#include <string.h>
#include "spi.h"
#include "cs1180.h"
#include "clock.h"

#define CS1180_RDATA    0X01
#define CS1180_RDATAC   0X03
#define CS1180_STOPC    0x0f
#define CS1180_RREG     0x10
#define CS1180_WREG     0x50
#define CS1180_CALSELF  0xf0
#define CS1180_OCALSELF 0xf1
#define CS1180_SLFGCAL  0xf2
#define CS1180_OCALSYS  0xf3
#define CS1180_GCALSYS  0xf4
#define CS1180_WAKEUP   0xfb
#define CS1180_SYNC     0xfc
#define CS1180_SLEEP    0xfd
#define CS1180_RESET    0xfe

static float _cs1180_gain = 1.0f;
#define CS1180_INIT_GAIN CS1180_GAIN_128X

static int cs1180_send_cmd(uint8_t data);
static uint8_t cs1180_read_data(uint8_t data);
static void cs1180_reset(void);

void cs_delay(void)
{
	uint32_t  count = 60;
	while(count--); 
}
static int _cs1180_ready = 0;
int cs1180_is_ready(void){
	return _cs1180_ready;
}

static void spi_write_reg(uint8_t reg, uint8_t *data, uint8_t len){
	cs1180_send_cmd(CS1180_WREG|reg);
	cs1180_send_cmd(len - 1);
	while(len -- > 0){
		cs1180_send_cmd(*data);
		data++;
	}
}


static void spi_read_reg(uint8_t reg, uint8_t *data, uint8_t len){
	cs1180_send_cmd(CS1180_RREG|reg);
	cs1180_send_cmd(len - 1);
	while(len -- > 0){
		*data = cs1180_read_data(0xFF);
		data++;
	}
}

static uint8_t cs1180_dumy_read(void){
	uint8_t data[16] = {0x5A, 0x5A, 0x5A};
	while (IS_CS1180_READY());
	cs1180_cs(0);
	cs_delay();
	spi_read_reg(0x0, data, 16);
	cs_delay();
	cs1180_cs(1);
	return data[0];
}

/* 对芯片的偏移误差和增益误差进行纠正 */
static void cs1180_self_calibrate(void)
{
	cs1180_cs(0);
	cs_delay();
	cs1180_send_cmd(CS1180_CALSELF);
	cs_delay();
	cs1180_cs(1);
	delay_us(50);
	/* wait calibrate finished */
	while (IS_CS1180_READY());
	while (!IS_CS1180_READY());
	delay_us(50 * 1000);
	while (IS_CS1180_READY()); //drop first data
}

/* 对芯片的偏移误差进行纠正 */
__attribute__((unused)) static void cs1180_self_offset_calibrate(void)
{
	cs1180_cs(0);
	cs1180_send_cmd(CS1180_OCALSELF);
	cs1180_cs(1);
	delay_us(50);
	/* wait calibrate finished */
	while (IS_CS1180_READY());
	while (!IS_CS1180_READY());
}

/* 对芯片的增益误差进行纠正 */
__attribute__((unused)) static void cs1180_self_gain_calibrate(void)
{
	cs1180_cs(0);
	cs1180_send_cmd(CS1180_SLFGCAL);
	cs1180_cs(1);
	delay_us(50);
	/* wait calibrate finished */
	while (IS_CS1180_READY());
	while (!IS_CS1180_READY());
}

/* 对系统的失调误差(偏移误差)进行纠正, 必须要求输入为差分电压为0,
*/
void cs1180_sys_offset_calibrate(void)
{
	cs1180_cs(0);
	cs_delay();
	cs1180_send_cmd(CS1180_OCALSYS);
	delay_us(50);
	cs1180_cs(1);
	delay_us(50);
	/* wait calibrate finished */
	while (IS_CS1180_READY());
	while (!IS_CS1180_READY());
	delay_us(10 * 1000);
	while (IS_CS1180_READY()); //drop first data	
}

/* 对系统的增益误差进行纠正,必须输入正满幅度的电压, SP700,SP600未提供满辐电压，故这一项不做 */
__attribute__((unused)) static void cs1180_sys_gain_calibrate(void)
{
	cs1180_cs(0);
	cs1180_send_cmd(CS1180_GCALSYS);
	cs1180_cs(1);
	delay_us(50);
	/* wait calibrate finished */
	while (IS_CS1180_READY());
	while (!IS_CS1180_READY());
}

static void _cs1180_adc_set_gain(int gain){
	/* 输出频率 15hz,参考电压1.235V 输出数据高位在前，
	 * 输入缓冲器关闭，采样频率 OSC/128,数据格式双极性
	 */
	uint8_t data[] = {0x00, 0x01, 0x00};
	data[0] = 0xF & gain;
	cs1180_cs(0);
	cs_delay();
	spi_write_reg(0x00, data, 3);
	cs_delay();
	cs1180_cs(1);
	_cs1180_gain = 1 << gain;
	cs1180_self_calibrate();
	cs1180_dumy_read();	
}

int cs1180_adc_set_gain(int gain){
	int count = 0;
	do {
		cs1180_reset();
		delay_us(10);
	
		_cs1180_adc_set_gain(gain);
		delay_us(10);

		if (cs1180_dumy_read() == gain){
			break;
		}
		count ++;
	}while(count <= 20);
	if (count >= 20) {
		if (cs1180_dumy_read() != gain){
			return -1;
		}
	}
	delay_us(10*1000);
	cs1180_sys_offset_calibrate();
	cs1180_dumy_read();
	return 0;
}


static void cs1180_reset(void){
	cs1180_cs(0);
	cs_delay();
	cs1180_send_cmd(CS1180_RESET);
	cs_delay();
	cs1180_cs(1);
}

void cs1180_adc_init(void){
	_cs1180_ready = 0;
	CS1180_PWR_ENABLE(0);
	delay_us(100 * 1000);
	CS1180_PWR_ENABLE(1);
	delay_us(200 * 1000);
	spi1_init();
	delay_us(10);
	_cs1180_ready = cs1180_adc_set_gain(CS1180_INIT_GAIN) == 0;
}


void cs1180_adc_shutdown(void){
	CS1180_PWR_ENABLE(0);
	spi1_deinit();
	_cs1180_ready = 0;
}

float cs1180_adc_sample(void)
{
	uint8_t data[3] = {0,0,0};
	int a = 0;

	while (IS_CS1180_READY()); //当drdy 为高时，不读取数据

	cs1180_cs(0);
	//spi_read_reg(0xD, data, 3);
	cs1180_send_cmd(CS1180_RDATA);
	data[0] = cs1180_read_data(0xFF);
	data[1] = cs1180_read_data(0xFF);
	data[2] = cs1180_read_data(0xFF);
	cs1180_cs(1);
	a = (data[0] << 16) | (data[1] << 8) | data[2];
	a >>= 4;

	if (a & 0x80000) {
		a = ~a;
		a = - (a&0x7FFFF);
	}else {
		a = a&0x7FFFF;
	}
	return ((float)a) / _cs1180_gain * 0.9f;/* 0.9是一个多个板子测试后的值，具体什么原因需要再分析*/
}


static int cs1180_send_cmd(uint8_t cmd){
	return spi1_send_byte(cmd, NULL);
}

static uint8_t cs1180_read_data(uint8_t data){
	uint8_t r_data = 0xFF;
	spi1_send_byte(data, &r_data);
	return r_data;
}