/*------------------------------------------------------------------------/
/  MMCv3/SDv1/SDv2 (in SPI mode) control module
/-------------------------------------------------------------------------/
/
/  Copyright (C) 2010, ChaN, all right reserved.
/
/ * This software is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/   personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/-------------------------------------------------------------------------*/
//Edited by A. Morrison to function on PIC32.

// Ported by Riccardo Leonardi to PIC32MX795F512L  (22/11/2011)
// Many thanks to Aiden Morrison's good work!
// changes: parametrization of SPI port number

/************************************************************************/
/* Ported by Bob Herlien (rah), MBARI.                                  */
/* 25mar2016, rah, Modified for oasis5 on FreeRTOS using PIC32MX470F512L*/
/************************************************************************/

#include <xc.h>
#include "diskio.h"
#include <dig_io.h>
#include <spi.h>
#include <clock.h>
#include <time.h>


/* Definitions for MMC/SDC command */
#define CMD0   (0)          /* GO_IDLE_STATE */
#define CMD1   (1)          /* SEND_OP_COND */
#define ACMD41 (41|0x80)    /* SEND_OP_COND (SDC) */
#define CMD8   (8)          /* SEND_IF_COND */
#define CMD9   (9)          /* SEND_CSD */
#define CMD10  (10)         /* SEND_CID */
#define CMD12  (12)         /* STOP_TRANSMISSION */
#define ACMD13 (13|0x80)    /* SD_STATUS (SDC) */
#define CMD16  (16)         /* SET_BLOCKLEN */
#define CMD17  (17)         /* READ_SINGLE_BLOCK */
#define CMD18  (18)         /* READ_MULTIPLE_BLOCK */
#define CMD23  (23)         /* SET_BLOCK_COUNT */
#define ACMD23 (23|0x80)    /* SET_WR_BLK_ERASE_COUNT (SDC) */
#define CMD24  (24)         /* WRITE_BLOCK */
#define CMD25  (25)         /* WRITE_MULTIPLE_BLOCK */
#define CMD41  (41)         /* SEND_OP_COND (ACMD) */
#define CMD55  (55)         /* APP_CMD */
#define CMD58  (58)         /* READ_OCR */


/* MMC/SDC card type definitions (CardType) */

#define CT_MMC              0x01
#define CT_SD1              0x02
#define CT_SD2              0x04
#define CT_SDC              (CT_SD1|CT_SD2)
#define CT_BLOCK            0x08


/* Port Controls  (Platform dependent) */
#define CS_LOW()		spiSelectSD()
#define CS_HIGH()		spi2Unselect()
//#define CS_LOW()        PORTCCLR = 8
//#define CS_HIGH()       PORTCSET = 8


// We have no WP, so only set SOCKINS, 25mar2016 rah
#define SOCKINS PORTCbits.RC2
// Flaky SD socket, show always present for now, 08apr2016 rah
//#define SOCKINS  0

#define FCLK_SLOW() spiSetSDBRG(15)     /* Set slow clock (100k-400k) */
#define FCLK_FAST() spiSetSDBRG(1)      /* Set fast clock (depends on the CSD) */


/*--------------------------------------------------------------------------
   Module Private Functions
---------------------------------------------------------------------------*/
static BYTE send_cmd (BYTE cmd, DWORD arg);
static int xmit_datablock (const BYTE *buff,BYTE token);


/************************************************************************/
/*  Module Private Data													*/
/************************************************************************/

static volatile DSTATUS Stat = STA_NOINIT;      /* Disk status */

static UINT CardType;


/*-----------------------------------------------------------------------*/
/* Exchange a byte between PIC and MMC via SPI  (Platform dependent)     */
/*-----------------------------------------------------------------------*/

#define xmit_spi(dat)		xchg_spi(dat)
#define rcvr_spi()      	xchg_spi(0xFF)
#define rcvr_spi_m(p)   	SPI2BUF = 0xFF; while (SPI2STATbits.SPIRBE); *(p) = (BYTE)SPI2BUF;
#define xmit_only_spi(dat)	SPI2BUF = dat

static
BYTE xchg_spi (BYTE dat)
{
    SPI2BUF = dat;

    while (SPI2STATbits.SPIRBE)
		;
    return (BYTE)SPI2BUF;
}

static BYTE rcvr_only_spi()
{
	while (SPI2STATbits.SPIRBE)
		;
	return((BYTE)SPI2BUF);
}


/*-----------------------------------------------------------------------*/
/* Wait for card ready                                                   */
/*-----------------------------------------------------------------------*/

static
BYTE wait_ready (void)
{
    BYTE		res;
	Nat32		stTick;

	stTick = clkGetTick();

    rcvr_spi();
    do
	{
        res = rcvr_spi();
	}
    while ((res != 0xFF) && ((clkGetTick() - stTick) < 500/MS_PER_TICK));

    return res;
}


/*-----------------------------------------------------------------------*/
/* Deselect the card and release SPI bus                                 */
/*-----------------------------------------------------------------------*/

static
void deselect (void)
{
	BYTE	dummy;

    CS_HIGH();
    rcvr_spi();			/* SPI bus is now OFF!  Can't do I/O		*/
}


/*-----------------------------------------------------------------------*/
/* Select the card and wait ready                                        */
/*-----------------------------------------------------------------------*/

static
int select (void)   /* 1:Successful, 0:Timeout */
{
    CS_LOW();
    if (wait_ready() != 0xFF) {
        deselect();
        return 0;
    }
    return 1;
}


/*-----------------------------------------------------------------------*/
/* Write Sector(s)                                                       */
/*-----------------------------------------------------------------------*/

#if _READONLY == 0
DRESULT disk_write (
    BYTE drv,               /* Physical drive nmuber (0) */
    const BYTE *buff,       /* Pointer to the data to be written */
    DWORD sector,           /* Start sector number (LBA) */
    UINT count              /* Sector count (1..255) */
)
{
    if (drv || !count) return RES_PARERR;
    if (Stat & STA_NOINIT) return RES_NOTRDY;
    if (Stat & STA_PROTECT) return RES_WRPRT;

    if (!(CardType & CT_BLOCK)) sector *= 512;  /* Convert to byte address if needed */

    if (count == 1) {       /* Single block write */
        if ((send_cmd(CMD24, sector) == 0)  /* WRITE_BLOCK */
            && xmit_datablock(buff, 0xFE))
            count = 0;
    }
    else {              /* Multiple block write */
        if (CardType & CT_SDC) send_cmd(ACMD23, count);
        if (send_cmd(CMD25, sector) == 0) { /* WRITE_MULTIPLE_BLOCK */
            do {
                if (!xmit_datablock(buff, 0xFC)) break;
                buff += 512;
            } while (--count);
            if (!xmit_datablock(0, 0xFD))   /* STOP_TRAN token */
                count = 1;
        }
    }
    deselect();

    return count ? RES_ERROR : RES_OK;
}
#endif /* _READONLY */



/*-----------------------------------------------------------------------*/
/* Power Control  (Platform dependent)                                   */
/*-----------------------------------------------------------------------*/
/* When the target system does not support socket power control, there   */
/* is nothing to do in these functions and chk_power always returns 1.   */

static
void power_on (void)
{
    FCLK_SLOW();                        		/* Set up slow SPI clock*/
	SPI2CONSET = _SPI2CON_ON_MASK;              /* Turn on SPI          */
}

static
void power_off (void)
{
    select();           /* Wait for card ready */
    deselect();

	SPI2CONCLR = _SPI2CON_ON_MASK;              /* Disable SPI          */

    Stat |= STA_NOINIT; /* Set STA_NOINIT */
}


/*-----------------------------------------------------------------------*/
/* Receive a data packet from MMC                                        */
/*-----------------------------------------------------------------------*/

static
int rcvr_datablock (    /* 1:OK, 0:Failed */
    BYTE *buff,         /* Data buffer to store received data */
    UINT btr            /* Byte count (must be multiple of 4) */
)
{
    BYTE		token;
	Nat32		stTick;
	int			i;

	stTick = clkGetTick();

    do {                            /* Wait for data packet in timeout of 100ms */
        token = rcvr_spi();
    }while ((token == 0xFF) && ((clkGetTick() - stTick) < 100/MS_PER_TICK));

    if(token != 0xFE) return 0;     /* If not valid data token, retutn with error */

	/* Prime FIFO with 2 bytes.									*/
	/* These will eventually push out the CRC, which we discard */
	xmit_only_spi(0xff); Nop();
	xmit_only_spi(0xff);

    do {                            /* Receive the data block into buffer */
        rcvr_spi_m(buff++);
        rcvr_spi_m(buff++);
        rcvr_spi_m(buff++);
        rcvr_spi_m(buff++);
    } while (btr -= 4);

	rcvr_only_spi();
	rcvr_only_spi();
	
    return 1;                       /* Return with success */
}


/*-----------------------------------------------------------------------*/
/* Send a data packet to MMC                                             */
/*-----------------------------------------------------------------------*/

#if _READONLY == 0
static
int xmit_datablock (    /* 1:OK, 0:Failed */
    const BYTE *buff,   /* 512 byte data block to be transmitted */
    BYTE token          /* Data token */
)
{
    BYTE resp;
    UINT bc = 508;

    if (wait_ready() != 0xFF) return 0;

    xmit_spi(token);				/* Xmit a token */
    if (token != 0xFD)	    		/* Not StopTran token */
	{
		xmit_only_spi(*buff++);		/* Prime FIFO with first 2 bytes */
		xmit_only_spi(*buff++);
		xmit_spi(*buff++);
		xmit_spi(*buff++);

        do {                        /* Xmit the 512 byte data block to the MMC */
            xmit_spi(*buff++);
            xmit_spi(*buff++);
            xmit_spi(*buff++);
            xmit_spi(*buff++);
        } while (bc -= 4);

		rcvr_only_spi();			/* Clear rcv FIFO of 2 extra bytes	*/
		rcvr_only_spi();
	
        xmit_spi(0xFF);             /* CRC (Dummy) */
        xmit_spi(0xFF);

        resp = rcvr_spi();          /* Receive a data response */
        if ((resp & 0x1F) != 0x05)  /* If not accepted, return with error */
            return 0;
    }

    return 1;
}
#endif  /* _READONLY */


/*-----------------------------------------------------------------------*/
/* Send a command packet to MMC                                          */
/*-----------------------------------------------------------------------*/

static
BYTE send_cmd (
    BYTE cmd,       /* Command byte */
    DWORD arg       /* Argument */
)
{
    BYTE n, res;


    if (cmd & 0x80) {   /* ACMD<n> is the command sequense of CMD55-CMD<n> */
        cmd &= 0x7F;
        res = send_cmd(CMD55, 0);
        if (res > 1) return res;
    }

    /* Select the card and wait for ready */
    deselect();
    if (!select()) return 0xFF;

    /* Send command packet */
    xmit_spi(0x40 | cmd);           /* Start + Command index */
    xmit_spi((BYTE)(arg >> 24));    /* Argument[31..24] */
    xmit_spi((BYTE)(arg >> 16));    /* Argument[23..16] */
    xmit_spi((BYTE)(arg >> 8));     /* Argument[15..8] */
    xmit_spi((BYTE)arg);            /* Argument[7..0] */
    n = 0x01;                       /* Dummy CRC + Stop */
    if (cmd == CMD0) n = 0x95;      /* Valid CRC for CMD0(0) */
    if (cmd == CMD8) n = 0x87;      /* Valid CRC for CMD8(0x1AA) */
    xmit_spi(n);

    /* Receive command response */
    if (cmd == CMD12) rcvr_spi();   /* Skip a stuff byte when stop reading */
    n = 10;                         /* Wait for a valid response in timeout of 10 attempts */

    do
	{
        res = rcvr_spi();
	}
    while ((res & 0x80) && --n);

    return res;         /* Return with the response value */
}



/*--------------------------------------------------------------------------

   Public Functions

---------------------------------------------------------------------------*/


/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive                                                 */
/*-----------------------------------------------------------------------*/

DSTATUS disk_initialize (
    BYTE drv        /* Physical drive nmuber (0) */
)
{
    BYTE n, cmd, ty, ocr[4];
	Nat32		stTick;

    if (drv) return STA_NOINIT;         /* Supports only single drive */

	if (SOCKINS)						/* CARD_DET hi means	 */
		return Stat;					/* No card in the socket */
	
    power_on();                         /* Force socket power on */
    FCLK_SLOW();
    for (n = 10; n; n--) rcvr_spi();    /* 80 dummy clocks */

    ty = 0;
    if (send_cmd(CMD0, 0) == 1)	           /* Enter Idle state */
	{
		stTick = clkGetTick();

        if (send_cmd(CMD8, 0x1AA) == 1) {   /* SDv2? */
            for (n = 0; n < 4; n++) 
				ocr[n] = rcvr_spi(); 			           	/* Get trailing return value of R7 resp */
            if (ocr[2] == 0x01 && ocr[3] == 0xAA)	 		/* The card can work at vdd range of 2.7-3.6V */
			{
				while (((clkGetTick() - stTick) < 1000/MS_PER_TICK) 
					   && send_cmd(ACMD41, 0x40000000))		/* Wait for leaving idle state (ACMD41 with HCS bit) */
					;
				
				if (((clkGetTick() - stTick) < 1000/MS_PER_TICK) &&
					(send_cmd(CMD58, 0) == 0))            /* Check CCS bit in the OCR */
				{
                    for (n = 0; n < 4; n++)
						ocr[n] = rcvr_spi();
                    ty = (ocr[0] & 0x40) ? CT_SD2|CT_BLOCK : CT_SD2;    /* SDv2 */
                }
            }
        } else {                            			/* SDv1 or MMCv3 */
            if (send_cmd(ACMD41, 0) <= 1)   {
                ty = CT_SD1; cmd = ACMD41;  			/* SDv1 */
            } else {
                ty = CT_MMC; cmd = CMD1;    			/* MMCv3 */
            }

			while (((clkGetTick() - stTick) < 1000/MS_PER_TICK) 
				   && send_cmd(cmd,0))
				;
			
			if (((clkGetTick() - stTick) < 1000/MS_PER_TICK) &&
				(send_cmd(CMD16, 512) != 0))			/* Set read/write block length to 512 */
                ty = 0;
        }
    }
    CardType = ty;
    deselect();

    if (ty) {           /* Initialization succeded */
        Stat &= ~STA_NOINIT;    /* Clear STA_NOINIT */
        FCLK_FAST();
    } else {            /* Initialization failed */
        power_off();
    }

    return Stat;
}



/*-----------------------------------------------------------------------*/
/* Get Disk Status                                                       */
/*-----------------------------------------------------------------------*/

DSTATUS disk_status (
    BYTE drv        /* Physical drive nmuber (0) */
)
{
    if (drv) return STA_NOINIT;     /* Supports only single drive */
    return Stat;
}



/*-----------------------------------------------------------------------*/
/* Read Sector(s)                                                        */
/*-----------------------------------------------------------------------*/

DRESULT disk_read (
    BYTE drv,       /* Physical drive nmuber (0) */
    BYTE *buff,     /* Pointer to the data buffer to store read data */
    DWORD sector,   /* Start sector number (LBA) */
    UINT count      /* Sector count (1..255) */
)
{
    if (drv || !count) return RES_PARERR;
    if (Stat & STA_NOINIT) return RES_NOTRDY;

    if (!(CardType & CT_BLOCK)) sector *= 512;  /* Convert to byte address if needed */

    if (count == 1) {       /* Single block read */
        if ((send_cmd(CMD17, sector) == 0)  /* READ_SINGLE_BLOCK */
            && rcvr_datablock(buff, 512))
            count = 0;
    }
    else {              /* Multiple block read */
        if (send_cmd(CMD18, sector) == 0) { /* READ_MULTIPLE_BLOCK */
            do {
                if (!rcvr_datablock(buff, 512)) break;
                buff += 512;
            } while (--count);
            send_cmd(CMD12, 0);             /* STOP_TRANSMISSION */
        }
    }
    deselect();

    return count ? RES_ERROR : RES_OK;
}


/*-----------------------------------------------------------------------*/
/* Miscellaneous Functions                                               */
/*-----------------------------------------------------------------------*/

DRESULT disk_ioctl (
    BYTE drv,       /* Physical drive nmuber (0) */
    BYTE ctrl,      /* Control code */
    void *buff      /* Buffer to send/receive data block */
)
{
    DRESULT res;
    BYTE n, csd[16], *ptr = buff;
    DWORD csize;


    if (drv) return RES_PARERR;
    if (Stat & STA_NOINIT) return RES_NOTRDY;

    res = RES_ERROR;
    switch (ctrl) {
        case CTRL_SYNC :    /* Flush dirty buffer if present */
            if (select()) {
                deselect();
                res = RES_OK;
            }
            break;

        case GET_SECTOR_COUNT : /* Get number of sectors on the disk (WORD) */
            if ((send_cmd(CMD9, 0) == 0) && rcvr_datablock(csd, 16)) {
                if ((csd[0] >> 6) == 1) {   /* SDv2? */
                    csize = csd[9] + ((WORD)csd[8] << 8) + 1;
                    *(DWORD*)buff = (DWORD)csize << 10;
                } else {                    /* SDv1 or MMCv2 */
                    n = (csd[5] & 15) + ((csd[10] & 128) >> 7) + ((csd[9] & 3) << 1) + 2;
                    csize = (csd[8] >> 6) + ((WORD)csd[7] << 2) + ((WORD)(csd[6] & 3) << 10) + 1;
                    *(DWORD*)buff = (DWORD)csize << (n - 9);
                }
                res = RES_OK;
            }
            break;

        case GET_SECTOR_SIZE :  /* Get sectors on the disk (WORD) */
            *(WORD*)buff = 512;
            res = RES_OK;
            break;

        case GET_BLOCK_SIZE :   /* Get erase block size in unit of sectors (DWORD) */
            if (CardType & CT_SD2) {    /* SDv2? */
                if (send_cmd(ACMD13, 0) == 0) {     /* Read SD status */
                    rcvr_spi();
                    if (rcvr_datablock(csd, 16)) {              /* Read partial block */
                        for (n = 64 - 16; n; n--)
							rcvr_spi();							/* Purge trailing data */
                        *(DWORD*)buff = 16UL << (csd[10] >> 4);
                        res = RES_OK;
                    }
                }
            } else {                    /* SDv1 or MMCv3 */
                if ((send_cmd(CMD9, 0) == 0) && rcvr_datablock(csd, 16)) {  /* Read CSD */
                    if (CardType & CT_SD1) {    /* SDv1 */
                        *(DWORD*)buff = (((csd[10] & 63) << 1) + ((WORD)(csd[11] & 128) >> 7) + 1) << ((csd[13] >> 6) - 1);
                    } else {                    /* MMCv3 */
                        *(DWORD*)buff = ((WORD)((csd[10] & 124) >> 2) + 1) * (((csd[11] & 3) << 3) + ((csd[11] & 224) >> 5) + 1);
                    }
                    res = RES_OK;
                }
            }
            break;

        case MMC_GET_TYPE :     /* Get card type flags (1 byte) */
            *ptr = CardType;
            res = RES_OK;
            break;

        case MMC_GET_CSD :  /* Receive CSD as a data block (16 bytes) */
            if ((send_cmd(CMD9, 0) == 0)    /* READ_CSD */
                && rcvr_datablock(buff, 16))
                res = RES_OK;
            break;

        case MMC_GET_CID :  /* Receive CID as a data block (16 bytes) */
            if ((send_cmd(CMD10, 0) == 0)   /* READ_CID */
                && rcvr_datablock(buff, 16))
                res = RES_OK;
            break;

        case MMC_GET_OCR :  /* Receive OCR as an R3 resp (4 bytes) */
            if (send_cmd(CMD58, 0) == 0) {  /* READ_OCR */
                for (n = 0; n < 4; n++)
                    *((BYTE*)buff+n) = rcvr_spi();
                res = RES_OK;
            }
            break;

        case MMC_GET_SDSTAT :   /* Receive SD statsu as a data block (64 bytes) */
            if (send_cmd(ACMD13, 0) == 0) { /* SD_STATUS */
                rcvr_spi();
                if (rcvr_datablock(buff, 64))
                    res = RES_OK;
            }
            break;

        default:
            res = RES_PARERR;
    }

    deselect();

    return res;
}


/************************************************************************/
/* Function    : get_fattime                                            */
/* Purpose     : Required interface routine for Fatfs                   */
/* Inputs      : None                                                   */
/* Outputs     : None                                                   */
/************************************************************************/
DWORD get_fattime(void)
{
	time_t		tod;
    struct tm   *tmptr;

	tod = clkTime();
	if ((tmptr = localtime(&tod)) == NULL)
        return(0);

    return(((((DWORD)tmptr->tm_year - 80) & 0x7f) << 25)
           | ((((DWORD)tmptr->tm_mon + 1) & 0xf) << 21)
           | (((DWORD)tmptr->tm_mday & 0x1f) << 16)
           | ((WORD)(tmptr->tm_hour & 0xf) << 11)
           | ((WORD)(tmptr->tm_min & 0x3f) << 5)
           | ((WORD)(tmptr->tm_sec & 0x3f) >> 1));

}