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Date:   Sat, 30 Sep 2023 16:32:09 +0100
From:   Jonathan Cameron <jic23@kernel.org>
To:     David Lechner <dlechner@baylibre.com>
Cc:     linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
        linux-staging@lists.linux.dev,
        David Lechner <david@lechnology.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Michael Hennerich <Michael.Hennerich@analog.com>,
        Nuno =?UTF-8?B?U8Oh?= <nuno.sa@analog.com>,
        Axel Haslam <ahaslam@baylibre.com>,
        Philip Molloy <pmolloy@baylibre.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 22/27] staging: iio: resolver: ad2s1210: convert LOS
 threshold to event attr
Message-ID: <20230930163209.17ee0020@jic23-huawei>
In-Reply-To: <20230929-ad2s1210-mainline-v3-22-fa4364281745@baylibre.com>
References: <20230929-ad2s1210-mainline-v3-0-fa4364281745@baylibre.com>
        <20230929-ad2s1210-mainline-v3-22-fa4364281745@baylibre.com>
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On Fri, 29 Sep 2023 12:23:27 -0500
David Lechner <dlechner@baylibre.com> wrote:

> From: David Lechner <david@lechnology.com>
> 
> From: David Lechner <dlechner@baylibre.com>
> 
> The AD2S1210 has a programmable threshold for the loss of signal (LOS)
> fault. This fault is triggered when either the sine or cosine input
> falls below the threshold voltage.
> 
> This patch converts the custom device LOS threshold attribute to an
> event falling edge threshold attribute on a new monitor signal channel.
> The monitor signal is an internal signal that combines the amplitudes
> of the sine and cosine inputs as well as the current angle and position
> output. This signal is used to detect faults in the input signals.
> 
> The attribute now uses millivolts instead of the raw register value in
> accordance with the IIO ABI.
> 
> Emitting the event will be implemented in a later patch.
> 
> Signed-off-by: David Lechner <dlechner@baylibre.com>

I think I'm fine with treating these internal signals like this, but
I would ideally like someone from Analog devices to take a look at how
these are being done and make sure our interpretations of the signals
make sense to them.  We are pushing the boundaries a little here (though
we have done similar before for fault events I think.)

Jonathan