Input: add Zhen Hua driver

	  To compile this driver as a module, choose M here: the

	  module will be called twidjoy.

config JOYSTICK_ZHENHUA

	tristate "5-byte Zhenhua RC transmitter"

	select SERIO

	help

	  Say Y here if you have a Zhen Hua PPM-4CH transmitter which is

	  supplied with a ready to fly micro electric indoor helicopters

	  such as EasyCopter, Lama, MiniCopter, DragonFly or Jabo and want

	  to use it via serial cable as a joystick.

	  To compile this driver as a module, choose M here: the

	  module will be called zhenhua.

config JOYSTICK_DB9

	tristate "Multisystem, Sega Genesis, Saturn joysticks and gamepads"

	depends on PARPORT

obj-$(CONFIG_JOYSTICK_TWIDJOY)		+= twidjoy.o

obj-$(CONFIG_JOYSTICK_WARRIOR)		+= warrior.o

obj-$(CONFIG_JOYSTICK_XPAD)		+= xpad.o

obj-$(CONFIG_JOYSTICK_ZHENHUA)		+= zhenhua.o

obj-$(CONFIG_JOYSTICK_IFORCE)		+= iforce/

/*

 *  derived from "twidjoy.c"

 *

 *  Copyright (c) 2008 Martin Kebert

 *  Copyright (c) 2001 Arndt Schoenewald

 *  Copyright (c) 2000-2001 Vojtech Pavlik

 *  Copyright (c) 2000 Mark Fletcher

 *

 */

/*

 * Driver to use 4CH RC transmitter using Zhen Hua 5-byte protocol (Walkera Lama,

 * EasyCopter etc.) as a joystick under Linux.

 *

 * RC transmitters using Zhen Hua 5-byte protocol are cheap four channels

 * transmitters for control a RC planes or RC helicopters with possibility to

 * connect on a serial port.

 * Data coming from transmitter is in this order:

 * 1. byte = synchronisation byte

 * 2. byte = X axis

 * 3. byte = Y axis

 * 4. byte = RZ axis

 * 5. byte = Z axis

 * (and this is repeated)

 *

 * For questions or feedback regarding this driver module please contact:

 * Martin Kebert <gkmarty@gmail.com> - but I am not a C-programmer nor kernel

 * coder :-(

 */

/*

 * 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/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/input.h>

#include <linux/serio.h>

#include <linux/init.h>

#define DRIVER_DESC	"RC transmitter with 5-byte Zhen Hua protocol joystick driver"

MODULE_DESCRIPTION(DRIVER_DESC);

MODULE_LICENSE("GPL");

/*

 * Constants.

 */

#define ZHENHUA_MAX_LENGTH 5

/*

 * Zhen Hua data.

 */

struct zhenhua {

	struct input_dev *dev;

	int idx;

	unsigned char data[ZHENHUA_MAX_LENGTH];

	char phys[32];

};

/* bits in all incoming bytes needs to be "reversed" */

static int zhenhua_bitreverse(int x)

{

	x = ((x & 0xaa) >> 1) | ((x & 0x55) << 1);

	x = ((x & 0xcc) >> 2) | ((x & 0x33) << 2);

	x = ((x & 0xf0) >> 4) | ((x & 0x0f) << 4);

	return x;

}

/*

 * zhenhua_process_packet() decodes packets the driver receives from the

 * RC transmitter. It updates the data accordingly.

 */

static void zhenhua_process_packet(struct zhenhua *zhenhua)

{

	struct input_dev *dev = zhenhua->dev;

	unsigned char *data = zhenhua->data;

	input_report_abs(dev, ABS_Y, data[1]);

	input_report_abs(dev, ABS_X, data[2]);

	input_report_abs(dev, ABS_RZ, data[3]);

	input_report_abs(dev, ABS_Z, data[4]);

	input_sync(dev);

}

/*

 * zhenhua_interrupt() is called by the low level driver when characters

 * are ready for us. We then buffer them for further processing, or call the

 * packet processing routine.

 */

static irqreturn_t zhenhua_interrupt(struct serio *serio, unsigned char data, unsigned int flags)

{

	struct zhenhua *zhenhua = serio_get_drvdata(serio);

	/* All Zhen Hua packets are 5 bytes. The fact that the first byte

	 * is allways 0xf7 and all others are in range 0x32 - 0xc8 (50-200)

	 * can be used to check and regain sync. */

	if (data == 0xef)

		zhenhua->idx = 0;	/* this byte starts a new packet */

	else if (zhenhua->idx == 0)

		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */

	if (zhenhua->idx < ZHENHUA_MAX_LENGTH)

		zhenhua->data[zhenhua->idx++] = zhenhua_bitreverse(data);

	if (zhenhua->idx == ZHENHUA_MAX_LENGTH) {

		zhenhua_process_packet(zhenhua);

		zhenhua->idx = 0;

	}

	return IRQ_HANDLED;

}

/*

 * zhenhua_disconnect() is the opposite of zhenhua_connect()

 */

static void zhenhua_disconnect(struct serio *serio)

{

	struct zhenhua *zhenhua = serio_get_drvdata(serio);

	serio_close(serio);

	serio_set_drvdata(serio, NULL);

	input_unregister_device(zhenhua->dev);

	kfree(zhenhua);

}

/*

 * zhenhua_connect() is the routine that is called when someone adds a

 * new serio device. It looks for the Twiddler, and if found, registers

 * it as an input device.

 */

static int zhenhua_connect(struct serio *serio, struct serio_driver *drv)

{

	struct zhenhua *zhenhua;

	struct input_dev *input_dev;

	int err = -ENOMEM;

	zhenhua = kzalloc(sizeof(struct zhenhua), GFP_KERNEL);

	input_dev = input_allocate_device();

	if (!zhenhua || !input_dev)

		goto fail1;

	zhenhua->dev = input_dev;

	snprintf(zhenhua->phys, sizeof(zhenhua->phys), "%s/input0", serio->phys);

	input_dev->name = "Zhen Hua 5-byte device";

	input_dev->phys = zhenhua->phys;

	input_dev->id.bustype = BUS_RS232;

	input_dev->id.vendor = SERIO_ZHENHUA;

	input_dev->id.product = 0x0001;

	input_dev->id.version = 0x0100;

	input_dev->dev.parent = &serio->dev;

	input_dev->evbit[0] = BIT(EV_ABS);

	input_set_abs_params(input_dev, ABS_X, 50, 200, 0, 0);

	input_set_abs_params(input_dev, ABS_Y, 50, 200, 0, 0);

	input_set_abs_params(input_dev, ABS_Z, 50, 200, 0, 0);

	input_set_abs_params(input_dev, ABS_RZ, 50, 200, 0, 0);

	serio_set_drvdata(serio, zhenhua);

	err = serio_open(serio, drv);

	if (err)

		goto fail2;

	err = input_register_device(zhenhua->dev);

	if (err)

		goto fail3;

	return 0;

 fail3:	serio_close(serio);

 fail2:	serio_set_drvdata(serio, NULL);

 fail1:	input_free_device(input_dev);

	kfree(zhenhua);

	return err;

}

/*

 * The serio driver structure.

 */

static struct serio_device_id zhenhua_serio_ids[] = {

	{

		.type	= SERIO_RS232,

		.proto	= SERIO_ZHENHUA,

		.id	= SERIO_ANY,

		.extra	= SERIO_ANY,

	},

	{ 0 }

};

MODULE_DEVICE_TABLE(serio, zhenhua_serio_ids);

static struct serio_driver zhenhua_drv = {

	.driver		= {

		.name	= "zhenhua",

	},

	.description	= DRIVER_DESC,

	.id_table	= zhenhua_serio_ids,

	.interrupt	= zhenhua_interrupt,

	.connect	= zhenhua_connect,

	.disconnect	= zhenhua_disconnect,

};

/*

 * The functions for inserting/removing us as a module.

 */

static int __init zhenhua_init(void)

{

	return serio_register_driver(&zhenhua_drv);

}

static void __exit zhenhua_exit(void)

{

	serio_unregister_driver(&zhenhua_drv);

}

module_init(zhenhua_init);

module_exit(zhenhua_exit);

#define SERIO_TOUCHWIN	0x33

#define SERIO_TAOSEVM	0x34

#define SERIO_FUJITSU	0x35

#define SERIO_ZHENHUA	0x36

#endif