linux-imx

/*

 * TI/National Semiconductor LP3943 GPIO driver

 *

 * Copyright 2013 Texas Instruments

 *

 * Author: Milo Kim <milo.kim@ti.com>

 *

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

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

 * the Free Software Foundation; version 2.

 */

​

#include <linux/bitops.h>

#include <linux/err.h>

#include <linux/gpio/driver.h>

#include <linux/i2c.h>

#include <linux/mfd/lp3943.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

​

enum lp3943_gpios {

    LP3943_GPIO1,

    LP3943_GPIO2,

    LP3943_GPIO3,

    LP3943_GPIO4,

    LP3943_GPIO5,

    LP3943_GPIO6,

    LP3943_GPIO7,

    LP3943_GPIO8,

    LP3943_GPIO9,

    LP3943_GPIO10,

    LP3943_GPIO11,

    LP3943_GPIO12,

    LP3943_GPIO13,

    LP3943_GPIO14,

    LP3943_GPIO15,

    LP3943_GPIO16,

    LP3943_MAX_GPIO,

};

​

struct lp3943_gpio {

    struct gpio_chip chip;

    struct lp3943 *lp3943;

    u16 input_mask;     /* 1 = GPIO is input direction, 0 = output */

};

​

static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)

{

    struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);

    struct lp3943 *lp3943 = lp3943_gpio->lp3943;

​

    /* Return an error if the pin is already assigned */

    if (test_and_set_bit(offset, &lp3943->pin_used))

        return -EBUSY;

​

    return 0;

}

​

static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset)

{

    struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);

    struct lp3943 *lp3943 = lp3943_gpio->lp3943;

​

    clear_bit(offset, &lp3943->pin_used);

}

​

static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset,

                u8 val)

{

    struct lp3943 *lp3943 = lp3943_gpio->lp3943;

    const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;

​

    return lp3943_update_bits(lp3943, mux[offset].reg, mux[offset].mask,

                  val << mux[offset].shift);

}

​

static int lp3943_gpio_direction_input(struct gpio_chip *chip, unsigned offset)

{

    struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);

​

    lp3943_gpio->input_mask |= BIT(offset);

​

    return lp3943_gpio_set_mode(lp3943_gpio, offset, LP3943_GPIO_IN);

}

​

static int lp3943_get_gpio_in_status(struct lp3943_gpio *lp3943_gpio,

                     struct gpio_chip *chip, unsigned offset)

{

    u8 addr, read;

    int err;

​