2 * Elo serial touchscreen driver
4 * Copyright (c) 2004 Vojtech Pavlik
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 as published by
10 * the Free Software Foundation.
14 * This driver can handle serial Elo touchscreens using either the Elo standard
15 * 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo
16 * legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte protocol.
19 #include <linux/errno.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/input.h>
24 #include <linux/serio.h>
25 #include <linux/init.h>
27 #define DRIVER_DESC "Elo serial touchscreen driver"
29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
30 MODULE_DESCRIPTION(DRIVER_DESC);
31 MODULE_LICENSE("GPL");
34 * Definitions & global arrays.
37 #define ELO_MAX_LENGTH 10
39 #define ELO10_LEAD_BYTE 'U'
41 #define ELO10_TOUCH_PACKET 'T'
44 * Per-touchscreen data.
48 struct input_dev *dev;
53 unsigned char data[ELO_MAX_LENGTH];
57 static void elo_process_data_10(struct elo *elo, unsigned char data, struct pt_regs *regs)
59 struct input_dev *dev = elo->dev;
61 elo->data[elo->idx] = data;
65 if (data != ELO10_LEAD_BYTE) {
66 pr_debug("elo: unsynchronized data: 0x%02x\n", data);
73 if (data != elo->csum) {
74 pr_debug("elo: bad checksum: 0x%02x, expected 0x%02x\n",
78 if (elo->data[1] != ELO10_TOUCH_PACKET) {
79 pr_debug(elo: "unexpected packet: 0x%02x\n", elo->data[1]);
82 input_regs(dev, regs);
83 input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
84 input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
85 input_report_abs(dev, ABS_PRESSURE, (elo->data[8] << 8) | elo->data[7]);
86 input_report_key(dev, BTN_TOUCH, elo->data[8] || elo->data[7]);
93 static void elo_process_data_6(struct elo *elo, unsigned char data, struct pt_regs *regs)
95 struct input_dev *dev = elo->dev;
97 elo->data[elo->idx] = data;
101 case 0: if ((data & 0xc0) != 0xc0) elo->idx = 0; break;
102 case 1: if ((data & 0xc0) != 0x80) elo->idx = 0; break;
103 case 2: if ((data & 0xc0) != 0x40) elo->idx = 0; break;
111 input_regs(dev, regs);
112 input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f));
113 input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f));
116 input_report_key(dev, BTN_TOUCH, 1);
131 if ((data & 0xf0) == 0) {
132 input_report_abs(dev, ABS_PRESSURE, elo->data[5]);
133 input_report_key(dev, BTN_TOUCH, !!elo->data[5]);
141 static void elo_process_data_3(struct elo *elo, unsigned char data, struct pt_regs *regs)
143 struct input_dev *dev = elo->dev;
145 elo->data[elo->idx] = data;
147 switch (elo->idx++) {
150 if ((data & 0x7f) != 0x01)
154 input_regs(dev, regs);
155 input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));
156 input_report_abs(dev, ABS_X, elo->data[1]);
157 input_report_abs(dev, ABS_Y, elo->data[2]);
164 static irqreturn_t elo_interrupt(struct serio *serio,
165 unsigned char data, unsigned int flags, struct pt_regs *regs)
167 struct elo *elo = serio_get_drvdata(serio);
171 elo_process_data_10(elo, data, regs);
176 elo_process_data_6(elo, data, regs);
180 elo_process_data_3(elo, data, regs);
188 * elo_disconnect() is the opposite of elo_connect()
191 static void elo_disconnect(struct serio *serio)
193 struct elo *elo = serio_get_drvdata(serio);
195 input_get_device(elo->dev);
196 input_unregister_device(elo->dev);
198 serio_set_drvdata(serio, NULL);
199 input_put_device(elo->dev);
204 * elo_connect() is the routine that is called when someone adds a
205 * new serio device that supports Gunze protocol and registers it as
209 static int elo_connect(struct serio *serio, struct serio_driver *drv)
212 struct input_dev *input_dev;
215 elo = kzalloc(sizeof(struct elo), GFP_KERNEL);
216 input_dev = input_allocate_device();
217 if (!elo || !input_dev) {
223 elo->id = serio->id.id;
224 elo->dev = input_dev;
225 snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);
227 input_dev->private = elo;
228 input_dev->name = "Elo Serial TouchScreen";
229 input_dev->phys = elo->phys;
230 input_dev->id.bustype = BUS_RS232;
231 input_dev->id.vendor = SERIO_ELO;
232 input_dev->id.product = elo->id;
233 input_dev->id.version = 0x0100;
234 input_dev->cdev.dev = &serio->dev;
236 input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
237 input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
241 case 0: /* 10-byte protocol */
242 input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
243 input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
244 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 255, 0, 0);
247 case 1: /* 6-byte protocol */
248 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);
250 case 2: /* 4-byte protocol */
251 input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
252 input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
255 case 3: /* 3-byte protocol */
256 input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
257 input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
261 serio_set_drvdata(serio, elo);
263 err = serio_open(serio, drv);
267 err = input_register_device(elo->dev);
273 fail3: serio_close(serio);
274 fail2: serio_set_drvdata(serio, NULL);
275 fail1: input_free_device(input_dev);
281 * The serio driver structure.
284 static struct serio_device_id elo_serio_ids[] = {
294 MODULE_DEVICE_TABLE(serio, elo_serio_ids);
296 static struct serio_driver elo_drv = {
300 .description = DRIVER_DESC,
301 .id_table = elo_serio_ids,
302 .interrupt = elo_interrupt,
303 .connect = elo_connect,
304 .disconnect = elo_disconnect,
308 * The functions for inserting/removing us as a module.
311 static int __init elo_init(void)
313 serio_register_driver(&elo_drv);
317 static void __exit elo_exit(void)
319 serio_unregister_driver(&elo_drv);
322 module_init(elo_init);
323 module_exit(elo_exit);