summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/wacom_w8001.c
blob: 56dc35c94bb12eb00102a0110044945574edbcf6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
/*
 * Wacom W8001 penabled serial touchscreen driver
 *
 * Copyright (c) 2008 Jaya Kumar
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file COPYING in the main directory of this archive for
 * more details.
 *
 * Layout based on Elo serial touchscreen driver by Vojtech Pavlik
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/init.h>
#include <linux/ctype.h>

#define DRIVER_DESC	"Wacom W8001 serial touchscreen driver"

MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

#define W8001_MAX_LENGTH	11
#define W8001_LEAD_MASK		0x80
#define W8001_LEAD_BYTE		0x80
#define W8001_TAB_MASK		0x40
#define W8001_TAB_BYTE		0x40

#define W8001_QUERY_PACKET	0x20

#define W8001_CMD_START		'1'
#define W8001_CMD_QUERY		'*'

struct w8001_coord {
	u8 rdy;
	u8 tsw;
	u8 f1;
	u8 f2;
	u16 x;
	u16 y;
	u16 pen_pressure;
	u8 tilt_x;
	u8 tilt_y;
};

/*
 * Per-touchscreen data.
 */

struct w8001 {
	struct input_dev *dev;
	struct serio *serio;
	struct completion cmd_done;
	int id;
	int idx;
	unsigned char response_type;
	unsigned char response[W8001_MAX_LENGTH];
	unsigned char data[W8001_MAX_LENGTH];
	char phys[32];
};

static void parse_data(u8 *data, struct w8001_coord *coord)
{
	memset(coord, 0, sizeof(*coord));

	coord->rdy = data[0] & 0x20;
	coord->tsw = data[0] & 0x01;
	coord->f1 = data[0] & 0x02;
	coord->f2 = data[0] & 0x04;

	coord->x = (data[1] & 0x7F) << 9;
	coord->x |= (data[2] & 0x7F) << 2;
	coord->x |= (data[6] & 0x60) >> 5;

	coord->y = (data[3] & 0x7F) << 9;
	coord->y |= (data[4] & 0x7F) << 2;
	coord->y |= (data[6] & 0x18) >> 3;

	coord->pen_pressure = data[5] & 0x7F;
	coord->pen_pressure |= (data[6] & 0x07) << 7 ;

	coord->tilt_x = data[7] & 0x7F;
	coord->tilt_y = data[8] & 0x7F;
}

static irqreturn_t w8001_interrupt(struct serio *serio,
				   unsigned char data, unsigned int flags)
{
	struct w8001 *w8001 = serio_get_drvdata(serio);
	struct input_dev *dev = w8001->dev;
	struct w8001_coord coord;
	unsigned char tmp;

	w8001->data[w8001->idx] = data;
	switch (w8001->idx++) {
	case 0:
		if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
			pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
			w8001->idx = 0;
		}
		break;

	case 8:
		tmp = w8001->data[0] & W8001_TAB_MASK;
		if (unlikely(tmp == W8001_TAB_BYTE))
			break;

		w8001->idx = 0;
		parse_data(w8001->data, &coord);
		input_report_abs(dev, ABS_X, coord.x);
		input_report_abs(dev, ABS_Y, coord.y);
		input_report_abs(dev, ABS_PRESSURE, coord.pen_pressure);
		input_report_key(dev, BTN_TOUCH, coord.tsw);
		input_sync(dev);
		break;

	case 10:
		w8001->idx = 0;
		memcpy(w8001->response, w8001->data, W8001_MAX_LENGTH);
		w8001->response_type = W8001_QUERY_PACKET;
		complete(&w8001->cmd_done);
		break;
	}

	return IRQ_HANDLED;
}

static int w8001_command(struct w8001 *w8001, unsigned char command,
			 bool wait_response)
{
	int rc;

	w8001->response_type = 0;
	init_completion(&w8001->cmd_done);

	rc = serio_write(w8001->serio, command);
	if (rc == 0 && wait_response) {

		wait_for_completion_timeout(&w8001->cmd_done, HZ);
		if (w8001->response_type != W8001_QUERY_PACKET)
			rc = -EIO;
	}

	return rc;
}

static int w8001_setup(struct w8001 *w8001)
{
	struct input_dev *dev = w8001->dev;
	struct w8001_coord coord;
	int error;

	error = w8001_command(w8001, W8001_CMD_QUERY, true);
	if (error)
		return error;

	parse_data(w8001->response, &coord);

	input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
	input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
	input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
	input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
	input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);

	return w8001_command(w8001, W8001_CMD_START, false);
}

/*
 * w8001_disconnect() is the opposite of w8001_connect()
 */

static void w8001_disconnect(struct serio *serio)
{
	struct w8001 *w8001 = serio_get_drvdata(serio);

	input_get_device(w8001->dev);
	input_unregister_device(w8001->dev);
	serio_close(serio);
	serio_set_drvdata(serio, NULL);
	input_put_device(w8001->dev);
	kfree(w8001);
}

/*
 * w8001_connect() is the routine that is called when someone adds a
 * new serio device that supports the w8001 protocol and registers it as
 * an input device.
 */

static int w8001_connect(struct serio *serio, struct serio_driver *drv)
{
	struct w8001 *w8001;
	struct input_dev *input_dev;
	int err;

	w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!w8001 || !input_dev) {
		err = -ENOMEM;
		goto fail1;
	}

	w8001->serio = serio;
	w8001->id = serio->id.id;
	w8001->dev = input_dev;
	init_completion(&w8001->cmd_done);
	snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);

	input_dev->name = "Wacom W8001 Penabled Serial TouchScreen";
	input_dev->phys = w8001->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_W8001;
	input_dev->id.product = w8001->id;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &serio->dev;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	serio_set_drvdata(serio, w8001);
	err = serio_open(serio, drv);
	if (err)
		goto fail2;

	err = w8001_setup(w8001);
	if (err)
		goto fail3;

	err = input_register_device(w8001->dev);
	if (err)
		goto fail3;

	return 0;

fail3:
	serio_close(serio);
fail2:
	serio_set_drvdata(serio, NULL);
fail1:
	input_free_device(input_dev);
	kfree(w8001);
	return err;
}

static struct serio_device_id w8001_serio_ids[] = {
	{
		.type	= SERIO_RS232,
		.proto	= SERIO_W8001,
		.id	= SERIO_ANY,
		.extra	= SERIO_ANY,
	},
	{ 0 }
};

MODULE_DEVICE_TABLE(serio, w8001_serio_ids);

static struct serio_driver w8001_drv = {
	.driver		= {
		.name	= "w8001",
	},
	.description	= DRIVER_DESC,
	.id_table	= w8001_serio_ids,
	.interrupt	= w8001_interrupt,
	.connect	= w8001_connect,
	.disconnect	= w8001_disconnect,
};

static int __init w8001_init(void)
{
	return serio_register_driver(&w8001_drv);
}

static void __exit w8001_exit(void)
{
	serio_unregister_driver(&w8001_drv);
}

module_init(w8001_init);
module_exit(w8001_exit);
OpenPOWER on IntegriCloud