/*
 * (C) Copyright 2014 Leo C. <erbl259-lmu@yahoo.de>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <stdio.h>

#include <libopencmsis/core_cm3.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/cm3/systick.h>
#include <libopencm3/stm32/rtc.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/timer.h>

#define ODR	0x0c
#define IDR	0x08


#include "debug.h"
#include "serial.h"
#include "z80-if.h"
#include "../z180/hdrom.h"

#define ESCCHAR		('^'-0x40)

#define S_10MS_TO	(1<<0)

/*
 * LED Connections
 */

#define LED_PORT	GPIOC
#define LED_BLUE_PIN	GPIO8
#define BLUE		8
#define LED_GREEN_PIN	GPIO9
#define GREEN		9


#define LED_BLUE_ON()     BBIO_PERIPH(LED_PORT+ODR, BLUE) = 1
#define LED_BLUE_OFF()    BBIO_PERIPH(LED_PORT+ODR, BLUE) = 0
#define LED_BLUE_TOGGLE() BBIO_PERIPH(LED_PORT+ODR, BLUE) = !BBIO_PERIPH(LED_PORT+ODR, BLUE)

#define LED_GREEN_ON()     BBIO_PERIPH(LED_PORT+ODR, GREEN) = 1
#define LED_GREEN_OFF()    BBIO_PERIPH(LED_PORT+ODR, GREEN) = 0
#define LED_GREEN_TOGGLE() BBIO_PERIPH(LED_PORT+ODR, GREEN) = !BBIO_PERIPH(LED_PORT+ODR, GREEN)


/*
 * Button connections
 */

//BBIO_PERIPH(GPIOA+IDR, 0);

#define KEY_PORT	GPIOA_IDR
#define KEY0		GPIO0
//#define KEY1		GPIO1
//#define KEY2		GPIO2

#define REPEAT_MASK	KEY0		// repeat: key0
#define REPEAT_START	100		// after 1s
#define REPEAT_NEXT	20		// every 200ms


typedef enum {
	NOTHING, PULSE, BLINK1, BLINK2
} LED_MODE;

typedef struct {
	uint8_t mode;
	uint8_t ontime, offtime;
} led_stat_t;

volatile uint8_t led_timer[2];
led_stat_t led_stat[2];

volatile int timeout_1s;
volatile uint32_t Stat;


/*--------------------------------------------------------------------------*/


static void clock_setup(void)
{
	//rcc_clock_setup_in_hse_8mhz_out_24mhz();
	rcc_clock_setup_in_hsi_out_24mhz();

	/* Enable clocks for:
		GPIO port A (for GPIO_USART1_TX and Button)
		GPIO port C (LEDs)
		USART1
		TIM16 (RST-Pin)
		TIM1  (IOCS1)
	*/
	rcc_peripheral_enable_clock(&RCC_APB2ENR,
			  RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPBEN
			| RCC_APB2ENR_IOPCEN | RCC_APB2ENR_IOPDEN
			| RCC_APB2ENR_USART1EN | RCC_APB2ENR_AFIOEN
			| RCC_APB2ENR_TIM1EN | RCC_APB2ENR_TIM16EN);
	/* Enable clocks for:
		TIM3
	*/
	rcc_peripheral_enable_clock(&RCC_APB1ENR,
			RCC_APB1ENR_TIM3EN);

	/* Enable clocks for:
		DMA1
	*/
	rcc_peripheral_enable_clock(&RCC_AHBENR,
			RCC_AHBENR_DMA1EN);
}

static void systick_setup(void)
{
	/* SysTick interrupt every N clock pulses: set reload to N-1 */
	STK_RVR = 24000000/1000 - 1;

	/* Set source to core clock, enable int and start counting. */
	STK_CSR = STK_CSR_CLKSOURCE_AHB | STK_CSR_TICKINT | STK_CSR_ENABLE;
}

#if 0
static void nvic_setup(void)
{
//	nvic_enable_irq(NVIC_RTC_IRQ);
//	nvic_set_priority(NVIC_RTC_IRQ, 1);
}
#endif

static void tim3_setup(void)
{
	TIM3_CR1 = TIM_CR1_CMS_EDGE | TIM_CR1_DIR_UP;

	TIM3_CCMR2 = 0
		| TIM_CCMR2_OC4M_FORCE_LOW
	/*	| TIM_CCMR2_OC4M_FORCE_HIGH	*/
	/*	| TIM_CCMR2_OC4M_PWM2		*/

	/*	| TIM_CCMR2_OC4PE		*/
	/*	| TIM_CCMR2_OC4FE		*/
		| TIM_CCMR2_CC4S_OUT;

	TIM3_CCER = TIM_CCER_CC4E
		| TIM_CCER_CC4P;

	TIM3_ARR = 48;	/* default */
	TIM3_CCR4 = 1;	/*  */
}

static void gpio_setup(void)
{

	/* Disable JTAG-DP, but leave SW-DP Enabled. (free PA15, PB3, PB4)
	   Remap SPI1 to PB3, PB4, PB5 and PA15.
	   Remap TIM3 (CH1/PC6, CH2/PC7, CH3/PC8, CH4/PC9)
	   Port D0/Port D1 mapping on OSC_IN/OSC_OUT
	*/
	gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON,
			AFIO_MAPR_SPI1_REMAP
			| AFIO_MAPR_TIM3_REMAP_FULL_REMAP
			| AFIO_MAPR_PD01_REMAP);

	/* LEDs and User Button. */
	gpio_set_mode(LED_PORT, GPIO_MODE_OUTPUT_2_MHZ,
		      GPIO_CNF_OUTPUT_PUSHPULL, LED_BLUE_PIN);
	gpio_set_mode(LED_PORT, GPIO_MODE_OUTPUT_10_MHZ,
		      GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, LED_GREEN_PIN);
	gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
		      GPIO_CNF_INPUT_FLOAT, GPIO0);
}


/*--------------------------------------------------------------------------*/

void delay_systicks(int ticks)
{
	int start, stop, now;

	start = STK_CVR;
	stop = start - ticks;
	if (stop < 0) {
		stop += STK_RVR;
		do {
			now = STK_CVR;
		} while ((now > stop) || (now <= start));
	} else {
		do {
			now = STK_CVR;
		} while ((now > stop) && (now <= start));
	}
}


/*--------------------------------------------------------------------------*/

static void led_toggle(uint8_t lednr) {
	if (lednr == 0)
		LED_BLUE_TOGGLE();
	else if (lednr == 1)
		LED_GREEN_TOGGLE();
}

static void led_on(uint8_t lednr) {
	if (lednr == 0)
		LED_BLUE_ON();
	else if (lednr == 1)
		LED_GREEN_ON();
}

static void led_off(uint8_t lednr) {
	if (lednr == 0)
		LED_BLUE_OFF();
	else if (lednr == 1)
		LED_GREEN_OFF();
}

static uint8_t led_is_on(uint8_t lednr) {
	if (lednr == 0)
		return BBIO_PERIPH(LED_PORT+ODR, BLUE);
	else if (lednr == 1)
		return BBIO_PERIPH(LED_PORT+ODR, GREEN);
	else
		return 0;
}

static void ledset(uint8_t lednr, uint8_t what, uint8_t len) {

	led_stat[lednr].mode = what;
	switch (what) {
	case PULSE:
		led_stat[lednr].ontime = len;
		led_stat[lednr].offtime = 0;
		led_timer[lednr] = len;
		led_on(lednr);
		break;
	case BLINK1:
	case BLINK2:
		if (what == BLINK1)
			led_stat[lednr].offtime = 100 - len;
		else
			led_stat[lednr].offtime = 200 - len;
		led_stat[lednr].ontime = len;
		led_timer[lednr] = len;
		led_on(lednr);
		break;
	default:
		break;
	}
}

/*--------------------------------------------------------------------------*/

static volatile uint16_t key_state,
		key_press, // key press detect
		key_rpt; // key long press and repeat


static uint16_t get_key_press(uint16_t key_mask) {
	__disable_irq();
	// read and clear atomic !
	key_mask &= key_press; // read key(s)
	key_press ^= key_mask; // clear key(s)
	__enable_irq();
	return key_mask;
}

/*
static uint16_t get_key_rpt(uint16_t key_mask) {
	__disable_irq();
	// read and clear atomic !
	key_mask &= key_rpt; // read key(s)
	key_rpt ^= key_mask; // clear key(s)
	__enable_irq();
	return key_mask;
}
*/

static uint16_t get_key_short(uint16_t key_mask) {
	__disable_irq();
	// read key state and key press atomic !
	return get_key_press(key_state & key_mask);
}

/*
static uint16_t get_key_long(uint16_t key_mask) {
	return get_key_press(get_key_rpt(key_mask));
}
*/

static void key_timerproc() {
	static uint16_t key_in_last, rpt;
	uint16_t key_in, c;

	key_in = KEY_PORT;

	c = key_in_last & key_in & ~key_state;

//	key_state = key_state  & key_in_last | (key_state  | key_in_last) & key_in;
//	key_state = key_state  & key_in      | (key_state  | key_in)      & key_in_last;

	key_state = c | ((key_in_last | key_in) & key_state);

//	key_state = (key_state&key_in_last) | (key_state&key_in) | (key_in_last&key_in);

	key_press |= c;

	key_in_last = key_in;


	if ((key_state & REPEAT_MASK) == 0) // check repeat function
		rpt = REPEAT_START;
	if (--rpt == 0) {
		rpt = REPEAT_NEXT; // repeat delay
		key_rpt |= key_state & REPEAT_MASK;
	}

}

/*--------------------------------------------------------------------------*/

void sys_tick_handler(void)
{
	static int_fast8_t tick_10ms = 0;
	static int_fast16_t count_ms = 0;

	int_fast8_t i;

	++tick_10ms;
	if (tick_10ms == 10)
	{
		Stat |= S_10MS_TO;

		tick_10ms = 0;

		i = led_timer[0];
		if (i)
			led_timer[0] = i - 1;
		i = led_timer[1];
		if (i)
			led_timer[1] = i - 1;

		key_timerproc();

		/* Drive timer procedure of low level disk I/O module */
		//disk_timerproc();
	}

	count_ms++;
	if (count_ms == 1000) {
		count_ms = 0;

		i = timeout_1s;
		if (i)
			timeout_1s = i - 1;
	}
}

void rtc_isr(void)
{
	/* The interrupt flag isn't cleared by hardware, we have to do it. */
	rtc_clear_flag(RTC_SEC);

}

/*--------------------------------------------------------------------------*/

void tim3_set(int mode)
{
	uint16_t cc_mode;

	cc_mode = TIM_CCMR2_CC4S_OUT;

	TIM3_CR1 = TIM_CR1_CMS_EDGE | TIM_CR1_DIR_UP /*| TIM_CR1_OPM */ ;

	if (mode < 0)
		cc_mode |= TIM_CCMR2_OC4M_FORCE_LOW;
	else if (mode == 0)
		cc_mode |= TIM_CCMR2_OC4M_FORCE_HIGH;
	else {
		TIM3_ARR = mode;
		TIM3_CCR4 = mode/2;
		cc_mode |= TIM_CCMR2_OC4M_PWM2;
	}

	TIM3_CCMR2 = cc_mode;

	if (mode > 0)
		TIM3_CR1 |= TIM_CR1_CEN;
}

/*--------------------------------------------------------------------------*/

static uint32_t z80_sram_cmp(uint32_t addr, uint32_t length, uint8_t wval, int inc)
{
	uint8_t rval;
	int_fast8_t errors = 0;

	DBG_P(1, "SRAM: Check %#.5x byte... ", length);
	while (length--) {
		if ((rval = z80_read(addr)) != wval) {
			if (errors == 0) {
				printf("\nSRAM: Address  W  R\n" \
				       "      -------------\n");
//					       12345  00 11
			}
			printf("       %.5lx  %.2x %.2x\n", addr, wval, rval);

			if (++errors > 16 )
				break;
		}
		addr++;
		wval += inc;
	}
	DBG_P(1, "Done.\n");

	return addr;
}

#if 0
static void z80_sram_fill(uint32_t addr, int length, uint8_t startval, int inc)
{
	printf("SRAM: Write %#.5x byte... ", length); //fflush(stdout);
	while (length--) {
		z80_write(addr, startval);
		++addr;
		startval += inc;
	}
	printf("Done.\n");
}


void z80_sram_fill_string(uint32_t addr, int length, const char *text)
{
	char c;
	const char *p = text;

	while (length--) {
		z80_write(addr++, c = *p++);
		if (c == 0)
			p = text;
	}
}


uint32_t z80_sram_cmp_string(uint32_t addr, int length, const char *text)
{
	char c;
	const char *p = text;

	while (length--) {
		c = *p++;
		if (z80_read(addr) != c)
			break;
		++addr;
		if (c == 0)
			p = text;
	}
	return addr;
}

const char * const qbfox = "Zhe quick brown fox jumps over the lazy dog!";
const char * const qbcat = "Zhe quick brown fox jumps over the lazy cat!";

#endif

uint8_t z80_get_byte(uint32_t adr)
{
	uint8_t data;

	z80_request_bus();
	data = z80_read(adr),
	z80_release_bus();

	return data;
}


/*--------------------------------------------------------------------------*/

static void do_10ms(void)
{
	for (uint_fast8_t i = 0; i < 2; i++) {
		switch (led_stat[i].mode) {
		case PULSE:
			if (led_timer[i] == 0) {
				led_off(i);
				led_stat[i].mode = NOTHING;
			}
			break;
		case BLINK1:
		case BLINK2:
			if (led_timer[i] == 0) {
				if (led_is_on(i))
					led_timer[i] = led_stat[i].offtime;
				else
					led_timer[i] = led_stat[i].ontime;
				led_toggle(i);
			}
			break;
		default:
			break;
		}
	}
}

struct msg_item {
	uint8_t fct;
	uint8_t sub_min, sub_max;
	void (*func)(uint8_t, int, uint8_t *);
};

uint32_t msg_to_addr(uint8_t *msg)
{
	uint32_t addr = msg[0] | (msg[1] << 8) | ((uint32_t)msg[2] << 16);

	return addr;

}

void do_msg_ini_msgfifo(uint8_t subf, int len, uint8_t * msg)
{
	(void)subf; (void)len;

	z80_init_msg_fifo(msg_to_addr(msg));
}


void do_msg_ini_memfifo(uint8_t subf, int len, uint8_t * msg)
{
	(void)len;

	z80_memfifo_init(subf - 1, msg_to_addr(msg));
}


void do_msg_char_out(uint8_t subf, int len, uint8_t * msg)
{
	(void)subf;

	while (len--)
		putchar(*msg++);
}


const struct msg_item z80_messages[] =
{
	{ 0,			/* fct nr. */
	  0, 0,			/* sub fct nr. from, to */
	  &do_msg_ini_msgfifo},
	{ 0,
	  1, 2,
	  &do_msg_ini_memfifo},
	{ 1,
	  1, 1,
	  &do_msg_char_out},
	{ 0xff,				/* end mark */
	  0, 0,
	  0},

};




void do_message(int len, uint8_t *msg)
{
	uint8_t fct, sub_fct;
	int_fast8_t i = 0;

	if (len >= 2) {
		fct = *msg++;
		sub_fct = *msg++;
		len -= 2;

		while (fct != z80_messages[i].fct)
			++i;

		if (z80_messages[i].fct == 0xff) {
			DBG_P(1, "do_message: Unknown function: %i, %i\n",
					fct, sub_fct);
			return; /* TODO: unknown message # */
		}

		while (fct == z80_messages[i].fct) {
			if (sub_fct >= z80_messages[i].sub_min && sub_fct <= z80_messages[i].sub_max )
				break;
			++i;
		}

		if (z80_messages[i].fct != fct) {
			DBG_P(1, "do_message: Unknown sub function: %i, %i\n",
					fct, sub_fct);
			return; /* TODO: unknown message sub# */
		}

		(z80_messages[i].func)(sub_fct, len, msg);


	} else {
		/* TODO: error */
		DBG_P(1, "do_message: to few arguments (%i); this shouldn't happen!\n", len);
	}
}



#define CTRBUF_LEN 256

void check_msg_fifo(void)
{
	int ch;
	static int_fast8_t state;
	static int msglen,idx;
	static uint8_t buffer[CTRBUF_LEN];

	while (state != 3 && (ch = z80_msg_fifo_getc()) >= 0) {
		switch (state) {
		case 0:		/* wait for start of message */
			if (ch == 0x81)	{
				msglen = 0;
				idx = 0;
				state = 1;
			}
			break;
		case 1:		/* get msg len */
			if (ch > 0 && ch <= CTRBUF_LEN) {
				msglen = ch;
				state = 2;
			} else
				state = 0;
			break;
		case 2: 	/* get message */
			buffer[idx++] = ch;
			if (idx == msglen)
				state = 3;
			break;
		}
	}

	if (state == 3) {
		do_message(msglen, buffer);
		state = 0;
	}
}


void z80_load_mem(void)
{
	unsigned sec = 0;
	uint32_t sec_base = hdrom_start;

	DBG_P(1, "Loading z80 memory... \n");

	while (sec < hdrom_sections) {
		DBG_P(2, "  From: 0x%.5lX to: 0x%.5lX    (%5li bytes)\n",
				hdrom_address[sec],
				hdrom_address[sec]+hdrom_length_of_sections[sec] - 1,
				hdrom_length_of_sections[sec]);

		z80_write_block((unsigned char *) &hdrom[sec_base],  /* src */
		                hdrom_address[sec],                  /* dest */
				hdrom_length_of_sections[sec]);      /* len */
		sec_base+=hdrom_length_of_sections[sec];
		sec++;
	}
}
/*--------------------------------------------------------------------------*/

int main(void)
{
	int_fast8_t state = 0;
	int ch;

	clock_setup();
	gpio_setup();
	tim3_setup();
	setvbuf(stdout, NULL, _IONBF, 0);
	serial_setup();
	printf("\n(STM32F100+HD64180)_stamp Tester\n");

	DBG_P(1, "z80_setup_bus... ");
	z80_setup_msg_fifo();
	z80_setup_bus();
	DBG_P(1, "done.\n");

	/*
	 * If the RTC is pre-configured just allow access, don't reconfigure.
	 * Otherwise enable it with the LSE as clock source and 0x7fff as
	 * prescale value.
	 */
	rtc_auto_awake(LSE, 0x7fff);

	systick_setup();

	DBG_P(1, "Get bus... ");
	z80_busreq(LOW);
	z80_reset(HIGH);
	z80_request_bus();
	DBG_P(1, "got it!\n");

	z80_memset(0, 0x76, 0x80000);
	//z80_sram_fill(0, 512 * 1024, 0x76, 0);
	z80_sram_cmp(0, (uint32_t)512 * 1024, 0x76, 0);

	z80_load_mem();
	z80_reset(LOW);
	DBG_P(1, "Bus released!\n");
	z80_release_bus();
	z80_reset(HIGH);
	DBG_P(1, "Reset released!\n");


	ledset(0, BLINK1, 50);

	while (1) {

		if (Stat & S_10MS_TO) {
			Stat &= ~S_10MS_TO;
			do_10ms();
		}

		if (get_key_short(KEY0)) {
			z80_reset_pulse();
		}

		if ((ch = serial_getc()) >= 0) {
			switch (state) {
			case 0:
				if (ch == ESCCHAR) {
					state = 1;
					/* TODO: Timer starten */
				} else
					z80_memfifo_putc(fifo_out, ch);
				break;
			case 1:
				switch (ch) {

				case 'h': /* test: green led on */
					tim3_set(-1);
					break;
				case 'l': /* test: green led off */
					tim3_set(0);
					break;
				case 'p': /* test: pulse on led pin */
					tim3_set(24000000 / 1000000 * 5); /* 5 us */
					break;
				case 'r':
					z80_reset_pulse();
					break;

				case ESCCHAR:
				default:
					z80_memfifo_putc(fifo_out, ch);
				}
				state = 0;
				break;
			}
		}

		check_msg_fifo();
	}

	return 0;
}