/*
* Touchwindow serial touchscreen driver
*
* Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
*
* Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
* Copyright (c) 2004 Vojtech Pavlik
* and Dan Streetman <ddstreet@ieee.org>
*/
/*
* 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 Rick Koch:
* The Touchwindow I used is made by Edmark Corp. and
* constantly outputs a stream of 0's unless it is touched.
* It then outputs 3 bytes: X, Y, and a copy of Y.
*/
#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 "Touchwindow serial touchscreen driver"
MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
/*
* Definitions & global arrays.
*/
#define TW_LENGTH 3
#define TW_MIN_XC 0
#define TW_MAX_XC 0xff
#define TW_MIN_YC 0
#define TW_MAX_YC 0xff
/*
* Per-touchscreen data.
*/
struct tw {
struct input_dev *dev;
struct serio *serio;
int idx;
int touched;
unsigned char data[TW_LENGTH];
char phys[32];
};
static irqreturn_t tw_interrupt(struct serio *serio,
unsigned char data, unsigned int flags)
{
struct tw *tw = serio_get_drvdata(serio);
struct input_dev *dev = tw->dev;
if (data) { /* touch */
tw->touched = 1;
tw->data[tw->idx++] = data;
/* verify length and that the two Y's are the same */
if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
input_report_abs(dev, ABS_X, tw->data[0]);
input_report_abs(dev, ABS_Y, tw->data[1]);
input_report_key(dev, BTN_TOUCH, 1);
input_sync(dev);
tw->idx = 0;
}
} else if (tw->touched) { /* untouch */
input_report_key(dev, BTN_TOUCH, 0);
input_sync(dev);
tw->idx = 0;
tw->touched = 0;
}
return IRQ_HANDLED;
}
/*
* tw_disconnect() is the opposite of tw_connect()
*/
static void tw_disconnect(struct serio *serio)
{
struct tw *tw = serio_get_drvdata(serio);
input_get_device(tw->dev);
input_unregister_device(tw->dev);
serio_close(serio);
serio_set_drvdata(serio, NULL);
input_put_device(tw->dev);
kfree(tw);
}
/*
* tw_connect() is the routine that is called when someone adds a
* new serio device that supports the Touchwin protocol and registers it as
* an input device.
*/
static int tw_connect(struct serio *serio, struct serio_driver *drv)
{
struct tw *tw;
struct input_dev *input_dev;
int err;
tw = kzalloc(sizeof(struct tw), GFP_KERNEL);
input_dev = input_allocate_device();
if (!tw || !input_dev) {
err = -ENOMEM;
goto fail1;
}
tw->serio = serio;
tw->dev = input_dev;
snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys);
input_dev->private = tw;
input_dev->name = "Touchwindow Serial TouchScreen";
input_dev->phys = tw->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_TOUCHWIN;
input_dev->id.product = 0;
input_dev->id.version = 0x0100;
input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0);
input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0);
serio_set_drvdata(serio, tw);
err = serio_open(serio, drv);
if (err)
goto fail2;
err = input_register_device(tw->dev);
if (err)
goto fail3;
return 0;
fail3: serio_close(serio);
fail2: serio_set_drvdata(serio, NULL);
fail1: input_free_device(input_dev);
kfree(tw);
return err;
}
/*
* The serio driver structure.
*/
static struct serio_device_id tw_serio_ids[] = {
{
.type = SERIO_RS232,
.proto = SERIO_TOUCHWIN,
.id = SERIO_ANY,
.extra = SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, tw_serio_ids);
static struct serio_driver tw_drv = {
.driver = {
.name = "touchwin",
},
.description = DRIVER_DESC,
.id_table = tw_serio_ids,
.interrupt = tw_interrupt,
.connect = tw_connect,
.disconnect = tw_disconnect,
};
/*
* The functions for inserting/removing us as a module.
*/
static int __init tw_init(void)
{
return serio_register_driver(&tw_drv);
}
static void __exit tw_exit(void)
{
serio_unregister_driver(&tw_drv);
}
module_init(tw_init);
module_exit(tw_exit);
