Re: [PATCH] spi: core: use gpio_request_one for configured gpio cs

From: "Martin Hundebøll" <martin.hundeboll-rjjw5hvvQKZaa/9Udqfwiw@public.gmane.org>
To: Chris Packham
	<Chris.Packham-6g8wRflRTwXFdCa3tKVlE6U/zSkkHjvu@public.gmane.org>,
	Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Andy Shevchenko
	<andy.shevchenko-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: "Martin Hundebøll" <mnhu-rjjw5hvvQKZaa/9Udqfwiw@public.gmane.org>,
	"Mika Westerberg"
	<mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
	"Jarkko Nikula"
	<jarkko.nikula-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
	linux-spi <linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH] spi: core: use gpio_request_one for configured gpio cs
Date: Mon, 24 Jul 2017 23:26:35 +0200	[thread overview]
Message-ID: <DBFEECA3-E21E-4DC5-B6B9-D1B12AD48E7A@prevas.dk> (raw)
In-Reply-To: <e668b7529837444085b9df3a563c3fe3-5g7mGxlPNYb6GjIOKuZY+ItlCAj8ZROq@public.gmane.org>

On July 24, 2017 11:16:17 PM GMT+02:00, Chris Packham <Chris.Packham@alliedtelesis.co.nz> wrote:
>On 25/07/17 00:42, Mark Brown wrote:
>> On Mon, Jul 24, 2017 at 01:49:14PM +0300, Andy Shevchenko wrote:
>>> On Mon, Jul 24, 2017 at 12:53 PM, Martin Hundebøll <mnhu@prevas.dk>
>wrote:
>>>> Some gpio controllers requires lines to be configured as outputs to
>make
>>>> subsequent calls to `gpio_set_value()` have any effect.
>> 
>>>> Add a call to `gpio_request_one()` for configured gpio chip-selects
>to
>>>> make it work on (at least) mvebu gpio controllers.
>> 
>>> More and more hacks around plain GPIO integers... :-(
>> 
>>> Perhaps we need to discuss how to convert SPI core to use GPIO
>>> descriptors everywhere.
>> 
>> The best way would be to test the work that Chris Packham submitted
>in
>> May to do this, it'll need a refresh now and it ought to get some
>> testing on ep93xx but sadly nobody working on ep93xx has responded -
>I
>> think at this point I'd probably just apply and let people test
>-next.
>> 
>
>My patchset kind of stalled. I can do a refresh if there's interest.
>But 
>I really do need some help from people with access to hardware (I can 
>cover spi-orion and spi-fsl-espi but that's about it). After the
>initial 
>RFC series I posted in May I found that iMX platforms use the integer 
>cs_gpio field for both native chipselects and gpio based ones (values <
>
>0 indicate native CS) so again I'd be coding blind trying to
>disentangle 
>that.

My submission was more or less a fly-by patch, but I'd be happy to test/debug patches on spi-imx if you CC me on the series.

Any other drivers with special gpio-cs handling?

// Martin

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