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 
27 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
28 MODULE_AUTHOR("John Sung <penmount.touch@gmail.com>");
29 MODULE_DESCRIPTION(DRIVER_DESC);
30 MODULE_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 
45 struct mt_slot {
46 	unsigned short x, y;
47 	bool active; /* is the touch valid? */
48 };
49 
50 /*
51  * Per-touchscreen data.
52  */
53 
54 struct 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 
70 static 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 
92 static 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 
103 static 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 
116 static 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 
133 static 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 
149 static 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 
165 static 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 
181 static 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 
199 static 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 
296 static 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 
306 MODULE_DEVICE_TABLE(serio, pm_serio_ids);
307 
308 static 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 
319 module_serio_driver(pm_drv);
320