/* * MicroTouch (3M) serial touchscreen driver * * Copyright (c) 2004 Vojtech Pavlik *//* * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. *//* * 2005/02/19 Dan Streetman <ddstreet@ieee.org> *   Copied elo.c and edited for MicroTouch protocol */#include <linux/errno.h>#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	"MicroTouch serial touchscreen driver"MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");MODULE_DESCRIPTION(DRIVER_DESC);MODULE_LICENSE("GPL");/* * Definitions & global arrays. */#define MTOUCH_FORMAT_TABLET_STATUS_BIT 0x80#define MTOUCH_FORMAT_TABLET_TOUCH_BIT 0x40#define MTOUCH_FORMAT_TABLET_LENGTH 5#define MTOUCH_RESPONSE_BEGIN_BYTE 0x01#define MTOUCH_RESPONSE_END_BYTE 0x0d/* todo: check specs for max length of all responses */#define MTOUCH_MAX_LENGTH 16#define MTOUCH_MIN_XC 0#define MTOUCH_MAX_XC 0x3fff#define MTOUCH_MIN_YC 0#define MTOUCH_MAX_YC 0x3fff#define MTOUCH_GET_XC(data) (((data[2])<<7) | data[1])#define MTOUCH_GET_YC(data) (((data[4])<<7) | data[3])#define MTOUCH_GET_TOUCHED(data) (MTOUCH_FORMAT_TABLET_TOUCH_BIT & data[0])static char *mtouch_name = "MicroTouch Serial TouchScreen";/* * Per-touchscreen data. */struct mtouch {	struct input_dev dev;	struct serio *serio;	int idx;	unsigned char data[MTOUCH_MAX_LENGTH];	char phys[32];};static void mtouch_process_format_tablet(struct mtouch *mtouch, struct pt_regs *regs){	struct input_dev *dev = &mtouch->dev;	if (MTOUCH_FORMAT_TABLET_LENGTH == ++mtouch->idx) {		input_regs(dev, regs);		input_report_abs(dev, ABS_X, MTOUCH_GET_XC(mtouch->data));		input_report_abs(dev, ABS_Y, MTOUCH_MAX_YC - MTOUCH_GET_YC(mtouch->data));		input_report_key(dev, BTN_TOUCH, MTOUCH_GET_TOUCHED(mtouch->data));		input_sync(dev);		mtouch->idx = 0;	}}static void mtouch_process_response(struct mtouch *mtouch, struct pt_regs *regs){	if (MTOUCH_RESPONSE_END_BYTE == mtouch->data[mtouch->idx++]) {		/* FIXME - process response */		mtouch->idx = 0;	} else if (MTOUCH_MAX_LENGTH == mtouch->idx) {		printk(KERN_ERR "mtouch.c: too many response bytes\n");		mtouch->idx = 0;	}}static irqreturn_t mtouch_interrupt(struct serio *serio,		unsigned char data, unsigned int flags, struct pt_regs *regs){	struct mtouch* mtouch = serio_get_drvdata(serio);	mtouch->data[mtouch->idx] = data;	if (MTOUCH_FORMAT_TABLET_STATUS_BIT & mtouch->data[0])		mtouch_process_format_tablet(mtouch, regs);	else if (MTOUCH_RESPONSE_BEGIN_BYTE == mtouch->data[0])		mtouch_process_response(mtouch, regs);	else		printk(KERN_DEBUG "mtouch.c: unknown/unsynchronized data from device, byte %x\n",mtouch->data[0]);	return IRQ_HANDLED;}/* * mtouch_disconnect() is the opposite of mtouch_connect() */static void mtouch_disconnect(struct serio *serio){	struct mtouch* mtouch = serio_get_drvdata(serio);	input_unregister_device(&mtouch->dev);	serio_close(serio);	serio_set_drvdata(serio, NULL);	kfree(mtouch);}/* * mtouch_connect() is the routine that is called when someone adds a * new serio device that supports MicroTouch (Format Tablet) protocol and registers it as * an input device. */static int mtouch_connect(struct serio *serio, struct serio_driver *drv){	struct mtouch *mtouch;	int err;	if (!(mtouch = kmalloc(sizeof(*mtouch), GFP_KERNEL)))		return -ENOMEM;	memset(mtouch, 0, sizeof(*mtouch));	init_input_dev(&mtouch->dev);	mtouch->dev.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);	mtouch->dev.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);	input_set_abs_params(&mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);	input_set_abs_params(&mtouch->dev, ABS_Y, MTOUCH_MIN_YC, MTOUCH_MAX_YC, 0, 0);	mtouch->serio = serio;	sprintf(mtouch->phys, "%s/input0", serio->phys);	mtouch->dev.private = mtouch;	mtouch->dev.name = mtouch_name;	mtouch->dev.phys = mtouch->phys;	mtouch->dev.id.bustype = BUS_RS232;	mtouch->dev.id.vendor = SERIO_MICROTOUCH;	mtouch->dev.id.product = 0;	mtouch->dev.id.version = 0x0100;	serio_set_drvdata(serio, mtouch);	err = serio_open(serio, drv);	if (err) {		serio_set_drvdata(serio, NULL);		kfree(mtouch);		return err;	}	input_register_device(&mtouch->dev);	printk(KERN_INFO "input: %s on %s\n", mtouch->dev.name, serio->phys);	return 0;}/* * The serio driver structure. */static struct serio_device_id mtouch_serio_ids[] = {	{		.type	= SERIO_RS232,		.proto	= SERIO_MICROTOUCH,		.id	= SERIO_ANY,		.extra	= SERIO_ANY,	},	{ 0 }};MODULE_DEVICE_TABLE(serio, mtouch_serio_ids);static struct serio_driver mtouch_drv = {	.driver		= {		.name	= "mtouch",	},	.description	= DRIVER_DESC,	.id_table	= mtouch_serio_ids,	.interrupt	= mtouch_interrupt,	.connect	= mtouch_connect,	.disconnect	= mtouch_disconnect,};/* * The functions for inserting/removing us as a module. */static int __init mtouch_init(void){	serio_register_driver(&mtouch_drv);	return 0;}static void __exit mtouch_exit(void){	serio_unregister_driver(&mtouch_drv);}module_init(mtouch_init);module_exit(mtouch_exit);