linux-imx

/*

 * Copyright 2009-2012 Freescale Semiconductor, Inc. All Rights Reserved.

 *

 * Author: Wu Guoxing <b39297@freescale.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; 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/init.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <linux/gpio/driver.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 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 = gpiochip_get_data(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);