Re: [PATCH v2 3/6] mtd: nand: vf610_nfc: add device tree bindings

From: Bill Pringlemeir
Date: Mon Mar 09 2015 - 16:16:41 EST


On 9 Mar 2015, stefan@xxxxxxxx wrote:

> Signed-off-by: Bill Pringlemeir <bpringlemeir@xxxxxxxxx>
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
> ---
> .../devicetree/bindings/mtd/vf610-nfc.txt | 39 ++++++++++++++++++++++
> 1 file changed, 39 insertions(+) create mode 100644
> Documentation/devicetree/bindings/mtd/vf610-nfc.txt
>
> diff --git a/Documentation/devicetree/bindings/mtd/vf610-nfc.txt
> b/Documentation/devicetree/bindings/mtd/vf610-nfc.txt
> new file mode 100644
> index 0000000..312c872
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/vf610-nfc.txt

[snip]

> +- reg: Address range of the mtd chip
> +- interrupts: Should contain the STMMAC interrupts

What is 'STMMAC'? Is that something I cribbed from another file? Ah, I
see 'spear_smi.txt' which is an NAND driver with a 'clock-frequency'
parameter (probably before 'assigned-clocks' support).

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/mtd/spear_smi.txt

I don't think 'STMMAC' makes sense.

+- interrupts: irq to be used

Maybe? Same as mxc-nand.txt. It is not so helpful though.

> +- nand-bus-width: see nand.txt
> +- nand-ecc-mode: see nand.txt
> +- nand-on-flash-bbt: see nand.txt
> +- clock-frequency : Optional clock rate to NFC in Hz

I guess this changed? We might want to put a note about what kind of
impact this might have on the bus. Ie,

assigned-clocks: Input SOC clock to the NAND controller.
assigned-clock-rates: The NAND bus timing is derived from this clock
rate and should not exceed maximum timing for any NAND memory chip
in a board stuffing. Typical NAND memory timings derived from this
clock are found in the SOC hardware reference manual.

Originally, the reason I made this file was because the
'clock-frequency' was non-standard. I guess it is nice to have it
anyways.

Fwiw,
Bill Pringlemeir.
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