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
76	switch (elo->idx++) {
77	case 0:
78		elo->csum = 0xaa;
79		if (data != ELO10_LEAD_BYTE) {
80			dev_dbg(&elo->serio->dev,
81				"unsynchronized data: 0x%02x\n", data);
82			elo->idx = 0;
83		}
84		break;
85
86	case 9:
87		elo->idx = 0;
88		if (data != elo->csum) {
89			dev_dbg(&elo->serio->dev,
90				"bad checksum: 0x%02x, expected 0x%02x\n",
91				 data, elo->csum);
92			break;
93		}
94		if (elo->data[1] != elo->expected_packet) {
95			if (elo->data[1] != ELO10_TOUCH_PACKET)
96				dev_dbg(&elo->serio->dev,
97					"unexpected packet: 0x%02x\n",
98					 elo->data[1]);
99			break;
100		}
101		if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) {
102			input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
103			input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
104			if (elo->data[2] & ELO10_PRESSURE)
105				input_report_abs(dev, ABS_PRESSURE,
106						(elo->data[8] << 8) | elo->data[7]);
107			input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH);
108			input_sync(dev);
109		} else if (elo->data[1] == ELO10_ACK_PACKET) {
110			if (elo->data[2] == '0')
111				elo->expected_packet = ELO10_TOUCH_PACKET;
112			complete(&elo->cmd_done);
113		} else {
114			memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN);
115			elo->expected_packet = ELO10_ACK_PACKET;
116		}
117		break;
118	}
119	elo->csum += data;
120}
121
122static void elo_process_data_6(struct elo *elo, unsigned char data)
123{
124	struct input_dev *dev = elo->dev;
125
126	elo->data[elo->idx] = data;
127
128	switch (elo->idx++) {
129
130	case 0:
131		if ((data & 0xc0) != 0xc0)
132			elo->idx = 0;
133		break;
134
135	case 1:
136		if ((data & 0xc0) != 0x80)
137			elo->idx = 0;
138		break;
139
140	case 2:
141		if ((data & 0xc0) != 0x40)
142			elo->idx = 0;
143		break;
144
145	case 3:
146		if (data & 0xc0) {
147			elo->idx = 0;
148			break;
149		}
150
151		input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f));
152		input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f));
153
154		if (elo->id == 2) {
155			input_report_key(dev, BTN_TOUCH, 1);
156			input_sync(dev);
157			elo->idx = 0;
158		}
159
160		break;
161
162	case 4:
163		if (data) {
164			input_sync(dev);
165			elo->idx = 0;
166		}
167		break;
168
169	case 5:
170		if ((data & 0xf0) == 0) {
171			input_report_abs(dev, ABS_PRESSURE, elo->data[5]);
172			input_report_key(dev, BTN_TOUCH, !!elo->data[5]);
173		}
174		input_sync(dev);
175		elo->idx = 0;
176		break;
177	}
178}
179
180static void elo_process_data_3(struct elo *elo, unsigned char data)
181{
182	struct input_dev *dev = elo->dev;
183
184	elo->data[elo->idx] = data;
185
186	switch (elo->idx++) {
187
188	case 0:
189		if ((data & 0x7f) != 0x01)
190			elo->idx = 0;
191		break;
192	case 2:
193		input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));
194		input_report_abs(dev, ABS_X, elo->data[1]);
195		input_report_abs(dev, ABS_Y, elo->data[2]);
196		input_sync(dev);
197		elo->idx = 0;
198		break;
199	}
200}
201
202static irqreturn_t elo_interrupt(struct serio *serio,
203		unsigned char data, unsigned int flags)
204{
205	struct elo *elo = serio_get_drvdata(serio);
206
207	switch (elo->id) {
208	case 0:
209		elo_process_data_10(elo, data);
210		break;
211
212	case 1:
213	case 2:
214		elo_process_data_6(elo, data);
215		break;
216
217	case 3:
218		elo_process_data_3(elo, data);
219		break;
220	}
221
222	return IRQ_HANDLED;
223}
224
225static int elo_command_10(struct elo *elo, unsigned char *packet)
226{
227	int rc = -1;
228	int i;
229	unsigned char csum = 0xaa + ELO10_LEAD_BYTE;
230
231	mutex_lock(&elo->cmd_mutex);
232
233	serio_pause_rx(elo->serio);
234	elo->expected_packet = toupper(packet[0]);
235	init_completion(&elo->cmd_done);
236	serio_continue_rx(elo->serio);
237
238	if (serio_write(elo->serio, ELO10_LEAD_BYTE))
239		goto out;
240
241	for (i = 0; i < ELO10_PACKET_LEN; i++) {
242		csum += packet[i];
243		if (serio_write(elo->serio, packet[i]))
244			goto out;
245	}
246
247	if (serio_write(elo->serio, csum))
248		goto out;
249
250	wait_for_completion_timeout(&elo->cmd_done, HZ);
251
252	if (elo->expected_packet == ELO10_TOUCH_PACKET) {
253		/* We are back in reporting mode, the command was ACKed */
254		memcpy(packet, elo->response, ELO10_PACKET_LEN);
255		rc = 0;
256	}
257
258 out:
259	mutex_unlock(&elo->cmd_mutex);
260	return rc;
261}
262
263static int elo_setup_10(struct elo *elo)
264{
265	static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" };
266	struct input_dev *dev = elo->dev;
267	unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD };
268
269	if (elo_command_10(elo, packet))
270		return -1;
271
272	dev->id.version = (packet[5] << 8) | packet[4];
273
274	input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0);
275	input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0);
276	if (packet[3] & ELO10_PRESSURE)
277		input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);
278
279	dev_info(&elo->serio->dev,
280		 "%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n",
281		 elo_types[(packet[1] -'0') & 0x03],
282		 packet[5], packet[4], packet[3], packet[7]);
283
284	return 0;
285}
286
287/*
288 * elo_disconnect() is the opposite of elo_connect()
289 */
290
291static void elo_disconnect(struct serio *serio)
292{
293	struct elo *elo = serio_get_drvdata(serio);
294
295	input_get_device(elo->dev);
296	input_unregister_device(elo->dev);
297	serio_close(serio);
298	serio_set_drvdata(serio, NULL);
299	input_put_device(elo->dev);
300	kfree(elo);
301}
302
303/*
304 * elo_connect() is the routine that is called when someone adds a
305 * new serio device that supports Gunze protocol and registers it as
306 * an input device.
307 */
308
309static int elo_connect(struct serio *serio, struct serio_driver *drv)
310{
311	struct elo *elo;
312	struct input_dev *input_dev;
313	int err;
314
315	elo = kzalloc(sizeof(struct elo), GFP_KERNEL);
316	input_dev = input_allocate_device();
317	if (!elo || !input_dev) {
318		err = -ENOMEM;
319		goto fail1;
320	}
321
322	elo->serio = serio;
323	elo->id = serio->id.id;
324	elo->dev = input_dev;
325	elo->expected_packet = ELO10_TOUCH_PACKET;
326	mutex_init(&elo->cmd_mutex);
327	init_completion(&elo->cmd_done);
328	snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);
329
330	input_dev->name = "Elo Serial TouchScreen";
331	input_dev->phys = elo->phys;
332	input_dev->id.bustype = BUS_RS232;
333	input_dev->id.vendor = SERIO_ELO;
334	input_dev->id.product = elo->id;
335	input_dev->id.version = 0x0100;
336	input_dev->dev.parent = &serio->dev;
337
338	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
339	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
340
341	serio_set_drvdata(serio, elo);
342	err = serio_open(serio, drv);
343	if (err)
344		goto fail2;
345
346	switch (elo->id) {
347
348	case 0: /* 10-byte protocol */
349		if (elo_setup_10(elo))
350			goto fail3;
351
352		break;
353
354	case 1: /* 6-byte protocol */
355		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);
356
357	case 2: /* 4-byte protocol */
358		input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
359		input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
360		break;
361
362	case 3: /* 3-byte protocol */
363		input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
364		input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
365		break;
366	}
367
368	err = input_register_device(elo->dev);
369	if (err)
370		goto fail3;
371
372	return 0;
373
374 fail3: serio_close(serio);
375 fail2:	serio_set_drvdata(serio, NULL);
376 fail1:	input_free_device(input_dev);
377	kfree(elo);
378	return err;
379}
380
381/*
382 * The serio driver structure.
383 */
384
385static struct serio_device_id elo_serio_ids[] = {
386	{
387		.type	= SERIO_RS232,
388		.proto	= SERIO_ELO,
389		.id	= SERIO_ANY,
390		.extra	= SERIO_ANY,
391	},
392	{ 0 }
393};
394
395MODULE_DEVICE_TABLE(serio, elo_serio_ids);
396
397static struct serio_driver elo_drv = {
398	.driver		= {
399		.name	= "elo",
400	},
401	.description	= DRIVER_DESC,
402	.id_table	= elo_serio_ids,
403	.interrupt	= elo_interrupt,
404	.connect	= elo_connect,
405	.disconnect	= elo_disconnect,
406};
407
408/*
409 * The functions for inserting/removing us as a module.
410 */
411
412static int __init elo_init(void)
413{
414	return serio_register_driver(&elo_drv);
415}
416
417static void __exit elo_exit(void)
418{
419	serio_unregister_driver(&elo_drv);
420}
421
422module_init(elo_init);
423module_exit(elo_exit);
424