#include "shimatta_sdio.h"
#include "shimatta_sdio_config.h"
#include <cmsis/core_cm4.h>
#include <stm32f4xx.h>

extern void sdio_wait_ms(unsigned int i);

#define SETAF(PORT,PIN,AF)  PORT->AFR[(PIN < 8 ? 0 : 1)] |= AF << ((PIN < 8 ? PIN : (PIN - 8)) * 4)

#define READCTRL ((BLOCKSIZE << 4) | SDIO_DCTRL_DMAEN)
#define DMAP2M (DMA_SxCR_CHSEL_2 | DMA_SxCR_PBURST_0 | DMA_SxCR_MBURST_0 | DMA_SxCR_MSIZE_1 | DMA_SxCR_PSIZE_1 | DMA_SxCR_MINC | DMA_SxCR_PFCTRL)
#define DMAM2P (DMA_SxCR_CHSEL_2 | DMA_SxCR_PBURST_0 | DMA_SxCR_MBURST_0 | DMA_SxCR_MSIZE_1 | DMA_SxCR_PSIZE_1 | DMA_SxCR_MINC | DMA_SxCR_PFCTRL | DMA_SxCR_DIR_0)
#define SHORT_ANS 1
#define LONG_ANS 3
#define NO_ANS 0

#define CCRCFAIL 1
#define CTIMEOUT 2
#define CNOTEXPETED 3

/* OCR Register Masks */
#define OCS_CCS (1<<30)
#define OCS_BUSY (1<<31)

enum acmd41_ret {ACMD41_RESP_INIT = 0, ACMD41_RESP_ERR, ACMD41_RESP_SDSC, ACMD41_RESP_SDXC};
enum cmd8_ret {CMD8_RESP_TIMEOUT = 0, CMD8_VOLTAGE_ACCEPTED, CMD8_VOLTAGE_DENIED};
typedef uint8_t CID_t;

static struct sd_info card_info; // = {.type = CARD_NONE};

/**
 * @brief checkNotInserted
 * @return return 0 if card is inserted, else 1
 */
static int sdio_check_inserted() {
#if SDIO_ENABLE_INS
	return ((INS_PORT->IDR & INS_PIN) == (INS_ACTIVE_LEVEL<<INS_PIN) ? 0 : 1);
#else
	return 0; // Assume Card is inserted
#endif
}

/**
 * @brief checkWriteProtection
 * @return 0 if card is writable.
 */
static int sdio_check_write_protection() {
#if SDIO_ENABLE_WRITEPROT
	return ((WRITEPROT_PORT->IDR & WRITEPROT_PIN) == (WRITEPROT_ACTIVE_LEVEL<<WRITEPROT_PIN) ? 1 : 0);
#else
	return 0; // Assume Card is not write protected
#endif
}

static void sdio_wait_cmd_sent()
{
	while (!(SDIO->STA & SDIO_STA_CMDSENT));
	SDIO->ICR |= SDIO_ICR_CMDSENTC;
}

static int sdio_send_cmd(uint8_t cmd, uint32_t arg, uint8_t expected_ans){
	/* Clear Flags */
	SDIO->ICR = SDIO_ICR_CCRCFAILC | SDIO_ICR_CMDRENDC | SDIO_ICR_CTIMEOUTC | SDIO_ICR_CMDSENTC;
	/* Send command */
	SDIO->ARG = arg;
	SDIO->CMD = (cmd & SDIO_CMD_CMDINDEX) | SDIO_CMD_CPSMEN | ((expected_ans << 6) & SDIO_CMD_WAITRESP);
	return 0;
}

static int sdio_get_response(uint8_t expected_command, uint8_t type_of_answer, uint32_t *response_buffer) {
	uint32_t sdio_status;

	/* Wait until command isn't active anymore */
	while (SDIO->STA & SDIO_STA_CMDACT);

	/* Wait for error or success */
	while (1) {
		sdio_status = SDIO->STA;

		/* Check if a valid response was received */
		if (sdio_status & SDIO_STA_CMDREND)
			break;

		if ((sdio_status & SDIO_STA_CMDSENT) && (type_of_answer == NO_ANS))
			break; // No response required

		/* Exclude ACMD41 and CMD2 from valid CRC check */
		if ((sdio_status & SDIO_STA_CCRCFAIL)) {
			if(expected_command == 0xff) {
				break;
			} else {
				return -CCRCFAIL;
			}
		}

		if (sdio_status & SDIO_STA_CTIMEOUT)
			return -CTIMEOUT;
	}

	/* Valid Respone Received */
	if (((SDIO->RESPCMD & SDIO_RESPCMD_RESPCMD) != expected_command) && (expected_command != 0xff))
		return -CNOTEXPETED; //Not the expected respose

	/* If case of a correct Response */
	*(response_buffer++) = SDIO->RESP1;

	/* Long response */
	if (type_of_answer == LONG_ANS) {
		*(response_buffer++) = SDIO->RESP2;
		*(response_buffer++) = SDIO->RESP3;
		*(response_buffer++) = SDIO->RESP4;
	}

	return 0;
}

/**
 * @brief Switch the card to application mode. It now accepts ACMDXX commands
 * @return 0 if successfuls
 */
static int sdio_switch_appmode_cmd55()
{
	int retry = 0x20;
	union sdio_status_conv converter;
	uint32_t response;
	do {
		/* Execute Command and check for valid response */
		sdio_send_cmd(55, (card_info.rca<<16)&0xFFFF0000, SHORT_ANS);

		if (!sdio_get_response(55, SHORT_ANS, &response))
		{
			/* Response valid. Check if Card has accepted switch to application command mode */
			converter.value = response;
			if (converter.statusstruct.APP_CMD == 1)
				return 0;
		}
	} while (--retry > 0);

	return -1;
}

enum acmd41_ret sdio_init_card_acmd41(uint8_t HCS){
	uint32_t response;
	int retry = 0x20;
	if (sdio_switch_appmode_cmd55())
		return ACMD41_RESP_ERR;

	do {
		sdio_send_cmd(41, (HCS ? (1<<30) : 0) | (1<<28) | (1<<20) |(1<<21)|(1<<22) |(1<<23)|(1<<19), SHORT_ANS);
		if (!sdio_get_response(0xFF, SHORT_ANS, &response)) {
			if (response & OCS_BUSY) {
				/* Card is ready... Who knows why this bit is called busy */
				if (response & OCS_CCS) {
					return ACMD41_RESP_SDXC;
				} else {
					return ACMD41_RESP_SDSC;
				}
			} else {
				return ACMD41_RESP_INIT;
			}
		}
	} while (--retry > 0);

	return ACMD41_RESP_ERR;
}

static int sdio_send_csd_cmd9(uint16_t rca, uint32_t *response_buffer) {
	int timeout = 0x20;
	int res;

	do {
		sdio_send_cmd(9, (rca<<16)&0xFFFF0000, LONG_ANS);
		res = sdio_get_response(0xFF, LONG_ANS, response_buffer);
		if (!res)
			break;
	} while (--timeout > 0);

	return res;
}

/**
 * @brief Send data buffer to SD card
 * @param dlen Data length. Must be a multiple of 4 bytes
 * @param blklen Log2 of block length (9 in case of 512 byte block)
 * @param buff Buffer to send
 */
static void sdio_write_buffer(uint32_t dlen, uint32_t log_blklen, const unsigned char *buff)
{
	uint32_t count;
	int byte_count;
	int byte_max;
	uint32_t fifo;

	SDIO->DLEN = dlen;

	/* Init Transfer */
	SDIO->ICR = SDIO_ICR_CCRCFAILC | SDIO_ICR_DCRCFAILC | SDIO_ICR_CTIMEOUTC | SDIO_ICR_DTIMEOUTC |
			SDIO_ICR_TXUNDERRC | SDIO_ICR_RXOVERRC | SDIO_ICR_CMDRENDC | SDIO_ICR_CMDSENTC | SDIO_ICR_DATAENDC |
			SDIO_ICR_STBITERRC | SDIO_ICR_DBCKENDC | SDIO_ICR_SDIOITC | SDIO_ICR_CEATAENDC;
	SDIO->DCTRL = (log_blklen<<4) | SDIO_DCTRL_DTEN;

	for (count = 0; count < dlen; count += 4) {
		fifo = 0;

		if ((dlen - count) < 4)
			byte_max = dlen - count;
		else
			byte_max = 4;

		for (byte_count = 0; byte_count < byte_max; byte_count++) {
			fifo >>= 8;
			fifo |= (((uint32_t)*(buff++)) << 24) & 0xFF000000;
		}

		/* Wait as long as FIFO is full */
		while (SDIO->STA & SDIO_STA_TXFIFOF);

		/* Write data to FIFO */
		SDIO->FIFO = fifo;
	}

	/* Wait for TX to complete */
	while (SDIO->STA & SDIO_STA_TXACT);
}

static int sdio_send_write_block_cmd24(uint32_t addr)
{
	uint32_t response;

	sdio_send_cmd(24, addr, SHORT_ANS);

	return sdio_get_response(24, SHORT_ANS, &response);
}

static int sdio_check_status_register_cmd13(uint16_t rca, uint32_t *status)
{
	int timeout = 0x20;
	uint32_t response;
	int res;

	do {
		sdio_send_cmd(13, (rca<<16)&0xFFFF0000, SHORT_ANS);
		if (!(res = sdio_get_response(13, SHORT_ANS, &response))) {
			*status = response;
			break;
		}
	} while (--timeout > 0);

	return res;
}

static int sdio_send_bus_width_acmd6(uint8_t bus_width)
{
	uint32_t response;
	int retry = 0x20;
	int ret;

	if (sdio_switch_appmode_cmd55()) return -1;
	do {
		sdio_send_cmd(0x6, (bus_width == 4 ? 0x2 : 0x0), SHORT_ANS);
		ret = sdio_get_response(0x6, SHORT_ANS, &response);
		if (!ret)
			return 0;

	} while (--retry > 0);

	return ret;

}

static int sdio_get_sector_count(uint16_t rca, uint32_t *sector_count)
{
	uint32_t csd[4];
	int res;
	uint32_t size, mult, read_len, csd_rev;

	if ((res = sdio_send_csd_cmd9(rca, csd))) {
		return -1;
	}

	csd_rev = ((csd[0] >> 30) & (0x3));

	if (csd_rev == 0) {
		/* SD v1 Card */
		size = ((csd[1] & 0x3FF) <<2) | (((csd[2]) & ((1<<31) | (1<<30)))>>30);
		mult = ((csd[2] & ((1<<17)|(1<<16)|(1<<15)))>>15);
		read_len = (1<<((csd[1] & ((1<<19)|(1<<18)|(1<<17)|(1<<16)))>>16));
		*sector_count = (((size +1)*(1<<(mult+2))*read_len) >> BLOCKSIZE);
	} else if (csd_rev == 1) {
		/* SD v2 Card */
		size = (((csd[1] & 0x3F)<<16) | ((csd[2] & 0xFFFF0000) >> 16));
		*sector_count = (size << (19-BLOCKSIZE));
	}

	return 0;
}

/**
 * @brief Switch the SDIo prescaler
 * @param Prescaler value
 */
static void sdio_switch_prescaler(uint8_t clkdiv)
{
	uint32_t reg;
	reg = SDIO->CLKCR;
	/* Clear prescaler */
	reg &= ~SDIO_CLKCR_CLKDIV;
	/* Set bits */
	reg |= (SDIO_CLKCR_CLKDIV & clkdiv);
	SDIO->CLKCR = reg;
}

/**
 * @brief initDetectandProtectionPins
 */
static void sdio_init_detect_pins()
{
#if SDIO_ENABLE_WRITEPROT==1
	WRITEPROT_PORT->PUPDR |= ((WRITEPROT_PULLUP ? 1 : 0)<<WRITEPROT_PIN*2);
#endif /* SDIO_ENABLE_WRITEPROT */
#if SDIO_ENABLE_INS==1
	INS_PORT->PUPDR |= ((INS_PULLUP? 1 : 0)<<INS_PIN*2);
#endif /* SDIO_ENABLE_INS */
	__DSB();
}

static void sdio_init_hw()
{
	//Init Clocks
	RCC->AHB1ENR    |= PORTCLKMASK | RCC_AHB1ENR_DMA2EN;
	RCC->APB2ENR    |= RCC_APB2ENR_SDIOEN;
	//Init Alternate Functions
	CLKPORT->MODER  |= (2<<CLKPIN*2);
	D0PORT->MODER   |= (2<<D0PIN*2);
	D0PORT->PUPDR   |= (1<<D0PIN*2);
	CMDPORT->MODER  |= (2<<CMDPIN*2);
	CMDPORT->PUPDR	|= (1<<CMDPIN*2);
#if BUSWIDTH==4
	D1PORT->MODER   |= (2<<D1PIN*2);
	D1PORT->PUPDR   |= (1<<D1PIN*2);
	D2PORT->MODER   |= (2<<D2PIN*2);
	D2PORT->PUPDR   |= (1<<D2PIN*2);
	D3PORT->MODER   |= (2<<D3PIN*2);
	D3PORT->PUPDR   |= (1<<D3PIN*2);
#endif
	//CLKPORT->AFR[(CLKPIN < 8 ? 0 : 1)] |= ALTFUNC << ((CLKPIN < 8 ? CLKPIN : (CLKPIN - 8)) * 4);
	SETAF(CLKPORT,  CLKPIN, ALTFUNC);
	SETAF(CMDPORT, CMDPIN, ALTFUNC);
	SETAF(D0PORT,   D0PIN,  ALTFUNC);
#if BUSWIDTH==4
	SETAF(D1PORT, D1PIN,  ALTFUNC);
	SETAF(D2PORT,   D2PIN,  ALTFUNC);
	SETAF(D3PORT,   D3PIN,  ALTFUNC);
#endif


	//Init Module

	//Set CLK Control Register
	SDIO->CLKCR = (HW_FLOW<<14) | ((BUSWIDTH == 4 ? 1 : 0)<<11) | SDIO_CLKCR_CLKEN |
			(INITCLK & SDIO_CLKCR_CLKDIV);

	//Set Data Timeout
	SDIO->DTIMER = DTIMEOUT;

	//Set Data Parameters
	//SDIO->DCTRL = (BLOCKSIZE << 4) | SDIO_DCTRL_DMAEN;
	//Set Power Register: Power up Card CLK
	SDIO->POWER = SDIO_POWER_PWRCTRL_0 | SDIO_POWER_PWRCTRL_1;

}

static int sdio_send_read_block_cmd17(uint32_t addr)
{
	uint32_t response;
	int retry;
	int ret;
	
	sdio_send_cmd(17, addr, SHORT_ANS);
	ret = sdio_get_response(17, SHORT_ANS, &response);
	return ret;
}

static int sdio_send_all_send_cid_cmd2()
{
	uint32_t response[4];
	int ret;
	int retry = 0x20;

	do {
		sdio_send_cmd(2, 0, LONG_ANS);
		if (!(ret = sdio_get_response(0xFF, LONG_ANS, response)))
			return 0;
	} while (retry-- > 0);

	return ret;
}

static int sdio_send_relative_address_cmd3(uint16_t* rca)
{
	uint32_t response;
	int retry = 0x20;

	do {
		sdio_send_cmd(3, 0, SHORT_ANS);
		if (!sdio_get_response(3, SHORT_ANS, &response)) {
			// TODO: Do some *optional* checking
			*rca = ((response & 0xFFFF0000) >> 16);
			return 0;
		}
	} while (retry-- > 0);
	return -1;
}

static int sdio_send_go_idle_cmd0() {
	sdio_send_cmd(0, 0x0, NO_ANS);
	sdio_wait_cmd_sent();
	return 0;
}

static enum cmd8_ret sdio_send_iface_condition_cmd8()
{
	uint32_t response;
	int res = 0;
	int retry = 0x20;

	do {
		sdio_send_cmd(8, 0x1CC, SHORT_ANS); // 3.3V supply requesR
		res = sdio_get_response(8, SHORT_ANS, &response);
		if (res == 0) {
			if (response & 0x100)
				return CMD8_VOLTAGE_ACCEPTED;
			else
				return CMD8_VOLTAGE_DENIED;
		}
	} while (retry-- > 0);

	return CMD8_RESP_TIMEOUT;
}

static int sdio_send_block_length_cmd16(uint32_t blocklen) {
	int timeout = 0x20;
	int res;
	uint32_t response;

	do {
		sdio_send_cmd(16, blocklen, SHORT_ANS);
		if (!(res = sdio_get_response(16, SHORT_ANS, &response))) {
			return 0;
		}
	}while(--timeout > 0);

	return res;
}

static int sdio_send_select_card_cmd7(uint16_t rca) {
	int timeout = 0x20;
	uint32_t response;
	union sdio_status_conv status;
	int res;

	/* Send CMD7. Selects card */
	do {
		sdio_send_cmd(7, (rca<<16)&0xFFFF0000, SHORT_ANS);
		if (!(res = sdio_get_response(7, SHORT_ANS, &response))) {
			break;
		}
	} while(--timeout > 0);

	/* Check, if card in in TRANS state */
	if (sdio_check_status_register_cmd13(rca, &(status.value)))
		res = -1;
	if (status.statusstruct.CURRENT_STATE != CURRENT_STATE_TRAN)
		res = -2;
	return res;
}

DSTATUS sdio_status()
{
	DSTATUS returnval = 0;

	if (sdio_check_inserted())
		returnval |= STA_NODISK;

	if (card_info.type == CARD_NONE)
		returnval |= STA_NOINIT;

	if (sdio_check_write_protection())
		returnval |= STA_PROTECT;

	return returnval;
}

DRESULT sdio_disk_ioctl(BYTE cmd, void* buff){
	DRESULT res = RES_OK;

	switch(cmd) {
	case GET_BLOCK_SIZE:
		*((DWORD*)buff) = (DWORD)0x01;
		break;
	case GET_SECTOR_SIZE:
		*((WORD*)buff) = (WORD)(1<<BLOCKSIZE);
		break;
	case GET_SECTOR_COUNT:
		if (card_info.type != CARD_NONE) {
			*((DWORD*)buff) = (DWORD)card_info.sector_count;
		} else {
			res = RES_ERROR;
		}
		break;
	case CTRL_SYNC:
		res = RES_OK;
		break;
	default:
		res = RES_PARERR;
		break;
	}

	return res;
}

DWORD __attribute__((weak)) get_fattime()
{
	return (1<<16) | (1<<24); // return Jan. 1st 1980 00:00:00
}

DSTATUS sdio_initialize(){
	int timeout = 0x3000;
	enum cmd8_ret res8;
	enum acmd41_ret resa41;
	uint8_t hcs_flag = 0;
	card_info.rca = 0;
	card_info.type = CARD_NONE;
	enum sdio_card_type detected_card = CARD_NONE;

	sdio_init_hw();
	sdio_wait_ms(2);
	sdio_init_detect_pins();
	if (sdio_check_inserted()) {
		return STA_NOINIT | STA_NODISK;
	}

	sdio_send_go_idle_cmd0();

	sdio_wait_ms(2);

	res8 = sdio_send_iface_condition_cmd8();
	switch (res8) {
	case CMD8_VOLTAGE_ACCEPTED: // SDV2 Card
		hcs_flag = 1;
		break;
	case CMD8_VOLTAGE_DENIED: // should not happen
		return STA_NOINIT;
		break;
	case CMD8_RESP_TIMEOUT: // SDV1 Card
		hcs_flag=0;
		break;
	default:
		return STA_NOINIT;
		break;
	}

	do {
		//SDIO_wait_ms(2);
		resa41 = sdio_init_card_acmd41(hcs_flag);
	} while ((resa41 == ACMD41_RESP_INIT) && (--timeout > 0));

	switch (resa41) {
	case ACMD41_RESP_SDSC:
		detected_card = (hcs_flag ? SD_V2_SC : SD_V1);
		break;
	case ACMD41_RESP_SDXC:
		detected_card = SD_V2_HC;
		break;
	default:
		return STA_NOINIT;
		break;
	}

	if (sdio_send_all_send_cid_cmd2())
		return STA_NOINIT;

	if (sdio_send_relative_address_cmd3(&card_info.rca))
		return STA_NOINIT;
	if (sdio_get_sector_count(card_info.rca, &card_info.sector_count))
		return STA_NOINIT;
	if (sdio_send_select_card_cmd7(card_info.rca))
		return STA_NOINIT;

	if (sdio_send_block_length_cmd16((uint32_t)(1<<BLOCKSIZE)))
		return STA_NOINIT;

	if (sdio_send_bus_width_acmd6(BUSWIDTH))
		return STA_NOINIT;

	sdio_switch_prescaler(WORKCLK);

	card_info.type = detected_card;

	if (sdio_check_write_protection()) {
		return STA_PROTECT;
	} else
		return 0;
}

DRESULT sdio_disk_read(BYTE *buff, DWORD sector, UINT count){
	uint32_t addr;
	uint32_t sdio_status;
	uint32_t fifo;
	uint32_t counter;
	union sdio_status_conv status; 

	addr = (card_info.type == SD_V2_HC ? (sector) : (sector*512));
	for (; count > 0; count--) {

		/* configure read DMA */
		//		DMA2->LIFCR = 0xffffffff;
		//		DMA2->HIFCR = 0xffffffff;
		//		DMASTREAM->NDTR = 0;
		//		DMASTREAM->FCR = DMA_SxFCR_FTH_0 | DMA_SxFCR_FTH_1 | DMA_SxFCR_DMDIS;
		//		DMASTREAM->M0AR = (uint32_t)(buff);
		//		DMASTREAM->PAR = (uint32_t)&(SDIO->FIFO);
		//		DMASTREAM->CR = DMAP2M | DMA_SxCR_PL_1 | DMA_SxCR_PL_1;
		//		DMASTREAM->CR |= DMA_SxCR_EN;


		do {
                        sdio_check_status_register_cmd13(card_info.rca, &status.value);
                } while (status.statusstruct.CURRENT_STATE != CURRENT_STATE_TRAN);

		SDIO->DLEN = (1 << BLOCKSIZE);
		SDIO->DTIMER = DTIMEOUT;

		SDIO->ICR = SDIO_ICR_CCRCFAILC | SDIO_ICR_DCRCFAILC | SDIO_ICR_CTIMEOUTC | SDIO_ICR_DTIMEOUTC |
				SDIO_ICR_TXUNDERRC | SDIO_ICR_RXOVERRC | SDIO_ICR_CMDRENDC | SDIO_ICR_CMDSENTC | SDIO_ICR_DATAENDC |
				SDIO_ICR_STBITERRC | SDIO_ICR_DBCKENDC | SDIO_ICR_SDIOITC | SDIO_ICR_CEATAENDC;
		SDIO->DCTRL = (BLOCKSIZE<<4) | SDIO_DCTRL_DTDIR | /*SDIO_DCTRL_DMAEN |*/ SDIO_DCTRL_DTEN;

		/* Init Transfer */
		if (sdio_send_read_block_cmd17(addr)) {
			return RES_ERROR;
		}

		counter = 0;
		while (counter < (1<<(BLOCKSIZE-2)) || !(SDIO->STA & (SDIO_STA_DBCKEND | SDIO_STA_DATAEND))) {
			/* TODO: Handle errors */
			if (SDIO->STA & (SDIO_STA_DCRCFAIL | SDIO_STA_DTIMEOUT | SDIO_STA_STBITERR))
			{
				return RES_ERROR;
			}

			if (SDIO->STA & SDIO_STA_RXDAVL) {
				counter++;
				fifo = SDIO->FIFO;
				*(buff++) = (BYTE)(fifo & 0xFF);
				fifo >>= 8;
				*(buff++) = (BYTE)(fifo & 0xFF);
				fifo >>= 8;
				*(buff++) = (BYTE)(fifo & 0xFF);
				fifo >>= 8;
				*(buff++) = (BYTE)(fifo & 0xFF);
			}

		}
		if (SDIO->STA & SDIO_STA_DCRCFAIL) return RES_ERROR;

		//while(DMASTREAM->CR & DMA_SxCR_EN);
		while(1) {
			__DSB();
			__DMB();
			sdio_status = SDIO->STA;
			if (sdio_status & SDIO_STA_DCRCFAIL) {
				return RES_ERROR;
			}
			if (sdio_status & SDIO_STA_DTIMEOUT) {
				return RES_ERROR;
			}

			if (sdio_status & SDIO_STA_DATAEND) {

				if (!(sdio_status & SDIO_STA_RXACT)) {
					break;
				}
			}
		}

		if (card_info.type == SD_V2_HC) {
			addr++;
		} else {
			addr += (1<<BLOCKSIZE);
		}
	}
	return RES_OK;
}

/**
 * @brief SDIO_disk_write
 * @param buff
 * @param sector
 * @param count
 * @warning Not yet implemented
 * @return
 */
DRESULT sdio_disk_write(const BYTE *buff, DWORD sector, UINT count)
{
	uint32_t addr;
	union sdio_status_conv status;
	uint32_t buff_offset = 0;
	int ret;

	if (sdio_check_write_protection())
		return RES_WRPRT;

	addr = (card_info.type == SD_V2_HC ? (sector) : (sector * 512));

	while (count) {
		do {
			sdio_check_status_register_cmd13(card_info.rca, &status.value);
		} while (status.statusstruct.READY_FOR_DATA != 1);

		ret = sdio_send_write_block_cmd24(addr);
		if (ret) {
			return RES_ERROR;
		}
		sdio_write_buffer(512, 9, &buff[buff_offset]);

		buff_offset += 512;
		addr += (card_info.type == SD_V2_HC ? 1 : 512);
		count--;
	}

	return RES_OK;
}