linux-imx

/*

 * gpio-reg: single register individually fixed-direction GPIOs

 *

 * Copyright (C) 2016 Russell King

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 */

#include <linux/gpio/driver.h>

#include <linux/gpio/gpio-reg.h>

#include <linux/io.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

​

struct gpio_reg {

    struct gpio_chip gc;

    spinlock_t lock;

    u32 direction;

    u32 out;

    void __iomem *reg;

    struct irq_domain *irqdomain;

    const int *irqs;

};

​

#define to_gpio_reg(x) container_of(x, struct gpio_reg, gc)

​

static int gpio_reg_get_direction(struct gpio_chip *gc, unsigned offset)

{

    struct gpio_reg *r = to_gpio_reg(gc);

​

    return r->direction & BIT(offset) ? 1 : 0;

}

​

static int gpio_reg_direction_output(struct gpio_chip *gc, unsigned offset,

    int value)

{

    struct gpio_reg *r = to_gpio_reg(gc);

​

    if (r->direction & BIT(offset))

        return -ENOTSUPP;

​

    gc->set(gc, offset, value);

    return 0;

}

​

static int gpio_reg_direction_input(struct gpio_chip *gc, unsigned offset)

{

    struct gpio_reg *r = to_gpio_reg(gc);

​

    return r->direction & BIT(offset) ? 0 : -ENOTSUPP;

}

​

static void gpio_reg_set(struct gpio_chip *gc, unsigned offset, int value)

{

    struct gpio_reg *r = to_gpio_reg(gc);

    unsigned long flags;

    u32 val, mask = BIT(offset);

​

    spin_lock_irqsave(&r->lock, flags);

    val = r->out;

    if (value)

        val |= mask;