gpio-mc9s08dz60.c

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/*
 * Copyright 2009-2012 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * Author: Wu Guoxing <[email protected]>
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/gpio.h>

#define GPIO_GROUP_NUM 2
#define GPIO_NUM_PER_GROUP 8
#define GPIO_NUM (GPIO_GROUP_NUM*GPIO_NUM_PER_GROUP)

struct mc9s08dz60 {
    struct i2c_client *client;
    struct gpio_chip chip;
};

static inline struct mc9s08dz60 *to_mc9s08dz60(struct gpio_chip *gc)
{
    return container_of(gc, struct mc9s08dz60, chip);
}


static void mc9s_gpio_to_reg_and_bit(int offset, u8 *reg, u8 *bit)
{
    *reg = 0x20 + offset / GPIO_NUM_PER_GROUP;
    *bit = offset % GPIO_NUM_PER_GROUP;
}

static int mc9s08dz60_get_value(struct gpio_chip *gc, unsigned offset)
{
    u8 reg, bit;
    s32 value;
    struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);

    mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
    value = i2c_smbus_read_byte_data(mc9s->client, reg);

    return (value >= 0) ? (value >> bit) & 0x1 : 0;
}

static int mc9s08dz60_set(struct mc9s08dz60 *mc9s, unsigned offset, int val)
{
    u8 reg, bit;
    s32 value;

    mc9s_gpio_to_reg_and_bit(offset, &reg, &bit);
    value = i2c_smbus_read_byte_data(mc9s->client, reg);
    if (value >= 0) {
        if (val)
            value |= 1 << bit;
        else
            value &= ~(1 << bit);

        return i2c_smbus_write_byte_data(mc9s->client, reg, value);
    } else
        return value;

}


static void mc9s08dz60_set_value(struct gpio_chip *gc, unsigned offset, int val)
{
    struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);

    mc9s08dz60_set(mc9s, offset, val);
}

static int mc9s08dz60_direction_output(struct gpio_chip *gc,
                       unsigned offset, int val)
{
    struct mc9s08dz60 *mc9s = to_mc9s08dz60(gc);

    return mc9s08dz60_set(mc9s, offset, val);
}

static int mc9s08dz60_probe(struct i2c_client *client,
                const struct i2c_device_id *id)
{
    struct mc9s08dz60 *mc9s;

    mc9s = devm_kzalloc(&client->dev, sizeof(*mc9s), GFP_KERNEL);
    if (!mc9s)
        return -ENOMEM;

    mc9s->chip.label = client->name;
    mc9s->chip.base = -1;
    mc9s->chip.dev = &client->dev;
    mc9s->chip.owner = THIS_MODULE;
    mc9s->chip.ngpio = GPIO_NUM;
    mc9s->chip.can_sleep = 1;
    mc9s->chip.get = mc9s08dz60_get_value;
    mc9s->chip.set = mc9s08dz60_set_value;
    mc9s->chip.direction_output = mc9s08dz60_direction_output;
    mc9s->client = client;
    i2c_set_clientdata(client, mc9s);

    return gpiochip_add(&mc9s->chip);
}

static int mc9s08dz60_remove(struct i2c_client *client)
{
    struct mc9s08dz60 *mc9s;

    mc9s = i2c_get_clientdata(client);

    return gpiochip_remove(&mc9s->chip);
}

static const struct i2c_device_id mc9s08dz60_id[] = {
    {"mc9s08dz60", 0},
    {},
};

MODULE_DEVICE_TABLE(i2c, mc9s08dz60_id);

static struct i2c_driver mc9s08dz60_i2c_driver = {
    .driver = {
        .owner = THIS_MODULE,
        .name = "mc9s08dz60",
    },
    .probe = mc9s08dz60_probe,
    .remove = mc9s08dz60_remove,
    .id_table = mc9s08dz60_id,
};

module_i2c_driver(mc9s08dz60_i2c_driver);

MODULE_AUTHOR("Freescale Semiconductor, Inc. "
        "Wu Guoxing <[email protected]>");
MODULE_DESCRIPTION("mc9s08dz60 gpio function on mx35 3ds board");
MODULE_LICENSE("GPL v2");