Re: [PATCH] Make EN2 pin optional in the TRF7970A driver
From: Rob Herring
Date: Mon Feb 13 2017 - 16:32:29 EST
On Mon, Feb 13, 2017 at 12:38 AM, Heiko Schocher <hs@xxxxxxx> wrote:
> Hello Rob,
> Am 10.02.2017 um 16:51 schrieb Rob Herring:
>> On Tue, Feb 07, 2017 at 06:22:04AM +0100, Heiko Schocher wrote:
>>> From: Guan Ben <ben.guan@xxxxxxxxxxxx>
>>> Make the EN2 pin optional. This is useful for boards,
>>> which have this pin fix wired, for example to ground.
>>> Signed-off-by: Guan Ben <ben.guan@xxxxxxxxxxxx>
>>> Signed-off-by: Mark Jonas <mark.jonas@xxxxxxxxxxxx>
>>> Signed-off-by: Heiko Schocher <hs@xxxxxxx>
>>> .../devicetree/bindings/net/nfc/trf7970a.txt | 4 ++--
>>> drivers/nfc/trf7970a.c | 26
>>> 2 files changed, 16 insertions(+), 14 deletions(-)
>>> diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
>>> index 32b35a0..5889a3d 100644
>>> --- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
>>> +++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
>>> @@ -5,8 +5,8 @@ Required properties:
>>> - spi-max-frequency: Maximum SPI frequency (<= 2000000).
>>> - interrupt-parent: phandle of parent interrupt handler.
>>> - interrupts: A single interrupt specifier.
>>> -- ti,enable-gpios: Two GPIO entries used for 'EN' and 'EN2' pins on the
>>> - TRF7970A.
>>> +- ti,enable-gpios: One or two GPIO entries used for 'EN' and 'EN2' pins
>>> on the
>>> + TRF7970A. EN2 is optional.
>> Could EN ever be optional/fixed? If so, perhaps deprecate this property
>> and do 2 properties, one for each pin.
> The hardware I have has the EN2 pin fix connected to ground. Looking
> into http://www.ti.com/lit/ds/slos743k/slos743k.pdf page 19 table 6-3
> and 6-4 the EN2 pin is a don;t core if EN = 1. If EN = 0 EN2 pin
> selects between Power Down and Sleep Mode ... I see no reason why
> this is not possible/allowed ...
> Hmm.. I do not like the idea of deprecating the "ti,enable-gpios"
> property into 2 seperate properties ... but if this would be a reason
> for not accepting this patch, I can do this ... How should I name
> the 2 new properties?
I guess if this ever happens, then we just add "ti,enable2-gpios" and
ti,enable-gpios continues to point to EN. We don't need to deprecate
anything (or maybe just deprecate having both GPIOs on single
In that case,
Acked-by: Rob Herring <robh@xxxxxxxxxx>
> "ti,pin-enable" and "ti,pin-enable2" ?
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