#include "spi_proto.h"
#include "spi.h"

uint8_t read[2];
uint8_t write[4];

void talk_to_slave(uint8_t opcode, uint8_t addr, uint8_t flags)
{
	write[0] = opcode;
	write[1] = addr;
	spi_mst_start_packet();
	spi_mst_write(wlen, flags & SPI_WRITE_DATA? 4 : 2);
	spi_mst_read(rlen, flags & SPI_READ_DATA? 2 : 0);
	spi_mst_end_packet();
}

uint16_t speak_raw(uint8_t opcode, uint8_t number, uint8_t flags, uint16_t value)
{
	write[2] = value >> 8;
	write[3] = value & 0xff;
	talk_to_slave(opcode, number, flags);
	return (read[0] << 8) | read[1];
}

uint8_t spi_proto_needs(uint8_t opcode)
{
	uint8_t r = SPI_NONE;
	switch(opcode)
	{
		case 1: case 2: case 3:
			r = SPI_READ_DATA;
			break;
		case 4: case 5:
			r = SPI_WRITE_DATA;
			break;
	}
	return r;
}


uint16_t read_temperature(uint8_t number)
{
	talk_to_slave(1, number, SPI_READ_DATA);
	return (read[0] << 8) | read[1];
}

uint8_t read_var8(uint8_t number)
{
	talk_to_slave(2, number, SPI_READ_DATA);
	return read[1];
}

uint16_t read_var16(uint8_t number)
{
	talk_to_slave(3, number, SPI_READ_DATA);
	return (read[0] << 8) | read[1];
}

void write_var8(uint8_t number, uint8_t value)
{
	write[2] = 0;
	write[3] = number;
	talk_to_slave(4, number, SPI_WRITE_DATA);
}

void write_var16(uint8_t number, uint16_t value)
{
	write[2] = value >> 8;
	write[3] = value & 0xff;
	talk_to_slave(5, number, SPI_WRITE_DATA);
}

void call_func(uint8_t number)
{
	talk_to_slave(6, number, SPI_NONE);
}