Subject: [PATCH 2/5 v3] ARM: at91: sam9g20 add i2c DT support

From: [email-masked] (Rob Herring)
Date: Fri, 09 Mar 2012 07:59:17 -0600

On 03/09/2012 03:53 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 11:08 Thu 08 Mar     , Rob Herring wrote:
>> On 03/08/2012 02:50 AM, Jean-Christophe PLAGNIOL-VILLARD wrote:
>>> For now on use i2c-gpio driver on the same pin as the hardware IP.
>>>
>>> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <[email-masked]>
>>> Cc: Nicolas Ferre <[email-masked]>
>>> Cc: devicetree-discuss at lists.ozlabs.org
>>> ---
>>> v3:
>>>
>>> 	update i2c binding (Rob comments)
>>>
>>> Best Regards,
>>> J.
>>>  arch/arm/boot/dts/at91sam9g20.dtsi |   13 +++++++++++++
>>>  1 files changed, 13 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/arch/arm/boot/dts/at91sam9g20.dtsi b/arch/arm/boot/dts/at91sam9g20.dtsi
>>> index 4b0dc99..072b2da 100644
>>> --- a/arch/arm/boot/dts/at91sam9g20.dtsi
>>> +++ b/arch/arm/boot/dts/at91sam9g20.dtsi
>>> @@ -189,4 +189,17 @@
>>>  			status = "disabled";
>>>  		};
>>>  	};
>>> +> > +	i2c-gpio at 0 {
>>
>> You updated the example, but not all the actual uses to i2c at 0.
> on purpose as on some soc we will have HW and soft binding
> 
> on the board you put the alias
> 

I'm not sure I follow.

If you use the h/w block, then you would have i2c@<addr> while for gpio
it's basically an index.

Also, I don't think you need an alias for i2c. You should not care about
bus numbering as devices should be sub nodes.

Rob

> Best Regards,
> J.
>>
>> Rob
>>
>>> +		compatible = "i2c-gpio";
>>> +		gpios = <&pioA 23 0 /* sda */
>>> +			 &pioA 24 0 /* scl */
>>> +			>;
>>> +		i2c-gpio,sda-open-drain;
>>> +		i2c-gpio,scl-open-drain;
>>> +		i2c-gpio,delay-us = <2>;	/* ~100 kHz */
>>> +		#address-cells = <1>;
>>> +		#size-cells = <0>;
>>> +		status = "disabled";
>>> +	};
>>>  };
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel