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Subject: Re: [PATCH] ARM: dts: am437x-gp-evm: Add wakeup interrupt source for
 pixcir_i2c_ts
To: Vignesh R <vigneshr@ti.com>
References: <1444801956-17817-1-git-send-email-vigneshr@ti.com>
 <561E165B.3000907@ti.com> <561E1C89.9080508@ti.com>
CC: Tony Lindgren <tony@atomide.com>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
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        <linux-kernel@vger.kernel.org>, "Gerlach, Dave" <d-gerlach@ti.com>
From: Roger Quadros <rogerq@ti.com>
Message-ID: <561E36BB.7000309@ti.com>
Date: Wed, 14 Oct 2015 14:04:27 +0300
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Vignesh,

On 14/10/15 12:12, Vignesh R wrote:
> 
> 
> On 10/14/2015 02:16 PM, Roger Quadros wrote:
> 
>>
>> On 14/10/15 08:52, Vignesh R wrote:
>>> On am437x-gp-evm, pixcir_i2c_ts can wakeup the system from lower power
>>> state via pinctrl and IO daisy chain using generic wakeirq framework.
>>> With commit 3fffd1283927 ("i2c: allow specifying separate wakeup
>>> interrupt in device tree") i2c core allows optional wakeirq to be
>>> specified via device tree. Add wakeup irq entry to enable pixcir_i2c_ts
>>> to wake the system from low power state.
>>>
>>> Signed-off-by: Vignesh R <vigneshr@ti.com>
>>> ---
>>>  arch/arm/boot/dts/am437x-gp-evm.dts | 5 +++++
>>>  1 file changed, 5 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/am437x-gp-evm.dts b/arch/arm/boot/dts/am437x-gp-evm.dts
>>> index 22038f21f228..69e93af7df0d 100644
>>> --- a/arch/arm/boot/dts/am437x-gp-evm.dts
>>> +++ b/arch/arm/boot/dts/am437x-gp-evm.dts
>>> @@ -581,8 +581,13 @@
>>>  
>>>  		attb-gpio = <&gpio3 22 GPIO_ACTIVE_HIGH>;
>>>  
>>> +		interrupts-extended = <&gpio3 22 GPIO_ACTIVE_HIGH>,
>>> +				      <&am43xx_pinmux 0x264>;
>>
>> How does this work?
>>
>> interrupts-extended property must have
>> 1) interrupt parent
>> 2) interrupt number
>> 3) interrupt flags
>>
>> Your change doesn't seem to comply with those requirements.
> 
> AFAIU, interrupts-extended has two parts: interrupt parent phandle and
> interrupt specifier.
> The number of cells in interrupt specifier is determined by
> interrupt-cells property of interrupt parent node.

Got it.

> In above case, gpio3 has interrupt-cells = 2 hence interrupt specifier
> has interrupt number and interrupt flag field.

But is GPIO_ACTIVE_HIGH an interrupt flag?

> But in case am43xx_pinmux node, interrupt-cells is 1 hence has no
> interrupt flag field.
> 
Understood, thanks. Might be worth adding a comment as to what 0x264 means though.

cheers,
-roger