OpenCloudOS-Kernel/arch/arm/plat-orion/gpio.c

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/*
* arch/arm/plat-orion/gpio.c
*
* Marvell Orion SoC GPIO handling.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <asm/gpio.h>
static DEFINE_SPINLOCK(gpio_lock);
static const char *gpio_label[GPIO_MAX]; /* non null for allocated GPIOs */
static unsigned long gpio_valid[BITS_TO_LONGS(GPIO_MAX)];
static inline void __set_direction(unsigned pin, int input)
{
u32 u;
u = readl(GPIO_IO_CONF(pin));
if (input)
u |= 1 << (pin & 31);
else
u &= ~(1 << (pin & 31));
writel(u, GPIO_IO_CONF(pin));
}
static void __set_level(unsigned pin, int high)
{
u32 u;
u = readl(GPIO_OUT(pin));
if (high)
u |= 1 << (pin & 31);
else
u &= ~(1 << (pin & 31));
writel(u, GPIO_OUT(pin));
}
/*
* GENERIC_GPIO primitives.
*/
int gpio_direction_input(unsigned pin)
{
unsigned long flags;
if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
pr_debug("%s: invalid GPIO %d\n", __func__, pin);
return -EINVAL;
}
spin_lock_irqsave(&gpio_lock, flags);
/*
* Some callers might not have used gpio_request(),
* so flag this pin as requested now.
*/
if (gpio_label[pin] == NULL)
gpio_label[pin] = "?";
/*
* Configure GPIO direction.
*/
__set_direction(pin, 1);
spin_unlock_irqrestore(&gpio_lock, flags);
return 0;
}
EXPORT_SYMBOL(gpio_direction_input);
int gpio_direction_output(unsigned pin, int value)
{
unsigned long flags;
u32 u;
if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
pr_debug("%s: invalid GPIO %d\n", __func__, pin);
return -EINVAL;
}
spin_lock_irqsave(&gpio_lock, flags);
/*
* Some callers might not have used gpio_request(),
* so flag this pin as requested now.
*/
if (gpio_label[pin] == NULL)
gpio_label[pin] = "?";
/*
* Disable blinking.
*/
u = readl(GPIO_BLINK_EN(pin));
u &= ~(1 << (pin & 31));
writel(u, GPIO_BLINK_EN(pin));
/*
* Configure GPIO output value.
*/
__set_level(pin, value);
/*
* Configure GPIO direction.
*/
__set_direction(pin, 0);
spin_unlock_irqrestore(&gpio_lock, flags);
return 0;
}
EXPORT_SYMBOL(gpio_direction_output);
int gpio_get_value(unsigned pin)
{
int val;
if (readl(GPIO_IO_CONF(pin)) & (1 << (pin & 31)))
val = readl(GPIO_DATA_IN(pin)) ^ readl(GPIO_IN_POL(pin));
else
val = readl(GPIO_OUT(pin));
return (val >> (pin & 31)) & 1;
}
EXPORT_SYMBOL(gpio_get_value);
void gpio_set_value(unsigned pin, int value)
{
unsigned long flags;
u32 u;
spin_lock_irqsave(&gpio_lock, flags);
/*
* Disable blinking.
*/
u = readl(GPIO_BLINK_EN(pin));
u &= ~(1 << (pin & 31));
writel(u, GPIO_BLINK_EN(pin));
/*
* Configure GPIO output value.
*/
__set_level(pin, value);
spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(gpio_set_value);
int gpio_request(unsigned pin, const char *label)
{
unsigned long flags;
int ret;
if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
pr_debug("%s: invalid GPIO %d\n", __func__, pin);
return -EINVAL;
}
spin_lock_irqsave(&gpio_lock, flags);
if (gpio_label[pin] == NULL) {
gpio_label[pin] = label ? label : "?";
ret = 0;
} else {
pr_debug("%s: GPIO %d already used as %s\n",
__func__, pin, gpio_label[pin]);
ret = -EBUSY;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return ret;
}
EXPORT_SYMBOL(gpio_request);
void gpio_free(unsigned pin)
{
if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
pr_debug("%s: invalid GPIO %d\n", __func__, pin);
return;
}
if (gpio_label[pin] == NULL)
pr_warning("%s: GPIO %d already freed\n", __func__, pin);
else
gpio_label[pin] = NULL;
}
EXPORT_SYMBOL(gpio_free);
/*
* Orion-specific GPIO API extensions.
*/
void __init orion_gpio_set_unused(unsigned pin)
{
/*
* Configure as output, drive low.
*/
__set_level(pin, 0);
__set_direction(pin, 0);
}
void __init orion_gpio_set_valid(unsigned pin, int valid)
{
if (valid)
__set_bit(pin, gpio_valid);
else
__clear_bit(pin, gpio_valid);
}
void orion_gpio_set_blink(unsigned pin, int blink)
{
unsigned long flags;
u32 u;
spin_lock_irqsave(&gpio_lock, flags);
/*
* Set output value to zero.
*/
__set_level(pin, 0);
u = readl(GPIO_BLINK_EN(pin));
if (blink)
u |= 1 << (pin & 31);
else
u &= ~(1 << (pin & 31));
writel(u, GPIO_BLINK_EN(pin));
spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(orion_gpio_set_blink);