/*
 * Main firmware program for the sysmocom rfdsatt-4ch (RF digital step attenuator; 4 channel)
 *
 * Copyright (C) 2021 Harald Welte <laforge@osmocom.org>
 *
 * This library 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 library 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 library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/usart.h>
#include <libopencm3/stm32/i2c.h>
#include <libopencm3/stm32/desig.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/cm3/scb.h>
#include <libopencm3/cm3/systick.h>

#include <librfn/time.h>

#include <libcommon/iob.h>
#include <libcommon/microvty.h>

#include <stdio.h>
#include <stdlib.h>

#include "attenuator.h"
#include "misc.h"

static uint32_t last_reset_cause;

extern const struct attenuator_cfg board_att_cfg;
extern struct attenuator_state *board_att_st[];

/* busy wait specified number of ms */
void msleep(uint32_t delay)
{
	uint32_t wake = time_now() + delay;
	do {
	} while (wake > time_now());
}

/***********************************************************************
 * hardware initialization
 ***********************************************************************/

static void clock_setup(void)
{
	rcc_clock_setup_pll(&rcc_hsi_configs[RCC_CLOCK_HSI_48MHZ]);
	/* HCLK=48MHz; ADC=6MHz; APB1=24MHz; APB2=48MHz; USB=48MHz */

	/* tick rate of 1ms */

	/* Enable GPIOC clock. */
	rcc_periph_clock_enable(RCC_GPIOA);
	rcc_periph_clock_enable(RCC_GPIOB);
	rcc_periph_clock_enable(RCC_GPIOC);

	/* Enable clocks for USARTs */
	rcc_periph_clock_enable(RCC_USART1);
	rcc_periph_clock_enable(RCC_USART2);
}

static void i2c_setup(void)
{
	rcc_periph_clock_enable(RCC_I2C1);

#ifdef STM32F1
	gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ,
		      GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN,
		      GPIO_I2C1_SCL | GPIO_I2C1_SDA);
#else
	gpio_set_af(GPIOB, GPIO_AF1, GPIO8 | GPIO9);
#endif

	/* disable before making config changes */
	i2c_peripheral_disable(I2C1);

#ifdef STM32F1
	/* APB1 runs at 24 MHz */
	i2c_set_clock_frequency(I2C1, 24);
#endif

	/* 400 kHz fast mode I2C */
	i2c_set_speed(I2C1, i2c_speed_fm_400k, 24);

	//...

	i2c_peripheral_enable(I2C1);
}

static void usart_setup(void)
{
	/* USART1: connected to debug header */

	/* Setup GPIO pin GPIO_USART1_TX. */
#ifdef STM32F1
	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
		      GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
#else
	gpio_set_af(GPIOA, GPIO_AF1, GPIO9 | GPIO10);
#endif
	/* Setup UART parameters. */
	usart_set_baudrate(USART1, 115200);
	usart_set_databits(USART1, 8);
	usart_set_stopbits(USART1, USART_STOPBITS_1);
	usart_set_mode(USART1, USART_MODE_TX_RX);
	usart_set_parity(USART1, USART_PARITY_NONE);
	usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
	/* Finally enable the USART. */
	usart_enable(USART1);

	/* USART2: connected to 2.5mm stereo jack */

	/* Setup GPIO pin GPIO_USART2_TX. */
#ifdef STM32F1
	gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
		      GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
#else
	gpio_set_af(GPIOA, GPIO_AF1, GPIO2 | GPIO13);
#endif
	/* Setup UART parameters. */
	usart_set_baudrate(USART2, 115200);
	usart_set_databits(USART2, 8);
	usart_set_stopbits(USART2, USART_STOPBITS_1);
	usart_set_mode(USART2, USART_MODE_TX_RX);
	usart_set_parity(USART2, USART_PARITY_NONE);
	usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
	/* Finally enable the USART. */
	usart_enable(USART2);
}

static void gpio_setup(void)
{
#ifdef STM32F1
	/* Set GPIO15 (in GPIO port B) to 'output push-pull'. */
	gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,
		      GPIO_CNF_OUTPUT_PUSHPULL, GPIO15);
#else
	gpio_mode_setup(GPIOB, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO15);
#endif
}

/***********************************************************************
 * uVTY interface
 ***********************************************************************/

DEFUN(reset, reset_cmd, "reset", "Reset the board")
{
	scb_reset_system();
}

DEFUN(uuid, uuid_cmd, "uuid", "Get the unique ID")
{
	char uuid[4*3*2+1];
	desig_get_unique_id_as_string(uuid, sizeof(uuid));
	printf("UUID: %s\r\n", uuid);
}

DEFUN(version, version_cmd, "version", "Get the firmware version")
{
	printf("Firmware Version: %s\r\n", GIT_VERSION);
}

DEFUN(att_set, att_set_cmd, "attenuator-set",
	"Set an attenuator (channel, stage, dB)")
{
	int channel, stage, dB;
	int rc;

	if (argc < 3) {
		printf("You muts specify three arguments (channel, stage, db)\r\n");
		return;
	}
	channel = atoi(argv[1]);
	stage = atoi(argv[2]);
	dB = atoi(argv[3]);

	printf("Setting attenuator channel %d stage %d to %d dB...\r\n", channel, stage, dB);

	rc = attenuator_set(channel, stage, dB*4);
	if (rc < 0)
		printf("Error setting attenuator: %d\r\n", rc);
}

/***********************************************************************
 * main
 ***********************************************************************/

static void print_banner(void)
{
	char uuid[4*3*2+1];
	desig_get_unique_id_as_string(uuid, sizeof(uuid));

	printf("\r\n======================================================================\r\n");
	printf("sysmocom RFDSATT main (build %s)\r\n", GIT_VERSION);
	printf("UUID: %s\r\n", uuid);
	printf("Reset cause(s): 0x%08lx\r\n", last_reset_cause);
	printf("======================================================================\r\n\r\n");
}

int main(void)
{
	/* get, store and clear the cause of the last reset */
	last_reset_cause = RCC_CSR & RCC_CSR_RESET_FLAGS;
	RCC_CSR |= RCC_CSR_RMVF;

	clock_setup();
	gpio_setup();
	usart_setup();
	iob_init(USART2);
	i2c_setup();
	attenuator_init(&board_att_cfg, board_att_st);

	microvty_init("rfdsat4ch> ");
	microvty_register(&reset_cmd);
	microvty_register(&uuid_cmd);
	microvty_register(&version_cmd);
	microvty_register(&att_set_cmd);

	print_banner();
	microvty_print_prompt();

	/* Blink the LED (PB15) on the board with every transmitted byte. */
	while (1) {
		int i;
		gpio_toggle(GPIOB, GPIO15);	/* LED on/off */
		//printf("Hello world\r\n");
		microvty_try_recv();
		for (i = 0; i < 800000; i++)	/* Wait a bit. */
			__asm__("nop");
	}

	return 0;
}