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
pm_mtevent(struct pm * pm,struct input_dev * input)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
pm_checkpacket(unsigned char * packet)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
pm_parse_9000(struct pm * pm)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
pm_parse_6000(struct pm * pm)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
pm_parse_3000(struct pm * pm)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
pm_parse_6250(struct pm * pm)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
pm_interrupt(struct serio * serio,unsigned char data,unsigned int flags)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
pm_disconnect(struct serio * serio)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
pm_connect(struct serio * serio,struct serio_driver * drv)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(*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