Commit bfee1a43 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by David Woodhouse
Browse files

mtd: orion_nand: use burst reads with double word accesses 



This is not 8 times faster than byte access, but still around 60% faster.

Signed-off-by: default avatarNicolas Pitre <nico@marvell.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 9dbc0902

drivers/mtd/nand/orion_nand.c

+23 −0
Original line number Original line Diff line number Diff line
@@ -47,6 +47,28 @@ static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl 
	writeb(cmd, nc->IO_ADDR_W + offs);

	writeb(cmd, nc->IO_ADDR_W + offs);

}

}





static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)

{

	struct nand_chip *chip = mtd->priv;

	void __iomem *io_base = chip->IO_ADDR_R;

	uint64_t *buf64;

	int i = 0;



	while (len && (unsigned long)buf & 7) {

		*buf++ = readb(io_base);

		len--;

	}

	buf64 = (uint64_t *)buf;

	while (i < len/8) {

		uint64_t x;

		asm ("ldrd\t%0, [%1]" : "=r" (x) : "r" (io_base));

		buf64[i++] = x;

	}

	i *= 8;

	while (i < len)

		buf[i++] = readb(io_base);

}



static int __init orion_nand_probe(struct platform_device *pdev)

static int __init orion_nand_probe(struct platform_device *pdev)

{

{

	struct mtd_info *mtd;

	struct mtd_info *mtd;
@@ -83,6 +105,7 @@ static int __init orion_nand_probe(struct platform_device *pdev) 
	nc->priv = board;

	nc->priv = board;

	nc->IO_ADDR_R = nc->IO_ADDR_W = io_base;

	nc->IO_ADDR_R = nc->IO_ADDR_W = io_base;

	nc->cmd_ctrl = orion_nand_cmd_ctrl;

	nc->cmd_ctrl = orion_nand_cmd_ctrl;

	nc->read_buf = orion_nand_read_buf;

	nc->ecc.mode = NAND_ECC_SOFT;

	nc->ecc.mode = NAND_ECC_SOFT;





	if (board->chip_delay)

	if (board->chip_delay)

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