/*
 * rfkill-regulator.c - Regulator consumer driver for rfkill
 *
 * Copyright (C) 2009  Guiming Zhuo <gmzhuo@gmail.com>
 * Copyright (C) 2011  Antonio Ospite <ospite@studenti.unina.it>
 *
 * Implementation inspired by leds-regulator driver.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/err.h>
#include <linux/of_irq.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/rfkill.h>
#include <linux/rfkill-regulator.h>

struct rfkill_regulator_data {
	struct rfkill *rf_kill;
	bool reg_enabled;

	struct regulator *vcc;
};

static int rfkill_regulator_set_block(void *data, bool blocked)
{
	struct rfkill_regulator_data *rfkill_data = data;
	int ret = 0;

	pr_debug("%s: blocked: %d\n", __func__, blocked);

	if (blocked) {
		if (rfkill_data->reg_enabled) {
			regulator_disable(rfkill_data->vcc);
			rfkill_data->reg_enabled = false;
		}
	} else {
		if (!rfkill_data->reg_enabled) {
			ret = regulator_enable(rfkill_data->vcc);
			if (!ret)
				rfkill_data->reg_enabled = true;
		}
	}

	pr_debug("%s: regulator_is_enabled after set_block: %d\n", __func__,
		regulator_is_enabled(rfkill_data->vcc));

	return ret;
}

static struct rfkill_ops rfkill_regulator_ops = {
	.set_block = rfkill_regulator_set_block,
};

static struct rfkill_regulator_platform_data *rfkill_regulator_get_pdata_from_of(struct device *dev)
{
	struct rfkill_regulator_platform_data *pdata;
	struct device_node *np = dev->of_node;

	if (!np) {
		np = of_find_matching_node(NULL, dev->driver->of_match_table);
		if (!np) {
			dev_notice(dev, "device tree node not available\n");
			return ERR_PTR(-ENODEV);
		}
	}

	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
		dev_err(dev, "can't allocate platform data\n");
		return ERR_PTR(-ENODEV);
	}
	of_property_read_u32(np, "type", &pdata->type);
	of_property_read_string(np, "name", &pdata->name);
	return pdata;
}

static int rfkill_regulator_probe(struct platform_device *pdev)
{
	struct rfkill_regulator_platform_data *pdata = pdev->dev.platform_data;
	struct rfkill_regulator_platform_data *p = NULL;
	struct rfkill_regulator_data *rfkill_data;
	struct regulator *vcc;
	struct rfkill *rf_kill;
	int ret = 0;

	if (pdata == NULL) {
		p = pdata = rfkill_regulator_get_pdata_from_of(&pdev->dev);
		if (IS_ERR(p)) {
			dev_err(&pdev->dev, "no platform data\n");
			return PTR_ERR(p);
		}
	}

	if (pdata->name == NULL || pdata->type == 0) {
		dev_err(&pdev->dev, "invalid name or type in platform data\n");
		ret = -EINVAL;
		goto out;
	}

	vcc = regulator_get_exclusive(&pdev->dev, "vrfkill");
	if (IS_ERR(vcc)) {
		dev_err(&pdev->dev, "Cannot get vcc for %s\n", pdata->name);
		ret = PTR_ERR(vcc);
		goto out;
	}

	rfkill_data = kzalloc(sizeof(*rfkill_data), GFP_KERNEL);
	if (rfkill_data == NULL) {
		ret = -ENOMEM;
		goto err_data_alloc;
	}

	rf_kill = rfkill_alloc(pdata->name, &pdev->dev,
				pdata->type,
				&rfkill_regulator_ops, rfkill_data);
	if (rf_kill == NULL) {
		ret = -ENOMEM;
		goto err_rfkill_alloc;
	}

	if (regulator_is_enabled(vcc)) {
		dev_dbg(&pdev->dev, "Regulator already enabled\n");
		rfkill_data->reg_enabled = true;
	}
	rfkill_data->vcc = vcc;
	rfkill_data->rf_kill = rf_kill;

	ret = rfkill_register(rf_kill);
	if (ret) {
		dev_err(&pdev->dev, "Cannot register rfkill device\n");
		goto err_rfkill_register;
	}

	platform_set_drvdata(pdev, rfkill_data);
	dev_info(&pdev->dev, "%s initialized\n", pdata->name);
	kfree(p);
	return 0;

err_rfkill_register:
	rfkill_destroy(rf_kill);
err_rfkill_alloc:
	kfree(rfkill_data);
err_data_alloc:
	regulator_put(vcc);
out:
	kfree(p);
	return ret;
}

static int rfkill_regulator_remove(struct platform_device *pdev)
{
	struct rfkill_regulator_data *rfkill_data = platform_get_drvdata(pdev);
	struct rfkill *rf_kill = rfkill_data->rf_kill;

	rfkill_unregister(rf_kill);
	rfkill_destroy(rf_kill);
	regulator_put(rfkill_data->vcc);
	kfree(rfkill_data);

	return 0;
}

static const struct of_device_id rfkill_regulator_of_match_table[] = {
	{ .compatible = "net,rfkill-reg" },
	{ }
};
MODULE_DEVICE_TABLE(of, rfkill_regulator_of_match_table);

static struct platform_driver rfkill_regulator_driver = {
	.probe = rfkill_regulator_probe,
	.remove = rfkill_regulator_remove,
	.driver = {
		.name = "rfkill-regulator",
		.owner = THIS_MODULE,
		.of_match_table = of_match_ptr(rfkill_regulator_of_match_table),
	},
};

module_platform_driver(rfkill_regulator_driver);

MODULE_AUTHOR("Guiming Zhuo <gmzhuo@gmail.com>");
MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
MODULE_DESCRIPTION("Regulator consumer driver for rfkill");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rfkill-regulator");