Re: SPI-ADC

From: arjun rath <rath.arjun-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Haavard Skinnemoen
	<haavard.skinnemoen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
Cc: "spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org"
	<spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>,
	"hskinnemoen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org"
	<hskinnemoen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
Subject: Re: SPI-ADC
Date: Mon, 26 Apr 2010 13:10:56 +0530	[thread overview]
Message-ID: <y2rdc6d3181004260040id92a844bt54bcfac75f1176c@mail.gmail.com> (raw)
In-Reply-To: <20100426092646.11d8d71c@hskinnemoen-d830>

>> The max124[0|1] is still a spi device so using the atmel_spi driver is
>> the correct route.  You just need to add the necessary support to the
>> driver to handle the SPI_READY mode.
>
> If there's only one master driver which supports this flag, it sounds
> to me like it would be a _lot_ easier in the long run to instead teach
> the device driver to deal with drivers which don't support this mode.
>
> The atmel_spi hardware doesn't have any hardware support for this mode
> as far as I know, so the implementation will be very CPU-intensive
> either way.
>
> But the best solution is probably to replace the ADC with one that
> doesn't have a completely boneheaded interface.
>
> Haavard

Now i written the program with simple IO port reading/writing since
those pins can be also configured as gpio pins.And when pulling the CS
line LOW and checking the probe DOUT data is showing in the CRO but
while reading the DOUT pin it always shows 1(high) only.

Really its getting tougher and tougher

On Mon, Apr 26, 2010 at 12:56 PM, Haavard Skinnemoen
<haavard.skinnemoen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> wrote:
> H Hartley Sweeten <hartleys-3FF4nKcrg1dE2c76skzGb0EOCMrvLtNR@public.gmane.org> wrote:
>> The max124[0|1] is still a spi device so using the atmel_spi driver is
>> the correct route.  You just need to add the necessary support to the
>> driver to handle the SPI_READY mode.
>
> If there's only one master driver which supports this flag, it sounds
> to me like it would be a _lot_ easier in the long run to instead teach
> the device driver to deal with drivers which don't support this mode.
>
> The atmel_spi hardware doesn't have any hardware support for this mode
> as far as I know, so the implementation will be very CPU-intensive
> either way.
>
> But the best solution is probably to replace the ADC with one that
> doesn't have a completely boneheaded interface.
>
> Haavard
>

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