Re: [PATCH 1/3] NFC: trf7970a: add device tree option for 27MHz clock

[Rob Herring]

On Thu, Dec 15, 2016 at 05:30:42PM -0500, Geoff Lansberry wrote:
> From: Geoff Lansberry <geoff@xxxxxxxxx>
> 
> ---
>  .../devicetree/bindings/net/nfc/trf7970a.txt       |  3 ++
>  drivers/nfc/trf7970a.c                             | 42 ++++++++++++++++------
>  2 files changed, 34 insertions(+), 11 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> index 32b35a0..9dda879 100644
> --- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> +++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> @@ -21,6 +21,8 @@ Optional SoC Specific Properties:
>  - t5t-rmb-extra-byte-quirk: Specify that the trf7970a has the erratum
>    where an extra byte is returned by Read Multiple Block commands issued
>    to Type 5 tags.
> +- crystal_27mhz: Set to specify that the input frequency to the trf7970a is 27.12MHz
> +

Can't you use 'clock-frequency = "27000000";'?

>  
>  Example (for ARM-based BeagleBone with TRF7970A on SPI1):
>  
> @@ -43,6 +45,7 @@ Example (for ARM-based BeagleBone with TRF7970A on SPI1):
>  		irq-status-read-quirk;
>  		en2-rf-quirk;
>  		t5t-rmb-extra-byte-quirk;
> +		crystal_27mhz;
>  		status = "okay";
>  	};
>  };