gpio-twl6040.c

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/*
 * Access to GPOs on TWL6040 chip
 *
 * Copyright (C) 2012 Texas Instruments, Inc.
 *
 * Authors:
 *  Sergio Aguirre <[email protected]>
 *  Peter Ujfalusi <[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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/of.h>

#include <linux/mfd/twl6040.h>

static struct gpio_chip twl6040gpo_chip;

static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
{
    struct twl6040 *twl6040 = dev_get_drvdata(chip->dev->parent);
    int ret = 0;

    ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
    if (ret < 0)
        return ret;

    return (ret >> offset) & 1;
}

static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
                    int value)
{
    /* This only drives GPOs, and can't change direction */
    return 0;
}

static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
{
    struct twl6040 *twl6040 = dev_get_drvdata(chip->dev->parent);
    int ret;
    u8 gpoctl;

    ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
    if (ret < 0)
        return;

    if (value)
        gpoctl = ret | (1 << offset);
    else
        gpoctl = ret & ~(1 << offset);

    twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
}

static struct gpio_chip twl6040gpo_chip = {
    .label          = "twl6040",
    .owner          = THIS_MODULE,
    .get            = twl6040gpo_get,
    .direction_output   = twl6040gpo_direction_out,
    .set            = twl6040gpo_set,
    .can_sleep      = 1,
};

/*----------------------------------------------------------------------*/

static int __devinit gpo_twl6040_probe(struct platform_device *pdev)
{
    struct twl6040_gpo_data *pdata = pdev->dev.platform_data;
    struct device *twl6040_core_dev = pdev->dev.parent;
    struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
    int ret;

    if (pdata)
        twl6040gpo_chip.base = pdata->gpio_base;
    else
        twl6040gpo_chip.base = -1;

    if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
        twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
    else
        twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */

    twl6040gpo_chip.dev = &pdev->dev;
#ifdef CONFIG_OF_GPIO
    twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
#endif

    ret = gpiochip_add(&twl6040gpo_chip);
    if (ret < 0) {
        dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
        twl6040gpo_chip.ngpio = 0;
    }

    return ret;
}

static int __devexit gpo_twl6040_remove(struct platform_device *pdev)
{
    return gpiochip_remove(&twl6040gpo_chip);
}

/* Note:  this hardware lives inside an I2C-based multi-function device. */
MODULE_ALIAS("platform:twl6040-gpo");

static struct platform_driver gpo_twl6040_driver = {
    .driver = {
        .name   = "twl6040-gpo",
        .owner  = THIS_MODULE,
    },
    .probe      = gpo_twl6040_probe,
    .remove     = gpo_twl6040_remove,
};

module_platform_driver(gpo_twl6040_driver);

MODULE_AUTHOR("Texas Instruments, Inc.");
MODULE_DESCRIPTION("GPO interface for TWL6040");
MODULE_LICENSE("GPL");