gpio-wm8350.c

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/*
 * gpiolib support for Wolfson WM835x PMICs
 *
 * Copyright 2009 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <[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.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/mfd/core.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>

#include <linux/mfd/wm8350/core.h>
#include <linux/mfd/wm8350/gpio.h>

struct wm8350_gpio_data {
    struct wm8350 *wm8350;
    struct gpio_chip gpio_chip;
};

static inline struct wm8350_gpio_data *to_wm8350_gpio(struct gpio_chip *chip)
{
    return container_of(chip, struct wm8350_gpio_data, gpio_chip);
}

static int wm8350_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
    struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
    struct wm8350 *wm8350 = wm8350_gpio->wm8350;

    return wm8350_set_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
                   1 << offset);
}

static int wm8350_gpio_get(struct gpio_chip *chip, unsigned offset)
{
    struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
    struct wm8350 *wm8350 = wm8350_gpio->wm8350;
    int ret;

    ret = wm8350_reg_read(wm8350, WM8350_GPIO_LEVEL);
    if (ret < 0)
        return ret;

    if (ret & (1 << offset))
        return 1;
    else
        return 0;
}

static void wm8350_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
    struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
    struct wm8350 *wm8350 = wm8350_gpio->wm8350;

    if (value)
        wm8350_set_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
    else
        wm8350_clear_bits(wm8350, WM8350_GPIO_LEVEL, 1 << offset);
}

static int wm8350_gpio_direction_out(struct gpio_chip *chip,
                     unsigned offset, int value)
{
    struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
    struct wm8350 *wm8350 = wm8350_gpio->wm8350;
    int ret;

    ret = wm8350_clear_bits(wm8350, WM8350_GPIO_CONFIGURATION_I_O,
                1 << offset);
    if (ret < 0)
        return ret;

    /* Don't have an atomic direction/value setup */
    wm8350_gpio_set(chip, offset, value);

    return 0;
}

static int wm8350_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
    struct wm8350_gpio_data *wm8350_gpio = to_wm8350_gpio(chip);
    struct wm8350 *wm8350 = wm8350_gpio->wm8350;

    if (!wm8350->irq_base)
        return -EINVAL;

    return wm8350->irq_base + WM8350_IRQ_GPIO(offset);
}

static struct gpio_chip template_chip = {
    .label          = "wm8350",
    .owner          = THIS_MODULE,
    .direction_input    = wm8350_gpio_direction_in,
    .get            = wm8350_gpio_get,
    .direction_output   = wm8350_gpio_direction_out,
    .set            = wm8350_gpio_set,
    .to_irq         = wm8350_gpio_to_irq,
    .can_sleep      = 1,
};

static int __devinit wm8350_gpio_probe(struct platform_device *pdev)
{
    struct wm8350 *wm8350 = dev_get_drvdata(pdev->dev.parent);
    struct wm8350_platform_data *pdata = wm8350->dev->platform_data;
    struct wm8350_gpio_data *wm8350_gpio;
    int ret;

    wm8350_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm8350_gpio),
                   GFP_KERNEL);
    if (wm8350_gpio == NULL)
        return -ENOMEM;

    wm8350_gpio->wm8350 = wm8350;
    wm8350_gpio->gpio_chip = template_chip;
    wm8350_gpio->gpio_chip.ngpio = 13;
    wm8350_gpio->gpio_chip.dev = &pdev->dev;
    if (pdata && pdata->gpio_base)
        wm8350_gpio->gpio_chip.base = pdata->gpio_base;
    else
        wm8350_gpio->gpio_chip.base = -1;

    ret = gpiochip_add(&wm8350_gpio->gpio_chip);
    if (ret < 0) {
        dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
        return ret;
    }

    platform_set_drvdata(pdev, wm8350_gpio);

    return ret;
}

static int __devexit wm8350_gpio_remove(struct platform_device *pdev)
{
    struct wm8350_gpio_data *wm8350_gpio = platform_get_drvdata(pdev);

    return gpiochip_remove(&wm8350_gpio->gpio_chip);
}

static struct platform_driver wm8350_gpio_driver = {
    .driver.name    = "wm8350-gpio",
    .driver.owner   = THIS_MODULE,
    .probe      = wm8350_gpio_probe,
    .remove     = __devexit_p(wm8350_gpio_remove),
};

static int __init wm8350_gpio_init(void)
{
    return platform_driver_register(&wm8350_gpio_driver);
}
subsys_initcall(wm8350_gpio_init);

static void __exit wm8350_gpio_exit(void)
{
    platform_driver_unregister(&wm8350_gpio_driver);
}
module_exit(wm8350_gpio_exit);

MODULE_AUTHOR("Mark Brown <[email protected]>");
MODULE_DESCRIPTION("GPIO interface for WM8350 PMICs");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8350-gpio");