Commit 32d42a85 authored by Pekon Gupta's avatar Pekon Gupta Committed by Brian Norris
Browse files

mtd: nand: omap: use drivers/mtd/nand/nand_bch.c wrapper for BCH ECC instead of lib/bch.c 



generic frame-work in mtd/nand/nand_bch.c is a wrapper above lib/bch.h which
encapsulates all control information specific to BCH ecc algorithm in software.
Thus this patch:
(1) replace omap specific implementations with equivalent wrapper in nand_bch.c
    so that generic code from nand_bch.c is re-used. like;
        omap3_correct_data_bch() -> nand_bch_correct_data()
        omap3_free_bch() -> nand_bch_free()
(2) replace direct calls to lib/bch.c with wrapper functions defined in nand_bch.c
	init_bch() -> nand_bch_init()

Signed-off-by: default avatarPekon Gupta <pekon@ti.com>
Tested-by: default avatarEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent b491da72

drivers/mtd/nand/omap2.c

+22 −74
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ 
#include <linux/of.h>

#include <linux/of_device.h>



#include <linux/bch.h>

#include <linux/mtd/nand_bch.h>

#include <linux/platform_data/elm.h>



#include <linux/platform_data/mtd-nand-omap2.h>
@@ -140,7 +140,6 @@ 
#define BCH_ECC_SIZE1		0x20	/* ecc_size1 = 32 */



#define BADBLOCK_MARKER_LENGTH		2

#define OMAP_ECC_BCH8_POLYNOMIAL	0x201b



#ifdef CONFIG_MTD_NAND_OMAP_BCH

static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
@@ -173,7 +172,6 @@ struct omap_nand_info { 
	int					buf_len;

	struct gpmc_nand_regs		reg;

	/* fields specific for BCHx_HW ECC scheme */

	struct bch_control             *bch;

	bool				is_elm_used;

	struct device			*elm_dev;

	struct device_node		*of_node;
@@ -1507,43 +1505,7 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data, 


	return stat;

}

#endif /* CONFIG_MTD_NAND_OMAP_BCH */



#ifdef CONFIG_MTD_NAND_ECC_BCH

/**

 * omap3_correct_data_bch - Decode received data and correct errors

 * @mtd: MTD device structure

 * @data: page data

 * @read_ecc: ecc read from nand flash

 * @calc_ecc: ecc read from HW ECC registers

 */

static int omap3_correct_data_bch(struct mtd_info *mtd, u_char *data,

				  u_char *read_ecc, u_char *calc_ecc)

{

	int i, count;

	/* cannot correct more than 8 errors */

	unsigned int errloc[8];

	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,

						   mtd);



	count = decode_bch(info->bch, NULL, 512, read_ecc, calc_ecc, NULL,

			   errloc);

	if (count > 0) {

		/* correct errors */

		for (i = 0; i < count; i++) {

			/* correct data only, not ecc bytes */

			if (errloc[i] < 8*512)

				data[errloc[i]/8] ^= 1 << (errloc[i] & 7);

			pr_debug("corrected bitflip %u\n", errloc[i]);

		}

	} else if (count < 0) {

		pr_err("ecc unrecoverable error\n");

	}

	return count;

}

#endif /* CONFIG_MTD_NAND_ECC_BCH */



#ifdef CONFIG_MTD_NAND_OMAP_BCH

/**

 * omap_write_page_bch - BCH ecc based write page function for entire page

 * @mtd:		mtd info structure
@@ -1660,28 +1622,6 @@ static int is_elm_present(struct omap_nand_info *info, 
}

#endif /* CONFIG_MTD_NAND_ECC_BCH */



#ifdef CONFIG_MTD_NAND_ECC_BCH

/**

 * omap3_free_bch - Release BCH ecc resources

 * @mtd: MTD device structure

 */

static void omap3_free_bch(struct mtd_info *mtd)

{

	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,

						   mtd);

	if (info->bch) {

		free_bch(info->bch);

		info->bch = NULL;

	}

}



#else



static void omap3_free_bch(struct mtd_info *mtd)

{

}

#endif /* CONFIG_MTD_NAND_ECC_BCH */



static int omap_nand_probe(struct platform_device *pdev)

{

	struct omap_nand_info		*info;
@@ -1714,13 +1654,13 @@ static int omap_nand_probe(struct platform_device *pdev) 
	info->pdev		= pdev;

	info->gpmc_cs		= pdata->cs;

	info->reg		= pdata->reg;

	info->bch		= NULL;

	info->of_node		= pdata->of_node;

	mtd			= &info->mtd;

	mtd->priv		= &info->nand;

	mtd->name		= dev_name(&pdev->dev);

	mtd->owner		= THIS_MODULE;

	nand_chip		= &info->nand;

	nand_chip->ecc.priv	= NULL;

	nand_chip->options	|= NAND_SKIP_BBTSCAN;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1903,7 +1843,7 @@ static int omap_nand_probe(struct platform_device *pdev) 
		nand_chip->ecc.bytes		= 7;

		nand_chip->ecc.strength		= 4;

		nand_chip->ecc.hwctl		= omap3_enable_hwecc_bch;

		nand_chip->ecc.correct		= omap3_correct_data_bch;

		nand_chip->ecc.correct		= nand_bch_correct_data;

		nand_chip->ecc.calculate	= omap3_calculate_ecc_bch4;

		/* define ECC layout */

		ecclayout->eccbytes		= nand_chip->ecc.bytes *
@@ -1913,10 +1853,11 @@ static int omap_nand_probe(struct platform_device *pdev) 
		ecclayout->oobfree->offset	= ecclayout->eccpos[0] +

							ecclayout->eccbytes;

		/* software bch library is used for locating errors */

		info->bch = init_bch(nand_chip->ecc.bytes,

					nand_chip->ecc.strength,

					OMAP_ECC_BCH8_POLYNOMIAL);

		if (!info->bch) {

		nand_chip->ecc.priv		= nand_bch_init(mtd,

							nand_chip->ecc.size,

							nand_chip->ecc.bytes,

							&nand_chip->ecc.layout);

		if (!nand_chip->ecc.priv) {

			pr_err("nand: error: unable to use s/w BCH library\n");

			err = -EINVAL;

		}
@@ -1968,7 +1909,7 @@ static int omap_nand_probe(struct platform_device *pdev) 
		nand_chip->ecc.bytes		= 13;

		nand_chip->ecc.strength		= 8;

		nand_chip->ecc.hwctl		= omap3_enable_hwecc_bch;

		nand_chip->ecc.correct		= omap3_correct_data_bch;

		nand_chip->ecc.correct		= nand_bch_correct_data;

		nand_chip->ecc.calculate	= omap3_calculate_ecc_bch8;

		/* define ECC layout */

		ecclayout->eccbytes		= nand_chip->ecc.bytes *
@@ -1978,10 +1919,11 @@ static int omap_nand_probe(struct platform_device *pdev) 
		ecclayout->oobfree->offset	= ecclayout->eccpos[0] +

							ecclayout->eccbytes;

		/* software bch library is used for locating errors */

		info->bch = init_bch(nand_chip->ecc.bytes,

					nand_chip->ecc.strength,

					OMAP_ECC_BCH8_POLYNOMIAL);

		if (!info->bch) {

		nand_chip->ecc.priv		= nand_bch_init(mtd,

							nand_chip->ecc.size,

							nand_chip->ecc.bytes,

							&nand_chip->ecc.layout);

		if (!nand_chip->ecc.priv) {

			pr_err("nand: error: unable to use s/w BCH library\n");

			err = -EINVAL;

			goto out_release_mem_region;
@@ -2067,7 +2009,10 @@ out_release_mem_region: 
		free_irq(info->gpmc_irq_fifo, info);

	release_mem_region(info->phys_base, info->mem_size);

out_free_info:

	omap3_free_bch(mtd);

	if (nand_chip->ecc.priv) {

		nand_bch_free(nand_chip->ecc.priv);

		nand_chip->ecc.priv = NULL;

	}

	kfree(info);



	return err;
@@ -2079,7 +2024,10 @@ static int omap_nand_remove(struct platform_device *pdev) 
	struct nand_chip *nand_chip = mtd->priv;

	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,

							mtd);

	omap3_free_bch(mtd);

	if (nand_chip->ecc.priv) {

		nand_bch_free(nand_chip->ecc.priv);

		nand_chip->ecc.priv = NULL;

	}



	if (info->dma)

		dma_release_channel(info->dma);

CRA Git | Maintained and supported by SUSTech CRA and CCSE