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
23MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
24MODULE_AUTHOR("John Sung <penmount.touch@gmail.com>");
25MODULE_DESCRIPTION(DRIVER_DESC);
26MODULE_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
41struct mt_slot {
42	unsigned short x, y;
43	bool active; /* is the touch valid? */
44};
45
46/*
47 * Per-touchscreen data.
48 */
49
50struct 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
66static 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
88static 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
99static 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
112static 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
129static 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
145static 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
161static 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
177static 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
195static 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
292static 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
302MODULE_DEVICE_TABLE(serio, pm_serio_ids);
303
304static 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
315module_serio_driver(pm_drv);
316