summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/hampshire.c
blob: 2da6cc31bb2187f0b62770bd09aa6c0923c36687 (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
/*
 * Hampshire serial touchscreen driver
 *
 * Copyright (c) 2010 Adam Bennett
 * Based on the dynapro driver (c) Tias Guns
 *
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

/*
 * 2010/04/08 Adam Bennett <abennett72@gmail.com>
 *   Copied dynapro.c and edited for Hampshire 4-byte protocol
 */

#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>

#define DRIVER_DESC	"Hampshire serial touchscreen driver"

MODULE_AUTHOR("Adam Bennett <abennett72@gmail.com>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Definitions & global arrays.
 */

#define HAMPSHIRE_FORMAT_TOUCH_BIT 0x40
#define HAMPSHIRE_FORMAT_LENGTH 4
#define HAMPSHIRE_RESPONSE_BEGIN_BYTE 0x80

#define HAMPSHIRE_MIN_XC 0
#define HAMPSHIRE_MAX_XC 0x1000
#define HAMPSHIRE_MIN_YC 0
#define HAMPSHIRE_MAX_YC 0x1000

#define HAMPSHIRE_GET_XC(data) (((data[3] & 0x0c) >> 2) | (data[1] << 2) | ((data[0] & 0x38) << 6))
#define HAMPSHIRE_GET_YC(data) ((data[3] & 0x03) | (data[2] << 2) | ((data[0] & 0x07) << 9))
#define HAMPSHIRE_GET_TOUCHED(data) (HAMPSHIRE_FORMAT_TOUCH_BIT & data[0])

/*
 * Per-touchscreen data.
 */

struct hampshire {
	struct input_dev *dev;
	struct serio *serio;
	int idx;
	unsigned char data[HAMPSHIRE_FORMAT_LENGTH];
	char phys[32];
};

static void hampshire_process_data(struct hampshire *phampshire)
{
	struct input_dev *dev = phampshire->dev;

	if (HAMPSHIRE_FORMAT_LENGTH == ++phampshire->idx) {
		input_report_abs(dev, ABS_X, HAMPSHIRE_GET_XC(phampshire->data));
		input_report_abs(dev, ABS_Y, HAMPSHIRE_GET_YC(phampshire->data));
		input_report_key(dev, BTN_TOUCH,
				 HAMPSHIRE_GET_TOUCHED(phampshire->data));
		input_sync(dev);

		phampshire->idx = 0;
	}
}

static irqreturn_t hampshire_interrupt(struct serio *serio,
		unsigned char data, unsigned int flags)
{
	struct hampshire *phampshire = serio_get_drvdata(serio);

	phampshire->data[phampshire->idx] = data;

	if (HAMPSHIRE_RESPONSE_BEGIN_BYTE & phampshire->data[0])
		hampshire_process_data(phampshire);
	else
		dev_dbg(&serio->dev, "unknown/unsynchronized data: %x\n",
			phampshire->data[0]);

	return IRQ_HANDLED;
}

static void hampshire_disconnect(struct serio *serio)
{
	struct hampshire *phampshire = serio_get_drvdata(serio);

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

/*
 * hampshire_connect() is the routine that is called when someone adds a
 * new serio device that supports hampshire protocol and registers it as
 * an input device. This is usually accomplished using inputattach.
 */

static int hampshire_connect(struct serio *serio, struct serio_driver *drv)
{
	struct hampshire *phampshire;
	struct input_dev *input_dev;
	int err;

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

	phampshire->serio = serio;
	phampshire->dev = input_dev;
	snprintf(phampshire->phys, sizeof(phampshire->phys),
		 "%s/input0", serio->phys);

	input_dev->name = "Hampshire Serial TouchScreen";
	input_dev->phys = phampshire->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_HAMPSHIRE;
	input_dev->id.product = 0;
	input_dev->id.version = 0x0001;
	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);
	input_set_abs_params(phampshire->dev, ABS_X,
			     HAMPSHIRE_MIN_XC, HAMPSHIRE_MAX_XC, 0, 0);
	input_set_abs_params(phampshire->dev, ABS_Y,
			     HAMPSHIRE_MIN_YC, HAMPSHIRE_MAX_YC, 0, 0);

	serio_set_drvdata(serio, phampshire);

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

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

	return 0;

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

/*
 * The serio driver structure.
 */

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

MODULE_DEVICE_TABLE(serio, hampshire_serio_ids);

static struct serio_driver hampshire_drv = {
	.driver		= {
		.name	= "hampshire",
	},
	.description	= DRIVER_DESC,
	.id_table	= hampshire_serio_ids,
	.interrupt	= hampshire_interrupt,
	.connect	= hampshire_connect,
	.disconnect	= hampshire_disconnect,
};

/*
 * The functions for inserting/removing us as a module.
 */

static int __init hampshire_init(void)
{
	return serio_register_driver(&hampshire_drv);
}

static void __exit hampshire_exit(void)
{
	serio_unregister_driver(&hampshire_drv);
}

module_init(hampshire_init);
module_exit(hampshire_exit);