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 
28 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
29 MODULE_AUTHOR("John Sung <penmount.touch@gmail.com>");
30 MODULE_DESCRIPTION(DRIVER_DESC);
31 MODULE_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 
46 struct mt_slot {
47 	unsigned short x, y;
48 	bool active; /* is the touch valid? */
49 };
50 
51 /*
52  * Per-touchscreen data.
53  */
54 
55 struct 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 
71 static 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 
93 static 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 
104 static 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 
117 static 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 
134 static 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 
150 static 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 
166 static 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 
182 static 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 
200 static 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 
297 static 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 
307 MODULE_DEVICE_TABLE(serio, pm_serio_ids);
308 
309 static 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 
324 static int __init pm_init(void)
325 {
326 	return serio_register_driver(&pm_drv);
327 }
328 
329 static void __exit pm_exit(void)
330 {
331 	serio_unregister_driver(&pm_drv);
332 }
333 
334 module_init(pm_init);
335 module_exit(pm_exit);
336