gpio-arizona.c

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/*
 * gpiolib support for Wolfson Arizona class devices
 *
 * Copyright 2012 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/platform_device.h>
#include <linux/seq_file.h>

#include <linux/mfd/arizona/core.h>
#include <linux/mfd/arizona/pdata.h>
#include <linux/mfd/arizona/registers.h>

struct arizona_gpio {
    struct arizona *arizona;
    struct gpio_chip gpio_chip;
};

static inline struct arizona_gpio *to_arizona_gpio(struct gpio_chip *chip)
{
    return container_of(chip, struct arizona_gpio, gpio_chip);
}

static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
    struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
    struct arizona *arizona = arizona_gpio->arizona;

    return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
                  ARIZONA_GPN_DIR, ARIZONA_GPN_DIR);
}

static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
{
    struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
    struct arizona *arizona = arizona_gpio->arizona;
    unsigned int val;
    int ret;

    ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
    if (ret < 0)
        return ret;

    if (val & ARIZONA_GPN_LVL)
        return 1;
    else
        return 0;
}

static int arizona_gpio_direction_out(struct gpio_chip *chip,
                     unsigned offset, int value)
{
    struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
    struct arizona *arizona = arizona_gpio->arizona;

    if (value)
        value = ARIZONA_GPN_LVL;

    return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
                  ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
}

static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
    struct arizona_gpio *arizona_gpio = to_arizona_gpio(chip);
    struct arizona *arizona = arizona_gpio->arizona;

    if (value)
        value = ARIZONA_GPN_LVL;

    regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
               ARIZONA_GPN_LVL, value);
}

static struct gpio_chip template_chip = {
    .label          = "arizona",
    .owner          = THIS_MODULE,
    .direction_input    = arizona_gpio_direction_in,
    .get            = arizona_gpio_get,
    .direction_output   = arizona_gpio_direction_out,
    .set            = arizona_gpio_set,
    .can_sleep      = 1,
};

static int __devinit arizona_gpio_probe(struct platform_device *pdev)
{
    struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
    struct arizona_pdata *pdata = arizona->dev->platform_data;
    struct arizona_gpio *arizona_gpio;
    int ret;

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

    arizona_gpio->arizona = arizona;
    arizona_gpio->gpio_chip = template_chip;
    arizona_gpio->gpio_chip.dev = &pdev->dev;

    switch (arizona->type) {
    case WM5102:
    case WM5110:
        arizona_gpio->gpio_chip.ngpio = 5;
        break;
    default:
        dev_err(&pdev->dev, "Unknown chip variant %d\n",
            arizona->type);
        return -EINVAL;
    }

    if (pdata && pdata->gpio_base)
        arizona_gpio->gpio_chip.base = pdata->gpio_base;
    else
        arizona_gpio->gpio_chip.base = -1;

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

    platform_set_drvdata(pdev, arizona_gpio);

    return ret;

err:
    return ret;
}

static int __devexit arizona_gpio_remove(struct platform_device *pdev)
{
    struct arizona_gpio *arizona_gpio = platform_get_drvdata(pdev);

    return gpiochip_remove(&arizona_gpio->gpio_chip);
}

static struct platform_driver arizona_gpio_driver = {
    .driver.name    = "arizona-gpio",
    .driver.owner   = THIS_MODULE,
    .probe      = arizona_gpio_probe,
    .remove     = __devexit_p(arizona_gpio_remove),
};

module_platform_driver(arizona_gpio_driver);

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