Date: Wed, 23 Dec 2015 03:49:08 -0800
From: =?utf-8?B?U8O2cmVu?= Brinkmann <soren.brinkmann@xilinx.com>
To: Ranjit Waghmode <ranjit.waghmode@xilinx.com>
CC: <robh+dt@kernel.org>, <pawel.moll@arm.com>, <mark.rutland@arm.com>,
        <ijc+devicetree@hellion.org.uk>, <galak@codeaurora.org>,
        <michal.simek@xilinx.com>, <corbet@lwn.net>, <lars@metafoo.de>,
        <devicetree@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <punnaia@xilinx.com>,
        <anirudh@xilinx.com>
Subject: Re: [RFC LINUX PATCH] dt: xilinx: xadc: provision to control clock
 frequency
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References: <1450866505-22069-1-git-send-email-ranjit.waghmode@xilinx.com>
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On Wed, 2015-12-23 at 03:58PM +0530, Ranjit Waghmode wrote:
> This patch adds parameter to the xilinx-xadc node for controlling
> clock frequency.
> 
> Following are the possible options for user to control the frequency:
> 	* 00 : 1/2 of clock frequency
> 	* 01 : 1/4 of clock frequency
> 	* 10 : 1/8 of clock frequency
> 	* 11 : 1/16 of clock frequency

How is this chosen? Are these just arbitrary values that you need for
some use-case? Or are these the options HW allows?

> 
> So this patch adds parameter tck-rate to set user defined values from
> above pool to control the clock frequency.

This is no longer describing HW, but configuring driver/HW. Why does
this have to be in DT? Why can't the driver request/set the frequency as
operation requires it?

	Thanks,
	Sören
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