[PATCH] powerpc: Add I2C bus multiplexer node for B4 and T4240QDS

Yang,Wei Wei.Yang at windriver.com
Wed Sep 4 14:27:11 EST 2013


On 09/04/2013 12:03 PM, Tang Yuantian-B29983 wrote:
> Hi,
> I noticed that there are already some nodes in i2c bus.

Sorry for my late response, yeah, just as you noticed, some eeprom nodes
already are inside i2c bus.:-)

Wei
> You should at least move the existing node into PCA9547.
>
> Thanks,
> Yuantian
>
>
>> -----Original Message-----
>> From: Linuxppc-dev [mailto:linuxppc-dev-
>> bounces+b29983=freescale.com at lists.ozlabs.org] On Behalf Of Jia Hongtao-
>> B38951
>> Sent: 2013年9月4日 星期三 11:38
>> To: Yang,Wei
>> Cc: Wood Scott-B07421; linuxppc-dev at lists.ozlabs.org
>> Subject: RE: [PATCH] powerpc: Add I2C bus multiplexer node for B4 and
>> T4240QDS
>>
>> Hi Wei,
>>
>> I totally agree that the i2c nodes topology should end up like you said.
>>
>> But I think adding sub-nodes should step by step.
>> Actually the hardware i2c topology are huge like on T4.
>> So I'd like to adding nodes when we needed.
>> If you think the sub-nodes are needed please send another patch based on
>> mine.
>> I think this is the more reasonable way.
>>
>> Thanks.
>>
>> -Hongtao
>>
>>
>>> -----Original Message-----
>>> From: Yang,Wei [mailto:Wei.Yang at windriver.com]
>>> Sent: Wednesday, September 04, 2013 9:27 AM
>>> To: Jia Hongtao-B38951
>>> Cc: linuxppc-dev at lists.ozlabs.org; Wood Scott-B07421; Jia
>>> Hongtao-B38951
>>> Subject: Re: [PATCH] powerpc: Add I2C bus multiplexer node for B4 and
>>> T4240QDS
>>>
>>> On 09/03/2013 03:51 PM, Jia Hongtao wrote:
>>>> In both B4 and T4240QDS platform PCA9547 I2C bus multiplexer is used.
>>> Hi Hongtao,
>>>
>>> If you want to support I2C bus multiplexer, for T4 and B4QDS platform,
>>> since some eeprom devices is connected to PCA9574 I2C bus multiplexer,
>>> so these devices should be connected to pca9547 node. Just like the
>>> following, what do you think of it?
>>>
>>> +                       pca9547 at 77 {
>>> +                               compatible = "philips,pca9547";
>>> +                               reg = <0x77>;
>>> +                               #address-cells = <1>;
>>> +                               #size-cells = <0>;
>>> +                               channel at 0 {
>>> +                                       #address-cells = <1>;
>>> +                                       #size-cells = <0>;
>>> +                                       reg = <0>;
>>> +                                               eeprom at 51 {
>>> +                                                       compatible =
>>> "at24,24c256";
>>> +                                                       reg = <0x51>;
>>> +                                               };
>>> +                                               eeprom at 52 {
>>> +                                                       compatible =
>>> "at24,24c256";
>>> +                                                       reg = <0x52>;
>>> +                                               };
>>> +                                               eeprom at 53 {
>>> +                                                       compatible =
>>> "at24,24c256";
>>> +                                                       reg = <0x53>;
>>> +                                               };
>>> +                                               eeprom at 54 {
>>> +                                                       compatible =
>>> "at24,24c256";
>>> +                                                       reg = <0x54>;
>>> +                                               };
>>> +                                               eeprom at 55 {
>>> +                                                       compatible =
>>> "at24,24c256";
>>> +                                                       reg = <0x55>;
>>> +                                               };
>>> +                                               eeprom at 56 {
>>> +                                                       compatible =
>>> "at24,24c256";
>>> +                                                       reg = <0x56>;
>>> +                                               };
>>> +                                               rtc at 68 {
>>> +                                                       compatible =
>>> "dallas,ds3232";
>>> +                                                       reg = <0x68>;
>>> +                                                       interrupts =
>>> <0x1 0x1 0 0>;
>>> +                                               };
>>> +                                       };
>>>
>>> Wei
>>>> Signed-off-by: Jia Hongtao <hongtao.jia at freescale.com>
>>>> ---
>>>>   arch/powerpc/boot/dts/b4qds.dtsi   | 4 ++++
>>>>   arch/powerpc/boot/dts/t4240qds.dts | 4 ++++
>>>>   2 files changed, 8 insertions(+)
>>>>
>>>> diff --git a/arch/powerpc/boot/dts/b4qds.dtsi
>>>> b/arch/powerpc/boot/dts/b4qds.dtsi
>>>> index e6d2f8f..2aa3399 100644
>>>> --- a/arch/powerpc/boot/dts/b4qds.dtsi
>>>> +++ b/arch/powerpc/boot/dts/b4qds.dtsi
>>>> @@ -120,6 +120,10 @@
>>>>   		};
>>>>
>>>>   		i2c at 118000 {
>>>> +			pca9547 at 77 {
>>>> +				compatible = "philips,pca9547";
>>>> +				reg = <0x77>;
>>>> +			};
>>>>   			eeprom at 50 {
>>>>   				compatible = "at24,24c64";
>>>>   				reg = <0x50>;
>>>> diff --git a/arch/powerpc/boot/dts/t4240qds.dts
>>>> b/arch/powerpc/boot/dts/t4240qds.dts
>>>> index 0555976..084db57 100644
>>>> --- a/arch/powerpc/boot/dts/t4240qds.dts
>>>> +++ b/arch/powerpc/boot/dts/t4240qds.dts
>>>> @@ -118,6 +118,10 @@
>>>>   		};
>>>>
>>>>   		i2c at 118000 {
>>>> +			pca9547 at 77 {
>>>> +				compatible = "philips,pca9547";
>>>> +				reg = <0x77>;
>>>> +			};
>>>>   			eeprom at 51 {
>>>>   				compatible = "at24,24c256";
>>>>   				reg = <0x51>;
>>
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