edid_emulator.c

#include <stm32f10x.h>
#include <math.h>
#include <stdlib.h>
#include "printf.h"

#define EDID_I2C_ADDR	0x50
#define EDID_I2C_CLOCK	100000

static uint8_t monitor_edid[] = {
	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x09, 0xd1, 0x43, 0x78, 0x45, 0x54, 0x00, 0x00, 0x2d, 0x14, 0x01, 0x03, 0x0e, 0x29, 0x17, 0x78, 0x2e, 0x3d, 0x85, 0xa6, 0x56, 0x4a, 0x9a, 0x24, 0x12, 0x50, 0x54, 0xa5, 0x6a, 0x80, 0x71, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x66, 0x21, 0x56, 0xaa, 0x51, 0x00, 0x1e, 0x30, 0x46, 0x8f, 0x33, 0x00, 0x9a, 0xe6, 0x10, 0x00, 0x00, 0x1e, 0x00, 0x00, 0x00, 0xff, 0x00, 0x38, 0x42, 0x41, 0x30, 0x32, 0x30, 0x30, 0x31, 0x30, 0x31, 0x39, 0x0a, 0x20, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x32, 0x4c, 0x1e, 0x3f, 0x0e, 0x00, 0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0xfc, 0x00, 0x42, 0x65, 0x6e, 0x51, 0x20, 0x47, 0x39, 0x32, 0x35, 0x48, 0x44, 0x41, 0x0a, 0x00, 0xd8, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x09, 0xd1, 0x43, 0x78, 0x45, 0x54, 0x00, 0x00, 0x2d, 0x14, 0x01, 0x03, 0x0e, 0x29, 0x17, 0x78, 0x2e, 0x3d, 0x85, 0xa6, 0x56, 0x4a, 0x9a, 0x24, 0x12, 0x50, 0x54, 0xa5, 0x6a, 0x80, 0x71, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x66, 0x21, 0x56, 0xaa, 0x51, 0x00, 0x1e, 0x30, 0x46, 0x8f, 0x33, 0x00, 0x9a, 0xe6, 0x10, 0x00, 0x00, 0x1e, 0x00, 0x00, 0x00, 0xff, 0x00, 0x38, 0x42, 0x41, 0x30, 0x32, 0x30, 0x30, 0x31, 0x30, 0x31, 0x39, 0x0a, 0x20, 0x00, 0x00, 0x00, 0xfd, 0x00, 0x32, 0x4c, 0x1e, 0x3f, 0x0e, 0x00, 0x0a, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0xfc, 0x00, 0x42, 0x65, 0x6e, 0x51, 0x20, 0x47, 0x39, 0x32, 0x35, 0x48, 0x44, 0x41, 0x0a, 0x00, 0xd8, 
};

static int monitor_edid_offset = 0;

static void usart1_init(uint32_t baudrate);
static void init_i2c_slave();
static void uart_putc(void *p, char c);

void main() {
	usart1_init(115200);
	init_printf(NULL, uart_putc);
	init_i2c_slave();
	tfp_printf("ohuenno!\r\n");
	while (1);
}

void I2C2_EV_IRQHandler() {
	switch (I2C_GetLastEvent(I2C2)) {
		case I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED:
		case I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED:
			I2C2 ->SR1;
			I2C2 ->SR2;
		break;
		
		// seek edid eeprom
		case I2C_EVENT_SLAVE_BYTE_RECEIVED:
			monitor_edid_offset = I2C_ReceiveData(I2C2);
		break;
		
		case I2C_EVENT_SLAVE_BYTE_TRANSMITTING:
		case I2C_EVENT_SLAVE_BYTE_TRANSMITTED:
			I2C_SendData(I2C2, monitor_edid[monitor_edid_offset]);
			++monitor_edid_offset;
		break;
		
		case I2C_EVENT_SLAVE_ACK_FAILURE:
			I2C2 ->SR1 &= 0x00FF;
		break;
		
		case I2C_EVENT_SLAVE_STOP_DETECTED:
			I2C2 ->SR1;
			I2C2->CR1 |= 0x1;
		break;
	}
}

void I2C2_ER_IRQHandler() {
	if ((I2C_ReadRegister(I2C2, I2C_Register_SR1) & 0xFF00) != 0x00)
		I2C2->SR1 &= 0x00FF;
}

static void usart1_init(uint32_t baudrate) {
	GPIO_InitTypeDef gpio;
	USART_InitTypeDef uart;
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
	gpio.GPIO_Pin = GPIO_Pin_9;
	gpio.GPIO_Mode = GPIO_Mode_AF_PP;
	gpio.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &gpio);
	
	gpio.GPIO_Pin = GPIO_Pin_10;
	gpio.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(GPIOA, &gpio);
	
	uart.USART_BaudRate = baudrate;
	uart.USART_WordLength = USART_WordLength_8b;
	uart.USART_StopBits = USART_StopBits_1;
	uart.USART_Parity = USART_Parity_No;
	uart.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
	uart.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
	USART_Init(USART1, &uart);
	
	USART_Cmd(USART1, ENABLE);
}

static void uart_putc(void *p, char c) {
	USART_SendData(USART1, c);
	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);
}

static void init_i2c_slave() {
	GPIO_InitTypeDef gpio;
	NVIC_InitTypeDef nvic;
	I2C_InitTypeDef i2c;
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
	
	gpio.GPIO_Pin		= GPIO_Pin_10 | GPIO_Pin_11;
	gpio.GPIO_Speed		= GPIO_Speed_50MHz;
	gpio.GPIO_Mode		= GPIO_Mode_AF_OD;
	GPIO_Init(GPIOB, &gpio);
	
	nvic.NVIC_IRQChannel					= I2C2_EV_IRQn;
	nvic.NVIC_IRQChannelPreemptionPriority	= 0;
	nvic.NVIC_IRQChannelSubPriority			= 0;
	nvic.NVIC_IRQChannelCmd					= ENABLE;
	NVIC_Init(&nvic);
	
	nvic.NVIC_IRQChannel = I2C2_ER_IRQn;
	NVIC_Init(&nvic);
	
	I2C_ITConfig(I2C2, I2C_IT_EVT, ENABLE);
	I2C_ITConfig(I2C2, I2C_IT_BUF, ENABLE);
	I2C_ITConfig(I2C2, I2C_IT_ERR, ENABLE);
	
	i2c.I2C_Mode				= I2C_Mode_I2C;
	i2c.I2C_DutyCycle			= I2C_DutyCycle_2;
	i2c.I2C_OwnAddress1			= EDID_I2C_ADDR << 1;
	i2c.I2C_Ack					= I2C_Ack_Enable;
	i2c.I2C_AcknowledgedAddress	= I2C_AcknowledgedAddress_7bit;
	i2c.I2C_ClockSpeed			= EDID_I2C_CLOCK;
	
	I2C_Init(I2C2, &i2c);
	I2C_StretchClockCmd(I2C2, ENABLE);
	I2C_Cmd(I2C2, ENABLE);
}