xref: /linux/drivers/input/touchscreen/penmount.c (revision 44f57d78) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Penmount serial touchscreen driver
4  *
5  * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
6  * Copyright (c) 2011 John Sung <penmount.touch@gmail.com>
7  *
8  * Based on ELO driver (drivers/input/touchscreen/elo.c)
9  * Copyright (c) 2004 Vojtech Pavlik
10  */
11 
12 
13 #include <linux/errno.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/input.h>
18 #include <linux/input/mt.h>
19 #include <linux/serio.h>
20 
21 #define DRIVER_DESC	"PenMount serial touchscreen driver"
22 
23 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
24 MODULE_AUTHOR("John Sung <penmount.touch@gmail.com>");
25 MODULE_DESCRIPTION(DRIVER_DESC);
26 MODULE_LICENSE("GPL");
27 
28 /*
29  * Definitions & global arrays.
30  */
31 
32 #define	PM_MAX_LENGTH	6
33 #define	PM_MAX_MTSLOT	16
34 #define	PM_3000_MTSLOT	2
35 #define	PM_6250_MTSLOT	12
36 
37 /*
38  * Multi-touch slot
39  */
40 
41 struct mt_slot {
42 	unsigned short x, y;
43 	bool active; /* is the touch valid? */
44 };
45 
46 /*
47  * Per-touchscreen data.
48  */
49 
50 struct pm {
51 	struct input_dev *dev;
52 	struct serio *serio;
53 	int idx;
54 	unsigned char data[PM_MAX_LENGTH];
55 	char phys[32];
56 	unsigned char packetsize;
57 	unsigned char maxcontacts;
58 	struct mt_slot slots[PM_MAX_MTSLOT];
59 	void (*parse_packet)(struct pm *);
60 };
61 
62 /*
63  * pm_mtevent() sends mt events and also emulates pointer movement
64  */
65 
66 static void pm_mtevent(struct pm *pm, struct input_dev *input)
67 {
68 	int i;
69 
70 	for (i = 0; i < pm->maxcontacts; ++i) {
71 		input_mt_slot(input, i);
72 		input_mt_report_slot_state(input, MT_TOOL_FINGER,
73 				pm->slots[i].active);
74 		if (pm->slots[i].active) {
75 			input_event(input, EV_ABS, ABS_MT_POSITION_X, pm->slots[i].x);
76 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, pm->slots[i].y);
77 		}
78 	}
79 
80 	input_mt_report_pointer_emulation(input, true);
81 	input_sync(input);
82 }
83 
84 /*
85  * pm_checkpacket() checks if data packet is valid
86  */
87 
88 static bool pm_checkpacket(unsigned char *packet)
89 {
90 	int total = 0;
91 	int i;
92 
93 	for (i = 0; i < 5; i++)
94 		total += packet[i];
95 
96 	return packet[5] == (unsigned char)~(total & 0xff);
97 }
98 
99 static void pm_parse_9000(struct pm *pm)
100 {
101 	struct input_dev *dev = pm->dev;
102 
103 	if ((pm->data[0] & 0x80) && pm->packetsize == ++pm->idx) {
104 		input_report_abs(dev, ABS_X, pm->data[1] * 128 + pm->data[2]);
105 		input_report_abs(dev, ABS_Y, pm->data[3] * 128 + pm->data[4]);
106 		input_report_key(dev, BTN_TOUCH, !!(pm->data[0] & 0x40));
107 		input_sync(dev);
108 		pm->idx = 0;
109 	}
110 }
111 
112 static void pm_parse_6000(struct pm *pm)
113 {
114 	struct input_dev *dev = pm->dev;
115 
116 	if ((pm->data[0] & 0xbf) == 0x30 && pm->packetsize == ++pm->idx) {
117 		if (pm_checkpacket(pm->data)) {
118 			input_report_abs(dev, ABS_X,
119 					pm->data[2] * 256 + pm->data[1]);
120 			input_report_abs(dev, ABS_Y,
121 					pm->data[4] * 256 + pm->data[3]);
122 			input_report_key(dev, BTN_TOUCH, pm->data[0] & 0x40);
123 			input_sync(dev);
124 		}
125 		pm->idx = 0;
126 	}
127 }
128 
129 static void pm_parse_3000(struct pm *pm)
130 {
131 	struct input_dev *dev = pm->dev;
132 
133 	if ((pm->data[0] & 0xce) == 0x40 && pm->packetsize == ++pm->idx) {
134 		if (pm_checkpacket(pm->data)) {
135 			int slotnum = pm->data[0] & 0x0f;
136 			pm->slots[slotnum].active = pm->data[0] & 0x30;
137 			pm->slots[slotnum].x = pm->data[2] * 256 + pm->data[1];
138 			pm->slots[slotnum].y = pm->data[4] * 256 + pm->data[3];
139 			pm_mtevent(pm, dev);
140 		}
141 		pm->idx = 0;
142 	}
143 }
144 
145 static void pm_parse_6250(struct pm *pm)
146 {
147 	struct input_dev *dev = pm->dev;
148 
149 	if ((pm->data[0] & 0xb0) == 0x30 && pm->packetsize == ++pm->idx) {
150 		if (pm_checkpacket(pm->data)) {
151 			int slotnum = pm->data[0] & 0x0f;
152 			pm->slots[slotnum].active = pm->data[0] & 0x40;
153 			pm->slots[slotnum].x = pm->data[2] * 256 + pm->data[1];
154 			pm->slots[slotnum].y = pm->data[4] * 256 + pm->data[3];
155 			pm_mtevent(pm, dev);
156 		}
157 		pm->idx = 0;
158 	}
159 }
160 
161 static irqreturn_t pm_interrupt(struct serio *serio,
162 		unsigned char data, unsigned int flags)
163 {
164 	struct pm *pm = serio_get_drvdata(serio);
165 
166 	pm->data[pm->idx] = data;
167 
168 	pm->parse_packet(pm);
169 
170 	return IRQ_HANDLED;
171 }
172 
173 /*
174  * pm_disconnect() is the opposite of pm_connect()
175  */
176 
177 static void pm_disconnect(struct serio *serio)
178 {
179 	struct pm *pm = serio_get_drvdata(serio);
180 
181 	serio_close(serio);
182 
183 	input_unregister_device(pm->dev);
184 	kfree(pm);
185 
186 	serio_set_drvdata(serio, NULL);
187 }
188 
189 /*
190  * pm_connect() is the routine that is called when someone adds a
191  * new serio device that supports PenMount protocol and registers it as
192  * an input device.
193  */
194 
195 static int pm_connect(struct serio *serio, struct serio_driver *drv)
196 {
197 	struct pm *pm;
198 	struct input_dev *input_dev;
199 	int max_x, max_y;
200 	int err;
201 
202 	pm = kzalloc(sizeof(struct pm), GFP_KERNEL);
203 	input_dev = input_allocate_device();
204 	if (!pm || !input_dev) {
205 		err = -ENOMEM;
206 		goto fail1;
207 	}
208 
209 	pm->serio = serio;
210 	pm->dev = input_dev;
211 	snprintf(pm->phys, sizeof(pm->phys), "%s/input0", serio->phys);
212 	pm->maxcontacts = 1;
213 
214 	input_dev->name = "PenMount Serial TouchScreen";
215 	input_dev->phys = pm->phys;
216 	input_dev->id.bustype = BUS_RS232;
217 	input_dev->id.vendor = SERIO_PENMOUNT;
218 	input_dev->id.product = 0;
219 	input_dev->id.version = 0x0100;
220 	input_dev->dev.parent = &serio->dev;
221 
222 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
223 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
224 
225 	switch (serio->id.id) {
226 	default:
227 	case 0:
228 		pm->packetsize = 5;
229 		pm->parse_packet = pm_parse_9000;
230 		input_dev->id.product = 0x9000;
231 		max_x = max_y = 0x3ff;
232 		break;
233 
234 	case 1:
235 		pm->packetsize = 6;
236 		pm->parse_packet = pm_parse_6000;
237 		input_dev->id.product = 0x6000;
238 		max_x = max_y = 0x3ff;
239 		break;
240 
241 	case 2:
242 		pm->packetsize = 6;
243 		pm->parse_packet = pm_parse_3000;
244 		input_dev->id.product = 0x3000;
245 		max_x = max_y = 0x7ff;
246 		pm->maxcontacts = PM_3000_MTSLOT;
247 		break;
248 
249 	case 3:
250 		pm->packetsize = 6;
251 		pm->parse_packet = pm_parse_6250;
252 		input_dev->id.product = 0x6250;
253 		max_x = max_y = 0x3ff;
254 		pm->maxcontacts = PM_6250_MTSLOT;
255 		break;
256 	}
257 
258 	input_set_abs_params(pm->dev, ABS_X, 0, max_x, 0, 0);
259 	input_set_abs_params(pm->dev, ABS_Y, 0, max_y, 0, 0);
260 
261 	if (pm->maxcontacts > 1) {
262 		input_mt_init_slots(pm->dev, pm->maxcontacts, 0);
263 		input_set_abs_params(pm->dev,
264 				     ABS_MT_POSITION_X, 0, max_x, 0, 0);
265 		input_set_abs_params(pm->dev,
266 				     ABS_MT_POSITION_Y, 0, max_y, 0, 0);
267 	}
268 
269 	serio_set_drvdata(serio, pm);
270 
271 	err = serio_open(serio, drv);
272 	if (err)
273 		goto fail2;
274 
275 	err = input_register_device(pm->dev);
276 	if (err)
277 		goto fail3;
278 
279 	return 0;
280 
281  fail3:	serio_close(serio);
282  fail2:	serio_set_drvdata(serio, NULL);
283  fail1:	input_free_device(input_dev);
284 	kfree(pm);
285 	return err;
286 }
287 
288 /*
289  * The serio driver structure.
290  */
291 
292 static const struct serio_device_id pm_serio_ids[] = {
293 	{
294 		.type	= SERIO_RS232,
295 		.proto	= SERIO_PENMOUNT,
296 		.id	= SERIO_ANY,
297 		.extra	= SERIO_ANY,
298 	},
299 	{ 0 }
300 };
301 
302 MODULE_DEVICE_TABLE(serio, pm_serio_ids);
303 
304 static struct serio_driver pm_drv = {
305 	.driver		= {
306 		.name	= "serio-penmount",
307 	},
308 	.description	= DRIVER_DESC,
309 	.id_table	= pm_serio_ids,
310 	.interrupt	= pm_interrupt,
311 	.connect	= pm_connect,
312 	.disconnect	= pm_disconnect,
313 };
314 
315 module_serio_driver(pm_drv);
316