On 02/06/2018 11:40 AM, Stefan Agner wrote:
> Add support for specified ECC strength/size using device tree
> properties nand-ecc-strength/nand-ecc-step-size.
>
> Signed-off-by: Stefan Agner <ste...@agner.ch>
> ---
> .../devicetree/bindings/mtd/gpmi-nand.txt | 5 ++++
> drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 29
> ++++++++++++++--------
> 2 files changed, 24 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
> b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
> index eb2d9919d063..ea6e9b735160 100644
> --- a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
> @@ -46,6 +46,11 @@ Optional properties:
> partitions written from Linux with this feature
> turned on may not be accessible by the BootROM
> code.
> + - nand-ecc-strength: integer representing the number of bits to correct
> + per ECC step. Needs to be a multiple of 2.
> + - nand-ecc-step-size: integer representing the number of data bytes
> + that are covered by a single ECC step. The driver
> + supports 512 and 1024.
>
> The device tree may optionally contain sub-nodes describing partitions of
> the
> address space. See partition.txt for more detail.
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> index 50f8d4a1b983..8cb378358e11 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> @@ -198,17 +198,15 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data
> *this)
> *
> * We may have available oob space in this case.
> */
> -static int set_geometry_by_ecc_info(struct gpmi_nand_data *this)
> +static int set_geometry_by_ecc_info(struct gpmi_nand_data *this,
> + unsigned int ecc_strength, unsigned int ecc_step)
> {
> struct bch_geometry *geo = &this->bch_geometry;
> struct nand_chip *chip = &this->nand;
> struct mtd_info *mtd = nand_to_mtd(chip);
> unsigned int block_mark_bit_offset;
>
> - if (!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0))
> - return -EINVAL;
> -
> - switch (chip->ecc_step_ds) {
> + switch (ecc_step) {
> case SZ_512:
> geo->gf_len = 13;
> break;
> @@ -221,8 +219,8 @@ static int set_geometry_by_ecc_info(struct gpmi_nand_data
> *this)
> chip->ecc_strength_ds, chip->ecc_step_ds);
> return -EINVAL;
> }
> - geo->ecc_chunk_size = chip->ecc_step_ds;
> - geo->ecc_strength = round_up(chip->ecc_strength_ds, 2);
> + geo->ecc_chunk_size = ecc_step;
> + geo->ecc_strength = round_up(ecc_strength, 2);
> if (!gpmi_check_ecc(this))
> return -EINVAL;
>
> @@ -230,7 +228,7 @@ static int set_geometry_by_ecc_info(struct gpmi_nand_data
> *this)
> if (geo->ecc_chunk_size < mtd->oobsize) {
> dev_err(this->dev,
> "unsupported nand chip. ecc size: %d, oob size : %d\n",
> - chip->ecc_step_ds, mtd->oobsize);
> + ecc_step, mtd->oobsize);
> return -EINVAL;
> }
>
> @@ -423,9 +421,20 @@ static int legacy_set_geometry(struct gpmi_nand_data
> *this)
>
> int common_nfc_set_geometry(struct gpmi_nand_data *this)
> {
> + struct nand_chip *chip = &this->nand;
> +
> + if (chip->ecc.strength > 0 && chip->ecc.size > 0)
> + return set_geometry_by_ecc_info(this, chip->ecc.strength,
> + chip->ecc.size);
> +
I was wondering how to keep, let's say u-boot, and kernel ecc setting
aligned, if users can specify the strength and step_ds in DT? Did u-boot
enable to get these parameters from DT?
> if ((of_property_read_bool(this->dev->of_node, "fsl,use-minimum-ecc"))
> - || legacy_set_geometry(this))
> - return set_geometry_by_ecc_info(this);
> + || legacy_set_geometry(this)) {
> + if (!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0))
> + return -EINVAL;
> +
> + return set_geometry_by_ecc_info(this, chip->ecc_strength_ds,
> + chip->ecc_step_ds);
> + }
>
> return 0;
> }
