linux-imx

/*

 * ZTE ZX296702 GPIO driver

 *

 * Author: Jun Nie <jun.nie@linaro.org>

 *

 * Copyright (C) 2015 Linaro Ltd.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/errno.h>

#include <linux/gpio/driver.h>

#include <linux/irqchip/chained_irq.h>

#include <linux/init.h>

#include <linux/of.h>

#include <linux/pinctrl/consumer.h>

#include <linux/platform_device.h>

#include <linux/pm.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

​

#define ZX_GPIO_DIR 0x00

#define ZX_GPIO_IVE 0x04

#define ZX_GPIO_IV  0x08

#define ZX_GPIO_IEP 0x0C

#define ZX_GPIO_IEN 0x10

#define ZX_GPIO_DI  0x14

#define ZX_GPIO_DO1 0x18

#define ZX_GPIO_DO0 0x1C

#define ZX_GPIO_DO  0x20

​

#define ZX_GPIO_IM  0x28

#define ZX_GPIO_IE  0x2C

​

#define ZX_GPIO_MIS 0x30

#define ZX_GPIO_IC  0x34

​

#define ZX_GPIO_NR  16

​

struct zx_gpio {

    raw_spinlock_t      lock;

​

    void __iomem        *base;

    struct gpio_chip    gc;

};

​

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

{

    struct zx_gpio *chip = gpiochip_get_data(gc);

    unsigned long flags;

    u16 gpiodir;

​

    if (offset >= gc->ngpio)

        return -EINVAL;

​

    raw_spin_lock_irqsave(&chip->lock, flags);

    gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);

    gpiodir &= ~BIT(offset);

    writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);

    raw_spin_unlock_irqrestore(&chip->lock, flags);