2 * Touchwindow serial touchscreen driver
4 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
6 * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
7 * Copyright (c) 2004 Vojtech Pavlik
8 * and Dan Streetman <ddstreet@ieee.org>
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License version 2 as published
14 * by the Free Software Foundation.
18 * 2005/02/19 Rick Koch:
19 * The Touchwindow I used is made by Edmark Corp. and
20 * constantly outputs a stream of 0's unless it is touched.
21 * It then outputs 3 bytes: X, Y, and a copy of Y.
24 #include <linux/errno.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/input.h>
29 #include <linux/serio.h>
30 #include <linux/init.h>
32 #define DRIVER_DESC "Touchwindow serial touchscreen driver"
34 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
35 MODULE_DESCRIPTION(DRIVER_DESC);
36 MODULE_LICENSE("GPL");
39 * Definitions & global arrays.
45 #define TW_MAX_XC 0xff
47 #define TW_MAX_YC 0xff
50 * Per-touchscreen data.
54 struct input_dev *dev;
58 unsigned char data[TW_LENGTH];
62 static irqreturn_t tw_interrupt(struct serio *serio,
63 unsigned char data, unsigned int flags, struct pt_regs *regs)
65 struct tw *tw = serio_get_drvdata(serio);
66 struct input_dev *dev = tw->dev;
68 if (data) { /* touch */
70 tw->data[tw->idx++] = data;
71 /* verify length and that the two Y's are the same */
72 if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
73 input_regs(dev, regs);
74 input_report_abs(dev, ABS_X, tw->data[0]);
75 input_report_abs(dev, ABS_Y, tw->data[1]);
76 input_report_key(dev, BTN_TOUCH, 1);
80 } else if (tw->touched) { /* untouch */
81 input_report_key(dev, BTN_TOUCH, 0);
91 * tw_disconnect() is the opposite of tw_connect()
94 static void tw_disconnect(struct serio *serio)
96 struct tw *tw = serio_get_drvdata(serio);
98 input_get_device(tw->dev);
99 input_unregister_device(tw->dev);
101 serio_set_drvdata(serio, NULL);
102 input_put_device(tw->dev);
107 * tw_connect() is the routine that is called when someone adds a
108 * new serio device that supports the Touchwin protocol and registers it as
112 static int tw_connect(struct serio *serio, struct serio_driver *drv)
115 struct input_dev *input_dev;
118 tw = kzalloc(sizeof(struct tw), GFP_KERNEL);
119 input_dev = input_allocate_device();
120 if (!tw || !input_dev) {
127 snprintf(tw->phys, sizeof(tw->phys), "%s/input0", serio->phys);
129 input_dev->private = tw;
130 input_dev->name = "Touchwindow Serial TouchScreen";
131 input_dev->phys = tw->phys;
132 input_dev->id.bustype = BUS_RS232;
133 input_dev->id.vendor = SERIO_TOUCHWIN;
134 input_dev->id.product = 0;
135 input_dev->id.version = 0x0100;
136 input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
137 input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
138 input_set_abs_params(tw->dev, ABS_X, TW_MIN_XC, TW_MAX_XC, 0, 0);
139 input_set_abs_params(tw->dev, ABS_Y, TW_MIN_YC, TW_MAX_YC, 0, 0);
141 serio_set_drvdata(serio, tw);
143 err = serio_open(serio, drv);
147 err = input_register_device(tw->dev);
153 fail3: serio_close(serio);
154 fail2: serio_set_drvdata(serio, NULL);
155 fail1: input_free_device(input_dev);
161 * The serio driver structure.
164 static struct serio_device_id tw_serio_ids[] = {
167 .proto = SERIO_TOUCHWIN,
174 MODULE_DEVICE_TABLE(serio, tw_serio_ids);
176 static struct serio_driver tw_drv = {
180 .description = DRIVER_DESC,
181 .id_table = tw_serio_ids,
182 .interrupt = tw_interrupt,
183 .connect = tw_connect,
184 .disconnect = tw_disconnect,
188 * The functions for inserting/removing us as a module.
191 static int __init tw_init(void)
193 serio_register_driver(&tw_drv);
197 static void __exit tw_exit(void)
199 serio_unregister_driver(&tw_drv);
202 module_init(tw_init);
203 module_exit(tw_exit);