/*
 * Copyright (c) 2011, NVIDIA Corporation.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rfkill.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>

struct rfkill_gpio_data {
        const char              *name;
        enum rfkill_type        type;
        struct gpio_desc        *reset_gpio;
        struct gpio_desc        *shutdown_gpio;

        struct rfkill           *rfkill_dev;
        struct clk              *clk;

        bool                    clk_enabled;
};

static int rfkill_gpio_set_power(void *data, bool blocked)
{
        struct rfkill_gpio_data *rfkill = data;

        if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
                clk_enable(rfkill->clk);

        gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
        gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);

        if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
                clk_disable(rfkill->clk);

        rfkill->clk_enabled = !blocked;

        return 0;
}

static const struct rfkill_ops rfkill_gpio_ops = {
        .set_block = rfkill_gpio_set_power,
};

static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };

static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
        { "reset-gpios", &reset_gpios, 1 },
        { "shutdown-gpios", &shutdown_gpios, 1 },
        { },
};

static int rfkill_gpio_acpi_probe(struct device *dev,
                                  struct rfkill_gpio_data *rfkill)
{
        const struct acpi_device_id *id;

        id = acpi_match_device(dev->driver->acpi_match_table, dev);
        if (!id)
                return -ENODEV;

        rfkill->type = (unsigned)id->driver_data;

        return acpi_dev_add_driver_gpios(ACPI_COMPANION(dev),
                                         acpi_rfkill_default_gpios);
}

static int rfkill_gpio_probe(struct platform_device *pdev)
{
        struct rfkill_gpio_data *rfkill;
        struct gpio_desc *gpio;
        const char *type_name;
        int ret;

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

        device_property_read_string(&pdev->dev, "name", &rfkill->name);
        device_property_read_string(&pdev->dev, "type", &type_name);

        if (!rfkill->name)
                rfkill->name = dev_name(&pdev->dev);

        rfkill->type = rfkill_find_type(type_name);

        if (ACPI_HANDLE(&pdev->dev)) {
                ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
                if (ret)
                        return ret;
        }

        rfkill->clk = devm_clk_get(&pdev->dev, NULL);

        gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
        if (IS_ERR(gpio))
                return PTR_ERR(gpio);

        rfkill->reset_gpio = gpio;

        gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW);
        if (IS_ERR(gpio))
                return PTR_ERR(gpio);

        rfkill->shutdown_gpio = gpio;

        /* Make sure at-least one GPIO is defined for this instance */
        if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
                dev_err(&pdev->dev, "invalid platform data\n");
                return -EINVAL;
        }

        rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
                                          rfkill->type, &rfkill_gpio_ops,
                                          rfkill);
        if (!rfkill->rfkill_dev)
                return -ENOMEM;

        ret = rfkill_register(rfkill->rfkill_dev);
        if (ret < 0)
                return ret;

        platform_set_drvdata(pdev, rfkill);

        dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);

        return 0;
}

static int rfkill_gpio_remove(struct platform_device *pdev)
{
        struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);

        rfkill_unregister(rfkill->rfkill_dev);
        rfkill_destroy(rfkill->rfkill_dev);

        acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));

        return 0;
}

#ifdef CONFIG_ACPI
static const struct acpi_device_id rfkill_acpi_match[] = {
        { "BCM4752", RFKILL_TYPE_GPS },
        { "LNV4752", RFKILL_TYPE_GPS },
        { },
};
MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
#endif

static struct platform_driver rfkill_gpio_driver = {
        .probe = rfkill_gpio_probe,
        .remove = rfkill_gpio_remove,
        .driver = {
                .name = "rfkill_gpio",
                .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
        },
};

module_platform_driver(rfkill_gpio_driver);

MODULE_DESCRIPTION("gpio rfkill");
MODULE_AUTHOR("NVIDIA");
MODULE_LICENSE("GPL");