drivers/input/mouse/vsxxxaa.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * Driver for	DEC VSXXX-AA mouse (hockey-puck mouse, ball or two rollers)
  *		DEC VSXXX-GA mouse (rectangular mouse, with ball)
  *		DEC VSXXX-AB tablet (digitizer with hair cross or stylus)
  *
  * Copyright (C) 2003-2004 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
  *
  * The packet format was initially taken from a patch to GPM which is (C) 2001
  * by	Karsten Merker <merker@linuxtag.org>
  * and	Maciej W. Rozycki <macro@ds2.pg.gda.pl>
  * Later on, I had access to the device's documentation (referenced below).
  */

 /*
  * 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
  */

 /*
  * Building an adaptor to DE9 / DB25 RS232
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
  * DISCLAIMER: Use this description AT YOUR OWN RISK! I'll not pay for
  * anything if you break your mouse, your computer or whatever!
  *
  * In theory, this mouse is a simple RS232 device. In practice, it has got
  * a quite uncommon plug and the requirement to additionally get a power
  * supply at +5V and -12V.
  *
  * If you look at the socket/jack (_not_ at the plug), we use this pin
  * numbering:
  *    _______
  *   / 7 6 5 \
  *  | 4 --- 3 |
  *   \  2 1  /
  *    -------
  *
  *	DEC socket	DE9	DB25	Note
  *	1 (GND)		5	7	-
  *	2 (RxD)		2	3	-
  *	3 (TxD)		3	2	-
  *	4 (-12V)	-	-	Somewhere from the PSU. At ATX, it's
  *					the thin blue wire at pin 12 of the
  *					ATX power connector. Only required for
  *					VSXXX-AA/-GA mice.
  *	5 (+5V)		-	-	PSU (red wires of ATX power connector
  *					on pin 4, 6, 19 or 20) or HDD power
  *					connector (also red wire).
  *	6 (+12V)	-	-	HDD power connector, yellow wire. Only
  *					required for VSXXX-AB digitizer.
  *	7 (dev. avail.)	-	-	The mouse shorts this one to pin 1.
  *					This way, the host computer can detect
  *					the mouse. To use it with the adaptor,
  *					simply don't connect this pin.
  *
  * So to get a working adaptor, you need to connect the mouse with three
  * wires to a RS232 port and two or three additional wires for +5V, +12V and
  * -12V to the PSU.
  *
  * Flow specification for the link is 4800, 8o1.
  *
  * The mice and tablet are described in "VCB02 Video Subsystem - Technical
  * Manual", DEC EK-104AA-TM-001. You'll find it at MANX, a search engine
  * specific for DEC documentation. Try
  * http://www.vt100.net/manx/details?pn=EK-104AA-TM-001;id=21;cp=1
  */

 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/input.h>
 #include <linux/config.h>
 #include <linux/serio.h>
 #include <linux/init.h>

 #define DRIVER_DESC "Driver for DEC VSXXX-AA and -GA mice and VSXXX-AB tablet"

 MODULE_AUTHOR ("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
 MODULE_DESCRIPTION (DRIVER_DESC);
 MODULE_LICENSE ("GPL");

 #undef VSXXXAA_DEBUG
 #ifdef VSXXXAA_DEBUG
 #define DBG(x...) printk (x)
 #else
 #define DBG(x...) do {} while (0)
 #endif

 #define VSXXXAA_INTRO_MASK	0x80
 #define VSXXXAA_INTRO_HEAD	0x80
 #define IS_HDR_BYTE(x)		(((x) & VSXXXAA_INTRO_MASK)	\
 					== VSXXXAA_INTRO_HEAD)

 #define VSXXXAA_PACKET_MASK	0xe0
 #define VSXXXAA_PACKET_REL	0x80
 #define VSXXXAA_PACKET_ABS	0xc0
 #define VSXXXAA_PACKET_POR	0xa0
 #define MATCH_PACKET_TYPE(data, type)	(((data) & VSXXXAA_PACKET_MASK) == (type))


 struct vsxxxaa {
 	struct input_dev *dev;
 	struct serio *serio;
 #define BUFLEN 15 /* At least 5 is needed for a full tablet packet */
 	unsigned char buf[BUFLEN];
 	unsigned char count;
 	unsigned char version;
 	unsigned char country;
 	unsigned char type;
 	char name[64];
 	char phys[32];
 };

 static void
 vsxxxaa_drop_bytes (struct vsxxxaa *mouse, int num)
 {
 	if (num >= mouse->count)
 		mouse->count = 0;
 	else {
 		memmove (mouse->buf, mouse->buf + num - 1, BUFLEN - num);
 		mouse->count -= num;
 	}
 }

 static void
 vsxxxaa_queue_byte (struct vsxxxaa *mouse, unsigned char byte)
 {
 	if (mouse->count == BUFLEN) {
 		printk (KERN_ERR "%s on %s: Dropping a byte of full buffer.\n",
 				mouse->name, mouse->phys);
 		vsxxxaa_drop_bytes (mouse, 1);
 	}
 	DBG (KERN_INFO "Queueing byte 0x%02x\n", byte);

 	mouse->buf[mouse->count++] = byte;
 }

 static void
 vsxxxaa_detection_done (struct vsxxxaa *mouse)
 {
 	switch (mouse->type) {
 		case 0x02:
 			strlcpy (mouse->name, "DEC VSXXX-AA/-GA mouse",
 				 sizeof (mouse->name));
 			break;

 		case 0x04:
 			strlcpy (mouse->name, "DEC VSXXX-AB digitizer",
 				 sizeof (mouse->name));
 			break;

 		default:
 			snprintf (mouse->name, sizeof (mouse->name),
 				  "unknown DEC pointer device (type = 0x%02x)",
 				  mouse->type);
 			break;
 	}

 	printk (KERN_INFO
 		"Found %s version 0x%02x from country 0x%02x on port %s\n",
 		mouse->name, mouse->version, mouse->country, mouse->phys);
 }

 /*
  * Returns number of bytes to be dropped, 0 if packet is okay.
  */
 static int
 vsxxxaa_check_packet (struct vsxxxaa *mouse, int packet_len)
 {
 	int i;

 	/* First byte must be a header byte */
 	if (!IS_HDR_BYTE (mouse->buf[0])) {
 		DBG ("vsck: len=%d, 1st=0x%02x\n", packet_len, mouse->buf[0]);
 		return 1;
 	}

 	/* Check all following bytes */
 	if (packet_len > 1) {
 		for (i = 1; i < packet_len; i++) {
 			if (IS_HDR_BYTE (mouse->buf[i])) {
 				printk (KERN_ERR "Need to drop %d bytes "
 						"of a broken packet.\n",
 						i - 1);
 				DBG (KERN_INFO "check: len=%d, b[%d]=0x%02x\n",
 						packet_len, i, mouse->buf[i]);
 				return i - 1;
 			}
 		}
 	}

 	return 0;
 }

 static __inline__ int
 vsxxxaa_smells_like_packet (struct vsxxxaa *mouse, unsigned char type, size_t len)
 {
 	return (mouse->count >= len) && MATCH_PACKET_TYPE (mouse->buf[0], type);
 }

 static void
 vsxxxaa_handle_REL_packet (struct vsxxxaa *mouse, struct pt_regs *regs)
 {
 	struct input_dev *dev = mouse->dev;
 	unsigned char *buf = mouse->buf;
 	int left, middle, right;
 	int dx, dy;

 	/*
 	 * Check for normal stream packets. This is three bytes,
 	 * with the first byte's 3 MSB set to 100.
 	 *
 	 * [0]:	1	0	0	SignX	SignY	Left	Middle	Right
 	 * [1]: 0	dx	dx	dx	dx	dx	dx	dx
 	 * [2]:	0	dy	dy	dy	dy	dy	dy	dy
 	 */

 	/*
 	 * Low 7 bit of byte 1 are abs(dx), bit 7 is
 	 * 0, bit 4 of byte 0 is direction.
 	 */
 	dx = buf[1] & 0x7f;
 	dx *= ((buf[0] >> 4) & 0x01)? 1: -1;

 	/*
 	 * Low 7 bit of byte 2 are abs(dy), bit 7 is
 	 * 0, bit 3 of byte 0 is direction.
 	 */
 	dy = buf[2] & 0x7f;
 	dy *= ((buf[0] >> 3) & 0x01)? -1: 1;

 	/*
 	 * Get button state. It's the low three bits
 	 * (for three buttons) of byte 0.
 	 */
 	left	= (buf[0] & 0x04)? 1: 0;
 	middle	= (buf[0] & 0x02)? 1: 0;
 	right	= (buf[0] & 0x01)? 1: 0;

 	vsxxxaa_drop_bytes (mouse, 3);

 	DBG (KERN_INFO "%s on %s: dx=%d, dy=%d, buttons=%s%s%s\n",
 			mouse->name, mouse->phys, dx, dy,
 			left? "L": "l", middle? "M": "m", right? "R": "r");

 	/*
 	 * Report what we've found so far...
 	 */
 	input_regs (dev, regs);
 	input_report_key (dev, BTN_LEFT, left);
 	input_report_key (dev, BTN_MIDDLE, middle);
 	input_report_key (dev, BTN_RIGHT, right);
 	input_report_key (dev, BTN_TOUCH, 0);
 	input_report_rel (dev, REL_X, dx);
 	input_report_rel (dev, REL_Y, dy);
 	input_sync (dev);
 }

 static void
 vsxxxaa_handle_ABS_packet (struct vsxxxaa *mouse, struct pt_regs *regs)
 {
 	struct input_dev *dev = mouse->dev;
 	unsigned char *buf = mouse->buf;
 	int left, middle, right, touch;
 	int x, y;

 	/*
 	 * Tablet position / button packet
 	 *
 	 * [0]:	1	1	0	B4	B3	B2	B1	Pr
 	 * [1]:	0	0	X5	X4	X3	X2	X1	X0
 	 * [2]:	0	0	X11	X10	X9	X8	X7	X6
 	 * [3]:	0	0	Y5	Y4	Y3	Y2	Y1	Y0
 	 * [4]:	0	0	Y11	Y10	Y9	Y8	Y7	Y6
 	 */

 	/*
 	 * Get X/Y position. Y axis needs to be inverted since VSXXX-AB
 	 * counts down->top while monitor counts top->bottom.
 	 */
 	x = ((buf[2] & 0x3f) << 6) | (buf[1] & 0x3f);
 	y = ((buf[4] & 0x3f) << 6) | (buf[3] & 0x3f);
 	y = 1023 - y;

 	/*
 	 * Get button state. It's bits <4..1> of byte 0.
 	 */
 	left	= (buf[0] & 0x02)? 1: 0;
 	middle	= (buf[0] & 0x04)? 1: 0;
 	right	= (buf[0] & 0x08)? 1: 0;
 	touch	= (buf[0] & 0x10)? 1: 0;

 	vsxxxaa_drop_bytes (mouse, 5);

 	DBG (KERN_INFO "%s on %s: x=%d, y=%d, buttons=%s%s%s%s\n",
 			mouse->name, mouse->phys, x, y,
 			left? "L": "l", middle? "M": "m",
 			right? "R": "r", touch? "T": "t");

 	/*
 	 * Report what we've found so far...
 	 */
 	input_regs (dev, regs);
 	input_report_key (dev, BTN_LEFT, left);
 	input_report_key (dev, BTN_MIDDLE, middle);
 	input_report_key (dev, BTN_RIGHT, right);
 	input_report_key (dev, BTN_TOUCH, touch);
 	input_report_abs (dev, ABS_X, x);
 	input_report_abs (dev, ABS_Y, y);
 	input_sync (dev);
 }

 static void
 vsxxxaa_handle_POR_packet (struct vsxxxaa *mouse, struct pt_regs *regs)
 {
 	struct input_dev *dev = mouse->dev;
 	unsigned char *buf = mouse->buf;
 	int left, middle, right;
 	unsigned char error;

 	/*
 	 * Check for Power-On-Reset packets. These are sent out
 	 * after plugging the mouse in, or when explicitely
 	 * requested by sending 'T'.
 	 *
 	 * [0]:	1	0	1	0	R3	R2	R1	R0
 	 * [1]:	0	M2	M1	M0	D3	D2	D1	D0
 	 * [2]:	0	E6	E5	E4	E3	E2	E1	E0
 	 * [3]:	0	0	0	0	0	Left	Middle	Right
 	 *
 	 * M: manufacturer location code
 	 * R: revision code
 	 * E: Error code. If it's in the range of 0x00..0x1f, only some
 	 *    minor problem occured. Errors >= 0x20 are considered bad
 	 *    and the device may not work properly...
 	 * D: <0010> == mouse, <0100> == tablet
 	 */

 	mouse->version = buf[0] & 0x0f;
 	mouse->country = (buf[1] >> 4) & 0x07;
 	mouse->type = buf[1] & 0x0f;
 	error = buf[2] & 0x7f;

 	/*
 	 * Get button state. It's the low three bits
 	 * (for three buttons) of byte 0. Maybe even the bit <3>
 	 * has some meaning if a tablet is attached.
 	 */
 	left	= (buf[0] & 0x04)? 1: 0;
 	middle	= (buf[0] & 0x02)? 1: 0;
 	right	= (buf[0] & 0x01)? 1: 0;

 	vsxxxaa_drop_bytes (mouse, 4);
 	vsxxxaa_detection_done (mouse);

 	if (error <= 0x1f) {
 		/* No (serious) error. Report buttons */
 		input_regs (dev, regs);
 		input_report_key (dev, BTN_LEFT, left);
 		input_report_key (dev, BTN_MIDDLE, middle);
 		input_report_key (dev, BTN_RIGHT, right);
 		input_report_key (dev, BTN_TOUCH, 0);
 		input_sync (dev);

 		if (error != 0)
 			printk (KERN_INFO "Your %s on %s reports error=0x%02x\n",
 					mouse->name, mouse->phys, error);

 	}

 	/*
 	 * If the mouse was hot-plugged, we need to force differential mode
 	 * now... However, give it a second to recover from it's reset.
 	 */
 	printk (KERN_NOTICE "%s on %s: Forceing standard packet format, "
 			"incremental streaming mode and 72 samples/sec\n",
 			mouse->name, mouse->phys);
 	mouse->serio->write (mouse->serio, 'S');	/* Standard format */
 	mdelay (50);
 	mouse->serio->write (mouse->serio, 'R');	/* Incremental */
 	mdelay (50);
 	mouse->serio->write (mouse->serio, 'L');	/* 72 samples/sec */
 }

 static void
 vsxxxaa_parse_buffer (struct vsxxxaa *mouse, struct pt_regs *regs)
 {
 	unsigned char *buf = mouse->buf;
 	int stray_bytes;

 	/*
 	 * Parse buffer to death...
 	 */
 	do {
 		/*
 		 * Out of sync? Throw away what we don't understand. Each
 		 * packet starts with a byte whose bit 7 is set. Unhandled
 		 * packets (ie. which we don't know about or simply b0rk3d
 		 * data...) will get shifted out of the buffer after some
 		 * activity on the mouse.
 		 */
 		while (mouse->count > 0 && !IS_HDR_BYTE(buf[0])) {
 			printk (KERN_ERR "%s on %s: Dropping a byte to regain "
 					"sync with mouse data stream...\n",
 					mouse->name, mouse->phys);
 			vsxxxaa_drop_bytes (mouse, 1);
 		}

 		/*
 		 * Check for packets we know about.
 		 */

 		if (vsxxxaa_smells_like_packet (mouse, VSXXXAA_PACKET_REL, 3)) {
 			/* Check for broken packet */
 			stray_bytes = vsxxxaa_check_packet (mouse, 3);
 			if (stray_bytes > 0) {
 				printk (KERN_ERR "Dropping %d bytes now...\n",
 						stray_bytes);
 				vsxxxaa_drop_bytes (mouse, stray_bytes);
 				continue;
 			}

 			vsxxxaa_handle_REL_packet (mouse, regs);
 			continue; /* More to parse? */
 		}

 		if (vsxxxaa_smells_like_packet (mouse, VSXXXAA_PACKET_ABS, 5)) {
 			/* Check for broken packet */
 			stray_bytes = vsxxxaa_check_packet (mouse, 5);
 			if (stray_bytes > 0) {
 				printk (KERN_ERR "Dropping %d bytes now...\n",
 						stray_bytes);
 				vsxxxaa_drop_bytes (mouse, stray_bytes);
 				continue;
 			}

 			vsxxxaa_handle_ABS_packet (mouse, regs);
 			continue; /* More to parse? */
 		}

 		if (vsxxxaa_smells_like_packet (mouse, VSXXXAA_PACKET_POR, 4)) {
 			/* Check for broken packet */
 			stray_bytes = vsxxxaa_check_packet (mouse, 4);
 			if (stray_bytes > 0) {
 				printk (KERN_ERR "Dropping %d bytes now...\n",
 						stray_bytes);
 				vsxxxaa_drop_bytes (mouse, stray_bytes);
 				continue;
 			}

 			vsxxxaa_handle_POR_packet (mouse, regs);
 			continue; /* More to parse? */
 		}

 		break; /* No REL, ABS or POR packet found */
 	} while (1);
 }

 static irqreturn_t
 vsxxxaa_interrupt (struct serio *serio, unsigned char data, unsigned int flags,
 		struct pt_regs *regs)
 {
 	struct vsxxxaa *mouse = serio_get_drvdata (serio);

 	vsxxxaa_queue_byte (mouse, data);
 	vsxxxaa_parse_buffer (mouse, regs);

 	return IRQ_HANDLED;
 }

 static void
 vsxxxaa_disconnect (struct serio *serio)
 {
 	struct vsxxxaa *mouse = serio_get_drvdata (serio);

 	serio_close (serio);
 	serio_set_drvdata (serio, NULL);
 	input_unregister_device (mouse->dev);
 	kfree (mouse);
 }

 static int
 vsxxxaa_connect (struct serio *serio, struct serio_driver *drv)
 {
 	struct vsxxxaa *mouse;
 	struct input_dev *input_dev;
 	int err = -ENOMEM;

 	mouse = kzalloc (sizeof (struct vsxxxaa), GFP_KERNEL);
 	input_dev = input_allocate_device ();
 	if (!mouse || !input_dev)
 		goto fail;

 	mouse->dev = input_dev;
 	mouse->serio = serio;
 	strlcat (mouse->name, "DEC VSXXX-AA/-GA mouse or VSXXX-AB digitizer",
 		 sizeof (mouse->name));
 	snprintf (mouse->phys, sizeof (mouse->phys), "%s/input0", serio->phys);

 	input_dev->name = mouse->name;
 	input_dev->phys = mouse->phys;
 	input_dev->id.bustype = BUS_RS232;
 	input_dev->cdev.dev = &serio->dev;
 	input_dev->private = mouse;

 	set_bit (EV_KEY, input_dev->evbit);		/* We have buttons */
 	set_bit (EV_REL, input_dev->evbit);
 	set_bit (EV_ABS, input_dev->evbit);
 	set_bit (BTN_LEFT, input_dev->keybit);		/* We have 3 buttons */
 	set_bit (BTN_MIDDLE, input_dev->keybit);
 	set_bit (BTN_RIGHT, input_dev->keybit);
 	set_bit (BTN_TOUCH, input_dev->keybit);		/* ...and Tablet */
 	set_bit (REL_X, input_dev->relbit);
 	set_bit (REL_Y, input_dev->relbit);
 	input_set_abs_params (input_dev, ABS_X, 0, 1023, 0, 0);
 	input_set_abs_params (input_dev, ABS_Y, 0, 1023, 0, 0);

 	serio_set_drvdata (serio, mouse);

 	err = serio_open (serio, drv);
 	if (err)
 		goto fail;

 	/*
 	 * Request selftest. Standard packet format and differential
 	 * mode will be requested after the device ID'ed successfully.
 	 */
 	serio->write (serio, 'T'); /* Test */

 	input_register_device (input_dev);

 	return 0;

  fail:	serio_set_drvdata (serio, NULL);
 	input_free_device (input_dev);
 	kfree (mouse);
 	return err;
 }

 static struct serio_device_id vsxxaa_serio_ids[] = {
 	{
 		.type	= SERIO_RS232,
 		.proto	= SERIO_VSXXXAA,
 		.id	= SERIO_ANY,
 		.extra	= SERIO_ANY,
 	},
 	{ 0 }
 };

 MODULE_DEVICE_TABLE(serio, vsxxaa_serio_ids);

 static struct serio_driver vsxxxaa_drv = {
 	.driver		= {
 		.name	= "vsxxxaa",
 	},
 	.description	= DRIVER_DESC,
 	.id_table	= vsxxaa_serio_ids,
 	.connect	= vsxxxaa_connect,
 	.interrupt	= vsxxxaa_interrupt,
 	.disconnect	= vsxxxaa_disconnect,
 };

 static int __init
 vsxxxaa_init (void)
 {
 	serio_register_driver(&vsxxxaa_drv);
 	return 0;
 }

 static void __exit
 vsxxxaa_exit (void)
 {
 	serio_unregister_driver(&vsxxxaa_drv);
 }

 module_init (vsxxxaa_init);
 module_exit (vsxxxaa_exit);
	/*
	* Driver for DEC VSXXX-AA mouse (hockey-puck mouse, ball or two rollers)
	* DEC VSXXX-GA mouse (rectangular mouse, with ball)
	* DEC VSXXX-AB tablet (digitizer with hair cross or stylus)
	*
	* Copyright (C) 2003-2004 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
	*
	* The packet format was initially taken from a patch to GPM which is (C) 2001
	* by Karsten Merker <merker@linuxtag.org>
	* and Maciej W. Rozycki <macro@ds2.pg.gda.pl>
	* Later on, I had access to the device's documentation (referenced below).
	*/

	/*
	* 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
	*/

	/*
	* Building an adaptor to DE9 / DB25 RS232
	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	*
	* DISCLAIMER: Use this description AT YOUR OWN RISK! I'll not pay for
	* anything if you break your mouse, your computer or whatever!
	*
	* In theory, this mouse is a simple RS232 device. In practice, it has got
	* a quite uncommon plug and the requirement to additionally get a power
	* supply at +5V and -12V.
	*
	* If you look at the socket/jack (_not_ at the plug), we use this pin
	* numbering:
	* _______
	* / 7 6 5 \
	* \| 4 --- 3 \|
	* \ 2 1 /
	* -------
	*
	* DEC socket DE9 DB25 Note
	* 1 (GND) 5 7 -
	* 2 (RxD) 2 3 -
	* 3 (TxD) 3 2 -
	* 4 (-12V) - - Somewhere from the PSU. At ATX, it's
	* the thin blue wire at pin 12 of the
	* ATX power connector. Only required for
	* VSXXX-AA/-GA mice.
	* 5 (+5V) - - PSU (red wires of ATX power connector
	* on pin 4, 6, 19 or 20) or HDD power
	* connector (also red wire).
	* 6 (+12V) - - HDD power connector, yellow wire. Only
	* required for VSXXX-AB digitizer.
	* 7 (dev. avail.) - - The mouse shorts this one to pin 1.
	* This way, the host computer can detect
	* the mouse. To use it with the adaptor,
	* simply don't connect this pin.
	*
	* So to get a working adaptor, you need to connect the mouse with three
	* wires to a RS232 port and two or three additional wires for +5V, +12V and
	* -12V to the PSU.
	*
	* Flow specification for the link is 4800, 8o1.
	*
	* The mice and tablet are described in "VCB02 Video Subsystem - Technical
	* Manual", DEC EK-104AA-TM-001. You'll find it at MANX, a search engine
	* specific for DEC documentation. Try
	* http://www.vt100.net/manx/details?pn=EK-104AA-TM-001;id=21;cp=1
	*/

	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/interrupt.h>
	#include <linux/input.h>
	#include <linux/config.h>
	#include <linux/serio.h>
	#include <linux/init.h>

	#define DRIVER_DESC "Driver for DEC VSXXX-AA and -GA mice and VSXXX-AB tablet"

	MODULE_AUTHOR ("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
	MODULE_DESCRIPTION (DRIVER_DESC);
	MODULE_LICENSE ("GPL");

	#undef VSXXXAA_DEBUG
	#ifdef VSXXXAA_DEBUG
	#define DBG(x...) printk (x)
	#else
	#define DBG(x...) do {} while (0)
	#endif

	#define VSXXXAA_INTRO_MASK 0x80
	#define VSXXXAA_INTRO_HEAD 0x80
	#define IS_HDR_BYTE(x) (((x) & VSXXXAA_INTRO_MASK) \
	== VSXXXAA_INTRO_HEAD)

	#define VSXXXAA_PACKET_MASK 0xe0
	#define VSXXXAA_PACKET_REL 0x80
	#define VSXXXAA_PACKET_ABS 0xc0
	#define VSXXXAA_PACKET_POR 0xa0
	#define MATCH_PACKET_TYPE(data, type) (((data) & VSXXXAA_PACKET_MASK) == (type))



	struct vsxxxaa {
	struct input_dev *dev;
	struct serio *serio;
	#define BUFLEN 15 /* At least 5 is needed for a full tablet packet */
	unsigned char buf[BUFLEN];
	unsigned char count;
	unsigned char version;
	unsigned char country;
	unsigned char type;
	char name[64];
	char phys[32];
	};

	static void
	vsxxxaa_drop_bytes (struct vsxxxaa *mouse, int num)
	{
	if (num >= mouse->count)
	mouse->count = 0;
	else {
	memmove (mouse->buf, mouse->buf + num - 1, BUFLEN - num);
	mouse->count -= num;
	}
	}

	static void
	vsxxxaa_queue_byte (struct vsxxxaa *mouse, unsigned char byte)
	{
	if (mouse->count == BUFLEN) {
	printk (KERN_ERR "%s on %s: Dropping a byte of full buffer.\n",
	mouse->name, mouse->phys);
	vsxxxaa_drop_bytes (mouse, 1);
	}
	DBG (KERN_INFO "Queueing byte 0x%02x\n", byte);

	mouse->buf[mouse->count++] = byte;
	}

	static void
	vsxxxaa_detection_done (struct vsxxxaa *mouse)
	{
	switch (mouse->type) {
	case 0x02:
	strlcpy (mouse->name, "DEC VSXXX-AA/-GA mouse",
	sizeof (mouse->name));
	break;

	case 0x04:
	strlcpy (mouse->name, "DEC VSXXX-AB digitizer",
	sizeof (mouse->name));
	break;

	default:
	snprintf (mouse->name, sizeof (mouse->name),
	"unknown DEC pointer device (type = 0x%02x)",
	mouse->type);
	break;
	}

	printk (KERN_INFO
	"Found %s version 0x%02x from country 0x%02x on port %s\n",
	mouse->name, mouse->version, mouse->country, mouse->phys);
	}

	/*
	* Returns number of bytes to be dropped, 0 if packet is okay.
	*/
	static int
	vsxxxaa_check_packet (struct vsxxxaa *mouse, int packet_len)
	{
	int i;

	/* First byte must be a header byte */
	if (!IS_HDR_BYTE (mouse->buf[0])) {
	DBG ("vsck: len=%d, 1st=0x%02x\n", packet_len, mouse->buf[0]);
	return 1;
	}

	/* Check all following bytes */
	if (packet_len > 1) {
	for (i = 1; i < packet_len; i++) {
	if (IS_HDR_BYTE (mouse->buf[i])) {
	printk (KERN_ERR "Need to drop %d bytes "
	"of a broken packet.\n",
	i - 1);
	DBG (KERN_INFO "check: len=%d, b[%d]=0x%02x\n",
	packet_len, i, mouse->buf[i]);
	return i - 1;
	}
	}
	}

	return 0;
	}

	static __inline__ int
	vsxxxaa_smells_like_packet (struct vsxxxaa *mouse, unsigned char type, size_t len)
	{
	return (mouse->count >= len) && MATCH_PACKET_TYPE (mouse->buf[0], type);
	}

	static void
	vsxxxaa_handle_REL_packet (struct vsxxxaa mouse, struct pt_regs regs)
	{
	struct input_dev *dev = mouse->dev;
	unsigned char *buf = mouse->buf;
	int left, middle, right;
	int dx, dy;

	/*
	* Check for normal stream packets. This is three bytes,
	* with the first byte's 3 MSB set to 100.
	*
	* [0]: 1 0 0 SignX SignY Left Middle Right
	* [1]: 0 dx dx dx dx dx dx dx
	* [2]: 0 dy dy dy dy dy dy dy
	*/

	/*
	* Low 7 bit of byte 1 are abs(dx), bit 7 is
	* 0, bit 4 of byte 0 is direction.
	*/
	dx = buf[1] & 0x7f;
	dx *= ((buf[0] >> 4) & 0x01)? 1: -1;

	/*
	* Low 7 bit of byte 2 are abs(dy), bit 7 is
	* 0, bit 3 of byte 0 is direction.
	*/
	dy = buf[2] & 0x7f;
	dy *= ((buf[0] >> 3) & 0x01)? -1: 1;

	/*
	* Get button state. It's the low three bits
	* (for three buttons) of byte 0.
	*/
	left = (buf[0] & 0x04)? 1: 0;
	middle = (buf[0] & 0x02)? 1: 0;
	right = (buf[0] & 0x01)? 1: 0;

	vsxxxaa_drop_bytes (mouse, 3);

	DBG (KERN_INFO "%s on %s: dx=%d, dy=%d, buttons=%s%s%s\n",
	mouse->name, mouse->phys, dx, dy,
	left? "L": "l", middle? "M": "m", right? "R": "r");

	/*
	* Report what we've found so far...
	*/
	input_regs (dev, regs);
	input_report_key (dev, BTN_LEFT, left);
	input_report_key (dev, BTN_MIDDLE, middle);
	input_report_key (dev, BTN_RIGHT, right);
	input_report_key (dev, BTN_TOUCH, 0);
	input_report_rel (dev, REL_X, dx);
	input_report_rel (dev, REL_Y, dy);
	input_sync (dev);
	}

	static void
	vsxxxaa_handle_ABS_packet (struct vsxxxaa mouse, struct pt_regs regs)
	{
	struct input_dev *dev = mouse->dev;
	unsigned char *buf = mouse->buf;
	int left, middle, right, touch;
	int x, y;

	/*
	* Tablet position / button packet
	*
	* [0]: 1 1 0 B4 B3 B2 B1 Pr
	* [1]: 0 0 X5 X4 X3 X2 X1 X0
	* [2]: 0 0 X11 X10 X9 X8 X7 X6
	* [3]: 0 0 Y5 Y4 Y3 Y2 Y1 Y0
	* [4]: 0 0 Y11 Y10 Y9 Y8 Y7 Y6
	*/

	/*
	* Get X/Y position. Y axis needs to be inverted since VSXXX-AB
	* counts down->top while monitor counts top->bottom.
	*/
	x = ((buf[2] & 0x3f) << 6) \| (buf[1] & 0x3f);
	y = ((buf[4] & 0x3f) << 6) \| (buf[3] & 0x3f);
	y = 1023 - y;

	/*
	* Get button state. It's bits <4..1> of byte 0.
	*/
	left = (buf[0] & 0x02)? 1: 0;
	middle = (buf[0] & 0x04)? 1: 0;
	right = (buf[0] & 0x08)? 1: 0;
	touch = (buf[0] & 0x10)? 1: 0;

	vsxxxaa_drop_bytes (mouse, 5);

	DBG (KERN_INFO "%s on %s: x=%d, y=%d, buttons=%s%s%s%s\n",
	mouse->name, mouse->phys, x, y,
	left? "L": "l", middle? "M": "m",
	right? "R": "r", touch? "T": "t");

	/*
	* Report what we've found so far...
	*/
	input_regs (dev, regs);
	input_report_key (dev, BTN_LEFT, left);
	input_report_key (dev, BTN_MIDDLE, middle);
	input_report_key (dev, BTN_RIGHT, right);
	input_report_key (dev, BTN_TOUCH, touch);
	input_report_abs (dev, ABS_X, x);
	input_report_abs (dev, ABS_Y, y);
	input_sync (dev);
	}

	static void
	vsxxxaa_handle_POR_packet (struct vsxxxaa mouse, struct pt_regs regs)
	{
	struct input_dev *dev = mouse->dev;
	unsigned char *buf = mouse->buf;
	int left, middle, right;
	unsigned char error;

	/*
	* Check for Power-On-Reset packets. These are sent out
	* after plugging the mouse in, or when explicitely
	* requested by sending 'T'.
	*
	* [0]: 1 0 1 0 R3 R2 R1 R0
	* [1]: 0 M2 M1 M0 D3 D2 D1 D0
	* [2]: 0 E6 E5 E4 E3 E2 E1 E0
	* [3]: 0 0 0 0 0 Left Middle Right
	*
	* M: manufacturer location code
	* R: revision code
	* E: Error code. If it's in the range of 0x00..0x1f, only some
	* minor problem occured. Errors >= 0x20 are considered bad
	* and the device may not work properly...
	* D: <0010> == mouse, <0100> == tablet
	*/

	mouse->version = buf[0] & 0x0f;
	mouse->country = (buf[1] >> 4) & 0x07;
	mouse->type = buf[1] & 0x0f;
	error = buf[2] & 0x7f;

	/*
	* Get button state. It's the low three bits
	* (for three buttons) of byte 0. Maybe even the bit <3>
	* has some meaning if a tablet is attached.
	*/
	left = (buf[0] & 0x04)? 1: 0;
	middle = (buf[0] & 0x02)? 1: 0;
	right = (buf[0] & 0x01)? 1: 0;

	vsxxxaa_drop_bytes (mouse, 4);
	vsxxxaa_detection_done (mouse);

	if (error <= 0x1f) {
	/* No (serious) error. Report buttons */
	input_regs (dev, regs);
	input_report_key (dev, BTN_LEFT, left);
	input_report_key (dev, BTN_MIDDLE, middle);
	input_report_key (dev, BTN_RIGHT, right);
	input_report_key (dev, BTN_TOUCH, 0);
	input_sync (dev);

	if (error != 0)
	printk (KERN_INFO "Your %s on %s reports error=0x%02x\n",
	mouse->name, mouse->phys, error);

	}

	/*
	* If the mouse was hot-plugged, we need to force differential mode
	* now... However, give it a second to recover from it's reset.
	*/
	printk (KERN_NOTICE "%s on %s: Forceing standard packet format, "
	"incremental streaming mode and 72 samples/sec\n",
	mouse->name, mouse->phys);
	mouse->serio->write (mouse->serio, 'S'); /* Standard format */
	mdelay (50);
	mouse->serio->write (mouse->serio, 'R'); /* Incremental */
	mdelay (50);
	mouse->serio->write (mouse->serio, 'L'); /* 72 samples/sec */
	}

	static void
	vsxxxaa_parse_buffer (struct vsxxxaa mouse, struct pt_regs regs)
	{
	unsigned char *buf = mouse->buf;
	int stray_bytes;

	/*
	* Parse buffer to death...
	*/
	do {
	/*
	* Out of sync? Throw away what we don't understand. Each
	* packet starts with a byte whose bit 7 is set. Unhandled
	* packets (ie. which we don't know about or simply b0rk3d
	* data...) will get shifted out of the buffer after some
	* activity on the mouse.
	*/
	while (mouse->count > 0 && !IS_HDR_BYTE(buf[0])) {
	printk (KERN_ERR "%s on %s: Dropping a byte to regain "
	"sync with mouse data stream...\n",
	mouse->name, mouse->phys);
	vsxxxaa_drop_bytes (mouse, 1);
	}

	/*
	* Check for packets we know about.
	*/

	if (vsxxxaa_smells_like_packet (mouse, VSXXXAA_PACKET_REL, 3)) {
	/* Check for broken packet */
	stray_bytes = vsxxxaa_check_packet (mouse, 3);
	if (stray_bytes > 0) {
	printk (KERN_ERR "Dropping %d bytes now...\n",
	stray_bytes);
	vsxxxaa_drop_bytes (mouse, stray_bytes);
	continue;
	}

	vsxxxaa_handle_REL_packet (mouse, regs);
	continue; /* More to parse? */
	}

	if (vsxxxaa_smells_like_packet (mouse, VSXXXAA_PACKET_ABS, 5)) {
	/* Check for broken packet */
	stray_bytes = vsxxxaa_check_packet (mouse, 5);
	if (stray_bytes > 0) {
	printk (KERN_ERR "Dropping %d bytes now...\n",
	stray_bytes);
	vsxxxaa_drop_bytes (mouse, stray_bytes);
	continue;
	}

	vsxxxaa_handle_ABS_packet (mouse, regs);
	continue; /* More to parse? */
	}

	if (vsxxxaa_smells_like_packet (mouse, VSXXXAA_PACKET_POR, 4)) {
	/* Check for broken packet */
	stray_bytes = vsxxxaa_check_packet (mouse, 4);
	if (stray_bytes > 0) {
	printk (KERN_ERR "Dropping %d bytes now...\n",
	stray_bytes);
	vsxxxaa_drop_bytes (mouse, stray_bytes);
	continue;
	}

	vsxxxaa_handle_POR_packet (mouse, regs);
	continue; /* More to parse? */
	}

	break; /* No REL, ABS or POR packet found */
	} while (1);
	}

	static irqreturn_t
	vsxxxaa_interrupt (struct serio *serio, unsigned char data, unsigned int flags,
	struct pt_regs *regs)
	{
	struct vsxxxaa *mouse = serio_get_drvdata (serio);

	vsxxxaa_queue_byte (mouse, data);
	vsxxxaa_parse_buffer (mouse, regs);

	return IRQ_HANDLED;
	}

	static void
	vsxxxaa_disconnect (struct serio *serio)
	{
	struct vsxxxaa *mouse = serio_get_drvdata (serio);

	serio_close (serio);
	serio_set_drvdata (serio, NULL);
	input_unregister_device (mouse->dev);
	kfree (mouse);
	}

	static int
	vsxxxaa_connect (struct serio serio, struct serio_driver drv)
	{
	struct vsxxxaa *mouse;
	struct input_dev *input_dev;
	int err = -ENOMEM;

	mouse = kzalloc (sizeof (struct vsxxxaa), GFP_KERNEL);
	input_dev = input_allocate_device ();
	if (!mouse \|\| !input_dev)
	goto fail;

	mouse->dev = input_dev;
	mouse->serio = serio;
	strlcat (mouse->name, "DEC VSXXX-AA/-GA mouse or VSXXX-AB digitizer",
	sizeof (mouse->name));
	snprintf (mouse->phys, sizeof (mouse->phys), "%s/input0", serio->phys);

	input_dev->name = mouse->name;
	input_dev->phys = mouse->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->cdev.dev = &serio->dev;
	input_dev->private = mouse;

	set_bit (EV_KEY, input_dev->evbit); /* We have buttons */
	set_bit (EV_REL, input_dev->evbit);
	set_bit (EV_ABS, input_dev->evbit);
	set_bit (BTN_LEFT, input_dev->keybit); /* We have 3 buttons */
	set_bit (BTN_MIDDLE, input_dev->keybit);
	set_bit (BTN_RIGHT, input_dev->keybit);
	set_bit (BTN_TOUCH, input_dev->keybit); /* ...and Tablet */
	set_bit (REL_X, input_dev->relbit);
	set_bit (REL_Y, input_dev->relbit);
	input_set_abs_params (input_dev, ABS_X, 0, 1023, 0, 0);
	input_set_abs_params (input_dev, ABS_Y, 0, 1023, 0, 0);

	serio_set_drvdata (serio, mouse);

	err = serio_open (serio, drv);
	if (err)
	goto fail;

	/*
	* Request selftest. Standard packet format and differential
	* mode will be requested after the device ID'ed successfully.
	*/
	serio->write (serio, 'T'); /* Test */

	input_register_device (input_dev);

	return 0;

	fail: serio_set_drvdata (serio, NULL);
	input_free_device (input_dev);
	kfree (mouse);
	return err;
	}

	static struct serio_device_id vsxxaa_serio_ids[] = {
	{
	.type = SERIO_RS232,
	.proto = SERIO_VSXXXAA,
	.id = SERIO_ANY,
	.extra = SERIO_ANY,
	},
	{ 0 }
	};

	MODULE_DEVICE_TABLE(serio, vsxxaa_serio_ids);

	static struct serio_driver vsxxxaa_drv = {
	.driver = {
	.name = "vsxxxaa",
	},
	.description = DRIVER_DESC,
	.id_table = vsxxaa_serio_ids,
	.connect = vsxxxaa_connect,
	.interrupt = vsxxxaa_interrupt,
	.disconnect = vsxxxaa_disconnect,
	};

	static int __init
	vsxxxaa_init (void)
	{
	serio_register_driver(&vsxxxaa_drv);
	return 0;
	}

	static void __exit
	vsxxxaa_exit (void)
	{
	serio_unregister_driver(&vsxxxaa_drv);
	}

	module_init (vsxxxaa_init);
	module_exit (vsxxxaa_exit);