Re: [PATCH v3 18/27] mtd: nand: omap2: Implement NAND ready using gpiolib

From: Roger Quadros
Date: Tue Oct 27 2015 - 04:44:52 EST


On 27/10/15 10:12, Boris Brezillon wrote:
> Hi Roger,
> On Tue, 27 Oct 2015 10:03:02 +0200
> Roger Quadros <rogerq@xxxxxx> wrote:
>> On 26/10/15 22:49, Brian Norris wrote:
>>> Others have been looking at using GPIOs for the ready/busy pin too. At a
>>> minimum, we need an updated DT binding doc for this, since I see you're
>>> adding this via device tree in a later patch (I don't see any DT binding
>>> patch for this; but I could just be overlooking it). It'd also be great
>>> if this support was moved to nand_dt_init() so other platforms can
>>> benefit, but I won't require that.
>>> Also, previous [0] proposers had suggested 'rb-gpios', not 'ready-gpio'
>>> (the hardware docs typically call it 'rb' for ready/busy, FWIW). I don't
>>> really care, but the name should be going into a doc, so we can choose
>>> the same one everywhere.
>>> EDIT: looks like the discussion was partly here [1] and it seems we're
>>> landing on "rb-gpios" in the latest version [2]. Can we stick with that?
>> Why should it be "rb-gpios" and not "rb-gpio"?
>> I don't think there are multiple gpios for r/b# function.
> Because it's supposed to be a generic binding, and some NAND chips
> embed several dies, thus exposing several CS and RB pins, hence the
> rb-gpios name.
> Also, as described here [1], the convention is to name your property
> <name>-gpios even if you only need one gpio.

Makes sense now. Thanks for the explanation.
I'll update this patch to use rb-gpios and update the binding doc as well.

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