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Date: Wed, 3 Jun 2009 21:24:52 +0530
Message-ID: <5d5443650906030854h40e98ff9tb2bd23a0f5e8dec6@mail.gmail.com>
Subject: Re: PWM class? (was: Re: MPC52xx simple GPIO support)
From: Trilok Soni <soni.trilok@gmail.com>
To: Jon Smirl <jonsmirl@gmail.com>
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Cc: Bill Gatliff <bgat@billgatliff.com>, ppc-dev <linuxppc-dev@ozlabs.org>,
	linux-kernel@vger.kernel.org, Stefan Strobl <nst@gersys.de>
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Hi Jon,

On Wed, Jun 3, 2009 at 9:08 PM, Jon Smirl <jonsmirl@gmail.com> wrote:
> On Wed, Jun 3, 2009 at 9:22 AM, Anton Vorontsov
> <avorontsov@ru.mvista.com> wrote:
>> On Wed, Jun 03, 2009 at 02:42:26PM +0200, Stefan Strobl wrote:
>> [...]
>>> The led class provides support for setting the brightness, which
>>> obviously the gpio driver doesn't support. The hardware (mpc52xx_gpt)
>>> would support it in PWM mode though. I'm now wandering how this could b=
e
>>> best implemented.
>>>
>>> 1) - Create some PWM class similar to the GPIO class
>>> =A0 =A0- Add support for PWM mode in mpc52xx_gpt.c that uses that PWM c=
lass
>>> =A0 =A0- And add an interface for the LED to use the PWM class
>>>
>>> 2) - Create an LED driver that accesses the mpc52xx_gpt directly.
>>>
>>> I think I would be overwhelmed trying to implement (1) but am confident
>>> to do (2). What do you think is the right approach?
>>
>> I'd suggest creating a generic PWM class, i.e. PWMLIB, alike to
>> GPIOLIB. (2) can be an acceptable approach for now, but for the
>> long-term solution (1) is the way to go.
>
> What happened to this one?
>
> http://ozlabs.org/pipermail/linuxppc-dev/2008-October/063562.html
>

Adding Bill to see if he has any updates.

--=20
---Trilok Soni
http://triloksoni.wordpress.com
http://www.linkedin.com/in/triloksoni