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From: "Sean Nyekjær" <sean.nyekjaer@prevas.dk>
To: Lars-Peter Clausen <lars@metafoo.de>, <linux-iio@vger.kernel.org>,
	Jonathan Cameron <jic23@kernel.org>
Subject: Re: [PATCH] iio:dac:ad5755 fixed SPI_MODE
Date: Thu, 28 Jan 2016 08:29:57 +0100	[thread overview]
Message-ID: <56A9C375.70501@prevas.dk> (raw)
In-Reply-To: <56A8E606.2030708@metafoo.de>



On 2016-01-27 16:45, Lars-Peter Clausen wrote:
> On 01/27/2016 04:33 PM, Sean Nyekjær wrote:
>> On 2016-01-27 15:45, Lars-Peter Clausen wrote:
>>> On 01/27/2016 03:39 PM, Sean Nyekjaer wrote:
>>>> According to datasheet data is latched on the falling edge of the SCK.
>>>>
>>>> I agree it works in SPI_MODE_0 on the eval kit, but in other configurations
>>>> with optic isolators (that adds a small delay). We are falling out of spec.
>>>>
>>>> Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
>>> Hi,
>>>
>>> The SPI mode is usually specified in the spi_board_info struct or devicetree
>>> rather than hardcoding it in the driver.
>>>
>>> - Lars
>> Hi
>> I know :-)
>> But, all devices in this family have only support for SPI_MODE_1. So why
>> leave it up to the spi_board_info or devicetree when only one mode is allowed?
> As far as I can see they should work with either SPI_MODE_1 or SPI_MODE_2.
> But it would certainly be nice if the SPI framework had support for
> auto-configuration, based on the support modes of the SPI controller and the
> device, in case no mode was explicit specified.
>
>> If you don't like this patch I think we should create some documentation for
>> the device, so other people don't have to use hours in debugging :-D
> https://wiki.analog.com/resources/tools-software/linux-drivers/iio-dac/ad5755?&#example_platform_device_initialization
Ops the gmail app on android is not very good answering text only emails :-)

Is there a reason why this documentation is not in the kernel?
It's also missing the options and examples for devicetree bindings...

Should I create the devicetree documentation instead of this patch?
I still think this patch is a better solution to prevent future problems 
with the driver.

/Sean

  reply	other threads:[~2016-01-28  7:40 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-27 14:39 [PATCH] iio:dac:ad5755 fixed SPI_MODE Sean Nyekjaer
2016-01-27 14:45 ` Lars-Peter Clausen
2016-01-27 15:33   ` Sean Nyekjær
2016-01-27 15:45     ` Lars-Peter Clausen
2016-01-28  7:29       ` Sean Nyekjær [this message]
2016-01-30 15:13         ` Lars-Peter Clausen

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