1/*
2 * Elo serial touchscreen driver
3 *
4 * Copyright (c) 2004 Vojtech Pavlik
5 */
6
7/*
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.
11 */
12
13/*
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.
17 */
18
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>
26#include <linux/ctype.h>
27
28#define DRIVER_DESC	"Elo serial touchscreen driver"
29
30MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
31MODULE_DESCRIPTION(DRIVER_DESC);
32MODULE_LICENSE("GPL");
33
34/*
35 * Definitions & global arrays.
36 */
37
38#define ELO_MAX_LENGTH		10
39
40#define ELO10_PACKET_LEN	8
41#define ELO10_TOUCH		0x03
42#define ELO10_PRESSURE		0x80
43
44#define ELO10_LEAD_BYTE		'U'
45
46#define ELO10_ID_CMD		'i'
47
48#define ELO10_TOUCH_PACKET	'T'
49#define ELO10_ACK_PACKET	'A'
50#define ELI10_ID_PACKET		'I'
51
52/*
53 * Per-touchscreen data.
54 */
55
56struct elo {
57	struct input_dev *dev;
58	struct serio *serio;
59	struct mutex cmd_mutex;
60	struct completion cmd_done;
61	int id;
62	int idx;
63	unsigned char expected_packet;
64	unsigned char csum;
65	unsigned char data[ELO_MAX_LENGTH];
66	unsigned char response[ELO10_PACKET_LEN];
67	char phys[32];
68};
69
70static void elo_process_data_10(struct elo *elo, unsigned char data)
71{
72	struct input_dev *dev = elo->dev;
73
74	elo->data[elo->idx] = data;
75	switch (elo->idx++) {
76		case 0:
77			elo->csum = 0xaa;
78			if (data != ELO10_LEAD_BYTE) {
79				pr_debug("elo: unsynchronized data: 0x%02x\n", data);
80				elo->idx = 0;
81			}
82			break;
83
84		case 9:
85			elo->idx = 0;
86			if (data != elo->csum) {
87				pr_debug("elo: bad checksum: 0x%02x, expected 0x%02x\n",
88					 data, elo->csum);
89				break;
90			}
91			if (elo->data[1] != elo->expected_packet) {
92				if (elo->data[1] != ELO10_TOUCH_PACKET)
93					pr_debug("elo: unexpected packet: 0x%02x\n",
94						 elo->data[1]);
95				break;
96			}
97			if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) {
98				input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
99				input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
100				if (elo->data[2] & ELO10_PRESSURE)
101					input_report_abs(dev, ABS_PRESSURE,
102							(elo->data[8] << 8) | elo->data[7]);
103				input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH);
104				input_sync(dev);
105			} else if (elo->data[1] == ELO10_ACK_PACKET) {
106				if (elo->data[2] == '0')
107					elo->expected_packet = ELO10_TOUCH_PACKET;
108				complete(&elo->cmd_done);
109			} else {
110				memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN);
111				elo->expected_packet = ELO10_ACK_PACKET;
112			}
113			break;
114	}
115	elo->csum += data;
116}
117
118static void elo_process_data_6(struct elo *elo, unsigned char data)
119{
120	struct input_dev *dev = elo->dev;
121
122	elo->data[elo->idx] = data;
123
124	switch (elo->idx++) {
125
126		case 0: if ((data & 0xc0) != 0xc0) elo->idx = 0; break;
127		case 1: if ((data & 0xc0) != 0x80) elo->idx = 0; break;
128		case 2: if ((data & 0xc0) != 0x40) elo->idx = 0; break;
129
130		case 3:
131			if (data & 0xc0) {
132				elo->idx = 0;
133				break;
134			}
135
136			input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f));
137			input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f));
138
139			if (elo->id == 2) {
140				input_report_key(dev, BTN_TOUCH, 1);
141				input_sync(dev);
142				elo->idx = 0;
143			}
144
145			break;
146
147		case 4:
148			if (data) {
149				input_sync(dev);
150				elo->idx = 0;
151			}
152			break;
153
154		case 5:
155			if ((data & 0xf0) == 0) {
156				input_report_abs(dev, ABS_PRESSURE, elo->data[5]);
157				input_report_key(dev, BTN_TOUCH, !!elo->data[5]);
158			}
159			input_sync(dev);
160			elo->idx = 0;
161			break;
162	}
163}
164
165static void elo_process_data_3(struct elo *elo, unsigned char data)
166{
167	struct input_dev *dev = elo->dev;
168
169	elo->data[elo->idx] = data;
170
171	switch (elo->idx++) {
172
173		case 0:
174			if ((data & 0x7f) != 0x01)
175				elo->idx = 0;
176			break;
177		case 2:
178			input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));
179			input_report_abs(dev, ABS_X, elo->data[1]);
180			input_report_abs(dev, ABS_Y, elo->data[2]);
181			input_sync(dev);
182			elo->idx = 0;
183			break;
184	}
185}
186
187static irqreturn_t elo_interrupt(struct serio *serio,
188		unsigned char data, unsigned int flags)
189{
190	struct elo *elo = serio_get_drvdata(serio);
191
192	switch(elo->id) {
193		case 0:
194			elo_process_data_10(elo, data);
195			break;
196
197		case 1:
198		case 2:
199			elo_process_data_6(elo, data);
200			break;
201
202		case 3:
203			elo_process_data_3(elo, data);
204			break;
205	}
206
207	return IRQ_HANDLED;
208}
209
210static int elo_command_10(struct elo *elo, unsigned char *packet)
211{
212	int rc = -1;
213	int i;
214	unsigned char csum = 0xaa + ELO10_LEAD_BYTE;
215
216	mutex_lock(&elo->cmd_mutex);
217
218	serio_pause_rx(elo->serio);
219	elo->expected_packet = toupper(packet[0]);
220	init_completion(&elo->cmd_done);
221	serio_continue_rx(elo->serio);
222
223	if (serio_write(elo->serio, ELO10_LEAD_BYTE))
224		goto out;
225
226	for (i = 0; i < ELO10_PACKET_LEN; i++) {
227		csum += packet[i];
228		if (serio_write(elo->serio, packet[i]))
229			goto out;
230	}
231
232	if (serio_write(elo->serio, csum))
233		goto out;
234
235	wait_for_completion_timeout(&elo->cmd_done, HZ);
236
237	if (elo->expected_packet == ELO10_TOUCH_PACKET) {
238		/* We are back in reporting mode, the command was ACKed */
239		memcpy(packet, elo->response, ELO10_PACKET_LEN);
240		rc = 0;
241	}
242
243 out:
244	mutex_unlock(&elo->cmd_mutex);
245	return rc;
246}
247
248static int elo_setup_10(struct elo *elo)
249{
250	static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" };
251	struct input_dev *dev = elo->dev;
252	unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD };
253
254	if (elo_command_10(elo, packet))
255		return -1;
256
257	dev->id.version = (packet[5] << 8) | packet[4];
258
259	input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0);
260	input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0);
261	if (packet[3] & ELO10_PRESSURE)
262		input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);
263
264	printk(KERN_INFO "elo: %sTouch touchscreen, fw: %02x.%02x, "
265		"features: %x02x, controller: 0x%02x\n",
266		elo_types[(packet[1] -'0') & 0x03],
267		packet[5], packet[4], packet[3], packet[7]);
268
269	return 0;
270}
271
272/*
273 * elo_disconnect() is the opposite of elo_connect()
274 */
275
276static void elo_disconnect(struct serio *serio)
277{
278	struct elo *elo = serio_get_drvdata(serio);
279
280	input_get_device(elo->dev);
281	input_unregister_device(elo->dev);
282	serio_close(serio);
283	serio_set_drvdata(serio, NULL);
284	input_put_device(elo->dev);
285	kfree(elo);
286}
287
288/*
289 * elo_connect() is the routine that is called when someone adds a
290 * new serio device that supports Gunze protocol and registers it as
291 * an input device.
292 */
293
294static int elo_connect(struct serio *serio, struct serio_driver *drv)
295{
296	struct elo *elo;
297	struct input_dev *input_dev;
298	int err;
299
300	elo = kzalloc(sizeof(struct elo), GFP_KERNEL);
301	input_dev = input_allocate_device();
302	if (!elo || !input_dev) {
303		err = -ENOMEM;
304		goto fail1;
305	}
306
307	elo->serio = serio;
308	elo->id = serio->id.id;
309	elo->dev = input_dev;
310	elo->expected_packet = ELO10_TOUCH_PACKET;
311	mutex_init(&elo->cmd_mutex);
312	init_completion(&elo->cmd_done);
313	snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);
314
315	input_dev->name = "Elo Serial TouchScreen";
316	input_dev->phys = elo->phys;
317	input_dev->id.bustype = BUS_RS232;
318	input_dev->id.vendor = SERIO_ELO;
319	input_dev->id.product = elo->id;
320	input_dev->id.version = 0x0100;
321	input_dev->dev.parent = &serio->dev;
322
323	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
324	input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
325
326	serio_set_drvdata(serio, elo);
327	err = serio_open(serio, drv);
328	if (err)
329		goto fail2;
330
331	switch (elo->id) {
332
333		case 0: /* 10-byte protocol */
334			if (elo_setup_10(elo))
335				goto fail3;
336
337			break;
338
339		case 1: /* 6-byte protocol */
340			input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);
341
342		case 2: /* 4-byte protocol */
343			input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
344			input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
345			break;
346
347		case 3: /* 3-byte protocol */
348			input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
349			input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
350			break;
351	}
352
353	err = input_register_device(elo->dev);
354	if (err)
355		goto fail3;
356
357	return 0;
358
359 fail3: serio_close(serio);
360 fail2:	serio_set_drvdata(serio, NULL);
361 fail1:	input_free_device(input_dev);
362	kfree(elo);
363	return err;
364}
365
366/*
367 * The serio driver structure.
368 */
369
370static struct serio_device_id elo_serio_ids[] = {
371	{
372		.type	= SERIO_RS232,
373		.proto	= SERIO_ELO,
374		.id	= SERIO_ANY,
375		.extra	= SERIO_ANY,
376	},
377	{ 0 }
378};
379
380MODULE_DEVICE_TABLE(serio, elo_serio_ids);
381
382static struct serio_driver elo_drv = {
383	.driver		= {
384		.name	= "elo",
385	},
386	.description	= DRIVER_DESC,
387	.id_table	= elo_serio_ids,
388	.interrupt	= elo_interrupt,
389	.connect	= elo_connect,
390	.disconnect	= elo_disconnect,
391};
392
393/*
394 * The functions for inserting/removing us as a module.
395 */
396
397static int __init elo_init(void)
398{
399	return serio_register_driver(&elo_drv);
400}
401
402static void __exit elo_exit(void)
403{
404	serio_unregister_driver(&elo_drv);
405}
406
407module_init(elo_init);
408module_exit(elo_exit);
409