/*
 * Copyright (C) 2012-2015 Freescale Semiconductor, Inc. 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 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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/pm.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/input-polldev.h>
#include <linux/miscdevice.h>
#include <linux/poll.h>

#define	SENSOR_IOCTL_BASE	'S'
#define	SENSOR_GET_MODEL_NAME		_IOR(SENSOR_IOCTL_BASE, 0, char *)
#define	SENSOR_GET_POWER_STATUS		_IOR(SENSOR_IOCTL_BASE, 2, int)
#define	SENSOR_SET_POWER_STATUS		_IOR(SENSOR_IOCTL_BASE, 3, int)
#define	SENSOR_GET_DELAY_TIME		_IOR(SENSOR_IOCTL_BASE, 4, int)
#define	SENSOR_SET_DELAY_TIME		_IOR(SENSOR_IOCTL_BASE, 5, int)
#define	SENSOR_GET_RAW_DATA		_IOR(SENSOR_IOCTL_BASE, 6, short[3])

#define FXAS2100X_I2C_ADDR	0x20
#define FXAS21000_CHIP_ID	0xD1
#define FXAS21002_CHID_ID_1	0xD6
#define FXAS21002_CHID_ID_2	0xD7

#define FXAS2100X_POSITION_DEFAULT	2
#define FXAS2100X_DELAY_DEFAULT		200

#define FXAS2100X_STATUS_ZYXDR	0x08
#define FXAS2100X_BUF_SIZE	6

#define FXAS2100X_POLL_INTERVAL	400
#define FXAS2100X_POLL_MAX	800
#define FXAS2100X_POLL_MIN	200
#define ABSMIN_GYRO_VAL		-32768
#define ABSMAX_GYRO_VAL		32768

#define FXAS2100X_DRIVER	"fxas2100x"

/* register enum for fxas2100x registers */
enum {
	FXAS2100X_STATUS = 0x00,
	FXAS2100X_OUT_X_MSB,
	FXAS2100X_OUT_X_LSB,
	FXAS2100X_OUT_Y_MSB,
	FXAS2100X_OUT_Y_LSB,
	FXAS2100X_OUT_Z_MSB,
	FXAS2100X_OUT_Z_LSB,
	FXAS2100X_DR_STATUS,
	FXAS2100X_F_STATUS,
	FXAS2100X_F_SETUP,
	FXAS2100X_F_EVENT,
	FXAS2100X_INT_SRC_FLAG,
	FXAS2100X_WHO_AM_I,
	FXAS2100X_CTRL_REG0,
	FXAS2100X_RT_CFG,
	FXAS2100X_RT_SRC,
	FXAS2100X_RT_THS,
	FXAS2100X_RT_COUNT,
	FXAS2100X_TEMP,
	FXAS2100X_CTRL_REG1,
	FXAS2100X_CTRL_REG2,
	FXAS2100X_CTRL_REG3, /* fxos21002 special */
	FXAS2100X_REG_END,
};

enum {
	STANDBY = 0,
	ACTIVED,
};

struct fxas2100x_data_axis {
	short x;
	short y;
	short z;
};

struct fxas2100x_data {
	struct i2c_client *client;
	struct input_polled_dev *input_polled;
	atomic_t active;
	atomic_t active_poll;
	atomic_t delay;
	atomic_t position;
	u8 chip_id;
};

static struct fxas2100x_data *g_fxas2100x_data;

static int fxas2100x_position_setting[8][3][3] = {
	{ {0, -1, 0}, {1, 0, 0}, {0, 0, 1} },
	{ {-1, 0, 0}, {0, -1, 0}, {0, 0, 1} },
	{ {0, 1, 0}, {-1, 0, 0}, {0, 0, 1} },
	{ {1, 0, 0}, {0, 1, 0}, {0, 0, 1} },
	{ {0, -1, 0}, {-1, 0, 0}, {0, 0, -1} },
	{ {-1, 0, 0}, {0, 1, 0}, {0, 0, -1} },
	{ {0, 1, 0}, {1, 0, 0}, {0, 0, -1} },
	{ {1, 0, 0}, {0, -1, 0}, {0, 0, -1} },
};

static int fxas2100x_data_convert(struct fxas2100x_data *pdata,
		struct fxas2100x_data_axis *axis_data)
{
	short rawdata[3], data[3];
	int i, j;
	int position = atomic_read(&pdata->position);

	if (position < 0 || position > 7)
		position = 0;
	rawdata[0] = axis_data->x;
	rawdata[1] = axis_data->y;
	rawdata[2] = axis_data->z;
	for (i = 0; i < 3; i++) {
		data[i] = 0;
		for (j = 0; j < 3; j++)
			data[i] += rawdata[j] * fxas2100x_position_setting[position][i][j];
	}
	axis_data->x = data[0];
	axis_data->y = data[1];
	axis_data->z = data[2];
	return 0;
}

static int fxas2100x_device_init(struct i2c_client *client)
{
	int result;
	u8 val;
	struct fxas2100x_data *pdata = i2c_get_clientdata(client);
	if (pdata->chip_id == FXAS21000_CHIP_ID)
		val = (0x01 << 2); /* fxas21000 dr 200HZ */
	else
		val = (0x02 << 2); /* fxas21002 dr 200HZ */
	result = i2c_smbus_write_byte_data(client, FXAS2100X_CTRL_REG1, val);
	if (result < 0)
		goto out;
	atomic_set(&pdata->active, STANDBY);
	return 0;
out:
	dev_err(&client->dev, "error when init fxas2100x:(%d)", result);
	return result;
}

static int fxas2100x_change_mode(struct i2c_client *client, int mode)
{
	u8 val;
	int ret;
	if (mode == ACTIVED) {
		val = i2c_smbus_read_byte_data(client, FXAS2100X_CTRL_REG1);
		val &= ~0x03;
		val |= 0x02;
		/* set bit 1 */
		ret = i2c_smbus_write_byte_data(client, FXAS2100X_CTRL_REG1, val);
	} else {
		val = i2c_smbus_read_byte_data(client, FXAS2100X_CTRL_REG1);
		val &= (~0x03);
		/* clear bit 0,1 */
		ret = i2c_smbus_write_byte_data(client, FXAS2100X_CTRL_REG1, val);
	}
	return ret;
}

static int fxas2100x_set_delay(struct i2c_client *client, int delay)
{
	return 0;
}

static int fxas2100x_device_stop(struct i2c_client *client)
{
	u8 val;
	val = i2c_smbus_read_byte_data(client, FXAS2100X_CTRL_REG1);
	val &= ~0x03;
	i2c_smbus_write_byte_data(client, FXAS2100X_CTRL_REG1, val);
	return 0;
}

static int fxas2100x_read_data(struct fxas2100x_data *pdata,
		struct fxas2100x_data_axis *data)
{
	struct i2c_client * client = pdata->client;
	int x, y, z;
	u8 tmp_data[FXAS2100X_BUF_SIZE];
	int ret;

	ret = i2c_smbus_read_i2c_block_data(client, FXAS2100X_OUT_X_MSB,
					    FXAS2100X_BUF_SIZE, tmp_data);
	if (ret < FXAS2100X_BUF_SIZE) {
		dev_err(&client->dev, "i2c block read failed\n");
		return -EIO;
	}
	data->x = ((tmp_data[0] << 8) & 0xff00) | tmp_data[1];
	data->y = ((tmp_data[2] << 8) & 0xff00) | tmp_data[3];
	data->z = ((tmp_data[4] << 8) & 0xff00) | tmp_data[5];
	if (pdata->chip_id == FXAS21000_CHIP_ID) {
		x = data->x;
		y = data->y;
		z = data->z;
		x = x * 4 / 5;
		y = y * 4 / 5;
		z = z * 4 / 5;
		data->x = x;
		data->y = y;
		data->z = z;
	}

	return 0;
}

/* fxas2100x miscdevice */
static long fxas2100x_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct fxas2100x_data *pdata = file->private_data;
	void __user *argp = (void __user *)arg;
	struct fxas2100x_data_axis data;
	long ret = 0;
	short sdata[3];
	int enable;
	int delay;

	if (!pdata) {
		printk(KERN_ERR "FXAS2100X struct datt point is NULL.");
		return -EFAULT;
	}

	switch (cmd) {
	case SENSOR_GET_MODEL_NAME:
		if (copy_to_user(argp, "FXAS2100X GYRO", strlen("FXAS2100X GYRO") + 1)) {
			printk(KERN_ERR "SENSOR_GET_MODEL_NAME copy_to_user failed.");
			ret = -EFAULT;
		}
		break;
	case SENSOR_GET_POWER_STATUS:
		enable = atomic_read(&pdata->active);
		if (copy_to_user(argp, &enable, sizeof(int))) {
			printk(KERN_ERR "SENSOR_SET_POWER_STATUS copy_to_user failed.");
			ret = -EFAULT;
		}
		break;
	case SENSOR_SET_POWER_STATUS:
		if (copy_from_user(&enable, argp, sizeof(int))) {
			printk(KERN_ERR "SENSOR_SET_POWER_STATUS copy_to_user failed.");
			ret = -EFAULT;
		}
		if (pdata->client) {
			ret = fxas2100x_change_mode(pdata->client, enable ? ACTIVED : STANDBY);
			if (!ret)
				atomic_set(&pdata->active, enable);
		}
		break;
	case SENSOR_GET_DELAY_TIME:
		delay = atomic_read(&pdata->delay);
		if (copy_to_user(argp, &delay, sizeof(delay))) {
			printk(KERN_ERR "SENSOR_GET_DELAY_TIME copy_to_user failed.");
			return -EFAULT;
		}
		break;
	case SENSOR_SET_DELAY_TIME:
		if (copy_from_user(&delay, argp, sizeof(int))) {
			printk(KERN_ERR "SENSOR_GET_DELAY_TIME copy_to_user failed.");
			ret = -EFAULT;
		}
		if (pdata->client && delay > 0 && delay <= 500) {
			ret = fxas2100x_set_delay(pdata->client, delay);
			if (!ret)
				atomic_set(&pdata->delay, delay);
		}
		break;
	case SENSOR_GET_RAW_DATA:
		ret = fxas2100x_read_data(pdata, &data);
		if (!ret) {
			fxas2100x_data_convert(pdata, &data);
			sdata[0] = data.x;
			sdata[1] = data.y;
			sdata[2] = data.z;
			if (copy_to_user(argp, sdata, sizeof(sdata))) {
				printk(KERN_ERR "SENSOR_GET_RAW_DATA copy_to_user failed.");
				ret = -EFAULT;
			}
		}
		break;
	default:
		ret = -1;
	}

	return ret;
}

static int fxas2100x_open(struct inode *inode, struct file *file)
{
	file->private_data = g_fxas2100x_data;
	return nonseekable_open(inode, file);
}

static int fxas2100x_release(struct inode *inode, struct file *file)
{
	/* note: releasing the wdt in NOWAYOUT-mode does not stop it */
	return 0;
}

static const struct file_operations fxas2100x_fops = {
	.owner = THIS_MODULE,
	.open = fxas2100x_open,
	.release = fxas2100x_release,
	.unlocked_ioctl = fxas2100x_ioctl,
};

static struct miscdevice fxas2100x_device = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "FreescaleGyroscope",
	.fops = &fxas2100x_fops,
};

static ssize_t fxas2100x_enable_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct fxas2100x_data *pdata = g_fxas2100x_data;
	int enable = 0;
	enable = atomic_read(&pdata->active);
	return sprintf(buf, "%d\n", enable);
}

static ssize_t fxas2100x_enable_store(struct device *dev,
				    struct device_attribute *attr,
				    const char *buf, size_t count)
{
	struct fxas2100x_data *pdata = g_fxas2100x_data;
	struct i2c_client *client = pdata->client;
	int ret;
	unsigned long enable;

	if (kstrtoul(buf, 10, &enable) < 0)
		return -EINVAL;

	enable = (enable > 0) ? 1 : 0;
	ret = fxas2100x_change_mode(client, (enable > 0 ? ACTIVED : STANDBY));
	if (!ret) {
		atomic_set(&pdata->active, enable);
		atomic_set(&pdata->active_poll, enable);
		dev_err(dev, "mma enable setting active \n");
	}
	return count;
}

static ssize_t fxas2100x_poll_delay_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct fxas2100x_data *pdata = g_fxas2100x_data;
	int delay = 0;

	delay = atomic_read(&pdata->delay);
	return sprintf(buf, "%d\n", delay);
}

static ssize_t fxas2100x_poll_delay_store(struct device *dev,
				    struct device_attribute *attr,
				    const char *buf, size_t count)
{
	struct fxas2100x_data *pdata = g_fxas2100x_data;
	struct i2c_client *client = pdata->client;
	int ret;
	int delay;

	delay = simple_strtoul(buf, NULL, 10);
	ret = fxas2100x_set_delay(client, delay);
	if (!ret)
		atomic_set(&pdata->delay, delay);
	return count;
}

static ssize_t fxas2100x_position_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct fxas2100x_data *pdata = g_fxas2100x_data;
	int position = 0;

	position = atomic_read(&pdata->position);
	return sprintf(buf, "%d\n", position);
}

static ssize_t fxas2100x_position_store(struct device *dev,
				      struct device_attribute *attr,
				      const char *buf, size_t count)
{
	struct fxas2100x_data *pdata = g_fxas2100x_data;
	int position;

	position = simple_strtoul(buf, NULL, 10);
	atomic_set(&pdata->position, position);
	return count;
}

static DEVICE_ATTR(enable, S_IWUSR | S_IRUGO, fxas2100x_enable_show, fxas2100x_enable_store);
static DEVICE_ATTR(poll_delay, S_IWUSR | S_IRUGO, fxas2100x_poll_delay_show, fxas2100x_poll_delay_store);
static DEVICE_ATTR(position, S_IWUSR | S_IRUGO, fxas2100x_position_show, fxas2100x_position_store);

static struct attribute *fxas2100x_attributes[] = {
	&dev_attr_enable.attr,
	&dev_attr_poll_delay.attr,
	&dev_attr_position.attr,
	NULL
};

static const struct attribute_group fxas2100x_attr_group = {
	.attrs	= fxas2100x_attributes,
};

static void fxas2100x_poll(struct input_polled_dev *dev)
{
	struct fxas2100x_data *pdata = g_fxas2100x_data;
	struct input_dev *idev = pdata->input_polled->input;
	struct fxas2100x_data_axis data;
	int ret;

	if (!(atomic_read(&pdata->active_poll)))
		return;

	ret = fxas2100x_read_data(pdata, &data);
	if (!ret) {
		fxas2100x_data_convert(pdata, &data);
		input_report_abs(idev, ABS_X, data.x);
		input_report_abs(idev, ABS_Y, data.y);
		input_report_abs(idev, ABS_Z, data.z);
		input_sync(idev);
	}
}

static int fxas2100x_register_polled_device(struct fxas2100x_data *pdata)
{
	struct input_polled_dev *ipoll_dev;
	struct input_dev *idev;
	int error;

	ipoll_dev = input_allocate_polled_device();
	if (!ipoll_dev)
		return -ENOMEM;

	ipoll_dev->private = pdata;
	ipoll_dev->poll = fxas2100x_poll;
	ipoll_dev->poll_interval = FXAS2100X_POLL_INTERVAL;
	ipoll_dev->poll_interval_min = FXAS2100X_POLL_MIN;
	ipoll_dev->poll_interval_max = FXAS2100X_POLL_MAX;
	idev = ipoll_dev->input;
	idev->name = FXAS2100X_DRIVER;
	idev->id.bustype = BUS_I2C;
	idev->dev.parent = &pdata->client->dev;

	idev->evbit[0] = BIT_MASK(EV_ABS);
	input_set_abs_params(idev, ABS_X, ABSMIN_GYRO_VAL, ABSMAX_GYRO_VAL, 0, 0);
	input_set_abs_params(idev, ABS_Y, ABSMIN_GYRO_VAL, ABSMAX_GYRO_VAL, 0, 0);
	input_set_abs_params(idev, ABS_Z, ABSMIN_GYRO_VAL, ABSMAX_GYRO_VAL, 0, 0);

	error = input_register_polled_device(ipoll_dev);
	if (error) {
		input_free_polled_device(ipoll_dev);
		return error;
	}

	pdata->input_polled = ipoll_dev;
	return 0;
}

static int fxas2100x_probe(struct i2c_client *client,
			   const struct i2c_device_id *id)
{
	int result, chip_id;
	struct fxas2100x_data *pdata;
	struct i2c_adapter *adapter;

	adapter = to_i2c_adapter(client->dev.parent);
	result = i2c_check_functionality(adapter,
					 I2C_FUNC_SMBUS_BYTE |
					 I2C_FUNC_SMBUS_BYTE_DATA);
	if (!result)
		goto err_out;

	chip_id = i2c_smbus_read_byte_data(client, FXAS2100X_WHO_AM_I);
	if (chip_id != FXAS21000_CHIP_ID && chip_id != FXAS21002_CHID_ID_1 &&
	    chip_id != FXAS21002_CHID_ID_2) {
		dev_err(&client->dev,
			"read chip ID 0x%x is not equal to 0x%x for fxas21000 or 0x%x/0x%x fxas21002!\n",
			chip_id, FXAS21000_CHIP_ID, FXAS21002_CHID_ID_1, FXAS21002_CHID_ID_2);
		result = -EINVAL;
		goto err_out;
	}

	pdata = kzalloc(sizeof(struct fxas2100x_data), GFP_KERNEL);
	if (!pdata) {
		result = -ENOMEM;
		dev_err(&client->dev, "alloc data memory error!\n");
		goto err_out;
	}

	/* Initialize the FXAS2100X chip */
	g_fxas2100x_data = pdata;
	pdata->client = client;
	pdata->chip_id = chip_id;
	atomic_set(&pdata->delay, FXAS2100X_DELAY_DEFAULT);
	atomic_set(&pdata->position, FXAS2100X_POSITION_DEFAULT);
	i2c_set_clientdata(client, pdata);
	result = misc_register(&fxas2100x_device);
	if (result != 0) {
		dev_err(&client->dev, "register acc miscdevice error");
		goto err_regsiter_misc;
	}

	/* for debug */
	if (client->irq <= 0) {
		result = fxas2100x_register_polled_device(g_fxas2100x_data);
		if (result)
			dev_err(&client->dev,
				"IRQ GPIO conf. error %d, error %d\n",
				client->irq, result);
	}

	result = sysfs_create_group(&fxas2100x_device.this_device->kobj,
				    &fxas2100x_attr_group);
	if (result) {
		dev_err(&client->dev, "create device file failed!\n");
		result = -EINVAL;
		goto err_create_sysfs;
	}
	fxas2100x_device_init(client);
	dev_info(&client->dev, "fxas2100x device driver probe successfully\n");
	return 0;
err_create_sysfs:
	misc_deregister(&fxas2100x_device);
err_regsiter_misc:
	kfree(pdata);
err_out:
	return result;
}

static int fxas2100x_remove(struct i2c_client *client)
{
	struct fxas2100x_data *pdata = i2c_get_clientdata(client);
	fxas2100x_device_stop(client);
	if (client->irq <= 0) {
		input_unregister_polled_device(pdata->input_polled);
		input_free_polled_device(pdata->input_polled);
	}
	misc_deregister(&fxas2100x_device);
	if (pdata != NULL)
		kfree(pdata);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int fxas2100x_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct fxas2100x_data *pdata = i2c_get_clientdata(client);

	if (atomic_read(&pdata->active))
		fxas2100x_device_stop(client);
	return 0;
}

static int fxas2100x_resume(struct device *dev)
{
	int val = 0;
	struct i2c_client *client = to_i2c_client(dev);
	struct fxas2100x_data *pdata = i2c_get_clientdata(client);

	if (atomic_read(&pdata->active)) {
		val = i2c_smbus_read_byte_data(client, FXAS2100X_CTRL_REG1);
		val &= ~0x03;
		val |= 0x02;
		i2c_smbus_write_byte_data(client, FXAS2100X_CTRL_REG1, val);
	}
	return 0;

}
#endif

static const struct i2c_device_id fxas2100x_id[] = {
	{ "fxas2100x", 0 },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, fxas2100x_id);

static SIMPLE_DEV_PM_OPS(fxas2100x_pm_ops, fxas2100x_suspend, fxas2100x_resume);
static struct i2c_driver fxas2100x_driver = {
	.driver		= {
		.name	= FXAS2100X_DRIVER,
		.owner	= THIS_MODULE,
		.pm	= &fxas2100x_pm_ops,
	},
	.probe		= fxas2100x_probe,
	.remove		= fxas2100x_remove,
	.id_table	= fxas2100x_id,
};

module_i2c_driver(fxas2100x_driver);

MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("FXAS2100X 3-Axis Gyrosope Sensor driver");
MODULE_LICENSE("GPL");