Commit eb659468 authored by David Vrabel's avatar David Vrabel Committed by Pierre Ossman
Browse files

sdio: extend sdio_readsb() and friends to handle any length of buffer 



Extend sdio_readsb(), sdio_writesb(), sdio_memcpy_fromio(), and
sdio_memcpy_toio() to handle any length of buffer by splitting the transfer
into several IO_RW_EXTENDED commands. Typically, a transfer would be split
into a single block mode transfer followed by a byte mode transfer for the
remainder but we also handle lack of block mode support and the block size
being greater than 512 (the maximum byte mode transfer size).

host->max_seg_size <= host->max_req_size so there's no need to check both
when determining the maximum data size for a single command.

Signed-off-by: default avatarDavid Vrabel <david.vrabel@csr.com>
Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 9a08f82b

drivers/mmc/core/sdio_io.c

+73 −20
Original line number Diff line number Diff line
@@ -189,6 +189,67 @@ int sdio_set_block_size(struct sdio_func *func, unsigned blksz) 


EXPORT_SYMBOL_GPL(sdio_set_block_size);



/* Split an arbitrarily sized data transfer into several

 * IO_RW_EXTENDED commands. */

static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,

	unsigned addr, int incr_addr, u8 *buf, unsigned size)

{

	unsigned remainder = size;

	unsigned max_blocks;

	int ret;



	/* Do the bulk of the transfer using block mode (if supported). */

	if (func->card->cccr.multi_block) {

		/* Blocks per command is limited by host count, host transfer

		 * size (we only use a single sg entry) and the maximum for

		 * IO_RW_EXTENDED of 511 blocks. */

		max_blocks = min(min(

			func->card->host->max_blk_count,

			func->card->host->max_seg_size / func->cur_blksize),

			511u);



		while (remainder > func->cur_blksize) {

			unsigned blocks;



			blocks = remainder / func->cur_blksize;

			if (blocks > max_blocks)

				blocks = max_blocks;

			size = blocks * func->cur_blksize;



			ret = mmc_io_rw_extended(func->card, write,

				func->num, addr, incr_addr, buf,

				blocks, func->cur_blksize);

			if (ret)

				return ret;



			remainder -= size;

			buf += size;

			if (incr_addr)

				addr += size;

		}

	}



	/* Write the remainder using byte mode. */

	while (remainder > 0) {

		size = remainder;

		if (size > func->cur_blksize)

			size = func->cur_blksize;

		if (size > 512)

			size = 512; /* maximum size for byte mode */



		ret = mmc_io_rw_extended(func->card, write, func->num, addr,

			 incr_addr, buf, 1, size);

		if (ret)

			return ret;



		remainder -= size;

		buf += size;

		if (incr_addr)

			addr += size;

	}

	return 0;

}



/**

 *	sdio_readb - read a single byte from a SDIO function

 *	@func: SDIO function to access
@@ -252,15 +313,13 @@ EXPORT_SYMBOL_GPL(sdio_writeb); 
 *	@addr: address to begin reading from

 *	@count: number of bytes to read

 *

 *	Reads up to 512 bytes from the address space of a given SDIO

 *	function. Return value indicates if the transfer succeeded or

 *	not.

 *	Reads from the address space of a given SDIO function. Return

 *	value indicates if the transfer succeeded or not.

 */

int sdio_memcpy_fromio(struct sdio_func *func, void *dst,

	unsigned int addr, int count)

{

	return mmc_io_rw_extended(func->card, 0, func->num, addr, 0, dst,

		count);

	return sdio_io_rw_ext_helper(func, 0, addr, 1, dst, count);

}

EXPORT_SYMBOL_GPL(sdio_memcpy_fromio);
@@ -271,15 +330,13 @@ EXPORT_SYMBOL_GPL(sdio_memcpy_fromio); 
 *	@src: buffer that contains the data to write

 *	@count: number of bytes to write

 *

 *	Writes up to 512 bytes to the address space of a given SDIO

 *	function. Return value indicates if the transfer succeeded or

 *	not.

 *	Writes to the address space of a given SDIO function. Return

 *	value indicates if the transfer succeeded or not.

 */

int sdio_memcpy_toio(struct sdio_func *func, unsigned int addr,

	void *src, int count)

{

	return mmc_io_rw_extended(func->card, 1, func->num, addr, 0, src,

		count);

	return sdio_io_rw_ext_helper(func, 1, addr, 1, src, count);

}

EXPORT_SYMBOL_GPL(sdio_memcpy_toio);
@@ -290,15 +347,13 @@ EXPORT_SYMBOL_GPL(sdio_memcpy_toio); 
 *	@addr: address of (single byte) FIFO

 *	@count: number of bytes to read

 *

 *	Reads up to 512 bytes from the specified FIFO of a given SDIO

 *	function. Return value indicates if the transfer succeeded or

 *	not.

 *	Reads from the specified FIFO of a given SDIO function. Return

 *	value indicates if the transfer succeeded or not.

 */

int sdio_readsb(struct sdio_func *func, void *dst, unsigned int addr,

	int count)

{

	return mmc_io_rw_extended(func->card, 0, func->num, addr, 1, dst,

		count);

	return sdio_io_rw_ext_helper(func, 0, addr, 0, dst, count);

}



EXPORT_SYMBOL_GPL(sdio_readsb);
@@ -310,15 +365,13 @@ EXPORT_SYMBOL_GPL(sdio_readsb); 
 *	@src: buffer that contains the data to write

 *	@count: number of bytes to write

 *

 *	Writes up to 512 bytes to the specified FIFO of a given SDIO

 *	function. Return value indicates if the transfer succeeded or

 *	not.

 *	Writes to the specified FIFO of a given SDIO function. Return

 *	value indicates if the transfer succeeded or not.

 */

int sdio_writesb(struct sdio_func *func, unsigned int addr, void *src,

	int count)

{

	return mmc_io_rw_extended(func->card, 1, func->num, addr, 1, src,

		count);

	return sdio_io_rw_ext_helper(func, 1, addr, 0, src, count);

}

EXPORT_SYMBOL_GPL(sdio_writesb);

drivers/mmc/core/sdio_ops.c

+12 −7
Original line number Diff line number Diff line
@@ -88,7 +88,7 @@ int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn, 
}



int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,

	unsigned addr, int bang, u8 *buf, unsigned size)

	unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz)

{

	struct mmc_request mrq;

	struct mmc_command cmd;
@@ -97,7 +97,9 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn, 


	BUG_ON(!card);

	BUG_ON(fn > 7);

	BUG_ON(size > 512);

	BUG_ON(blocks == 1 && blksz > 512);

	WARN_ON(blocks == 0);

	WARN_ON(blksz == 0);



	memset(&mrq, 0, sizeof(struct mmc_request));

	memset(&cmd, 0, sizeof(struct mmc_command));
@@ -109,18 +111,21 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn, 
	cmd.opcode = SD_IO_RW_EXTENDED;

	cmd.arg = write ? 0x80000000 : 0x00000000;

	cmd.arg |= fn << 28;

	cmd.arg |= bang ? 0x00000000 : 0x04000000;

	cmd.arg |= incr_addr ? 0x04000000 : 0x00000000;

	cmd.arg |= addr << 9;

	cmd.arg |= (size == 512) ? 0 : size;

	if (blocks == 1 && blksz <= 512)

		cmd.arg |= (blksz == 512) ? 0 : blksz;	/* byte mode */

	else

		cmd.arg |= 0x08000000 | blocks;		/* block mode */

	cmd.flags = MMC_RSP_R5 | MMC_CMD_ADTC;



	data.blksz = size;

	data.blocks = 1;

	data.blksz = blksz;

	data.blocks = blocks;

	data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;

	data.sg = &sg;

	data.sg_len = 1;



	sg_init_one(&sg, buf, size);

	sg_init_one(&sg, buf, blksz * blocks);



	mmc_set_data_timeout(&data, card);

drivers/mmc/core/sdio_ops.h

+1 −1
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr); 
int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,

	unsigned addr, u8 in, u8* out);

int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,

	unsigned addr, int bang, u8 *data, unsigned size);

	unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz);



#endif

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