[PATCH 1/2] mtd: parsers: trx: Allow to specify trx-magic in DT

[Rafał Miłecki]

On 15.03.2021 18:07, Hauke Mehrtens wrote:
> Buffalo uses a different TRX magic for every device, to be able to use
> this trx parser, make it possible to specify the TRX magic in device
> tree. If no TRX magic is specified in device tree, the standard value
> will be used. This value should only be specified if a vendor chooses to
> use a non standard TRX magic.
> 
> Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
> ---
>   .../bindings/mtd/partitions/brcm,trx.txt      |  5 +++++
>   drivers/mtd/parsers/parser_trx.c              | 21 ++++++++++++++++++-
>   2 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
> index b677147ca4e1..715a18ca36bd 100644
> --- a/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
> +++ b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
> @@ -28,6 +28,11 @@ detected by a software parsing TRX header.
>   Required properties:
>   - compatible : (required) must be "brcm,trx"
>   
> +Optional properties:
> +
> +- trx-magic: TRX magic, if it is different from the default magic
> +	     0x30524448 as a u32.

It may need to be brcm,trx-magic and ack for sending a separated bt-bindings patch.


> diff --git a/drivers/mtd/parsers/parser_trx.c b/drivers/mtd/parsers/parser_trx.c
> index 8541182134d4..fd424587caa4 100644
> --- a/drivers/mtd/parsers/parser_trx.c
> +++ b/drivers/mtd/parsers/parser_trx.c
> @@ -47,6 +47,24 @@ static const char *parser_trx_data_part_name(struct mtd_info *master,
>   	return "rootfs";
>   }
>   
> +static uint32_t parser_trx_get_magic(struct mtd_info *mtd)
> +{
> +	uint32_t trx_magic = TRX_MAGIC;
> +	struct device_node *np;
> +	int err;
> +
> +	np = mtd_get_of_node(mtd);
> +	if (!np)
> +		return trx_magic;

This check seems redundant, of_ returns -EINVAL also for NULL node.


> +	/* Get different magic from device tree if specified */
> +	err = of_property_read_u32(np, "trx-magic", &trx_magic);
> +	if (err != 0 && err != -EINVAL)
> +		pr_err("failed to parse \"trx-magic\" DT attribute, use default: %d\n", err);

I'm not native, but shouldn't that be s/use/using/ ?


> +
> +	return trx_magic;
> +}