/* Copyright (c) 2018, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/slab.h>
#include <linux/irqdomain.h>
#include <linux/regmap.h>
#include <asoc/wcd-irq.h>

static int wcd_map_irq(struct wcd_irq_info *irq_info, int irq)
{
	if (!irq_info) {
		pr_err("%s: Null IRQ handle\n", __func__);
		return -EINVAL;
	}
	return regmap_irq_get_virq(irq_info->irq_chip, irq);
}

/**
 * wcd_request_irq: Request a thread handler for the given IRQ
 * @irq_info: pointer to IRQ info structure
 * @irq: irq number
 * @name: name for the IRQ thread
 * @handler: irq handler
 * @data: data pointer
 *
 * Returns 0 on success or error on failure
 */
int wcd_request_irq(struct wcd_irq_info *irq_info, int irq, const char *name,
			irq_handler_t handler, void *data)
{
	if (!irq_info) {
		pr_err("%s: Null IRQ handle\n", __func__);
		return -EINVAL;
	}
	irq = wcd_map_irq(irq_info, irq);
	if (irq < 0)
		return irq;

	return request_threaded_irq(irq, NULL, handler,
				    IRQF_ONESHOT | IRQF_TRIGGER_RISING,
				    name, data);
}
EXPORT_SYMBOL(wcd_request_irq);

/**
 * wcd_free_irq: Free the IRQ resources allocated during request_irq
 * @irq_info: pointer to IRQ info structure
 * @irq: irq number
 * @data: data pointer
 */
void wcd_free_irq(struct wcd_irq_info *irq_info, int irq, void *data)
{
	if (!irq_info) {
		pr_err("%s: Null IRQ handle\n", __func__);
		return;
	}

	irq = wcd_map_irq(irq_info, irq);
	if (irq < 0)
		return;

	free_irq(irq, data);
}
EXPORT_SYMBOL(wcd_free_irq);

/**
 * wcd_enable_irq: Enable the given IRQ
 * @irq_info: pointer to IRQ info structure
 * @irq: irq number
 */
void wcd_enable_irq(struct wcd_irq_info *irq_info, int irq)
{
	if (!irq_info)
		pr_err("%s: Null IRQ handle\n", __func__);
	else
		enable_irq(wcd_map_irq(irq_info, irq));
}
EXPORT_SYMBOL(wcd_enable_irq);

/**
 * wcd_disable_irq: Disable the given IRQ
 * @irq_info: pointer to IRQ info structure
 * @irq: irq number
 */
void wcd_disable_irq(struct wcd_irq_info *irq_info, int irq)
{
	if (!irq_info)
		pr_err("%s: Null IRQ handle\n", __func__);
	else
		disable_irq_nosync(wcd_map_irq(irq_info, irq));
}
EXPORT_SYMBOL(wcd_disable_irq);

static void wcd_irq_chip_disable(struct irq_data *data)
{
}

static void wcd_irq_chip_enable(struct irq_data *data)
{
}

static struct irq_chip wcd_irq_chip = {
	.name = NULL,
	.irq_disable = wcd_irq_chip_disable,
	.irq_enable = wcd_irq_chip_enable,
};

static struct lock_class_key wcd_irq_lock_class;

static int wcd_irq_chip_map(struct irq_domain *irqd, unsigned int virq,
			irq_hw_number_t hw)
{
	irq_set_chip_and_handler(virq, &wcd_irq_chip, handle_simple_irq);
	irq_set_lockdep_class(virq, &wcd_irq_lock_class);
	irq_set_nested_thread(virq, 1);
	irq_set_noprobe(virq);

	return 0;
}

static const struct irq_domain_ops wcd_domain_ops = {
	.map = wcd_irq_chip_map,
};

/**
 * wcd_irq_init: Initializes IRQ module
 * @irq_info: pointer to IRQ info structure
 *
 * Returns 0 on success or error on failure
 */
int wcd_irq_init(struct wcd_irq_info *irq_info, struct irq_domain **virq)
{
	int ret = 0;

	if (!irq_info) {
		pr_err("%s: Null IRQ handle\n", __func__);
		return -EINVAL;
	}

	wcd_irq_chip.name = irq_info->codec_name;

	*virq = irq_domain_add_linear(NULL, 1, &wcd_domain_ops, NULL);
	if (!(*virq)) {
		pr_err("%s: Failed to add IRQ domain\n", __func__);
		return -EINVAL;
	}

	ret = devm_regmap_add_irq_chip(irq_info->dev, irq_info->regmap,
				 irq_create_mapping(*virq, 0),
				 IRQF_ONESHOT, 0, irq_info->wcd_regmap_irq_chip,
				 &irq_info->irq_chip);
	if (ret)
		pr_err("%s: Failed to add IRQs: %d\n",
			__func__, ret);

	return ret;
}
EXPORT_SYMBOL(wcd_irq_init);

/**
 * wcd_irq_exit: Uninitialize regmap IRQ and free IRQ resources
 * @irq_info: pointer to IRQ info structure
 *
 * Returns 0 on success or error on failure
 */
int wcd_irq_exit(struct wcd_irq_info *irq_info, struct irq_domain *virq)
{
	if (!irq_info) {
		pr_err("%s: Null pointer handle\n", __func__);
		return -EINVAL;
	}

	regmap_del_irq_chip(irq_find_mapping(virq, 0), irq_info->irq_chip);

	return 0;
}
EXPORT_SYMBOL(wcd_irq_exit);