Re: [PATCH] S3C24XX large page NAND support

Matthieu CASTET
2007-07-12T10:08:04Z

Ben Dooks wrote:
> This adds support for using large page NAND devices
> with the S3C24XX NAND controllers. This also adds the
> file Documentation/arm/Samsung-S3C24XX/NAND.txt to
> describe the differences.
>
> The basic stratergy is to maintain 3 bytes of ECC for
> each 256 byte block read from the NAND which is similar
> to the default kernel layout (altough we are using the
> hardware ECC generator to make our ECC calculations).
>
> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
>
> Index: linux-2.6.21-tmp/drivers/mtd/nand/s3c2410.c
> ===================================================================
> --- linux-2.6.21-tmp.orig/drivers/mtd/nand/s3c2410.c 2007-04-26 04:08:32.000000000 +0100
> +++ linux-2.6.21-tmp/drivers/mtd/nand/s3c2410.c 2007-05-22 12:26:49.000000000 +0100
> @@ -473,7 +473,7 @@ static int s3c2440_nand_calculate_ecc(st
> ecc_code[1] = ecc >> 8;
> ecc_code[2] = ecc >> 16;
>
> - pr_debug("%s: returning ecc %06lx\n", __func__, ecc);
> + pr_debug("%s: returning ecc %06lx\n", __func__, ecc & 0xffffff);
>
> return 0;
> }
> @@ -630,9 +630,6 @@ static void s3c2410_nand_init_chip(struc
> chip->ecc.calculate = s3c2410_nand_calculate_ecc;
> chip->ecc.correct = s3c2410_nand_correct_data;
> chip->ecc.mode = NAND_ECC_HW;
> - chip->ecc.size = 512;
> - chip->ecc.bytes = 3;
> - chip->ecc.layout = &nand_hw_eccoob;
>
> switch (info->cpu_type) {
> case TYPE_S3C2410:
> @@ -656,6 +653,34 @@ static void s3c2410_nand_init_chip(struc
> }
> }
>
> +/* s3c2410_nand_update_chip
> + *
> + * post-probe chip update, to change any items, such as the
> + * layout for large page nand
> + */
> +
> +static void s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
> + struct s3c2410_nand_mtd *nmtd)
> +{
> + struct nand_chip *chip = &nmtd->chip;
> +
> + printk("%s: chip %p: %d\n", __func__, chip, chip->page_shift);
> +
> + if (hardware_ecc) {
> + /* change the behaviour depending on wether we are using
> + * the large or small page nand device */
> +
> + if (chip->page_shift > 10) {
> + chip->ecc.size = 256;
> + chip->ecc.bytes = 3;
> + } else {
> + chip->ecc.size = 512;
> + chip->ecc.bytes = 3;
> + chip->ecc.layout = &nand_hw_eccoob;
> + }
> + }
> +}
> +
> /* s3c2410_nand_probe
> *
> * called by device layer when it finds a device matching
> @@ -762,9 +787,12 @@ static int s3c24xx_nand_probe(struct pla
>
> s3c2410_nand_init_chip(info, nmtd, sets);
>
> - nmtd->scan_res = nand_scan(&nmtd->mtd, (sets) ? sets->nr_chips : 1);
> + nmtd->scan_res = nand_scan_ident(&nmtd->mtd,
> + (sets) ? sets->nr_chips : 1);
>
> if (nmtd->scan_res == 0) {
> + s3c2410_nand_update_chip(info, nmtd);
> + nand_scan_tail(&nmtd->mtd);
> s3c2410_nand_add_partition(info, nmtd, sets);
> }
Shouldn't nand_scan_ident and nand_scan_tail be used here ?

Matthieu