gpio-iop.c
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/*
* arch/arm/plat-iop/gpio.c
* GPIO handling for Intel IOP3xx processors.
*
* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*/
#include <linux/device.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/export.h>
#include <linux/platform_device.h>
#include <linux/bitops.h>
#include <linux/io.h>
#define IOP3XX_N_GPIOS 8
#define GPIO_IN 0
#define GPIO_OUT 1
#define GPIO_LOW 0
#define GPIO_HIGH 1
/* Memory base offset */
static void __iomem *base;
#define IOP3XX_GPIO_REG(reg) (base + (reg))
#define IOP3XX_GPOE IOP3XX_GPIO_REG(0x0000)
#define IOP3XX_GPID IOP3XX_GPIO_REG(0x0004)
#define IOP3XX_GPOD IOP3XX_GPIO_REG(0x0008)
static void gpio_line_config(int line, int direction)
{
unsigned long flags;
u32 val;
local_irq_save(flags);
val = readl(IOP3XX_GPOE);
if (direction == GPIO_IN) {
val |= BIT(line);
} else if (direction == GPIO_OUT) {
val &= ~BIT(line);
}
writel(val, IOP3XX_GPOE);
local_irq_restore(flags);
}
static int gpio_line_get(int line)
{
return !!(readl(IOP3XX_GPID) & BIT(line));
}
static void gpio_line_set(int line, int value)
{
unsigned long flags;
u32 val;
local_irq_save(flags);
val = readl(IOP3XX_GPOD);
if (value == GPIO_LOW) {
val &= ~BIT(line);
} else if (value == GPIO_HIGH) {
val |= BIT(line);
}
writel(val, IOP3XX_GPOD);
local_irq_restore(flags);
}
static int iop3xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
gpio_line_config(gpio, GPIO_IN);
return 0;
}
static int iop3xx_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, int level)
{
gpio_line_set(gpio, level);
gpio_line_config(gpio, GPIO_OUT);
return 0;
}
static int iop3xx_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
return gpio_line_get(gpio);
}
static void iop3xx_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
{
gpio_line_set(gpio, value);
}
static struct gpio_chip iop3xx_chip = {
.label = "iop3xx",
.direction_input = iop3xx_gpio_direction_input,
.get = iop3xx_gpio_get_value,
.direction_output = iop3xx_gpio_direction_output,
.set = iop3xx_gpio_set_value,
.base = 0,
.ngpio = IOP3XX_N_GPIOS,
};
static int iop3xx_gpio_probe(struct platform_device *pdev)
{
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
return gpiochip_add(&iop3xx_chip);
}
static struct platform_driver iop3xx_gpio_driver = {
.driver = {
.name = "gpio-iop",
.owner = THIS_MODULE,
},
.probe = iop3xx_gpio_probe,
};
static int __init iop3xx_gpio_init(void)
{
return platform_driver_register(&iop3xx_gpio_driver);
}
arch_initcall(iop3xx_gpio_init);