/******************************************************************************
 *  Copyright (C) 2013-2020 NXP
 *   *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 ******************************************************************************/
/*
 * Copyright (C) 2010 Trusted Logic S.A.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include "common.h"
#include "common_ese.h"
/**
 * i2c_disable_irq()
 *
 * Check if interrupt is disabled or not
 * and disable interrupt
 *
 * Return: int
 */
int i2c_disable_irq(struct nfc_dev *dev)
{
	unsigned long flags;

	spin_lock_irqsave(&dev->i2c_dev.irq_enabled_lock, flags);
	if (dev->i2c_dev.irq_enabled) {
		disable_irq_nosync(dev->i2c_dev.client->irq);
		dev->i2c_dev.irq_enabled = false;
	}
	spin_unlock_irqrestore(&dev->i2c_dev.irq_enabled_lock, flags);

	return 0;
}

/**
 * i2c_enable_irq()
 *
 * Check if interrupt is enabled or not
 * and enable interrupt
 *
 * Return: int
 */
int i2c_enable_irq(struct nfc_dev *dev)
{
	unsigned long flags;

	spin_lock_irqsave(&dev->i2c_dev.irq_enabled_lock, flags);
	if (!dev->i2c_dev.irq_enabled) {
		dev->i2c_dev.irq_enabled = true;
		enable_irq(dev->i2c_dev.client->irq);
	}
	spin_unlock_irqrestore(&dev->i2c_dev.irq_enabled_lock, flags);

	return 0;
}

static irqreturn_t i2c_irq_handler(int irq, void *dev_id)
{
	nfc_dev_t *nfc_dev = dev_id;
	i2c_dev_t *i2c_dev = &nfc_dev->i2c_dev;
	if (device_may_wakeup(&i2c_dev->client->dev))
		pm_wakeup_event(&i2c_dev->client->dev, WAKEUP_SRC_TIMEOUT);

	i2c_disable_irq(nfc_dev);
	wake_up(&nfc_dev->read_wq);

	return IRQ_HANDLED;
}

int i2c_read(struct nfc_dev *dev, char *buf, size_t count)
{
	int ret;
	pr_debug("%s : reading %zu bytes.\n", __func__, count);
	/* Read data */
	ret = i2c_master_recv(dev->i2c_dev.client, buf, count);
	if (ret <= 0) {
		pr_err("%s: i2c_master_recv returned %d\n", __func__, ret);
		goto err;
	}
	if (ret > count) {
		pr_err("%s: received too many bytes from i2c (%d)\n",
		       __func__, ret);
		ret = -EIO;
	}
err:
	return ret;
}

int i2c_write(struct nfc_dev *dev, const char *buf, size_t count,
	      int max_retry_cnt)
{
	int ret = -EINVAL;
	int retry_cnt;

	pr_debug("%s : writing %zu bytes.\n", __func__, count);

	for (retry_cnt = 1; retry_cnt <= max_retry_cnt; retry_cnt++) {
		ret = i2c_master_send(dev->i2c_dev.client, buf, count);
		if (ret <= 0) {
			pr_warn("%s: write failed, Maybe in Standby Mode - Retry(%d)\n", __func__,
				retry_cnt);
			usleep_range(1000, 1100);
		} else if (ret == count)
			break;
	}
	return ret;
}

ssize_t nfc_i2c_dev_read(struct file * filp, char __user *buf,
			 size_t count, loff_t * offset)
{
	int ret;
	char tmp[MAX_BUFFER_SIZE];
	nfc_dev_t *nfc_dev = filp->private_data;
	i2c_dev_t *i2c_dev = &nfc_dev->i2c_dev;

	if (count > MAX_BUFFER_SIZE)
		count = MAX_BUFFER_SIZE;

	pr_debug("%s : reading   %zu bytes.\n", __func__, count);
	mutex_lock(&nfc_dev->read_mutex);
	if (!gpio_get_value(nfc_dev->gpio.irq)) {
		if (filp->f_flags & O_NONBLOCK) {
			pr_err(":f_falg has O_NONBLOCK. EAGAIN\n");
			ret = -EAGAIN;
			goto err;
		}
		while (1) {
			ret = 0;
			if (!i2c_dev->irq_enabled) {
				i2c_dev->irq_enabled = true;
				enable_irq(i2c_dev->client->irq);
			}
			if (!gpio_get_value(nfc_dev->gpio.irq)) {
				ret = wait_event_interruptible(nfc_dev->read_wq,
							       !i2c_dev->
							       irq_enabled);

				if (ret) {
					pr_err("error wakeup of read wq\n");
					goto err;
				}
			}
			i2c_disable_irq(nfc_dev);

			if (gpio_get_value(nfc_dev->gpio.irq))
				break;
			if (!gpio_get_value(nfc_dev->gpio.ven)) {
				pr_info("%s: releasing read\n", __func__);
				ret = -EIO;
				goto err;
			}
			pr_warn("%s: spurious interrupt detected\n", __func__);
		}
	}

	memset(tmp, 0x00, count);
	/* Read data */
	ret = i2c_read(nfc_dev, tmp, count);
	if (ret <= 0) {
		pr_err("%s: i2c_read returned %d\n", __func__, ret);
		goto err;
	}
	/* check if it's response of cold reset command
	 * NFC HAL process shouldn't receive this data as
	 * command was sent by driver
	 */
	if (nfc_dev->cold_reset.rsp_pending) {
		if (IS_PROP_CMD_RSP(tmp)) {
			/* Read data */
			ret =
				i2c_read(nfc_dev, &tmp[NCI_PAYLOAD_IDX],
					 tmp[NCI_PAYLOAD_LEN_IDX]);
			if (ret <= 0) {
				pr_err("%s: failure to read prop cold reset/protection rsp header\n", __func__);
				goto err;
			}
			wakeup_on_prop_rsp(nfc_dev, tmp);
			mutex_unlock(&nfc_dev->read_mutex);
			/*
			 * NFC process doesn't know about cold reset command
			 * being sent as it was initiated by eSE process
			 * we shouldn't return any data to NFC process
			 */
			return 0;
		}
	}
	if (copy_to_user(buf, tmp, ret)) {
		pr_warn("%s : failed to copy to user space\n", __func__);
		ret = -EFAULT;
	}

err:
	mutex_unlock(&nfc_dev->read_mutex);
	return ret;
}

ssize_t nfc_i2c_dev_write(struct file * filp, const char __user *buf,
			  size_t count, loff_t * offset)
{
	int ret;
	char tmp[MAX_DL_BUFFER_SIZE];
	nfc_dev_t *nfc_dev = filp->private_data;

	if (count > MAX_DL_BUFFER_SIZE)
		count = MAX_DL_BUFFER_SIZE;

	if (copy_from_user(tmp, buf, count)) {
		pr_err("%s : failed to copy from user space\n", __func__);
		return -EFAULT;
	}
	ret = i2c_write(nfc_dev, tmp, count, NO_RETRY);
	if (ret != count) {
		pr_err("%s: failed to write %d\n", __func__, ret);
		ret = -EIO;
	}

	return ret;
}

static const struct file_operations nfc_i2c_dev_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.read = nfc_i2c_dev_read,
	.write = nfc_i2c_dev_write,
	.open = nfc_dev_open,
	.release = nfc_dev_close,
	.unlocked_ioctl = nfc_dev_ioctl,
};

int nfc_i2c_dev_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	int ret = 0;
	nfc_dev_t *nfc_dev = NULL;
	i2c_dev_t *i2c_dev = NULL;
	platform_gpio_t nfc_gpio;
	pr_debug("%s: enter\n", __func__);
	/*retrive details of gpios from dt */
	ret = nfc_parse_dt(&client->dev, &nfc_gpio, PLATFORM_IF_I2C);
	if (ret) {
		pr_err("%s : failed to parse dt\n", __func__);
		goto err;
	}

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		pr_err("%s : need I2C_FUNC_I2C\n", __func__);
		ret = -ENODEV;
		goto err;
	}
	nfc_dev = kzalloc(sizeof(nfc_dev_t), GFP_KERNEL);
	if (nfc_dev == NULL) {
		ret = -ENOMEM;
		goto err;
	}
	nfc_dev->interface = PLATFORM_IF_I2C;
	nfc_dev->nfc_state = NFC_STATE_NCI;
	nfc_dev->i2c_dev.client = client;
	i2c_dev = &nfc_dev->i2c_dev;
	nfc_dev->nfc_read = i2c_read;
	nfc_dev->nfc_write = i2c_write;
	nfc_dev->nfc_enable_intr = i2c_enable_irq;
	nfc_dev->nfc_disable_intr = i2c_disable_irq;

	ret = configure_gpio(nfc_gpio.ven, GPIO_OUTPUT);
	if (ret) {
		pr_err("%s: unable to request nfc reset gpio [%d]\n", __func__, nfc_gpio.ven);
		goto err;
	}
	ret = configure_gpio(nfc_gpio.irq, GPIO_IRQ);
	if (ret <= 0) {
		pr_err("%s: unable to request nfc irq gpio [%d]\n", __func__, nfc_gpio.irq);
		goto err;
	}
	client->irq = ret;
	ret = configure_gpio(nfc_gpio.dwl_req, GPIO_OUTPUT);
	if (ret) {
		pr_err("%s: unable to request nfc firm downl gpio [%d]\n", __func__,
		       nfc_gpio.dwl_req);
	}

	/*copy the retrived gpio details from DT */
	memcpy(&nfc_dev->gpio, &nfc_gpio, sizeof(struct platform_gpio));

	/* init mutex and queues */
	init_waitqueue_head(&nfc_dev->read_wq);
	mutex_init(&nfc_dev->read_mutex);
	mutex_init(&nfc_dev->dev_ref_mutex);
	mutex_init(&nfc_dev->ese_access_mutex);
	spin_lock_init(&i2c_dev->irq_enabled_lock);
	common_ese_init(nfc_dev);
	ret = nfc_misc_register(nfc_dev, &nfc_i2c_dev_fops, DEV_COUNT,
				NFC_CHAR_DEV_NAME, CLASS_NAME);
	if (ret) {
		pr_err("%s: nfc_misc_register failed\n", __func__);
		goto err_mutex_destroy;
	}
	/* interrupt initializations */
	pr_info("%s : requesting IRQ %d\n", __func__, client->irq);
	i2c_dev->irq_enabled = true;
	ret = request_irq(client->irq, i2c_irq_handler,
			  IRQF_TRIGGER_HIGH, client->name, nfc_dev);
	if (ret) {
		pr_err("%s: request_irq failed\n", __func__);
		goto err_nfc_misc_unregister;
	}
	i2c_disable_irq(nfc_dev);
	device_init_wakeup(&client->dev, true);
	device_set_wakeup_capable(&client->dev, true);
	i2c_set_clientdata(client, nfc_dev);
	i2c_dev->irq_wake_up = false;

	//reset nfc
	usleep_range(10000, 10100);
	gpio_set_value(nfc_dev->gpio.ven, 1);
	usleep_range(10000, 10100);

	pr_info("%s probing nfc i2c successfully", __func__);
	return 0;
err_nfc_misc_unregister:
	nfc_misc_unregister(nfc_dev, DEV_COUNT);
err_mutex_destroy:
	mutex_destroy(&nfc_dev->dev_ref_mutex);
	mutex_destroy(&nfc_dev->read_mutex);
	mutex_destroy(&nfc_dev->ese_access_mutex);
	mutex_destroy(&nfc_dev->cold_reset.sync_mutex);
err:
	gpio_free_all(nfc_dev);
	kfree(nfc_dev);
	pr_err("%s: probing not successful, check hardware\n", __func__);
	return ret;
}

int nfc_i2c_dev_remove(struct i2c_client *client)
{
	int ret = 0;
	nfc_dev_t *nfc_dev = NULL;
	pr_info("%s: remove device\n", __func__);
	nfc_dev = i2c_get_clientdata(client);
	if (!nfc_dev) {
		pr_err("%s: device doesn't exist anymore\n", __func__);
		ret = -ENODEV;
		return ret;
	}
	if (nfc_dev->dev_ref_count > 0) {
		pr_err("%s: device already in use\n", __func__);
		return -EBUSY;
	}
	device_init_wakeup(&client->dev, false);
	free_irq(client->irq, nfc_dev);
	nfc_misc_unregister(nfc_dev, DEV_COUNT);
	mutex_destroy(&nfc_dev->read_mutex);
	mutex_destroy(&nfc_dev->ese_access_mutex);
	mutex_destroy(&nfc_dev->cold_reset.sync_mutex);
	gpio_free_all(nfc_dev);
	kfree(nfc_dev);
	return ret;
}

int nfc_i2c_dev_suspend(struct device *device)
{
	struct i2c_client *client = to_i2c_client(device);
	nfc_dev_t *nfc_dev = i2c_get_clientdata(client);
	i2c_dev_t *i2c_dev = &nfc_dev->i2c_dev;

	if (device_may_wakeup(&client->dev) && i2c_dev->irq_enabled) {
		if (!enable_irq_wake(client->irq))
			i2c_dev->irq_wake_up = true;
	}
	return 0;
}

int nfc_i2c_dev_resume(struct device *device)
{
	struct i2c_client *client = to_i2c_client(device);
	nfc_dev_t *nfc_dev = i2c_get_clientdata(client);
	i2c_dev_t *i2c_dev = &nfc_dev->i2c_dev;

	if (device_may_wakeup(&client->dev) && i2c_dev->irq_wake_up) {
		if (!disable_irq_wake(client->irq))
			i2c_dev->irq_wake_up = false;
	}
	return 0;
}

static const struct i2c_device_id nfc_i2c_dev_id[] = {
	{NFC_I2C_DEV_ID, 0},
	{}
};

static const struct of_device_id nfc_i2c_dev_match_table[] = {
	{.compatible = NFC_I2C_DRV_STR,},
	{}
};

static const struct dev_pm_ops nfc_i2c_dev_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(nfc_i2c_dev_suspend, nfc_i2c_dev_resume)
};

static struct i2c_driver nfc_i2c_dev_driver = {
	.id_table = nfc_i2c_dev_id,
	.probe = nfc_i2c_dev_probe,
	.remove = nfc_i2c_dev_remove,
	.driver = {
		.name = NFC_I2C_DRV_STR,
		.pm = &nfc_i2c_dev_pm_ops,
		.of_match_table = nfc_i2c_dev_match_table,
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
};

MODULE_DEVICE_TABLE(of, nfc_i2c_dev_match_table);

static int __init nfc_i2c_dev_init(void)
{
	int ret = 0;
	pr_info("Loading NXP NFC I2C driver\n");
	ret = i2c_add_driver(&nfc_i2c_dev_driver);
	if (ret != 0)
		pr_err("NFC I2C add driver error ret %d\n", ret);
	return ret;
}

module_init(nfc_i2c_dev_init);

static void __exit nfc_i2c_dev_exit(void)
{
	pr_info("Unloading NXP NFC I2C driver\n");
	i2c_del_driver(&nfc_i2c_dev_driver);
}

module_exit(nfc_i2c_dev_exit);

MODULE_DESCRIPTION("NXP NFC I2C driver");
MODULE_LICENSE("GPL");