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From: Sascha Hauer <s.hauer@pengutronix.de>
To: Patrick <kpa_info@yahoo.fr>
Cc: barebox@lists.infradead.org
Subject: Re: GPIO commands on OMAP4
Date: Thu, 5 Apr 2012 15:49:57 +0200	[thread overview]
Message-ID: <20120405134957.GE3852@pengutronix.de> (raw)
In-Reply-To: <4F7D68A1.9000800@yahoo.fr>

On Thu, Apr 05, 2012 at 11:40:49AM +0200, Patrick wrote:
> Dear mailing-list,
> 
> I am using a pcm049 phyCORE omap4430 module from Phytec with BareBox
> 2011.09.0 patched with BSP from Phytec.
> 
> I would like to use the GPIO command to read a switch at startup.
> This chip is connected on ABE_MCBSP1_DX (gpio_116). I have edited
> the boards/pcm049/mux.c files to change the configuration of this
> GPIO as follow: {ABE_MCBSP1_DX, (DIS | IEN | M3)} instead of
> {ABE_MCBSP1_DX, (SAFE_MODE)}.
> 
> I then use the "gpio_get_value 116" command followed by "echo $?" to
> read the value. I always read a 0. On Linux I could read the right
> value depending of the position of the switch, so it's not an
> hardware problems.
> 
> I have tried with one of the two LEDs on the module (gpio_152) and I
> could change the LED state and read it back with gpio_get_value.
> 
> I do not understand what I am doing wrong. Any help will be appreciated.

What you tried should work. The only thing I can imagine is that you
need a gpio_direction_input before reading the value.

Sascha

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  parent reply	other threads:[~2012-04-05 13:50 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-05  9:40 Patrick
2012-04-05 12:45 ` Patrick
2012-04-05 13:49 ` Sascha Hauer [this message]
2012-04-05 14:38   ` Patrick
2012-04-05 14:58     ` Patrick
2012-04-05 16:19       ` Sascha Hauer

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