public inbox for u-boot@lists.denx.de
 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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox