1/*
2 * Penmount serial touchscreen driver
3 *
4 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
5 * Copyright (c) 2011 John Sung <penmount.touch@gmail.com>
6 *
7 * Based on ELO driver (drivers/input/touchscreen/elo.c)
8 * Copyright (c) 2004 Vojtech Pavlik
9 */
10
11/*
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.
15 */
16
17#include <linux/errno.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/slab.h>
21#include <linux/input.h>
22#include <linux/input/mt.h>
23#include <linux/serio.h>
24#include <linux/init.h>
25
26#define DRIVER_DESC	"PenMount serial touchscreen driver"
27
28MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
29MODULE_AUTHOR("John Sung <penmount.touch@gmail.com>");
30MODULE_DESCRIPTION(DRIVER_DESC);
31MODULE_LICENSE("GPL");
32
33/*
34 * Definitions & global arrays.
35 */
36
37#define	PM_MAX_LENGTH	6
38#define	PM_MAX_MTSLOT	16
39#define	PM_3000_MTSLOT	2
40#define	PM_6250_MTSLOT	12
41
42/*
43 * Multi-touch slot
44 */
45
46struct mt_slot {
47	unsigned short x, y;
48	bool active; /* is the touch valid? */
49};
50
51/*
52 * Per-touchscreen data.
53 */
54
55struct pm {
56	struct input_dev *dev;
57	struct serio *serio;
58	int idx;
59	unsigned char data[PM_MAX_LENGTH];
60	char phys[32];
61	unsigned char packetsize;
62	unsigned char maxcontacts;
63	struct mt_slot slots[PM_MAX_MTSLOT];
64	void (*parse_packet)(struct pm *);
65};
66
67/*
68 * pm_mtevent() sends mt events and also emulates pointer movement
69 */
70
71static void pm_mtevent(struct pm *pm, struct input_dev *input)
72{
73	int i;
74
75	for (i = 0; i < pm->maxcontacts; ++i) {
76		input_mt_slot(input, i);
77		input_mt_report_slot_state(input, MT_TOOL_FINGER,
78				pm->slots[i].active);
79		if (pm->slots[i].active) {
80			input_event(input, EV_ABS, ABS_MT_POSITION_X, pm->slots[i].x);
81			input_event(input, EV_ABS, ABS_MT_POSITION_Y, pm->slots[i].y);
82		}
83	}
84
85	input_mt_report_pointer_emulation(input, true);
86	input_sync(input);
87}
88
89/*
90 * pm_checkpacket() checks if data packet is valid
91 */
92
93static bool pm_checkpacket(unsigned char *packet)
94{
95	int total = 0;
96	int i;
97
98	for (i = 0; i < 5; i++)
99		total += packet[i];
100
101	return packet[5] == (unsigned char)~(total & 0xff);
102}
103
104static void pm_parse_9000(struct pm *pm)
105{
106	struct input_dev *dev = pm->dev;
107
108	if ((pm->data[0] & 0x80) && pm->packetsize == ++pm->idx) {
109		input_report_abs(dev, ABS_X, pm->data[1] * 128 + pm->data[2]);
110		input_report_abs(dev, ABS_Y, pm->data[3] * 128 + pm->data[4]);
111		input_report_key(dev, BTN_TOUCH, !!(pm->data[0] & 0x40));
112		input_sync(dev);
113		pm->idx = 0;
114	}
115}
116
117static void pm_parse_6000(struct pm *pm)
118{
119	struct input_dev *dev = pm->dev;
120
121	if ((pm->data[0] & 0xbf) == 0x30 && pm->packetsize == ++pm->idx) {
122		if (pm_checkpacket(pm->data)) {
123			input_report_abs(dev, ABS_X,
124					pm->data[2] * 256 + pm->data[1]);
125			input_report_abs(dev, ABS_Y,
126					pm->data[4] * 256 + pm->data[3]);
127			input_report_key(dev, BTN_TOUCH, pm->data[0] & 0x40);
128			input_sync(dev);
129		}
130		pm->idx = 0;
131	}
132}
133
134static void pm_parse_3000(struct pm *pm)
135{
136	struct input_dev *dev = pm->dev;
137
138	if ((pm->data[0] & 0xce) == 0x40 && pm->packetsize == ++pm->idx) {
139		if (pm_checkpacket(pm->data)) {
140			int slotnum = pm->data[0] & 0x0f;
141			pm->slots[slotnum].active = pm->data[0] & 0x30;
142			pm->slots[slotnum].x = pm->data[2] * 256 + pm->data[1];
143			pm->slots[slotnum].y = pm->data[4] * 256 + pm->data[3];
144			pm_mtevent(pm, dev);
145		}
146		pm->idx = 0;
147	}
148}
149
150static void pm_parse_6250(struct pm *pm)
151{
152	struct input_dev *dev = pm->dev;
153
154	if ((pm->data[0] & 0xb0) == 0x30 && pm->packetsize == ++pm->idx) {
155		if (pm_checkpacket(pm->data)) {
156			int slotnum = pm->data[0] & 0x0f;
157			pm->slots[slotnum].active = pm->data[0] & 0x40;
158			pm->slots[slotnum].x = pm->data[2] * 256 + pm->data[1];
159			pm->slots[slotnum].y = pm->data[4] * 256 + pm->data[3];
160			pm_mtevent(pm, dev);
161		}
162		pm->idx = 0;
163	}
164}
165
166static irqreturn_t pm_interrupt(struct serio *serio,
167		unsigned char data, unsigned int flags)
168{
169	struct pm *pm = serio_get_drvdata(serio);
170
171	pm->data[pm->idx] = data;
172
173	pm->parse_packet(pm);
174
175	return IRQ_HANDLED;
176}
177
178/*
179 * pm_disconnect() is the opposite of pm_connect()
180 */
181
182static void pm_disconnect(struct serio *serio)
183{
184	struct pm *pm = serio_get_drvdata(serio);
185
186	serio_close(serio);
187
188	input_unregister_device(pm->dev);
189	kfree(pm);
190
191	serio_set_drvdata(serio, NULL);
192}
193
194/*
195 * pm_connect() is the routine that is called when someone adds a
196 * new serio device that supports PenMount protocol and registers it as
197 * an input device.
198 */
199
200static int pm_connect(struct serio *serio, struct serio_driver *drv)
201{
202	struct pm *pm;
203	struct input_dev *input_dev;
204	int max_x, max_y;
205	int err;
206
207	pm = kzalloc(sizeof(struct pm), GFP_KERNEL);
208	input_dev = input_allocate_device();
209	if (!pm || !input_dev) {
210		err = -ENOMEM;
211		goto fail1;
212	}
213
214	pm->serio = serio;
215	pm->dev = input_dev;
216	snprintf(pm->phys, sizeof(pm->phys), "%s/input0", serio->phys);
217	pm->maxcontacts = 1;
218
219	input_dev->name = "PenMount Serial TouchScreen";
220	input_dev->phys = pm->phys;
221	input_dev->id.bustype = BUS_RS232;
222	input_dev->id.vendor = SERIO_PENMOUNT;
223	input_dev->id.product = 0;
224	input_dev->id.version = 0x0100;
225	input_dev->dev.parent = &serio->dev;
226
227	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
228	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
229
230	switch (serio->id.id) {
231	default:
232	case 0:
233		pm->packetsize = 5;
234		pm->parse_packet = pm_parse_9000;
235		input_dev->id.product = 0x9000;
236		max_x = max_y = 0x3ff;
237		break;
238
239	case 1:
240		pm->packetsize = 6;
241		pm->parse_packet = pm_parse_6000;
242		input_dev->id.product = 0x6000;
243		max_x = max_y = 0x3ff;
244		break;
245
246	case 2:
247		pm->packetsize = 6;
248		pm->parse_packet = pm_parse_3000;
249		input_dev->id.product = 0x3000;
250		max_x = max_y = 0x7ff;
251		pm->maxcontacts = PM_3000_MTSLOT;
252		break;
253
254	case 3:
255		pm->packetsize = 6;
256		pm->parse_packet = pm_parse_6250;
257		input_dev->id.product = 0x6250;
258		max_x = max_y = 0x3ff;
259		pm->maxcontacts = PM_6250_MTSLOT;
260		break;
261	}
262
263	input_set_abs_params(pm->dev, ABS_X, 0, max_x, 0, 0);
264	input_set_abs_params(pm->dev, ABS_Y, 0, max_y, 0, 0);
265
266	if (pm->maxcontacts > 1) {
267		input_mt_init_slots(pm->dev, pm->maxcontacts);
268		input_set_abs_params(pm->dev,
269				     ABS_MT_POSITION_X, 0, max_x, 0, 0);
270		input_set_abs_params(pm->dev,
271				     ABS_MT_POSITION_Y, 0, max_y, 0, 0);
272	}
273
274	serio_set_drvdata(serio, pm);
275
276	err = serio_open(serio, drv);
277	if (err)
278		goto fail2;
279
280	err = input_register_device(pm->dev);
281	if (err)
282		goto fail3;
283
284	return 0;
285
286 fail3:	serio_close(serio);
287 fail2:	serio_set_drvdata(serio, NULL);
288 fail1:	input_free_device(input_dev);
289	kfree(pm);
290	return err;
291}
292
293/*
294 * The serio driver structure.
295 */
296
297static struct serio_device_id pm_serio_ids[] = {
298	{
299		.type	= SERIO_RS232,
300		.proto	= SERIO_PENMOUNT,
301		.id	= SERIO_ANY,
302		.extra	= SERIO_ANY,
303	},
304	{ 0 }
305};
306
307MODULE_DEVICE_TABLE(serio, pm_serio_ids);
308
309static struct serio_driver pm_drv = {
310	.driver		= {
311		.name	= "serio-penmount",
312	},
313	.description	= DRIVER_DESC,
314	.id_table	= pm_serio_ids,
315	.interrupt	= pm_interrupt,
316	.connect	= pm_connect,
317	.disconnect	= pm_disconnect,
318};
319
320/*
321 * The functions for inserting/removing us as a module.
322 */
323
324static int __init pm_init(void)
325{
326	return serio_register_driver(&pm_drv);
327}
328
329static void __exit pm_exit(void)
330{
331	serio_unregister_driver(&pm_drv);
332}
333
334module_init(pm_init);
335module_exit(pm_exit);
336