mtd: nand: simplify nand_bch_init() usage

nand_bch_init() requires several arguments which could directly be deduced
from the mtd device. Get rid of those useless parameters.

nand_bch_init() is also requiring the caller to provide a proper eccbytes
value, while this value could be deduced from the ecc.size and
ecc.strength value. Fallback to eccbytes calculation when it is set to 0.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index a36f15b..191e4f7 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4279,10 +4279,8 @@ int nand_scan_tail(struct mtd_info *mtd)
                }
 
                /* See nand_bch_init() for details. */
-               ecc->bytes = DIV_ROUND_UP(
-                               ecc->strength * fls(8 * ecc->size), 8);
-               ecc->priv = nand_bch_init(mtd, ecc->size, ecc->bytes,
-                                              &ecc->layout);
+               ecc->bytes = 0;
+               ecc->priv = nand_bch_init(mtd);
                if (!ecc->priv) {
                        pr_warn("BCH ECC initialization failed!\n");
                        BUG();

diff --git a/drivers/mtd/nand/nand_bch.c b/drivers/mtd/nand/nand_bch.c
index a87c1b6..b585bae 100644 (file)
--- a/drivers/mtd/nand/nand_bch.c
+++ b/drivers/mtd/nand/nand_bch.c
@@ -107,9 +107,6 @@ EXPORT_SYMBOL(nand_bch_correct_data);
 /**
  * nand_bch_init - [NAND Interface] Initialize NAND BCH error correction
  * @mtd:       MTD block structure
- * @eccsize:   ecc block size in bytes
- * @eccbytes:  ecc length in bytes
- * @ecclayout: output default layout
  *
  * Returns:
  *  a pointer to a new NAND BCH control structure, or NULL upon failure
@@ -123,14 +120,21 @@ EXPORT_SYMBOL(nand_bch_correct_data);
  * @eccsize = 512  (thus, m=13 is the smallest integer such that 2^m-1 > 512*8)
  * @eccbytes = 7   (7 bytes are required to store m*t = 13*4 = 52 bits)
  */
-struct nand_bch_control *
-nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
-             struct nand_ecclayout **ecclayout)
+struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 {
+       struct nand_chip *nand = mtd_to_nand(mtd);
        unsigned int m, t, eccsteps, i;
-       struct nand_ecclayout *layout;
+       struct nand_ecclayout *layout = nand->ecc.layout;
        struct nand_bch_control *nbc = NULL;
        unsigned char *erased_page;
+       unsigned int eccsize = nand->ecc.size;
+       unsigned int eccbytes = nand->ecc.bytes;
+       unsigned int eccstrength = nand->ecc.strength;
+
+       if (!eccbytes && eccstrength) {
+               eccbytes = DIV_ROUND_UP(eccstrength * fls(8 * eccsize), 8);
+               nand->ecc.bytes = eccbytes;
+       }
 
        if (!eccsize || !eccbytes) {
                printk(KERN_WARNING "ecc parameters not supplied\n");
@@ -158,7 +162,7 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
        eccsteps = mtd->writesize/eccsize;
 
        /* if no ecc placement scheme was provided, build one */
-       if (!*ecclayout) {
+       if (!layout) {
 
                /* handle large page devices only */
                if (mtd->oobsize < 64) {
@@ -184,7 +188,7 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
                layout->oobfree[0].offset = 2;
                layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes;
 
-               *ecclayout = layout;
+               nand->ecc.layout = layout;
        }
 
        /* sanity checks */
@@ -192,7 +196,7 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
                printk(KERN_WARNING "eccsize %u is too large\n", eccsize);
                goto fail;
        }
-       if ((*ecclayout)->eccbytes != (eccsteps*eccbytes)) {
+       if (layout->eccbytes != (eccsteps*eccbytes)) {
                printk(KERN_WARNING "invalid ecc layout\n");
                goto fail;
        }
@@ -216,6 +220,9 @@ nand_bch_init(struct mtd_info *mtd, unsigned int eccsize, unsigned int eccbytes,
        for (i = 0; i < eccbytes; i++)
                nbc->eccmask[i] ^= 0xff;
 
+       if (!eccstrength)
+               nand->ecc.strength = (eccbytes * 8) / fls(8 * eccsize);
+
        return nbc;
 fail:
        nand_bch_free(nbc);

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index c553f78..0749ca1 100644 (file)
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1807,13 +1807,19 @@ static int omap_nand_probe(struct platform_device *pdev)
                goto return_error;
        }
 
+       /*
+        * Bail out earlier to let NAND_ECC_SOFT code create its own
+        * ecclayout instead of using ours.
+        */
+       if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW) {
+               nand_chip->ecc.mode = NAND_ECC_SOFT;
+               goto scan_tail;
+       }
+
        /* populate MTD interface based on ECC scheme */
        ecclayout               = &info->oobinfo;
+       nand_chip->ecc.layout   = ecclayout;
        switch (info->ecc_opt) {
-       case OMAP_ECC_HAM1_CODE_SW:
-               nand_chip->ecc.mode = NAND_ECC_SOFT;
-               break;
-
        case OMAP_ECC_HAM1_CODE_HW:
                pr_info("nand: using OMAP_ECC_HAM1_CODE_HW\n");
                nand_chip->ecc.mode             = NAND_ECC_HW;
@@ -1861,10 +1867,7 @@ static int omap_nand_probe(struct platform_device *pdev)
                ecclayout->oobfree->offset      = 1 +
                                ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
                /* software bch library is used for locating errors */
-               nand_chip->ecc.priv             = nand_bch_init(mtd,
-                                                       nand_chip->ecc.size,
-                                                       nand_chip->ecc.bytes,
-                                                       &ecclayout);
+               nand_chip->ecc.priv             = nand_bch_init(mtd);
                if (!nand_chip->ecc.priv) {
                        dev_err(&info->pdev->dev, "unable to use BCH library\n");
                        err = -EINVAL;
@@ -1925,10 +1928,7 @@ static int omap_nand_probe(struct platform_device *pdev)
                ecclayout->oobfree->offset      = 1 +
                                ecclayout->eccpos[ecclayout->eccbytes - 1] + 1;
                /* software bch library is used for locating errors */
-               nand_chip->ecc.priv             = nand_bch_init(mtd,
-                                                       nand_chip->ecc.size,
-                                                       nand_chip->ecc.bytes,
-                                                       &ecclayout);
+               nand_chip->ecc.priv             = nand_bch_init(mtd);
                if (!nand_chip->ecc.priv) {
                        dev_err(&info->pdev->dev, "unable to use BCH library\n");
                        err = -EINVAL;
@@ -2002,9 +2002,6 @@ static int omap_nand_probe(struct platform_device *pdev)
                goto return_error;
        }
 
-       if (info->ecc_opt == OMAP_ECC_HAM1_CODE_SW)
-               goto scan_tail;
-
        /* all OOB bytes from oobfree->offset till end off OOB are free */
        ecclayout->oobfree->length = mtd->oobsize - ecclayout->oobfree->offset;
        /* check if NAND device's OOB is enough to store ECC signatures */
@@ -2015,7 +2012,6 @@ static int omap_nand_probe(struct platform_device *pdev)
                err = -EINVAL;
                goto return_error;
        }
-       nand_chip->ecc.layout = ecclayout;
 
 scan_tail:
        /* second phase scan */

diff --git a/include/linux/mtd/nand_bch.h b/include/linux/mtd/nand_bch.h
index fb0bc34..98f20ef 100644 (file)
--- a/include/linux/mtd/nand_bch.h
+++ b/include/linux/mtd/nand_bch.h
@@ -32,9 +32,7 @@ int nand_bch_correct_data(struct mtd_info *mtd, u_char *dat, u_char *read_ecc,
 /*
  * Initialize BCH encoder/decoder
  */
-struct nand_bch_control *
-nand_bch_init(struct mtd_info *mtd, unsigned int eccsize,
-             unsigned int eccbytes, struct nand_ecclayout **ecclayout);
+struct nand_bch_control *nand_bch_init(struct mtd_info *mtd);
 /*
  * Release BCH encoder/decoder resources
  */
@@ -58,9 +56,7 @@ nand_bch_correct_data(struct mtd_info *mtd, unsigned char *buf,
        return -ENOTSUPP;
 }
 
-static inline struct nand_bch_control *
-nand_bch_init(struct mtd_info *mtd, unsigned int eccsize,
-             unsigned int eccbytes, struct nand_ecclayout **ecclayout)
+static inline struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
 {
        return NULL;
 }