[PATCH v2 1/2] of_mtd: Add helpers to get ECC strength and ECC step size

[Boris BREZILLON]

Hi Ezequiel,

Le 18/02/2014 19:51, Ezequiel Garcia a écrit :
> This commit adds simple helpers to obtain the devicetree properties
> that specify the ECC strength and ECC step size to use on a given
> NAND controller.

As already discussed with you, IMHO these 2 properties should both
be available to be meaningful, hence, we should provide an helper
function that gets both properties or return an error if one of them
is missing.

Do you plan to provide a default value (within controller drivers) if one
of these properties is missing ? In this case seperating the helper
functions make sense.

Best Regards,

Boris

> Signed-off-by: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
> ---
>   drivers/of/of_mtd.c    | 34 ++++++++++++++++++++++++++++++++++
>   include/linux/of_mtd.h | 12 ++++++++++++
>   2 files changed, 46 insertions(+)
>
> diff --git a/drivers/of/of_mtd.c b/drivers/of/of_mtd.c
> index a27ec94..b7361ed 100644
> --- a/drivers/of/of_mtd.c
> +++ b/drivers/of/of_mtd.c
> @@ -50,6 +50,40 @@ int of_get_nand_ecc_mode(struct device_node *np)
>   EXPORT_SYMBOL_GPL(of_get_nand_ecc_mode);
>   
>   /**
> + * of_get_nand_ecc_step_size - Get ECC step size associated to
> + * the required ECC strength (see below).
> + * @np:	Pointer to the given device_node
> + *
> + * return the ECC step size, or errno in error case.
> + */
> +int of_get_nand_ecc_step_size(struct device_node *np)
> +{
> +	int ret;
> +	u32 val;
> +
> +	ret = of_property_read_u32(np, "nand-ecc-step-size", &val);
> +	return ret ? ret : val;
> +}
> +EXPORT_SYMBOL_GPL(of_get_nand_ecc_step_size);
> +
> +/**
> + * of_get_nand_ecc_strength - Get required ECC strength over the
> + * correspnding step size as defined by 'nand-ecc-size'
> + * @np:	Pointer to the given device_node
> + *
> + * return the ECC strength, or errno in error case.
> + */
> +int of_get_nand_ecc_strength(struct device_node *np)
> +{
> +	int ret;
> +	u32 val;
> +
> +	ret = of_property_read_u32(np, "nand-ecc-strength", &val);
> +	return ret ? ret : val;
> +}
> +EXPORT_SYMBOL_GPL(of_get_nand_ecc_strength);
> +
> +/**
>    * of_get_nand_bus_width - Get nand bus witdh for given device_node
>    * @np:	Pointer to the given device_node
>    *
> diff --git a/include/linux/of_mtd.h b/include/linux/of_mtd.h
> index cb32d9c..c078f99 100644
> --- a/include/linux/of_mtd.h
> +++ b/include/linux/of_mtd.h
> @@ -13,6 +13,8 @@
>   
>   #include <linux/of.h>
>   int of_get_nand_ecc_mode(struct device_node *np);
> +int of_get_nand_ecc_step_size(struct device_node *np)
> +int of_get_nand_ecc_strength(struct device_node *np)
>   int of_get_nand_bus_width(struct device_node *np);
>   bool of_get_nand_on_flash_bbt(struct device_node *np);
>   
> @@ -23,6 +25,16 @@ static inline int of_get_nand_ecc_mode(struct device_node *np)
>   	return -ENOSYS;
>   }
>   
> +static inline int of_get_nand_ecc_step_size(struct device_node *np)
> +{
> +	return -ENOSYS;
> +}
> +
> +static inline int of_get_nand_ecc_strength(struct device_node *np)
> +{
> +	return -ENOSYS;
> +}
> +
>   static inline int of_get_nand_bus_width(struct device_node *np)
>   {
>   	return -ENOSYS;