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