[ARM] gpio_free might sleep, arm architecture

According to the documentation gpio_free should only be called from task
context only.  To make this more explicit add a might sleep to all
implementations.

This patch changes the gpio_free implementations for the arm architecture.
 DaVinci is skipped on purpose to simplify the merge process for patches
switching it over to use gpiolib as per request by David Brownell.

Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-at91/include/mach/gpio.h

@@ -13,6 +13,7 @@
 #ifndef __ASM_ARCH_AT91RM9200_GPIO_H
 #define __ASM_ARCH_AT91RM9200_GPIO_H
 
+#include <linux/kernel.h>
 #include <asm/irq.h>
 
 #define PIN_BASE		NR_AIC_IRQS
@@ -220,6 +221,7 @@ static inline int gpio_request(unsigned gpio, const char *label)
 
 static inline void gpio_free(unsigned gpio)
 {
+	might_sleep();
 }
 
 extern int gpio_direction_input(unsigned gpio);

arch/arm/mach-imx/include/mach/gpio.h

@@ -1,5 +1,6 @@
 #ifndef _IMX_GPIO_H
 
+#include <linux/kernel.h>
 #include <mach/imx-regs.h>
 
 #define IMX_GPIO_ALLOC_MODE_NORMAL	0
@@ -63,6 +64,8 @@ static inline int gpio_request(unsigned gpio, const char *label)
 
 static inline void gpio_free(unsigned gpio)
 {
+	might_sleep();
+
 	imx_gpio_free(gpio);
 }
 

arch/arm/mach-ixp4xx/include/mach/gpio.h

@@ -25,6 +25,7 @@
 #ifndef __ASM_ARCH_IXP4XX_GPIO_H
 #define __ASM_ARCH_IXP4XX_GPIO_H
 
+#include <linux/kernel.h>
 #include <mach/hardware.h>
 
 static inline int gpio_request(unsigned gpio, const char *label)
@@ -34,6 +35,8 @@ static inline int gpio_request(unsigned gpio, const char *label)
 
 static inline void gpio_free(unsigned gpio)
 {
+	might_sleep();
+
 	return;
 }
 

arch/arm/mach-ks8695/include/mach/gpio.h

@@ -11,6 +11,8 @@
 #ifndef __ASM_ARCH_GPIO_H_
 #define __ASM_ARCH_GPIO_H_
 
+#include <linux/kernel.h>
+
 #define KS8695_GPIO_0		0
 #define KS8695_GPIO_1		1
 #define KS8695_GPIO_2		2
@@ -74,6 +76,7 @@ static inline int gpio_request(unsigned int pin, const char *label)
 
 static inline void gpio_free(unsigned int pin)
 {
+	might_sleep();
 }
 
 #endif

arch/arm/mach-ns9xxx/gpio.c

@@ -8,6 +8,7 @@
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  */
+#include <linux/kernel.h>
 #include <linux/compiler.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
@@ -63,6 +64,7 @@ EXPORT_SYMBOL(gpio_request);
 
 void gpio_free(unsigned gpio)
 {
+	might_sleep();
 	clear_bit(gpio, gpiores);
 	return;
 }

arch/arm/mach-orion5x/gpio.c

@@ -165,6 +165,8 @@ EXPORT_SYMBOL(gpio_request);
 
 void gpio_free(unsigned pin)
 {
+	might_sleep();
+
 	if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
 		pr_debug("%s: invalid GPIO %d\n", __func__, pin);
 		return;