linux-imx

/*

 * Kontron PLD GPIO driver

 *

 * Copyright (c) 2010-2013 Kontron Europe GmbH

 * Author: Michael Brunner <michael.brunner@kontron.com>

 *

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

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

 * by the Free Software Foundation.

 *

 * 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.

 */

​

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/bitops.h>

#include <linux/errno.h>

#include <linux/platform_device.h>

#include <linux/gpio/driver.h>

#include <linux/mfd/kempld.h>

​

#define KEMPLD_GPIO_MAX_NUM     16

#define KEMPLD_GPIO_MASK(x)     (BIT((x) % 8))

#define KEMPLD_GPIO_DIR_NUM(x)      (0x40 + (x) / 8)

#define KEMPLD_GPIO_LVL_NUM(x)      (0x42 + (x) / 8)

#define KEMPLD_GPIO_EVT_LVL_EDGE    0x46

#define KEMPLD_GPIO_IEN         0x4A

​

struct kempld_gpio_data {

    struct gpio_chip        chip;

    struct kempld_device_data   *pld;

};

​

/*

 * Set or clear GPIO bit

 * kempld_get_mutex must be called prior to calling this function.

 */

static void kempld_gpio_bitop(struct kempld_device_data *pld,

                  u8 reg, u8 bit, u8 val)

{

    u8 status;

​

    status = kempld_read8(pld, reg);

    if (val)

        status |= KEMPLD_GPIO_MASK(bit);

    else

        status &= ~KEMPLD_GPIO_MASK(bit);

    kempld_write8(pld, reg, status);

}

​

static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit)

{

    u8 status;

​

    kempld_get_mutex(pld);

    status = kempld_read8(pld, reg);

    kempld_release_mutex(pld);

​

    return !!(status & KEMPLD_GPIO_MASK(bit));