/*
 * 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>

#include <linux/rfkill-gpio.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;
        char                    *reset_name;
        char                    *shutdown_name;
        struct clk              *clk;

        bool                    clk_enabled;
};

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

        if (blocked) {
                gpiod_set_value(rfkill->shutdown_gpio, 0);
                gpiod_set_value(rfkill->reset_gpio, 0);
                if (!IS_ERR(rfkill->clk) && rfkill->clk_enabled)
                        clk_disable(rfkill->clk);
        } else {
                if (!IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
                        clk_enable(rfkill->clk);
                gpiod_set_value(rfkill->reset_gpio, 1);
                gpiod_set_value(rfkill->shutdown_gpio, 1);
        }

        rfkill->clk_enabled = blocked;

        return 0;
}

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

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->name = dev_name(dev);
        rfkill->type = (unsigned)id->driver_data;

        return 0;
}

static int rfkill_gpio_probe(struct platform_device *pdev)
{
        struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
        struct rfkill_gpio_data *rfkill;
        const char *clk_name = NULL;
        struct gpio_desc *gpio;
        int ret;
        int len;

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

        if (ACPI_HANDLE(&pdev->dev)) {
                ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
                if (ret)
                        return ret;
        } else if (pdata) {
                clk_name = pdata->power_clk_name;
                rfkill->name = pdata->name;
                rfkill->type = pdata->type;
        } else {
                return -ENODEV;
        }

        len = strlen(rfkill->name);
        rfkill->reset_name = devm_kzalloc(&pdev->dev, len + 7, GFP_KERNEL);
        if (!rfkill->reset_name)
                return -ENOMEM;

        rfkill->shutdown_name = devm_kzalloc(&pdev->dev, len + 10, GFP_KERNEL);
        if (!rfkill->shutdown_name)
                return -ENOMEM;

        snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name);
        snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name);

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

        gpio = devm_gpiod_get_index(&pdev->dev, rfkill->reset_name, 0);
        if (!IS_ERR(gpio)) {
                ret = gpiod_direction_output(gpio, 0);
                if (ret)
                        return ret;
                rfkill->reset_gpio = gpio;
        }

        gpio = devm_gpiod_get_index(&pdev->dev, rfkill->shutdown_name, 1);
        if (!IS_ERR(gpio)) {
                ret = gpiod_direction_output(gpio, 0);
                if (ret)
                        return ret;
                rfkill->shutdown_gpio = gpio;
        }

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

        if (pdata && pdata->gpio_runtime_setup) {
                ret = pdata->gpio_runtime_setup(pdev);
                if (ret) {
                        dev_err(&pdev->dev, "can't set up gpio\n");
                        return ret;
                }
        }

        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);
        struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;

        if (pdata && pdata->gpio_runtime_close)
                pdata->gpio_runtime_close(pdev);
        rfkill_unregister(rfkill->rfkill_dev);
        rfkill_destroy(rfkill->rfkill_dev);

        return 0;
}

static const struct acpi_device_id rfkill_acpi_match[] = {
        { "BCM4752", RFKILL_TYPE_GPS },
        { },
};

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

module_platform_driver(rfkill_gpio_driver);

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