gpio.c

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/*
 * SDK7786 FPGA USRGPIR Support.
 *
 * Copyright (C) 2010  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <mach/fpga.h>

#define NR_FPGA_GPIOS   8

static const char *usrgpir_gpio_names[NR_FPGA_GPIOS] = {
    "in0", "in1", "in2", "in3", "in4", "in5", "in6", "in7",
};

static int usrgpir_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
    /* always in */
    return 0;
}

static int usrgpir_gpio_get(struct gpio_chip *chip, unsigned gpio)
{
    return !!(fpga_read_reg(USRGPIR) & (1 << gpio));
}

static struct gpio_chip usrgpir_gpio_chip = {
    .label          = "sdk7786-fpga",
    .names          = usrgpir_gpio_names,
    .direction_input    = usrgpir_gpio_direction_input,
    .get            = usrgpir_gpio_get,
    .base           = -1, /* don't care */
    .ngpio          = NR_FPGA_GPIOS,
};

static int __init usrgpir_gpio_setup(void)
{
    return gpiochip_add(&usrgpir_gpio_chip);
}
device_initcall(usrgpir_gpio_setup);