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linux/3.3: backport an upstream GPIO patch

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The backported patch introduces new flags to
automatically export GPIOs when using the
convenience unctions gpio_request_one() or
gpio_request_array().

This will be used by ar71xx/ramips platforms.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 34081
This commit is contained in:
Gabor Juhos 2012-11-05 11:04:43 +00:00
parent aa0944ff72
commit 5e43b934fd
1 changed files with 68 additions and 0 deletions
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68
target/linux/generic/patches-3.3/070-gpio-add-flags-to-export-GPIOs-when-requesting.patch Normal file
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@ -0,0 +1,68 @@
From fc3a1f04f5040255cbc086c419e4237f29f89f88 Mon Sep 17 00:00:00 2001
From: Wolfram Sang <w.sang@pengutronix.de>
Date: Tue, 13 Dec 2011 18:34:01 +0100
Subject: [PATCH] gpio: add flags to export GPIOs when requesting
commit fc3a1f04f5040255cbc086c419e4237f29f89f88 upstream.
Introduce new flags to automatically export GPIOs when using the convenience
functions gpio_request_one() or gpio_request_array(). This eases support for
custom boards where lots of GPIOs need to be exported for customer
applications.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
Documentation/gpio.txt | 3 +++
drivers/gpio/gpiolib.c | 12 +++++++++++-
include/linux/gpio.h | 5 +++++
3 files changed, 19 insertions(+), 1 deletion(-)
--- a/Documentation/gpio.txt
+++ b/Documentation/gpio.txt
@@ -303,6 +303,9 @@ where 'flags' is currently defined to sp
* GPIOF_INIT_LOW - as output, set initial level to LOW
* GPIOF_INIT_HIGH - as output, set initial level to HIGH
+ * GPIOF_EXPORT_DIR_FIXED - export gpio to sysfs, keep direction
+ * GPIOF_EXPORT_DIR_CHANGEABLE - also export, allow changing direction
+
since GPIOF_INIT_* are only valid when configured as output, so group valid
combinations as:
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1289,8 +1289,18 @@ int gpio_request_one(unsigned gpio, unsi
(flags & GPIOF_INIT_HIGH) ? 1 : 0);
if (err)
- gpio_free(gpio);
+ goto free_gpio;
+ if (flags & GPIOF_EXPORT) {
+ err = gpio_export(gpio, flags & GPIOF_EXPORT_CHANGEABLE);
+ if (err)
+ goto free_gpio;
+ }
+
+ return 0;
+
+ free_gpio:
+ gpio_free(gpio);
return err;
}
EXPORT_SYMBOL_GPL(gpio_request_one);
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -14,6 +14,11 @@
#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
+#define GPIOF_EXPORT (1 << 2)
+#define GPIOF_EXPORT_CHANGEABLE (1 << 3)
+#define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT)
+#define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)
+
/**
* struct gpio - a structure describing a GPIO with configuration
* @gpio: the GPIO number