kernel-ark/arch/arm/mach-ns9xxx/gpio.c
Uwe Kleine-König 9c6568501c [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>
2008-10-30 14:41:50 +00:00

148 lines
2.9 KiB
C

/*
* arch/arm/mach-ns9xxx/gpio.c
*
* Copyright (C) 2006,2007 by Digi International Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* 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>
#include <linux/module.h>
#include <linux/bitops.h>
#include <mach/gpio.h>
#include <mach/processor.h>
#include <mach/processor-ns9360.h>
#include <asm/bug.h>
#include <asm/types.h>
#include "gpio-ns9360.h"
#if defined(CONFIG_PROCESSOR_NS9360)
#define GPIO_MAX 72
#elif defined(CONFIG_PROCESSOR_NS9750)
#define GPIO_MAX 49
#endif
/* protects BBU_GCONFx and BBU_GCTRLx */
static spinlock_t gpio_lock = __SPIN_LOCK_UNLOCKED(gpio_lock);
/* only access gpiores with atomic ops */
static DECLARE_BITMAP(gpiores, GPIO_MAX + 1);
static inline int ns9xxx_valid_gpio(unsigned gpio)
{
#if defined(CONFIG_PROCESSOR_NS9360)
if (processor_is_ns9360())
return gpio <= 72;
else
#endif
#if defined(CONFIG_PROCESSOR_NS9750)
if (processor_is_ns9750())
return gpio <= 49;
else
#endif
{
BUG();
return 0;
}
}
int gpio_request(unsigned gpio, const char *label)
{
if (likely(ns9xxx_valid_gpio(gpio)))
return test_and_set_bit(gpio, gpiores) ? -EBUSY : 0;
else
return -EINVAL;
}
EXPORT_SYMBOL(gpio_request);
void gpio_free(unsigned gpio)
{
might_sleep();
clear_bit(gpio, gpiores);
return;
}
EXPORT_SYMBOL(gpio_free);
int gpio_direction_input(unsigned gpio)
{
if (likely(ns9xxx_valid_gpio(gpio))) {
int ret = -EINVAL;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
#if defined(CONFIG_PROCESSOR_NS9360)
if (processor_is_ns9360())
ret = __ns9360_gpio_configure(gpio, 0, 0, 3);
else
#endif
BUG();
spin_unlock_irqrestore(&gpio_lock, flags);
return ret;
} else
return -EINVAL;
}
EXPORT_SYMBOL(gpio_direction_input);
int gpio_direction_output(unsigned gpio, int value)
{
if (likely(ns9xxx_valid_gpio(gpio))) {
int ret = -EINVAL;
unsigned long flags;
gpio_set_value(gpio, value);
spin_lock_irqsave(&gpio_lock, flags);
#if defined(CONFIG_PROCESSOR_NS9360)
if (processor_is_ns9360())
ret = __ns9360_gpio_configure(gpio, 1, 0, 3);
else
#endif
BUG();
spin_unlock_irqrestore(&gpio_lock, flags);
return ret;
} else
return -EINVAL;
}
EXPORT_SYMBOL(gpio_direction_output);
int gpio_get_value(unsigned gpio)
{
#if defined(CONFIG_PROCESSOR_NS9360)
if (processor_is_ns9360())
return ns9360_gpio_get_value(gpio);
else
#endif
{
BUG();
return -EINVAL;
}
}
EXPORT_SYMBOL(gpio_get_value);
void gpio_set_value(unsigned gpio, int value)
{
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
#if defined(CONFIG_PROCESSOR_NS9360)
if (processor_is_ns9360())
ns9360_gpio_set_value(gpio, value);
else
#endif
BUG();
spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(gpio_set_value);