From mboxrd@z Thu Jan  1 00:00:00 1970
From: ipaton0@gmail.com (Iain Paton)
Date: Fri, 09 May 2014 15:16:17 +0100
Subject: [PATCH v2] ARM: dts: imx6: add new board RIoTboard
In-Reply-To: <20140509120845.GO2794@dragon>
References: <53695C34.5000604@gmail.com> <20140508054106.GH2794@dragon>
 <536B4ACD.30001@gmail.com> <20140509030938.GK2794@dragon>
 <536C8837.9090802@gmail.com> <20140509120845.GO2794@dragon>
Message-ID: <536CE331.7030001@gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 09/05/14 13:08, Shawn Guo wrote:
> On Fri, May 09, 2014 at 08:48:07AM +0100, Iain Paton wrote:
>> On 09/05/14 04:09, Shawn Guo wrote:
>>> On Thu, May 08, 2014 at 10:13:49AM +0100, Iain Paton wrote:
>>
>>>> +&ecspi1 {
>>>> +	fsl,spi-num-chipselects = <1>;
>>>> +	cs-gpios = <&gpio5 17 0>;
>>>> +	pinctrl-names = "default";
>>>> +	pinctrl-0 = <&pinctrl_ecspi1>;
>>>> +	status = "okay";
>>>> +
>>>> +	spidev at 0 {
>>>> +		spi-max-frequency = <24000000>;
>>>> +		reg = <0>;
>>>> +		compatible = "spidev";
>>>> +	};
>>>
>>> What's this?  Is this the common way we code spi devices in device tree?
>>
>> I'd appreciate your guidance here, what would you prefer?
>>
>> My reasons for adding spidev were as follows:
>>
>> 1. The SPI pins are not used on the board, they go to an expansion header.
>> 2. Board is targeted at makers who are likely to want to attach 
>>    external devices.
>> 3. Experience has been that if they don't find an easy and already 
>>    configured way to use something they reach for devmem2 or similar.
>> 4. devicetree is often seen as being too hard by people who come to these
>>    boards from things like arduino
>>
>> I've already had questions on how to find the physical address of /dev/i2c-0 
>> seemingly due to some of the above.
>>
>> I'm happy to drop the spidev entries if that's what you'd prefer, but if I
>> do that I'm undecided if I should then just drop the ecspi sections as well 
>> and free up more gpio pins on the expansion header for other uses.
> 
> You can decide if you want to drop or keep the ecspi sections.  I prefer
> to drop those spidev nodes, before we're not sure this is the right way
> to go.

I'll likely drop them then.  Am I ok to leave the pin groups in the iomuxc
when nothing uses them, or would you prefer I only include what's actually 
being used ?