Re: [PATCHv4 4/5] of/mtd/nand: add generic binding and helper for NAND_BBT_NO_OOB_BBM

Brian Norris
2014-07-24T02:06:27Z

(BTW, that's a mighty CC list you have! I'm not sure all CC'd parties
are interested in this series; e.g., Russel and the ARM list seem
unrelated)

Hi Lothar,

Sorry for the delay on this. I get busy enough that I can't/don't reply
to everything quickly...

On Thu, Jun 12, 2014 at 03:20:44PM +0200, Lothar Waßmann wrote:
> add a boolean property 'nand-no-oob-bbm' and helper function to be
> able to set the NAND_BBT_NO_OOB_BBM flag in DT capable NAND drivers
> and use it for i.MX and MXS nand drivers.

If I'm understanding your previous conversations with Huang correctly,
you *must* use NAND_BBT_NO_OOB_BBM if you're going to use the
fsl,no-blockmark-swap option. Correct? If so, then you might not need
a separate 'nand-no-oob-bbm' binding; your driver should imply from
'fsl,no-blockmark-swap' that it must also enable NAND_BBT_NO_OOB_BBM.

Also, as I noted in [1], I don't really like exposing a ton of
individual boolean DT properties like this. (At least this property is
orthogonal to the bad block table; I was a little off-base in [1].)

Brian

[1] http://lists.infradead.org/pipermail/linux-mtd/2014-July/054764.html

> Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
> ---
> Documentation/devicetree/bindings/mtd/nand.txt | 1 +
> drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 3 +++
> drivers/mtd/nand/mxc_nand.c | 2 ++
> drivers/of/of_mtd.c | 12 ++++++++++++
> include/linux/of_mtd.h | 6 ++++++
> 5 files changed, 24 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentation/devicetree/bindings/mtd/nand.txt
> index b53f92e..e46bfbe 100644
> --- a/Documentation/devicetree/bindings/mtd/nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/nand.txt
> @@ -5,6 +5,7 @@
> "soft_bch".
> - nand-bus-width : 8 or 16 bus width if not present 8
> - nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
> +- nand-no-oob-bbm: boolean to disable writing bad block markers to flash
>
> - nand-ecc-strength: integer representing the number of bits to correct
> per ECC step.
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> index 959cb9b..37537b4 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> @@ -1724,6 +1724,9 @@ static int gpmi_nand_init(struct gpmi_nand_data *this)
> if (of_get_nand_on_flash_bbt(this->dev->of_node)) {
> chip->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
>
> + if (of_get_nand_no_oob_bbm(this->dev->of_node))
> + chip->bbt_options |= NAND_BBT_NO_OOB_BBM;
> +
> if (of_property_read_bool(this->dev->of_node,
> "fsl,no-blockmark-swap"))
> this->swap_block_mark = false;
> diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
> index dba262b..bb54a2a 100644
> --- a/drivers/mtd/nand/mxc_nand.c
> +++ b/drivers/mtd/nand/mxc_nand.c
> @@ -1496,6 +1496,8 @@ static int mxcnd_probe(struct platform_device *pdev)
> this->bbt_md = &bbt_mirror_descr;
> /* update flash based bbt */
> this->bbt_options |= NAND_BBT_USE_FLASH;
> + if (of_get_nand_no_oob_bbm(pdev->dev.of_node))
> + this->bbt_options |= NAND_BBT_NO_OOB_BBM;
> }
>
> init_completion(&host->op_completion);
> diff --git a/drivers/of/of_mtd.c b/drivers/of/of_mtd.c
> index b7361ed..d947acc 100644
> --- a/drivers/of/of_mtd.c
> +++ b/drivers/of/of_mtd.c
> @@ -117,3 +117,15 @@ bool of_get_nand_on_flash_bbt(struct device_node *np)
> return of_property_read_bool(np, "nand-on-flash-bbt");
> }
> EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt);
> +
> +/**
> + * of_get_nand_no_oob_bbm - Get nand no oob bbm for given device_node
> + * @np: Pointer to the given device_node
> + *
> + * return true if present, false otherwise
> + */
> +bool of_get_nand_no_oob_bbm(struct device_node *np)
> +{
> + return of_property_read_bool(np, "nand-no-oob-bbm");
> +}
> +EXPORT_SYMBOL_GPL(of_get_nand_no_oob_bbm);
> diff --git a/include/linux/of_mtd.h b/include/linux/of_mtd.h
> index e266caa..6ece1a9 100644
> --- a/include/linux/of_mtd.h
> +++ b/include/linux/of_mtd.h
> @@ -17,6 +17,7 @@ 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);
> +bool of_get_nand_no_oob_bbm(struct device_node *np);
>
> #else /* CONFIG_OF_MTD */
>
> @@ -45,6 +46,11 @@ static inline bool of_get_nand_on_flash_bbt(struct device_node *np)
> return false;
> }
>
> +static inline bool of_get_nand_no_oob_bbm(struct device_node *np)
> +{
> + return false;
> +}
> +
> #endif /* CONFIG_OF_MTD */
>
> #endif /* __LINUX_OF_MTD_H */