare next setting
				*prefix = busvoodoo_global_string; // display next setting
			}
			break;
		case BUSVOODOO_UART_SETTING_HWFLOWCTL:
			if (NULL==line || 0==strlen(line)) { // use default setting
				busvoodoo_uart_setting = BUSVOODOO_UART_SETTING_DRIVE; // go to next setting
			} else if (1==strlen(line)) { // setting provided
				if ('1'==line[0] || '2'==line[0]) { // setting provided
					busvoodoo_uart_hwflowctl = ('2'==line[0]); // 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("1) push-pull (3.3V)\n");
				printf("2) open-drain, with embedded pull-up resistors (2kO)\n");
				printf("3) open-drain, with external pull-up resistors\n");
				snprintf(busvoodoo_global_string, LENGTH(busvoodoo_global_string), "drive mode (1,2,3) [%c]", busvoodoo_uart_drive ? '1' : (busvoodoo_uart_pullup ? '2' : '3')); // show drive mode
				*prefix = busvoodoo_global_string; // 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 if (1==strlen(line)) { // setting provided
				uint8_t drive = atoi(line); // parse setting
				if (1==drive || 2==drive || 3==drive) { // check setting
					busvoodoo_uart_drive = (1==drive); // remember setting
					busvoodoo_uart_pullup = (2==drive); // 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(RCC_AFIO); // enable clock for USART alternate function
				rcc_periph_clock_enable(RCC_USART(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
				usart_set_parity(USART(BUSVOODOO_USART_ID), busvoodoo_uart_parity); // set parity
				usart_set_stopbits(USART(BUSVOODOO_USART_ID), busvoodoo_uart_stopbits); // set stop bits
				if (busvoodoo_uart_hwflowctl) {
					usart_set_flow_control(USART(BUSVOODOO_USART_ID), USART_FLOWCONTROL_RTS_CTS); // set RTS/CTS flow control
				} else {
					usart_set_flow_control(USART(BUSVOODOO_USART_ID), USART_FLOWCONTROL_NONE); // set no flow control
				}
				usart_set_mode(USART(BUSVOODOO_USART_ID), USART_MODE_TX_RX); // full-duplex communication
				rcc_periph_clock_enable(RCC_USART_PORT(BUSVOODOO_USART_ID)); // enable clock for USART GPIO peripheral
				if (busvoodoo_uart_drive) { // use push-pull drive mode
					gpio_set_mode(USART_TX_PORT(BUSVOODOO_USART_ID), GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, USART_TX_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART transmit
					gpio_set(USART_RX_PORT(BUSVOODOO_USART_ID), USART_RX_PIN(BUSVOODOO_USART_ID)); // pull up to avoid noise when not connected
					gpio_set_mode(USART_RX_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, USART_RX_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART receive
					if (busvoodoo_uart_hwflowctl) { // use open drain drive mode
						gpio_set_mode(USART_RTS_PORT(BUSVOODOO_USART_ID), GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, USART_RTS_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART transmit
						gpio_set(USART_CTS_PORT(BUSVOODOO_USART_ID), USART_CTS_PIN(BUSVOODOO_USART_ID)); // pull up to block transmission unless requested
						gpio_set_mode(USART_CTS_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, USART_CTS_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART receive
					}
				} else {
					gpio_set_mode(USART_TX_PORT(BUSVOODOO_USART_ID), GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, USART_TX_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART transmit
					gpio_set_mode(USART_RX_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_RX_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART receive
					if (busvoodoo_uart_hwflowctl) {
						gpio_set_mode(USART_RTS_PORT(BUSVOODOO_USART_ID), GPIO_MODE_OUTPUT_10_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, USART_RTS_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART transmit
						gpio_set_mode(USART_CTS_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_CTS_PIN(BUSVOODOO_USART_ID)); // setup GPIO pin USART receive
					}
				}
				if (!busvoodoo_uart_drive && busvoodoo_uart_pullup) { // enable embedded pull-ups if used
					busvoodoo_embedded_pullup(true); // set embedded pull-ups
					printf("use LV to set pull-up voltage\n");
				}
				usart_enable(USART(BUSVOODOO_USART_ID)); // enable USART
				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(*prefix); // set mode title on OLED display
				char* pinout_io[10] = {"GND", "5V", "3V3", "LV", "Rx", "Tx", NULL, NULL, NULL, NULL}; // UART mode pinout
				if (busvoodoo_uart_hwflowctl) { // hardware flow control is used
					pinout_io[6] = "RTS"; // update pin name
					pinout_io[7] = "CTS"; // update pin name
				}
				for (uint8_t i=0; i<LENGTH(pinout_io) && i<LENGTH(busvoodoo_global_pinout_io); i++) {
					busvoodoo_global_pinout_io[i] = pinout_io[i]; // set pin names
				}
				busvoodoo_oled_text_pinout((const char**)pinout_io, 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_disable(RCC_USART(BUSVOODOO_USART_ID)); // disable domain clock
	gpio_set_mode(USART_TX_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_TX_PIN(BUSVOODOO_USART_ID)); // set pin back to floating input
	gpio_set_mode(USART_RX_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_RX_PIN(BUSVOODOO_USART_ID)); // set pin back to floating input
	gpio_set_mode(USART_RTS_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_RTS_PIN(BUSVOODOO_USART_ID)); // set pin back to floating input
	gpio_set_mode(USART_CTS_PORT(BUSVOODOO_USART_ID), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, USART_CTS_PIN(BUSVOODOO_USART_ID)); // set pin back to floating input
	busvoodoo_embedded_pullup(false); // disable embedded pull-ups
}

// command handlers

/** command to transmit a string
 *  @param[in] argument string to transmit (CR+LF when none provided)
 */
static void busvoodoo_uart_command_transmit(void* argument)
{
	if (NULL==argument || 0==strlen(argument)) { // nothing to transmit
		argument = "\r\n"; // transmit CR+LF
	}
	printf("press any key to exit\n");
	for (uint16_t i=0; ((char*)(argument))[i] && !user_input_available; i++) {
		while ((0==(USART_SR(USART(BUSVOODOO_USART_ID)) & USART_SR_TXE) && !user_input_available)); // wait for transmit buffer to be empty
		if (USART_SR(USART(BUSVOODOO_USART_ID)) & USART_SR_TXE) { // we can send a character
			printf("%c", ((char*)(argument))[i]); // echo character to transmit
			busvoodoo_led_red_pulse(BUSVOODOO_LED_PULSE); // pulse red LED to show transmission
			usart_send(USART(BUSVOODOO_USART_ID), ((char*)(argument))[i]); // transmit character
		}
	}
	if (user_input_available) { // user interrupted flow
		user_input_get(); // discard user input
	}
	if (strcmp(argument, "\r\n")) {
		printf("\n");
	}
}

/** 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_pulse(BUSVOODOO_LED_PULSE); // 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_pulse(BUSVOODOO_LED_PULSE); // 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_pulse(BUSVOODOO_LED_PULSE); // enable blue LED to show reception
			printf("%c", c); // print received character
		}
	}
	printf("\n"); // get to next line
}

/** UART menu commands */
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 ASCII text (empty for CR+LF)",
		MENU_ARGUMENT_STRING,
		"[text]",
		&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,
};