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From: haojian.zhuang@gmail.com (Haojian Zhuang)
To: linux-arm-kernel@lists.infradead.org
Subject: How to add GPIO outputs to the PXA2xx MFP configuration?
Date: Fri, 30 Mar 2012 09:33:30 +0800	[thread overview]
Message-ID: <CAN1soZwzBqDGTX+a-maVr5baaoZ7qwgdvXyPeya5R80cN_iA0w@mail.gmail.com> (raw)
In-Reply-To: <1332958336.11131.YahooMailClassic@web29001.mail.ird.yahoo.com>

On Thu, Mar 29, 2012 at 2:12 AM, Paul Parsons <lost.distance@yahoo.com> wrote:
> On PXA2xx platforms, the MFP API (described in Documentation/arm/pxa/mfp.txt)
> provides values for the following:
>
> 1. GPIO inputs (e.g. GPIO105_GPIO).
> 2. Alternate function inputs (e.g. GPIO105_CIF_DD_1).
> 3. Alternate function outputs (e.g. GPIO105_KP_MKOUT_2).
>
> It does not provide values for GPIO outputs (i.e. AF0 outputs).
>
> One cannot use the macro used by the MFP API internally - MFP_CFG_OUT() - to
> define new GPIO output values, since that macro is forbidden in platform code.
>
> Without the ability to add GPIO outputs to the MFP configuration, it is not
> possible to drive GPIO outputs high during sleep mode.
>
> This would be useful, for example, on the hx4700 platform, where driving the
> infrared powerdown GPIO 105 high during sleep mode would save some mA.
>
> So my question is: what method should one use to add GPIO outputs to the MFP
> configuration?
>
> One possible method, namely manually defining values in the platform code:
>
> ? ? ? ?MFP_PIN_GPIO105 | MFP_AF0 | MFP_DIR_OUT | MFP_LPM_DRIVE_HIGH,
>
> is essentially no different from using the forbidden MFP_CFG_OUT() macro.
>

Does MFP_CFG_OUT() help you? This macro is defined in mfp-pxa2xx.h.

  reply	other threads:[~2012-03-30  1:33 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-28 18:12 How to add GPIO outputs to the PXA2xx MFP configuration? Paul Parsons
2012-03-30  1:33 ` Haojian Zhuang [this message]
2012-03-30 10:41   ` Paul Parsons
2012-03-30 13:25     ` Haojian Zhuang
2012-03-30 14:30       ` Paul Parsons
2012-03-30 14:50         ` Haojian Zhuang
2012-03-30 14:59 ` Igor Grinberg
2012-03-30 15:06   ` Paul Parsons
2012-03-30 15:28     ` Igor Grinberg
2012-03-30 15:34     ` Igor Grinberg
2012-03-30 15:52       ` Paul Parsons
2012-03-30 17:59         ` Igor Grinberg
2012-03-30 21:13           ` Paul Parsons
2012-03-30 21:40             ` Paul Parsons

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