/* * Elo 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. *//* * This driver can handle serial Elo touchscreens using either the Elo standard * 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo * legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte 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	"Elo serial touchscreen driver"MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");MODULE_DESCRIPTION(DRIVER_DESC);MODULE_LICENSE("GPL");/* * Definitions & global arrays. */#define	ELO_MAX_LENGTH	10/* * Per-touchscreen data. */struct elo {	struct input_dev *dev;	struct serio *serio;	int id;	int idx;	unsigned char csum;	unsigned char data[ELO_MAX_LENGTH];	char phys[32];};static void elo_process_data_10(struct elo* elo, unsigned char data, struct pt_regs *regs){	struct input_dev *dev = elo->dev;	elo->csum += elo->data[elo->idx] = data;	switch (elo->idx++) {		case 0:			if (data != 'U') {				elo->idx = 0;				elo->csum = 0;			}			break;		case 1:			if (data != 'T') {				elo->idx = 0;				elo->csum = 0;			}			break;		case 9:			if (elo->csum) {				input_regs(dev, regs);				input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);				input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);				input_report_abs(dev, ABS_PRESSURE, (elo->data[8] << 8) | elo->data[7]);				input_report_key(dev, BTN_TOUCH, elo->data[8] || elo->data[7]);				input_sync(dev);			}			elo->idx = 0;			elo->csum = 0;			break;	}}static void elo_process_data_6(struct elo* elo, unsigned char data, struct pt_regs *regs){	struct input_dev *dev = elo->dev;	elo->data[elo->idx] = data;	switch (elo->idx++) {		case 0: if ((data & 0xc0) != 0xc0) elo->idx = 0; break;		case 1: if ((data & 0xc0) != 0x80) elo->idx = 0; break;		case 2: if ((data & 0xc0) != 0x40) elo->idx = 0; break;		case 3:			if (data & 0xc0) {				elo->idx = 0;				break;			}			input_regs(dev, regs);			input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f));			input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f));			if (elo->id == 2) {				input_report_key(dev, BTN_TOUCH, 1);				input_sync(dev);				elo->idx = 0;			}			break;		case 4:			if (data) {				input_sync(dev);				elo->idx = 0;			}			break;		case 5:			if ((data & 0xf0) == 0) {				input_report_abs(dev, ABS_PRESSURE, elo->data[5]);				input_report_key(dev, BTN_TOUCH, !!elo->data[5]);			}			input_sync(dev);			elo->idx = 0;			break;	}}static void elo_process_data_3(struct elo* elo, unsigned char data, struct pt_regs *regs){	struct input_dev *dev = elo->dev;	elo->data[elo->idx] = data;	switch (elo->idx++) {		case 0:			if ((data & 0x7f) != 0x01)				elo->idx = 0;			break;		case 2:			input_regs(dev, regs);			input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));			input_report_abs(dev, ABS_X, elo->data[1]);			input_report_abs(dev, ABS_Y, elo->data[2]);			input_sync(dev);			elo->idx = 0;			break;	}}static irqreturn_t elo_interrupt(struct serio *serio,		unsigned char data, unsigned int flags, struct pt_regs *regs){	struct elo* elo = serio_get_drvdata(serio);	switch(elo->id) {		case 0:			elo_process_data_10(elo, data, regs);			break;		case 1:		case 2:			elo_process_data_6(elo, data, regs);			break;		case 3:			elo_process_data_3(elo, data, regs);			break;	}	return IRQ_HANDLED;}/* * elo_disconnect() is the opposite of elo_connect() */static void elo_disconnect(struct serio *serio){	struct elo* elo = serio_get_drvdata(serio);	input_unregister_device(elo->dev);	serio_close(serio);	serio_set_drvdata(serio, NULL);	kfree(elo);}/* * elo_connect() is the routine that is called when someone adds a * new serio device that supports Gunze protocol and registers it as * an input device. */static int elo_connect(struct serio *serio, struct serio_driver *drv){	struct elo *elo;	struct input_dev *input_dev;	int err;	elo = kzalloc(sizeof(struct elo), GFP_KERNEL);	input_dev = input_allocate_device();	if (!elo || !input_dev) {		err = -ENOMEM;		goto fail;	}	elo->serio = serio;	elo->id = serio->id.id;	elo->dev = input_dev;	snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);	input_dev->private = elo;	input_dev->name = "Elo Serial TouchScreen";	input_dev->phys = elo->phys;	input_dev->id.bustype = BUS_RS232;	input_dev->id.vendor = SERIO_ELO;	input_dev->id.product = elo->id;	input_dev->id.version = 0x0100;	input_dev->cdev.dev = &serio->dev;	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);	input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);	switch (elo->id) {		case 0: /* 10-byte protocol */			input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);			input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);			input_set_abs_params(input_dev, ABS_PRESSURE, 0, 255, 0, 0);			break;		case 1: /* 6-byte protocol */			input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);		case 2: /* 4-byte protocol */			input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);			input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);			break;		case 3: /* 3-byte protocol */			input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);			input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);			break;	}	serio_set_drvdata(serio, elo);	err = serio_open(serio, drv);	if (err)		goto fail;	input_register_device(elo->dev);	return 0; fail:	serio_set_drvdata(serio, NULL);	input_free_device(input_dev);	kfree(elo);	return err;}/* * The serio driver structure. */static struct serio_device_id elo_serio_ids[] = {	{		.type	= SERIO_RS232,		.proto	= SERIO_ELO,		.id	= SERIO_ANY,		.extra	= SERIO_ANY,	},	{ 0 }};MODULE_DEVICE_TABLE(serio, elo_serio_ids);static struct serio_driver elo_drv = {	.driver		= {		.name	= "elo",	},	.description	= DRIVER_DESC,	.id_table	= elo_serio_ids,	.interrupt	= elo_interrupt,	.connect	= elo_connect,	.disconnect	= elo_disconnect,};/* * The functions for inserting/removing us as a module. */static int __init elo_init(void){	serio_register_driver(&elo_drv);	return 0;}static void __exit elo_exit(void){	serio_unregister_driver(&elo_drv);}module_init(elo_init);module_exit(elo_exit);