All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Benoît Thébaudeau" <benoit.thebaudeau@advansee.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] mxc: Make gpio_get_value() use PSR
Date: Mon, 20 Aug 2012 22:55:41 +0200 (CEST)	[thread overview]
Message-ID: <1991832745.2612487.1345496141598.JavaMail.root@advansee.com> (raw)

gpio_get_value() should use PSR like Linux, not DR, because DR does not always
reflect the pin state, while PSR does. This is especially useful to detect a
short circuit on a GPIO pin configured as output, or to read the level of a pin
controlled by a non-GPIO IOMUX function.

Signed-off-by: Beno?t Th?baudeau <benoit.thebaudeau@advansee.com>
Cc: Stefano Babic <sbabic@denx.de>
---
This patch depends on http://patchwork.ozlabs.org/patch/178694/ .

 .../drivers/gpio/mxc_gpio.c                        |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c
index 6615535..e9bf278 100644
--- u-boot-imx-84ab1cb.orig/drivers/gpio/mxc_gpio.c
+++ u-boot-imx-84ab1cb/drivers/gpio/mxc_gpio.c
@@ -116,7 +116,7 @@ int gpio_get_value(unsigned gpio)
 
 	regs = (struct gpio_regs *)gpio_ports[port];
 
-	val = (readl(&regs->gpio_dr) >> gpio) & 0x01;
+	val = (readl(&regs->gpio_psr) >> gpio) & 0x01;
 
 	return val;
 }

             reply	other threads:[~2012-08-20 20:55 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-20 20:55 Benoît Thébaudeau [this message]
2012-08-21  6:20 ` [U-Boot] [PATCH] mxc: Make gpio_get_value() use PSR Stefano Babic
2012-08-23 14:03 ` Stefano Babic

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1991832745.2612487.1345496141598.JavaMail.root@advansee.com \
    --to=benoit.thebaudeau@advansee.com \
    --cc=u-boot@lists.denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.