linux-imx

/*

 * Digital I/O driver for Technologic Systems I2C FPGA Core

 *

 * Copyright (C) 2015 Technologic Systems

 * Copyright (C) 2016 Savoir-Faire Linux

 *

 * 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.

 *

 * This program is distributed "as is" WITHOUT ANY WARRANTY of any

 * kind, whether expressed or implied; without even the implied warranty

 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License version 2 for more details.

 */

​

#include <linux/gpio/driver.h>

#include <linux/i2c.h>

#include <linux/of_device.h>

#include <linux/module.h>

#include <linux/regmap.h>

​

#define DEFAULT_PIN_NUMBER  32

/*

 * Register bits used by the GPIO device

 * Some boards, such as TS-7970 do not have a separate input bit

 */

#define TS4900_GPIO_OE      0x01

#define TS4900_GPIO_OUT     0x02

#define TS4900_GPIO_IN      0x04

#define TS7970_GPIO_IN      0x02

​

struct ts4900_gpio_priv {

    struct regmap *regmap;

    struct gpio_chip gpio_chip;

    unsigned int input_bit;

};

​

static int ts4900_gpio_get_direction(struct gpio_chip *chip,

                     unsigned int offset)

{

    struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);

    unsigned int reg;

​

    regmap_read(priv->regmap, offset, &reg);

​

    return !(reg & TS4900_GPIO_OE);

}

​

static int ts4900_gpio_direction_input(struct gpio_chip *chip,

                       unsigned int offset)

{

    struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);

​

    /*

     * This will clear the output enable bit, the other bits are

     * dontcare when this is cleared

     */

    return regmap_write(priv->regmap, offset, 0);

}

​

static int ts4900_gpio_direction_output(struct gpio_chip *chip,

                    unsigned int offset, int value)