#include "DrvSdSpi.h"
#include "BSPSpi.h"

#include <string.h>

static uint8_t sd_type = 0; // SD卡的类型 
static unsigned char gSDCsd[16] = {0};

// SD片选 
static uint8_t Drv_SdSelect(void);
static void Drv_SdDisselect(void);
void Drv_SdSpiCs(uint8_t value);
uint8_t Drv_SdSpiRWByte(uint8_t data);
void Drv_SdSpiSetSpeed(uint8_t mode);

// 数据指令收发函数
static uint8_t Drv_SdSendCmd(uint8_t cmd, uint32_t arg, uint8_t crc);
static unsigned char Drv_SDGetResponse(unsigned char response);
static unsigned char Drv_SDRecvData(unsigned char *buf, unsigned short len);
static unsigned char Drv_SDSendBlock(unsigned char *buf, unsigned char cmd);
static unsigned char Drv_SDGetCsd(unsigned char *csd_data);

// sd等待卡片准备好 
uint8_t Drv_SdWaitReady(void);

// SD卡初始化
uint8_t Drv_SdInit(void);

// 读取和写入SD卡
unsigned char Drv_SdReadDisk(unsigned char *buf, unsigned int sector, unsigned char cnt);
unsigned char Drv_SdWriteDisk(unsigned char *buf, unsigned int sector, unsigned char cnt);

// 获取SD卡总扇区数
unsigned int Drv_SdGetSectorCount(void);

// 向SD卡发送指令
static uint8_t Drv_SdSendCmd(uint8_t cmd, uint32_t arg, uint8_t crc)
{
    uint8_t response;
    uint8_t retry_limit = 0x1f;

    Drv_SdDisselect();

    if (Drv_SdSelect() != 0) {
        return 0xff;
    }

    Drv_SdSpiRWByte(cmd | 0x40);
    for (int shift = 24; shift >= 0; shift -= 8) {
        Drv_SdSpiRWByte((uint8_t)((arg >> shift) & 0xff));
    }
    Drv_SdSpiRWByte(crc);

    if (cmd == CMD12) {
        Drv_SdSpiRWByte(0xff);
    }
    do {
        response = Drv_SdSpiRWByte(0xff);
    } while ((response & 0x80) && retry_limit--);

    return response;
}

// sd等待卡片准备好 
uint8_t Drv_SdWaitReady(void)
{
    uint8_t rec;
    uint32_t retry_time = 0;
    do {
        rec = Drv_SdSpiRWByte(0xff);
        if (0xff == rec) {
            return 0;
        }
        retry_time++;
        if (retry_time % 0xffffff == 0) {
            /* 长时间没有成功，进行重新初始化 */
            Bsp_SpiInit(BSP_SPI3);
            Drv_SdSpiCs(1); 
        }
    } while (retry_time < 0xfffffff);
    return 1;
}

// SD片选 
static uint8_t Drv_SdSelect(void)
{
    Drv_SdSpiCs(0);
    if (Drv_SdWaitReady() == 0) {
        return 0;
    }
    Drv_SdDisselect();
    return 1;
}

// SD取消片选 
static void Drv_SdDisselect(void)
{
    Drv_SdSpiCs(1);
    Drv_SdSpiRWByte(0xff);
}

void Drv_SdSpiCs(unsigned char value)
{
    Bsp_SpiCS(BSP_SPI3, value);
}

// 设置SD通信速度
void Drv_SdSpiSetSpeed(uint8_t mode)
{
    uint32_t speed;
    if (mode == USR_DRV_SD_LOW_SPEED_MODE) {
        speed = USR_DRV_SD_LOW_SPEED;
    } else if (mode == USR_DRV_SD_HIGH_SPEED_MODE) {
        speed = USR_DRV_SD_HIGH_SPEED;
    }
    Bsp_SpiSetSpeed(BSP_SPI3, speed);
}

// 设置SD读写函数
uint8_t Drv_SdSpiRWByte(uint8_t data)
{
    return Bsp_RWByte(BSP_SPI3, data);
}

// 从SD卡读取一个数据包的内容
static unsigned char Drv_SDRecvData(unsigned char *buf, unsigned short len)
{
    if (Drv_SDGetResponse(0xfe)) {
        return 1;
    }
    while (len--) {
        *buf = Drv_SdSpiRWByte(0xff);
        buf++;
    }
    Drv_SdSpiRWByte(0xff);
    Drv_SdSpiRWByte(0xff);
    return 0;
}

// 向SD卡写入一个数据包的内容512字节
static unsigned char Drv_SDSendBlock(unsigned char *buf, unsigned char cmd)
{
    unsigned char rt;
    unsigned short i;
    rt = Drv_SdWaitReady();
    if (0 != rt) {
        return 1;
    }
    Drv_SdSpiRWByte(cmd);
    if (cmd != 0xfd) {
        for (i = 0; i < 512; i++) {
            Drv_SdSpiRWByte(buf[i]);
        }
        Drv_SdSpiRWByte(0xff);
        Drv_SdSpiRWByte(0xff);
        rt = Drv_SdSpiRWByte(0xff);
        if ((rt & 0x1F) != 0x05) {
            return 2;
        }
    }
    return 0;
}

// 等待SD回应
static unsigned char Drv_SDGetResponse(unsigned char response)
{
    unsigned short count = 0xffff;
    while ((Drv_SdSpiRWByte(0xff) != response) && count) {
        count--;	  
    }
    if (count == 0) {
        return MSD_RESPONSE_FAILURE;
    } else {
        return 0;
    }
}

// 获取SD卡的CSD信息包括容量和速度信息
static unsigned char Drv_SDGetCsd(unsigned char *csd_data)
{
    unsigned char rt;
    rt = Drv_SdSendCmd(CMD9, 0, 0x01);
    if (rt == 0x00) {
        rt = Drv_SDRecvData(csd_data, 16);
    }
    Drv_SdDisselect();
    if (rt != 0x00) {
        return 1;
    }
    return 0;
}

// 获取SD卡总扇区数
unsigned int Drv_SdGetSectorCount(void)
{
    unsigned int capacity; // 记录扇区数量
    unsigned char n;
    unsigned short csize;
    memset(gSDCsd, 0, sizeof(gSDCsd));
    /* 获取CSD信息 */
    if (Drv_SDGetCsd(gSDCsd) != 0x00) {
        return 0;
    }
    if ((gSDCsd[0] & 0xc0) == 0x40) {
        csize = gSDCsd[9] + ((unsigned short)gSDCsd[8] << 8) + 1;
        capacity = (unsigned int)csize << 10;
    } else {    
        n = (gSDCsd[5] & 15) + ((gSDCsd[10] & 128) >> 7) + ((gSDCsd[9] & 3) << 1) + 2;
        csize = (gSDCsd[8] >> 6) + ((unsigned short)gSDCsd[7] << 2) + ((unsigned short)(gSDCsd[6] & 3) << 10) + 1;
        capacity = (unsigned int)csize << (n - 9);
    }
    return capacity;
}

// SD卡初始化
uint8_t Drv_SdInit(void)
{
    unsigned char RxData; // 返回值
    unsigned short RetryTime;  // 用来进行超时计数
    unsigned char buf[4];
    
    unsigned short i;

    Bsp_SpiInit(BSP_SPI3); 
    Drv_SdSpiCs(0);
    Drv_SdSpiSetSpeed(USR_DRV_SD_LOW_SPEED_MODE); // 初始化的时候要是低速模式
    for(i = 0; i < 100; i++) {
        RxData = Drv_SdSpiRWByte(0xff); // 发送最少74个脉冲，保守起见多发送一点
    }
    /* 格式化命令 */
    Drv_SdSpiRWByte(CMD0 | 0x40);
    Drv_SdSpiRWByte((unsigned char)((0 >> 24) & 0xff));
    Drv_SdSpiRWByte((unsigned char)((0 >> 16) & 0xff));
    Drv_SdSpiRWByte((unsigned char)((0 >> 8) & 0xff));
    Drv_SdSpiRWByte((unsigned char)(0 & 0xff));
    Drv_SdSpiRWByte(0x95);
    
    RetryTime = 20;
    do {
        RxData = Drv_SdSendCmd(CMD0, 0, 0x95);//
    } while((RxData != 0x01) && RetryTime--);
    
    sd_type = 0; // 设置默认没有卡
    if(RxData == 0x01) {
        if(Drv_SdSendCmd(CMD8, 0x1AA, 0x87) == 1) // SD 协议版本V2.0
        {
            for(i = 0; i < 4; i++) {
                buf[i] = Drv_SdSpiRWByte(0xff);
            }
            if(buf[2] == 0x01 && buf[3] == 0xaa) // 判断卡是否支持2.7V~3.6V
            {
                RetryTime = 0xfffe;
                do {
                    Drv_SdSendCmd(CMD55, 0, 0x01);
                    RxData = Drv_SdSendCmd(ACMD41, 0x40000000, 0x01);
                } while(RxData && RetryTime--);
                if(RetryTime && (Drv_SdSendCmd(CMD58, 0, 0x01)) == 0) // 鉴别SD2.0卡版本
                {
                    for(i = 0; i < 4; i++) {
                        buf[i] = Drv_SdSpiRWByte(0xff); // 得到OCR值
                    }
                    // 检查CSS
                    if (buf[0] & 0x40) {
                        sd_type = SD_TYPE_V2HC;
                    }
                    else {
                        sd_type = SD_TYPE_V2;
                    }                        
                }
            }
        } else { // SD V1.x/ MMC V3
            Drv_SdSendCmd(CMD55, 0, 0X01);
            RxData = Drv_SdSendCmd(ACMD41, 0, 0X01);
            if(RxData <= 1) {        
                sd_type = SD_TYPE_V1;
                RetryTime = 0xfffe;
                do { // 等待退出IDLE模式
                    Drv_SdSendCmd(CMD55, 0, 0X01);
                    RxData = Drv_SdSendCmd(ACMD41, 0, 0X01);
                } while(RxData && RetryTime--);
            } else { // MMC卡不支持CMD55余CMD41识别
                sd_type = SD_TYPE_MMC; // MMC V3
                RetryTime = 0xfffe;
                do { // 等待退出IDLE模式                      
                    RxData = Drv_SdSendCmd(CMD1, 0, 0X01);
                } while(RxData && RetryTime--);  
            }
            if((RetryTime == 0) || (Drv_SdSendCmd(CMD16, 512, 0X01) != 0)) {
                sd_type = SD_TYPE_ERR; // 错误的卡，未能识别
            }
        }
    }
    Drv_SdDisselect();
    Drv_SdSpiSetSpeed(USR_DRV_SD_HIGH_SPEED_MODE);
    if(sd_type != 0) {
        return 0;
    } else if(RxData != 0) {
        return RxData;
    }        
    return 0xaa; // 其他错误
}

// 读取SD卡
unsigned char Drv_SdReadDisk(unsigned char *buf, unsigned int sector, unsigned char cnt)
{
    unsigned char rt;
    if(sd_type != SD_TYPE_V2HC) {
        sector <<= 9; // 转换为字节地址
    }
    if(cnt == 1) {
        rt = Drv_SdSendCmd(CMD17, sector, 0x01); // 读命令
        if (rt == 0) // 指令发送成功
        {
            rt = Drv_SDRecvData(buf, 512); // 接收512个字节       
        }
    } else {
        rt = Drv_SdSendCmd(CMD18, sector, 0X01); // 连续读命令
        do
        {
            rt = Drv_SDRecvData(buf, 512); // 接收512个字节
            buf += 512;  
        } while(--cnt && rt == 0);     
        Drv_SdSendCmd(CMD12, 0, 0X01); // 发送停止命令
    }   
    Drv_SdDisselect(); // 取消片选
    return rt;
}

// 写入SD卡
unsigned char Drv_SdWriteDisk(unsigned char *buf, unsigned int sector, unsigned char cnt)
{
    unsigned char rt;
    if(sd_type != SD_TYPE_V2HC) {
        sector *= 512; // 转换为字节地址
    }
    if (cnt == 1) {
        rt = Drv_SdSendCmd(CMD24, sector, 0x01);
        if(rt == 0) {
            rt = Drv_SDSendBlock(buf, 0xfe);     
        }
    } else {
        if(sd_type != SD_TYPE_MMC) {
            Drv_SdSendCmd(CMD55, 0, 0X01);    
            Drv_SdSendCmd(CMD23, cnt, 0X01);
        }
        rt = Drv_SdSendCmd(CMD25, sector, 0X01); // 连续读取
        if(rt == 0) {
            do {
                rt = Drv_SDSendBlock(buf, 0xfc); // 接收512个字节   
                buf += 512;  
            } while(--cnt && rt == 0);
            rt = Drv_SDSendBlock(0, 0xfd); // 接收512个字节
        }
    }   
    Drv_SdDisselect();
    return rt;
}