/* 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 global definitions and methods (code)
 *  @file busvoodoo_global.c
 *  @author King Kévin <kingkevin@cuvoodoo.info>
 *  @date 2018
 */

/* standard libraries */
#include <stdint.h> // standard integer types
#include <math.h> // math 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/adc.h> // ADC utilities
#include <libopencm3/stm32/dac.h> // DAC utilities

/* own libraries */
#include "global.h" // board definitions
#include "busvoodoo_global.h" // BusVoodoo definitions

const char* busvoodoo_io_names[13] = {"I2C_SMBA/SPI_NSS/I2S_WS", "SDIO_CMD", "USART_CTS/SPI_SCK/I2S_CK", "SDIO_D3/UART_RX", "I2C_SDA/USART_RX", "SDIO_D0", "SPI_MOSI/I2S_SD", "SDIO_CK/USART_CK", "I2C_SCL/USART_TX", "SDIO_D1", "I2S_MCK", "USART_RTS/SPI_MISO", "SDIO_D2/UART_TX"};
const uint32_t busvoodoo_io_ports[13] = {GPIOB, GPIOD, GPIOB, GPIOC, GPIOB, GPIOC, GPIOB, GPIOC, GPIOB, GPIOC, GPIOC, GPIOB, GPIOC};
const uint32_t busvoodoo_io_pins[13] = {GPIO12, GPIO2, GPIO13, GPIO11, GPIO11, GPIO8, GPIO15, GPIO12, GPIO10, GPIO9, GPIO6, GPIO14, GPIO10};
const uint8_t busvoodoo_io_groups[13] = {6, 6, 4, 4, 1, 1, 5, 5, 2, 2, 3, 3, 3};

bool busvoodoo_full = false;

void busvoodoo_setup(void)
{
	// enable all GPIO domains since we use pins on all ports
	rcc_periph_clock_enable(RCC_GPIOA); // enable clock for all GPIO domains
	rcc_periph_clock_enable(RCC_GPIOB); // enable clock for all GPIO domains
	rcc_periph_clock_enable(RCC_GPIOC); // enable clock for all GPIO domains
	rcc_periph_clock_enable(RCC_GPIOD); // enable clock for all GPIO domains
	busvoodoo_safe_state(); // switch off all outputs

	// check if this BusVoodoo is a full version
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_12V_CHANNEL)); // enable clock for GPIO domain for 12V channel
	gpio_set(ADC12_IN_PORT(BUSVOODOO_12V_CHANNEL), ADC12_IN_PIN(BUSVOODOO_12V_CHANNEL)); // pull ADC 12V high
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_12V_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, ADC12_IN_PIN(BUSVOODOO_12V_CHANNEL)); // set 12V channel as digital input with pull-up capabilities
	// on a full version (fully populated board) the ADC 12V signal will be pulled low
	if (gpio_get(ADC12_IN_PORT(BUSVOODOO_12V_CHANNEL), ADC12_IN_PIN(BUSVOODOO_12V_CHANNEL))) { // check is ADC 12V is pulled low
		busvoodoo_full = false;
	} else {
		busvoodoo_full = true;
	}

	// setup ADC to measure the 5V, 3.3V, xV, and 12V power rails voltages
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_5V_CHANNEL)); // enable clock for GPIO domain for 5V channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_5V_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_5V_CHANNEL)); // set 5V channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_3V3_CHANNEL)); // enable clock for GPIO domain for 3.3V channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_3V3_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_3V3_CHANNEL)); // set 3.3V channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_XV_CHANNEL)); // enable clock for GPIO domain for xV channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_XV_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_XV_CHANNEL)); // set xV channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC12_IN(BUSVOODOO_12V_CHANNEL)); // enable clock for GPIO domain for 12V channel
	gpio_set_mode(ADC12_IN_PORT(BUSVOODOO_12V_CHANNEL), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, ADC12_IN_PIN(BUSVOODOO_12V_CHANNEL)); // set 12V channel as analogue input for the ADC
	rcc_periph_clock_enable(RCC_ADC1); // enable clock for ADC domain
	adc_off(ADC1); // switch off ADC while configuring it
	adc_set_sample_time_on_all_channels(ADC1, ADC_SMPR_SMP_28DOT5CYC); // use 28.5 cycles to sample (long enough to be stable)
	adc_enable_temperature_sensor(ADC1); // enable internal voltage reference
	adc_enable_external_trigger_regular(ADC1, ADC_CR2_EXTSEL_SWSTART); // use software trigger to start conversion
	uint8_t channels[] = {ADC_CHANNEL17, ADC_CHANNEL(BUSVOODOO_5V_CHANNEL), ADC_CHANNEL(BUSVOODOO_3V3_CHANNEL), ADC_CHANNEL(BUSVOODOO_XV_CHANNEL), ADC_CHANNEL(BUSVOODOO_12V_CHANNEL)}; // voltages to convert: internal, 5V, 3.3V, xV, 12V
	adc_set_regular_sequence(ADC1, LENGTH(channels), channels); // set channels to convert
	adc_enable_discontinuous_mode_regular(ADC1, LENGTH(channels)); // convert all channels	
	adc_power_on(ADC1); // switch on ADC
	sleep_us(1); // wait t_stab for the ADC to stabilize
	adc_reset_calibration(ADC1); // remove previous non-calibration
	adc_calibration(ADC1); // calibrate ADC for less accuracy errors

	// setup DAC to control xV and 12V voltage outputs
	gpio_set_mode(GPIO(BUSVOODOO_XVCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_XVCTL_PIN)); // set xV pin as analog (the DAC will use it as output)
	rcc_periph_clock_enable(RCC_DAC); // enable clock for DAC domain
	dac_disable(BUSVOODOO_XVCTL_CHANNEL); // disable output to configure it properly
	dac_buffer_enable(BUSVOODOO_XVCTL_CHANNEL); // enable output buffer to be able to drive larger loads (should be per default)
	if (busvoodoo_full) {
		gpio_set_mode(GPIO(BUSVOODOO_12VCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_12VCTL_PIN)); // set 12V pin as analog (the DAC will use it as output)
		dac_disable(BUSVOODOO_12VCTL_CHANNEL); // disable output to configure it properly
		dac_buffer_enable(BUSVOODOO_12VCTL_CHANNEL); // enable output buffer to be able to drive larger loads (should be per default)
	}
	dac_set_trigger_source(DAC_CR_TSEL1_SW); // use software to trigger the voltage change
	dac_set_trigger_source(DAC_CR_TSEL2_SW); // use software to trigger the voltage change
}

void busvoodoo_safe_state(void)
{
	// disable voltage outputs
	gpio_set(GPIO(BUSVOODOO_VOUTEN_PORT), GPIO(BUSVOODOO_VOUTEN_PIN)); // disable 5V and 3.3V output on connector
	gpio_set_mode(GPIO(BUSVOODOO_VOUTEN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_VOUTEN_PIN)); // set pin as output (open-drain pulled high to disable the pMOS)
	gpio_clear(GPIO(BUSVOODOO_XVEN_PORT), GPIO(BUSVOODOO_XVEN_PIN)); // disable xV voltage regulator
	gpio_set_mode(GPIO(BUSVOODOO_XVEN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO(BUSVOODOO_XVEN_PIN)); // set pin as output (push-pull, pulled low for safety)
	gpio_set(GPIO(BUSVOODOO_12VEN_PORT), GPIO(BUSVOODOO_12VEN_PIN)); // disable 12V voltage regulator
	gpio_set_mode(GPIO(BUSVOODOO_12VEN_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_12VEN_PIN)); // set pin as output (open-drain pulled high to disable the pMOS)

	// set DAC channel back to analog
	gpio_set_mode(GPIO(BUSVOODOO_XVCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_XVCTL_PIN)); // set xV pin as analog
	gpio_set_mode(GPIO(BUSVOODOO_12VCTL_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_ANALOG, GPIO(BUSVOODOO_12VCTL_PIN)); // set 12V pin as analog

	// disable embedded pull-ups
	gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON, 0); // disable JTAG (but keep SWD) so to use the underlying GPIOs (PA15, PB3, PB4)
	gpio_set(GPIO(BUSVOODOO_5VPULLUP_PORT), GPIO(BUSVOODOO_5VPULLUP_PIN)); // set pin high to disable 5V embedded pull-up
	gpio_set_mode(GPIO(BUSVOODOO_5VPULLUP_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_5VPULLUP_PIN)); // set pin as output (open-drain pulled high to disable the pMOS)
	gpio_set(GPIO(BUSVOODOO_OEPULLUP_PORT), GPIO(BUSVOODOO_OEPULLUP_PIN)); // set pin high to disable embedded pull-up bus switch
	gpio_set_mode(GPIO(BUSVOODOO_OEPULLUP_PORT), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO(BUSVOODOO_OEPULLUP_PIN)); // set pin as output (open-drain pulled high to disable the bus switch)

	// disable all signal I/O outputs
	for (uint8_t pin=0; pin<LENGTH(busvoodoo_io_ports) && pin<LENGTH(busvoodoo_io_pins); pin++) {
		gpio_set_mode(busvoodoo_io_ports[pin], GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, busvoodoo_io_pins[pin]); // set pin back to input (floating)
	}

	// disable all RS-232 and some RS-485 signals (put back to input floating)
	gpio_set_mode(GPIO(BUSVOODOO_RS232_TX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_TX_PIN));
	gpio_set_mode(GPIO(BUSVOODOO_RS232_RX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_RX_PIN));
	gpio_set_mode(GPIO(BUSVOODOO_RS232_RTS_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_RTS_PIN));
	gpio_set_mode(GPIO(BUSVOODOO_RS232_CTS_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_RS232_CTS_PIN));
	gpio_set(GPIO(BUSVOODOO_RS232_EN_PORT), GPIO(BUSVOODOO_RS232_EN_PIN)); // set high to disable receiver
	gpio_clear(GPIO(BUSVOODOO_RS232_SHDN_PORT), GPIO(BUSVOODOO_RS232_SHDN_PIN)); // set low to disable transmitter

	// disable all CAN and some RS-458 signals (put back to input floating)
	gpio_set_mode(GPIO(BUSVOODOO_CAN_TX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_CAN_TX_PIN));
	gpio_set_mode(GPIO(BUSVOODOO_CAN_RX_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_CAN_RX_PIN));
	gpio_set_mode(GPIO(BUSVOODOO_CAN_EN_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_CAN_EN_PIN));
	gpio_set_mode(GPIO(BUSVOODOO_CAN_S_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO(BUSVOODOO_CAN_S_PIN));
}

float busvoodoo_vreg_get(uint8_t channel)
{
	if (channel!=BUSVOODOO_5V_CHANNEL && channel!=BUSVOODOO_3V3_CHANNEL && channel!=BUSVOODOO_XV_CHANNEL && channel!=BUSVOODOO_12V_CHANNEL) { // check channel
		return NAN;
	}
	uint16_t channels[5] = {0}; // to start converted values: internal reference 1.2V, 5V rail, 3.3V rail, xV rail, 12V rail
	adc_start_conversion_regular(ADC1); // start conversion to get first voltage
	for  (uint8_t channel_i=0; channel_i<LENGTH(channels); channel_i++) { // get all conversions
		while (!adc_eoc(ADC1)); // wait until conversion finished
		channels[channel_i] = adc_read_regular(ADC1); // read voltage value (clears flag)
	}
	float to_return = NAN; // voltage to return
	switch (channel) { // get converter value and calculate according to the voltage divider on this channel
		case BUSVOODOO_5V_CHANNEL:
			to_return = channels[1]/(10.0/(10.0+10.0));
			break;
		case BUSVOODOO_3V3_CHANNEL:
			to_return = channels[2]/(10.0/(10.0+10.0));
			break;
		case BUSVOODOO_XV_CHANNEL:
			to_return = channels[3]/(10.0/(10.0+10.0));
			break;
		case BUSVOODOO_12V_CHANNEL:
			to_return = channels[4]/(1.5/(10.0+1.5));
			break;
		default: // unknown channel
			to_return = NAN;
			break;
	}
	if (!isnan(to_return)) {
		to_return *= 1.2/channels[0]; // calculate voltage from converted values using internal 1.2V voltage reference
	}
	return to_return;
}

float busvoodoo_vreg_set(uint8_t channel, float voltage)
{
	if (channel!=BUSVOODOO_XV_CHANNEL && channel!=BUSVOODOO_12V_CHANNEL) { // check channel
		return NAN;
	}
	if (BUSVOODOO_12V_CHANNEL==channel && !busvoodoo_full) { // the 12V voltage regulator is only present on the full version
		return NAN;
	}

	float volt = NAN; // common variable for voltages
	if (BUSVOODOO_XV_CHANNEL==channel) { // set voltage on xV low drop-out voltage regulator
		if (voltage<=0.0) { // disable voltage regulator
			gpio_clear(GPIO(BUSVOODOO_XVEN_PORT), GPIO(BUSVOODOO_XVEN_PIN)); // disable xV voltage regulator
			dac_disable(BUSVOODOO_XVCTL_CHANNEL); // disable xV control
		} else { // enable voltage regulator
			if (voltage>4.5) { // enforce upper voltage limit (5.0V rail minus LDO and diodes)
				voltage = 4.5;
			}	
			volt = busvoodoo_vreg_get(BUSVOODOO_3V3_CHANNEL); // get reference voltage
			if (isnan(voltage)) {
				return NAN;
			}
			uint16_t dac_set = BUSVOODOO_XV_SET(voltage)/volt*4095; // DAC value corresponding to the voltage
			dac_load_data_buffer_single(dac_set, RIGHT12, BUSVOODOO_XVCTL_CHANNEL); // set output so the voltage regulator is set to 2.5V
			dac_software_trigger(BUSVOODOO_XVCTL_CHANNEL); // transfer the value to the DAC
			dac_enable(BUSVOODOO_XVCTL_CHANNEL); // enable DAC
			gpio_set(GPIO(BUSVOODOO_XVEN_PORT), GPIO(BUSVOODOO_XVEN_PIN)); // enable xV voltage regulator
		}
		sleep_ms(5); // let voltage settle
		volt = busvoodoo_vreg_get(BUSVOODOO_XV_CHANNEL); // get xV voltage to return
	} else if (BUSVOODOO_12V_CHANNEL==channel && busvoodoo_full) {// set voltage on 12V boost voltage regulator
		if (voltage<=0.0) { // disable voltage regulator
			gpio_set(GPIO(BUSVOODOO_12VEN_PORT), GPIO(BUSVOODOO_12VEN_PIN)); // disable 12V voltage regulator
			    dac_disable(BUSVOODOO_12VCTL_CHANNEL); // disable 12V control
		} else {
			if (voltage>24.0) { // enforce upper voltage limit (diodes limit is 30V, ADC input limit is 25V)
				voltage = 24.0;
			}
			volt = busvoodoo_vreg_get(BUSVOODOO_3V3_CHANNEL); // get reference voltage
			if (isnan(voltage)) {
				return NAN;
			}
			uint16_t dac_set = BUSVOODOO_12V_SET(voltage)/volt*4095; // DAC value corresponding to the voltage
			dac_load_data_buffer_single(dac_set, RIGHT12, BUSVOODOO_12VCTL_CHANNEL); // set output so the voltage regulator is set to desired output voltage
			dac_software_trigger(BUSVOODOO_12VCTL_CHANNEL); // transfer the value to the DAC
			dac_enable(BUSVOODOO_12VCTL_CHANNEL); // enable DAC
			gpio_clear(GPIO(BUSVOODOO_12VEN_PORT), GPIO(BUSVOODOO_12VEN_PIN)); // enable 12V voltage regulator
		}
		sleep_ms(10); // let the voltage regulator start and voltage settle
		volt = busvoodoo_vreg_get(BUSVOODOO_12V_CHANNEL); // get 12V voltage
	} else { // don't know about other voltage regulators
		volt = NAN;
	}

	return volt; // return measured voltage
}