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From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: imx25-pinfunc: remove SION from all modes
Date: Tue, 19 Apr 2016 22:19:58 +0100	[thread overview]
Message-ID: <20160419211958.GD19428@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1461095114-11745-1-git-send-email-u.kleine-koenig@pengutronix.de>

On Tue, Apr 19, 2016 at 09:45:14PM +0200, Uwe Kleine-K?nig wrote:
> With the SION bit set a pin can be read as GPIO even though it's not muxed
> as GPIO. This is useful at times. The downside however is that the signal
> is not only routed to the GPIO IP but also all other IPs that can make use
> of the pin. This resulted in more than one issue for me in the past. Things
> like spi transfers that result in usb reenumeration or setting a GPIO to a
> value that triggers an RTS irq for an UART.

Isn't SION required for all GPIOs such that reading the value of a GPIO
pin returns the actual state of the pin, not the output value written
to it?

What about the ethernet pins?  I know that on iMX6, SION is required for
correct functionality of certain phy clocking modes, and I wouldn't be
surprised if this was true in earlier designs as well.

-- 
RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

  reply	other threads:[~2016-04-19 21:19 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-19 19:45 [PATCH] ARM: imx25-pinfunc: remove SION from all modes Uwe Kleine-König
2016-04-19 21:19 ` Russell King - ARM Linux [this message]
2016-04-20  7:51   ` Uwe Kleine-König
2016-04-20  8:46   ` Lothar Waßmann
2016-04-20  8:58     ` Uwe Kleine-König
2016-06-03 13:32       ` Uwe Kleine-König
2016-06-03 14:01         ` Shawn Guo
2016-06-03 19:31           ` Uwe Kleine-König
2016-06-13 10:16             ` Uwe Kleine-König
2016-06-13 10:17               ` [PATCH 1/2] ARM: imx25-pinfunc: document SION being important for MX25_PAD_SD1_CMD__SD1_CMD Uwe Kleine-König
2016-06-13 10:17                 ` [PATCH 2/2] ARM: imx25-pinfunc: remove SION from all modes Uwe Kleine-König
2016-06-16  0:32               ` [PATCH] " Shawn Guo

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