gpio-tps6586x.c

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/*
 * TI TPS6586x GPIO driver
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 * Author: Laxman dewangan <[email protected]>
 *
 * Based on tps6586x.c
 * Copyright (c) 2010 CompuLab Ltd.
 * Mike Rapoport <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mfd/tps6586x.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>

/* GPIO control registers */
#define TPS6586X_GPIOSET1   0x5d
#define TPS6586X_GPIOSET2   0x5e

struct tps6586x_gpio {
    struct gpio_chip gpio_chip;
    struct device *parent;
};

static inline struct tps6586x_gpio *to_tps6586x_gpio(struct gpio_chip *chip)
{
    return container_of(chip, struct tps6586x_gpio, gpio_chip);
}

static int tps6586x_gpio_get(struct gpio_chip *gc, unsigned offset)
{
    struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
    uint8_t val;
    int ret;

    ret = tps6586x_read(tps6586x_gpio->parent, TPS6586X_GPIOSET2, &val);
    if (ret)
        return ret;

    return !!(val & (1 << offset));
}

static void tps6586x_gpio_set(struct gpio_chip *gc, unsigned offset,
                  int value)
{
    struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);

    tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET2,
            value << offset, 1 << offset);
}

static int tps6586x_gpio_output(struct gpio_chip *gc, unsigned offset,
                int value)
{
    struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
    uint8_t val, mask;

    tps6586x_gpio_set(gc, offset, value);

    val = 0x1 << (offset * 2);
    mask = 0x3 << (offset * 2);

    return tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET1,
                val, mask);
}

static int __devinit tps6586x_gpio_probe(struct platform_device *pdev)
{
    struct tps6586x_platform_data *pdata;
    struct tps6586x_gpio *tps6586x_gpio;
    int ret;

    pdata = dev_get_platdata(pdev->dev.parent);
    tps6586x_gpio = devm_kzalloc(&pdev->dev,
                sizeof(*tps6586x_gpio), GFP_KERNEL);
    if (!tps6586x_gpio) {
        dev_err(&pdev->dev, "Could not allocate tps6586x_gpio\n");
        return -ENOMEM;
    }

    tps6586x_gpio->parent = pdev->dev.parent;

    tps6586x_gpio->gpio_chip.owner = THIS_MODULE;
    tps6586x_gpio->gpio_chip.label = pdev->name;
    tps6586x_gpio->gpio_chip.dev = &pdev->dev;
    tps6586x_gpio->gpio_chip.ngpio = 4;
    tps6586x_gpio->gpio_chip.can_sleep = 1;

    /* FIXME: add handling of GPIOs as dedicated inputs */
    tps6586x_gpio->gpio_chip.direction_output = tps6586x_gpio_output;
    tps6586x_gpio->gpio_chip.set    = tps6586x_gpio_set;
    tps6586x_gpio->gpio_chip.get    = tps6586x_gpio_get;

#ifdef CONFIG_OF_GPIO
    tps6586x_gpio->gpio_chip.of_node = pdev->dev.parent->of_node;
#endif
    if (pdata && pdata->gpio_base)
        tps6586x_gpio->gpio_chip.base = pdata->gpio_base;
    else
        tps6586x_gpio->gpio_chip.base = -1;

    ret = gpiochip_add(&tps6586x_gpio->gpio_chip);
    if (ret < 0) {
        dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
        return ret;
    }

    platform_set_drvdata(pdev, tps6586x_gpio);

    return ret;
}

static int __devexit tps6586x_gpio_remove(struct platform_device *pdev)
{
    struct tps6586x_gpio *tps6586x_gpio = platform_get_drvdata(pdev);

    return gpiochip_remove(&tps6586x_gpio->gpio_chip);
}

static struct platform_driver tps6586x_gpio_driver = {
    .driver.name    = "tps6586x-gpio",
    .driver.owner   = THIS_MODULE,
    .probe      = tps6586x_gpio_probe,
    .remove     = __devexit_p(tps6586x_gpio_remove),
};

static int __init tps6586x_gpio_init(void)
{
    return platform_driver_register(&tps6586x_gpio_driver);
}
subsys_initcall(tps6586x_gpio_init);

static void __exit tps6586x_gpio_exit(void)
{
    platform_driver_unregister(&tps6586x_gpio_driver);
}
module_exit(tps6586x_gpio_exit);

MODULE_ALIAS("platform:tps6586x-gpio");
MODULE_DESCRIPTION("GPIO interface for TPS6586X PMIC");
MODULE_AUTHOR("Laxman Dewangan <[email protected]>");
MODULE_LICENSE("GPL");