/*-----------------------------------------------------------------------*/
/* MMCv3/SDv1/SDv2 (in SPI mode) control module  (C)ChaN, 2007             */
/*-----------------------------------------------------------------------*/
/* Only spi_rcvr(), spi_xmit(), disk_timerproc() and some macros         */
/* are platform dependent.                                               */
/*-----------------------------------------------------------------------*/

#include <avr/io.h>
#include <stdbool.h>
#include "timer.h"
#include "spi.h"
#include "diskio.h"
#include "debug.h"
#include "print-utils.h"


/* Definitions for MMC/SDC command */
#define CMD0	(0)			/* GO_IDLE_STATE */
#define CMD1	(1)			/* SEND_OP_COND (MMC) */
#define	ACMD41	(0x80+41)	/* 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	(0x80+13)	/* 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 (MMC) */
#define	ACMD23	(0x80+23)	/* SET_WR_BLK_ERASE_COUNT (SDC) */
#define CMD24	(24)		/* WRITE_BLOCK */
#define CMD25	(25)		/* WRITE_MULTIPLE_BLOCK */
#define CMD55	(55)		/* APP_CMD */
#define CMD58	(58)		/* READ_OCR */


/* SD card socket connections */
#if 0
//#define MMC_PORT		PORTG		/* Socket contact port */
//#define MMC_INPORT		PING
//#define SD_WP_PIN		5			/* Write protect switch */
#endif

/* SD card SPI access */
#define SD_CD_PORT		PORTG
#define SD_CD_DDR		DDRG
#define SD_CD_INPORT		PING
#define SD_CD_PIN		3			/* Card detect switch */

#define SD_WP_PORT		PORTG
#define SD_WP_DDR		DDRG
#define SD_WP_INPORT		PING
//#define SD_WP_PIN		5			/* Write protect switch */

#define SD_CS_PORT		PORTG
#define SD_CS_DDR		DDRG
#define SD_CS_PIN		4			/* Chip select pin */


/* Port Controls  (Platform dependent) */

#ifdef SD_CD_PIN
static inline
bool sd_cd(void)
{
	return (SD_CD_INPORT & _BV(SD_CD_PIN)) == 0;
}
#endif

#ifdef SD_WP_PIN
static inline
bool sd_wp(void)
{
	return (SD_WP_INPORT & _BV(SD_WP_PIN)) == 0;
}
#endif

#define CS_LOW()	SD_CS_PORT &= ~(1<<SD_CS_PIN)	/* MMC CS = L */
#define CS_HIGH()	SD_CS_PORT |=  (1<<SD_CS_PIN)	/* MMC CS = H */

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

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

 Module Private Functions

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

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

static
BYTE CardType; 			/* Card type flags */

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

static
int wait_ready (void)	/* 1:OK, 0:Timeout */
{
	uint32_t to = get_timer(0);

	/* Wait for ready in timeout of 500ms */
	do {
		if (spi_rcvr() == 0xFF) {
			return 1;
		}
	} while (get_timer(to) < 500);

	return 0;
}

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

static
void deselect (void)
{
//	debug("*** enter deselect()\n");
	CS_HIGH();
	/* Dummy clock (TODO: force DO hi-z for multiple slave SPI) */
	spi_rcvr();
//	debug("***  exit deselect()\n");
}



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

static
int select (void)	/* 1:Successful, 0:Timeout */
{
//	debug("*** enter select()\n");
	CS_LOW();
	/* Dummy clock (force DO enabled) */
	spi_rcvr();

	if (wait_ready()) {
//		debug("***  exit select() == 1\n");
		return 1;	/* OK */
	}
	deselect();
//	debug("***  exit select() == 0\n");

	return 0;	/* Timeout */
}

/*-----------------------------------------------------------------------*/
/* 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)
{
//	debug("*** enter power_on()\n");

#ifdef SD_PWR_PIN
	SD_PWR_DDR |= _BV(SD_PWR_PIN); // Turns on PWR pin as output
	SD_PWR_PORT &= ~_BV(SD_PWR_PIN); // Drives PWR pin high

	for (uint32_t to = get_timer(0); get_timer(to) < 30;)
		; /* Wait for 30ms */
#endif

#ifdef SD_CD_PIN
	/* Card detect, input with pullup */
	SD_CD_DDR &= ~_BV(SD_CD_PIN);
	SD_CD_PORT |= _BV(SD_CD_PIN);
#endif
#ifdef SD_WP_PIN
	SD_WP_DDR &= ~_BV(SD_WP_PIN);
	SD_WP_PORT |= _BV(SD_WP_PIN);
#endif
	SD_CS_PORT |= _BV(SD_CS_PIN);
	SD_CS_DDR |= _BV(SD_CS_PIN); // Turns on CS pin as output

//	debug("***  exit power_on()\n");
}

static
void power_off (void)
{
//	debug("*** enter power_off()\n");
	select();				/* Wait for card ready */
	deselect();

#ifdef SD_PWR_PIN
	SD_PWR_PORT |= (1 << SD_PWR_PIN); /* Socket power OFF */
#endif
	disk_stat |= STA_NOINIT; /* Set STA_NOINIT */
//	debug("***  exit power_off()\n");
}

#if 0
static
int chk_power(void) /* Socket power state: 0=off, 1=on */
{
#ifdef SD_PWR_PIN
	return (SD_PWR_PORT & (1 << SD_PWR_PIN)) ? 0 : 1;
#else
	return 1;
#endif /* SD_PWR_PIN */
}
#endif

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

static
int rcvr_datablock (
	BYTE *buff,			/* Data buffer to store received data */
UINT btr /* Byte count (must be multiple of 4) */
) {
	BYTE token, tmp;
	uint32_t to = get_timer(0);

	/* Wait for data packet in timeout of 200ms */
	do {
		token = spi_rcvr();
	} while ((token == 0xFF) && get_timer(to) < 200);
	if(token != 0xFE) return 0;		/* If not valid data token, retutn with error */

	tmp = spi_rcvr(); /* shift in first byte */
	spi_write(0xff); /* start shift in next byte */
	while (--btr) {
		*buff++ = tmp;
		asm volatile (""::"r"(buff), "r"(btr));
		spi_wait();
		tmp = SPDR;
		spi_write(0xff);
	}
	*buff = tmp; /* store last byte in buffer while SPI module shifts in crc part1 */
	spi_wait();
	spi_rcvr(); /* second crc */

	return 1; /* Return with success */
}

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

#if	_USE_WRITE
static
int xmit_datablock (
		const BYTE *buff, /* 512 byte data block to be transmitted */
		BYTE token /* Data/Stop token */
)
{
	BYTE resp, tmp;
	UINT btr;

	if (!wait_ready()) return 0;

	spi_write(token); /* Xmit data token */
	if (token != 0xFD) { /* Is data token */
		btr = 512;
		do {
			tmp = *buff++;
			spi_wait();
			spi_write(tmp);
		}while (--btr);
		spi_wait();
		spi_xmit(0xff); /* CRC (Dummy) */
		spi_xmit(0xff);
		resp = spi_rcvr(); /* Reveive data response */
		return ((resp & 0x1F) != 0x05) ? 0 : 1; /* If not accepted, return with error */
	}

	spi_wait();
	return 1;
}
#endif /* _USE_WRITE */

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

static
BYTE send_cmd (		/* Returns R1 resp (bit7==1:Send failed) */
	BYTE cmd,		/* Command index */
					 DWORD arg /* Argument */
) {
	union {
		DWORD as32;
		BYTE as8[4];
	} argtmp;
	BYTE n, res;

//	debug("*** send_cmd( %.2x )\n", cmd);

	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 except to stop multiple block read */
	if (cmd != CMD12) {
		deselect();
		if (!select())
			return 0xFF;
	}

	/* Send command packet */
	spi_xmit(0x40 | cmd); /* Start + Command index */
	argtmp.as32 = arg;
	spi_xmit(argtmp.as8[3]); /* Argument[31..24] */
	spi_xmit(argtmp.as8[2]); /* Argument[23..16] */
	spi_xmit(argtmp.as8[1]); /* Argument[15..8] */
	spi_xmit(argtmp.as8[0]); /* 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) */
	spi_xmit(n);

	/* Receive command response */
	if (cmd == CMD12)
		spi_rcvr(); /* Skip a stuff byte when stop reading */
	n = 10; /* Wait for a valid response in timeout of 10 attempts */
	do
		res = spi_rcvr();
	while ((res & 0x80) && --n);

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

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

 Public Functions

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

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

#define MMC_INIT_TO 1000	/* 1s */

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

	if (drv)
		return STA_NOINIT; /* Supports only single drive */
	if (disk_stat & STA_NODISK)
		return disk_stat; /* No card in the socket */

	power_on(); /* Force socket power on */
	FCLK_SLOW();
	for (n = 10; n; n--)
		spi_rcvr(); /* 80 dummy clocks */

	ty = 0;
	if (send_cmd(CMD0, 0) == 1) { /* Enter Idle state */
		/* Init timeout timer */
		uint32_t timer = get_timer(0);

		if (send_cmd(CMD8, 0x1AA) == 1) {	/* SDv2? */
			for (n = 0; n < 4; n++) ocr[n] = spi_rcvr();		/* 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 (get_timer(timer) < MMC_INIT_TO && send_cmd(ACMD41, 1UL << 30));	/* Wait for leaving idle state (ACMD41 with HCS bit) */
				if (get_timer(timer) < MMC_INIT_TO && send_cmd(CMD58, 0) == 0) {		/* Check CCS bit in the OCR */
					for (n = 0; n < 4; n++) ocr[n] = spi_rcvr();
					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 */
			}

			/* Wait for leaving idle state */
			while (get_timer(timer) < MMC_INIT_TO && send_cmd(cmd, 0));

			/* Set R/W block length to 512 */
			if (!(get_timer(timer) < MMC_INIT_TO) || send_cmd(CMD16, 512) != 0)
				ty = 0;
		}
	}
	CardType = ty;
	deselect();

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

	return disk_stat;
}

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

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

	if (drv || !count) return RES_PARERR;
	if (disk_stat & STA_NOINIT) return RES_NOTRDY;

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

	cmd = count > 1 ? CMD18 : CMD17;			/*  READ_MULTIPLE_BLOCK : READ_SINGLE_BLOCK */
	if (send_cmd(cmd, sector) == 0) {
		do {
			if (!rcvr_datablock(buff, 512))
				break;
			buff += 512;
		} while (--count);
		if (cmd == CMD18)
			send_cmd(CMD12, 0);	/* STOP_TRANSMISSION */
	}
	deselect();

	return count ? RES_ERROR : RES_OK;
}

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

#if _USE_WRITE
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 (disk_stat & STA_NOINIT) return RES_NOTRDY;
	if (disk_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 /* _USE_WRITE */

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

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

	if (drv)
		return RES_PARERR;

	res = RES_ERROR;

	if (disk_stat & STA_NOINIT) return RES_NOTRDY;

	switch (cmd) {
	case CTRL_SYNC :		/* Make sure that no pending write process. Do not remove this or written sector might not left updated. */
		if (select())
			res = RES_OK;
		break;

	case GET_SECTOR_COUNT: /* Get number of sectors on the disk (DWORD) */
		if ((send_cmd(CMD9, 0) == 0) && rcvr_datablock(csd, 16)) {
			if ((csd[0] >> 6) == 1) {	/* SDC ver 2.00 */
				csize = csd[9] + ((WORD)csd[8] << 8) + ((DWORD)(csd[7] & 63) << 16) + 1;
				*(DWORD*)buff = csize << 10;
			} else {					/* SDC ver 1.XX or MMC*/
				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 = csize << (n - 9);
			}
			res = RES_OK;
		}
		break;

	case GET_BLOCK_SIZE:	/* Get erase block size in unit of sector (DWORD) */
		if (CardType & CT_SD2) {	/* SDv2? */
			if (send_cmd(ACMD13, 0) == 0) { /* Read SD status */
				spi_rcvr();
				if (rcvr_datablock(csd, 16)) { /* Read partial block */
					for (n = 64 - 16; n; n--)
						spi_rcvr(); /* 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;

	/* Following commands are never used by FatFs module */

	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(ptr, 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(ptr, 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 = 4; n; n--)
				*ptr++ = spi_rcvr();
			res = RES_OK;
		}
		break;

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

	case CTRL_POWER_OFF :	/* Power off */
		power_off();
		disk_stat |= STA_NOINIT;
		res = RES_OK;
		break;

	default:
		res = RES_PARERR;
	}

	deselect();

	return res;
}
#endif /* _USE_IOCTL */

/*-----------------------------------------------------------------------*/
/* Device Timer Interrupt Procedure  (Platform dependent)                */
/*-----------------------------------------------------------------------*/
/* This function must be called in period of 10ms                        */

void disk_timerproc (void)
{
	BYTE s;

	s = disk_stat;

#ifdef SD_WP_PIN
	if (sd_wp())				/* Write protected */
		s |= STA_PROTECT;
	else					/* Write enabled */
		s &= ~STA_PROTECT;
#endif

#ifdef SD_CD_PIN
	if (sd_cd())				/* Card inserted */
		s &= ~STA_NODISK;
	else					/* Socket empty */
		s |= (STA_NODISK | STA_NOINIT);
#endif

	disk_stat = s;				/* Update MMC status */
}