From: Lars-Peter Clausen <lars@metafoo.de>
To: "Sean Nyekjær" <sean.nyekjaer@prevas.dk>, linux-iio@vger.kernel.org
Subject: Re: [PATCH] iio:dac:ad5755 fixed SPI_MODE
Date: Wed, 27 Jan 2016 16:45:10 +0100 [thread overview]
Message-ID: <56A8E606.2030708@metafoo.de> (raw)
In-Reply-To: <56A8E344.8070803@prevas.dk>
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
next prev parent reply other threads:[~2016-01-27 15:45 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 [this message]
2016-01-28 7:29 ` Sean Nyekjær
2016-01-30 15:13 ` Lars-Peter Clausen
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