/*******************************************************************************************************
** Descriptions:		sd 卡驅(qū)動(dòng)軟件包: SD卡物理層 用戶API函數(shù)
********************************************************************************************************/
#include    "define.h"


/* SD卡信息結(jié)構(gòu)體變量 the information structure variable of SD Card */
sd_struct sds;			

/* 超時(shí)時(shí)間單位表(單位:0.000000001ns) timeout unit table */
const uint32 time_unit[8] = {1000000000,100000000,10000000,
							 1000000,100000,10000,1000,100};

/* 超時(shí)時(shí)間表 timeout value table */							 
const uint8 time_value[16] = { 0,10,12,13,15,20,25,30,
                              35,40,45,50,55,60,70,80};
 
/* 超時(shí)時(shí)間因數(shù)表 timeout factor table */                              
const uint8 r2w_fator[6] = {1,2,4,8,16,32};                           
    
/********************************************************************************************
		
用戶API函數(shù):  初始化,讀,寫,擦 SD卡  User API Function: Initialize,read,write,erase SD Card 
				
********************************************************************************************/

				
/*******************************************************************************************************************
** 函數(shù)名稱: INT8U SD_Initialize()				Name:	  INT8U SD_Initialize()
** 功能描述: 初始化SD卡							Function: initialize sd card
** 輸　  入: 無									Input:	  NULL
** 輸 　 出: 0:   正確    >0:   錯(cuò)誤碼		  	Output:	  0:  right		>0:  error code
********************************************************************************************************************/
uint8 SD_Initialize(void)
{
	uint8 recbuf[4],ret;
    
    SD_HardWareInit();					    		/* 初始化讀寫SD卡的硬件條件 Initialize the hardware that access SD Card */

    SPI_CS_Assert();								/* 1. 置CS為低 assert CS */  
	SD_SPIDelay(30);								/* 2. 至少延時(shí) 74 clock delay more than 74 clock */
    SPI_CS_Deassert();								/* 3. 置CS為高 dessert CS */
    SD_SPIDelay(3);									/* 4. 延時(shí)2(8 clock) delay 2(8 clock) */
    
    ret = SD_ResetSD();								/* 5. 發(fā)出CMDO命令復(fù)位SD卡 send CMD0 command to reset sd card */
    if (ret != SD_NO_ERR)
        return ret;									
 	
 	ret = SD_ActiveInit();							/* 6. 激活卡進(jìn)入初始化過程. active card initialize process */
 	if (ret != SD_NO_ERR)
 		return ret;
        
   	ret = SD_ReadOCR(4, recbuf);  					/* 7. 讀OCR寄存器,查詢卡支持的電壓值 read OCR register,get the supported voltage */
    if (ret != SD_NO_ERR)
        return ret;
    
    if ((recbuf[1] & MSK_OCR_33) != MSK_OCR_33)
        return SD_ERR_VOL_NOTSUSP;					/* 不支持3.3V,返回錯(cuò)誤碼  not support 3.3V,return error code */
    
    SPI_ClkToMax();									/* 8. 設(shè)置SPI時(shí)鐘到最大值 set SPI clock to maximum */
        
#if SD_CRC_EN        
    ret = SD_EnableCRC(1);							/* 使能CRC校驗(yàn) enable CRC check */
	if (ret != SD_NO_ERR)  
	  	return ret;
#endif

    ret = SD_SetBlockLen(SD_BLOCKSIZE);				/* 9. 設(shè)置塊的長(zhǎng)度: 512Bytes Set the block length: 512Bytes */
    if (ret != SD_NO_ERR)  
        return ret;
        
	return (SD_GetCardInfo());						/* 10. 讀CSD寄存器,獲取SD卡信息 read CSD register, get the information of SD card */
}

/*******************************************************************************************************************
** 函數(shù)名稱: INT8U SD_GetCardInfo()				Name:	  INT8U SD_GetCardInfo()
** 功能描述: 獲得SD卡的信息						Function: get the information of SD card
** 輸　  入: INT8U cardtype: 卡類型				Input:    INT8U cardtype: card type	
** 輸 　 出: 0:   正確    >0:   錯(cuò)誤碼		  	Output:	  0:  right		>0:  error code
*******************************************************************************************************************/
uint8 SD_GetCardInfo()
{
	uint32 tmp;
	uint8 csdbuf[16],ret;
		
	ret = SD_ReadCSD(16,csdbuf);	 								    		/* 讀CSD寄存器    read CSD register */
	if (ret != SD_NO_ERR)	
		return ret;	
		
	SD_CalTimeout(csdbuf);														/* 計(jì)算超時(shí)時(shí)間值 calculate timeout value */
		
	/* 計(jì)算塊的最大長(zhǎng)度  */														/* calculate the size of a sector */
	sds.block_len = 1 << (csdbuf[READ_BL_LEN_POS] & READ_BL_LEN_MSK);  			/* (2 ^ READ_BL_LEN) */
	
	/* 計(jì)算卡中塊的個(gè)數(shù) */														/* calculate the sector numbers of the SD Card */
	sds.block_num = ((csdbuf[C_SIZE_POS1] & C_SIZE_MSK1) << 10) +
	      			 (csdbuf[C_SIZE_POS2] << 2) +
	 	 			((csdbuf[C_SIZE_POS3] & C_SIZE_MSK3) >> 6) + 1;				/* (C_SIZE + 1)*/
		 	  															
	tmp = ((csdbuf[C_SIZE_MULT_POS1] & C_SIZE_MULT_MSK1) << 1) +   
	      ((csdbuf[C_SIZE_MULT_POS2] & C_SIZE_MULT_MSK2) >> 7) + 2;				/* (C_SIZE_MULT + 2) */
    	
    /* 獲得卡中塊的數(shù)量 */														/* get the block numbers in card */
	sds.block_num = sds.block_num * (1 << tmp);									/* (C_SIZE + 1) * 2 ^ (C_SIZE_MULT + 2) */
																			
	/* 計(jì)算扇區(qū)大小 */															/*calculate the size of sector */
	sds.erase_unit = ((csdbuf[SECTOR_SIZE_POS1] & SECTOR_SIZE_MSK1) << 1) +  			
	                 ((csdbuf[SECTOR_SIZE_POS2] & SECTOR_SIZE_MSK2) >> 7) + 1; /* SD (SECTOR_SIZE + 1) */
	    			
	return SD_NO_ERR;															/* 返回執(zhí)行成功 return perform sucessfully */
}


/*******************************************************************************************************************
** 函數(shù)名稱: INT8U SD_CalTimeout()				Name:	  INT8U SD_CalTimeout()
** 功能描述: 計(jì)算讀/寫/擦超時(shí)時(shí)間				Function: get the information of SD card
** 輸　  入: INT8U cardtype: 卡類型				Input:    INT8U cardtype: card type	
			 INT8U *csdbuf : CSD寄存器內(nèi)容		 	      INT8U *csdbuf : CSD register content
** 輸 　 出: 0:   正確    >0:   錯(cuò)誤碼		  	Output:	  0:  right		>0:  error code
*******************************************************************************************************************/
void SD_CalTimeout(uint8 *csdbuf)
{
	uint32 tmp;
	uint8 time_u,time_v,fator;
	
	sds.timeout_read = READ_TIMEOUT_100MS;								/* 默認(rèn)讀超時(shí)為100ms */
	sds.timeout_write = WRITE_TIMEOUT_250MS;							/* 默認(rèn)寫超時(shí)為250ms */
	sds.timeout_erase = WRITE_TIMEOUT_250MS;
		
	time_u = (csdbuf[TAAC_POS] & TAAC_MSK);								/* 讀超時(shí)時(shí)間單位 read timeout unit */
	time_v = (csdbuf[TAAC_POS] & NSAC_MSK) >> 3;						/* 讀超時(shí)時(shí)間值   read timeout value */
	fator = (csdbuf[R2WFACTOR_POS] & R2WFACTOR_MSK) >> 2;				/* 寫超時(shí)時(shí)間因數(shù) write timeout factor */
	
	if(time_v == 0)	return;
	if(fator >= 6) return;
	
	tmp = SPI_CLOCK * time_value[time_v] / 10 / time_unit[time_u];		/* TACC * f (單位 unit: clock) */
	tmp = tmp + csdbuf[NSAC_POS] * 100;									/* TACC * f + NSAC * 100 (單位 unit: clock) */
	
	/* 計(jì)算得到的超時(shí)值 the timeout value of being calculated */
	sds.timeout_read = tmp;
	sds.timeout_write = tmp * r2w_fator[fator];							/* (TACC * f + NSAC * 100) * R2WFACTOR (單位 unit:clock)*/
	
	sds.timeout_read  = sds.timeout_read * 100 / 8;						/* 實(shí)際值為計(jì)算值的100倍 */
	sds.timeout_write = sds.timeout_write * 100 / 8;
	
	if (sds.timeout_read > READ_TIMEOUT_100MS)							/* 取計(jì)算值與默認(rèn)值中的最小值 */
		sds.timeout_read = READ_TIMEOUT_100MS;
	
	if (sds.timeout_write > WRITE_TIMEOUT_250MS)
		sds.timeout_write = WRITE_TIMEOUT_250MS;

	sds.timeout_erase = sds.timeout_write;
}
/*******************************************************************************************************************
** 函數(shù)名稱: INT8U SD_CalTimeout()				Name:	  INT8U SD_CalTimeout()
** 功能描述: 計(jì)算讀/寫/擦超時(shí)時(shí)間				Function: get the information of SD card
** 輸　  入: INT8U *cardtype: 卡類型接收緩沖 	Input:    INT8U *cardtype: card type receive buff
** 輸 　 出: 0:   正確    >0:   錯(cuò)誤碼		  	Output:	  0:  right		>0:  error code
** 函數(shù)說明: 該命令不斷重復(fù)發(fā)送到SD卡，直到響應(yīng)R1的Bit0(Idle)位為0，表示SD卡內(nèi)部初始化處理完成。
		     當(dāng)響應(yīng)的Idle位為0時(shí)，SD卡就完全進(jìn)入SPI模式了。當(dāng)然重復(fù)發(fā)送命令CMD1是有次數(shù)限制的，
		     最大次數(shù)為宏定義SD_IDLE_WAIT_MAX.
*******************************************************************************************************************/
uint8 SD_ActiveInit(void)
{
	uint8 param[4] = {0,0,0,0},resp[5],ret;
	uint32 i = 0;

 	do 
    {													/* 發(fā)出CMD1, 查詢卡的狀態(tài), send CMD1 to poll card status */
        ret = SD_SendCmd(CMD1, param, CMD1_R, resp);
        if (ret != SD_NO_ERR)
       		return ret;
  
        i++;
    }
	while (((resp[0] & MSK_IDLE) == MSK_IDLE) && (i < SD_IDLE_WAIT_MAX));
														/* 如果響應(yīng)R1的最低位Idle位為1,則繼續(xù)循環(huán) */
														
    if (i >= SD_IDLE_WAIT_MAX)
        return SD_ERR_TIMEOUT_WAITIDLE;					/* 超時(shí),返回錯(cuò)誤 time out,return error */

	return SD_NO_ERR;
}