linux/arch/mips/ar7/gpio.c

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/*
* Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
* Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
* Copyright (C) 2009 Florian Fainelli <florian@openwrt.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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/module.h>
#include <linux/gpio.h>
#include <asm/mach-ar7/gpio.h>
struct ar7_gpio_chip {
void __iomem *regs;
struct gpio_chip chip;
};
static int ar7_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
struct ar7_gpio_chip *gpch =
container_of(chip, struct ar7_gpio_chip, chip);
void __iomem *gpio_in = gpch->regs + AR7_GPIO_INPUT;
return readl(gpio_in) & (1 << gpio);
}
static void ar7_gpio_set_value(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct ar7_gpio_chip *gpch =
container_of(chip, struct ar7_gpio_chip, chip);
void __iomem *gpio_out = gpch->regs + AR7_GPIO_OUTPUT;
unsigned tmp;
tmp = readl(gpio_out) & ~(1 << gpio);
if (value)
tmp |= 1 << gpio;
writel(tmp, gpio_out);
}
static int ar7_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
struct ar7_gpio_chip *gpch =
container_of(chip, struct ar7_gpio_chip, chip);
void __iomem *gpio_dir = gpch->regs + AR7_GPIO_DIR;
writel(readl(gpio_dir) | (1 << gpio), gpio_dir);
return 0;
}
static int ar7_gpio_direction_output(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct ar7_gpio_chip *gpch =
container_of(chip, struct ar7_gpio_chip, chip);
void __iomem *gpio_dir = gpch->regs + AR7_GPIO_DIR;
ar7_gpio_set_value(chip, gpio, value);
writel(readl(gpio_dir) & ~(1 << gpio), gpio_dir);
return 0;
}
static struct ar7_gpio_chip ar7_gpio_chip = {
.chip = {
.label = "ar7-gpio",
.direction_input = ar7_gpio_direction_input,
.direction_output = ar7_gpio_direction_output,
.set = ar7_gpio_set_value,
.get = ar7_gpio_get_value,
.base = 0,
.ngpio = AR7_GPIO_MAX,
}
};
int ar7_gpio_enable(unsigned gpio)
{
void __iomem *gpio_en = ar7_gpio_chip.regs + AR7_GPIO_ENABLE;
writel(readl(gpio_en) | (1 << gpio), gpio_en);
return 0;
}
EXPORT_SYMBOL(ar7_gpio_enable);
int ar7_gpio_disable(unsigned gpio)
{
void __iomem *gpio_en = ar7_gpio_chip.regs + AR7_GPIO_ENABLE;
writel(readl(gpio_en) & ~(1 << gpio), gpio_en);
return 0;
}
EXPORT_SYMBOL(ar7_gpio_disable);
static int __init ar7_gpio_init(void)
{
int ret;
ar7_gpio_chip.regs = ioremap_nocache(AR7_REGS_GPIO,
AR7_REGS_GPIO + 0x10);
if (!ar7_gpio_chip.regs) {
printk(KERN_ERR "ar7-gpio: failed to ioremap regs\n");
return -ENOMEM;
}
ret = gpiochip_add(&ar7_gpio_chip.chip);
if (ret) {
printk(KERN_ERR "ar7-gpio: failed to add gpiochip\n");
return ret;
}
printk(KERN_INFO "ar7-gpio: registered %d GPIOs\n",
ar7_gpio_chip.chip.ngpio);
return ret;
}
arch_initcall(ar7_gpio_init);