1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Touchright serial touchscreen driver
4 *
5 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
6 *
7 * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
8 * Copyright (c) 2004 Vojtech Pavlik
9 * and Dan Streetman <ddstreet@ieee.org>
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/serio.h>
19
20#define DRIVER_DESC "Touchright serial touchscreen driver"
21
22MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
23MODULE_DESCRIPTION(DRIVER_DESC);
24MODULE_LICENSE("GPL");
25
26/*
27 * Definitions & global arrays.
28 */
29
30#define TR_FORMAT_TOUCH_BIT 0x01
31#define TR_FORMAT_STATUS_BYTE 0x40
32#define TR_FORMAT_STATUS_MASK ~TR_FORMAT_TOUCH_BIT
33
34#define TR_LENGTH 5
35
36#define TR_MIN_XC 0
37#define TR_MAX_XC 0x1ff
38#define TR_MIN_YC 0
39#define TR_MAX_YC 0x1ff
40
41/*
42 * Per-touchscreen data.
43 */
44
45struct tr {
46 struct input_dev *dev;
47 struct serio *serio;
48 int idx;
49 unsigned char data[TR_LENGTH];
50 char phys[32];
51};
52
53static irqreturn_t tr_interrupt(struct serio *serio,
54 unsigned char data, unsigned int flags)
55{
56 struct tr *tr = serio_get_drvdata(serio);
57 struct input_dev *dev = tr->dev;
58
59 tr->data[tr->idx] = data;
60
61 if ((tr->data[0] & TR_FORMAT_STATUS_MASK) == TR_FORMAT_STATUS_BYTE) {
62 if (++tr->idx == TR_LENGTH) {
63 input_report_abs(dev, ABS_X,
64 value: (tr->data[1] << 5) | (tr->data[2] >> 1));
65 input_report_abs(dev, ABS_Y,
66 value: (tr->data[3] << 5) | (tr->data[4] >> 1));
67 input_report_key(dev, BTN_TOUCH,
68 value: tr->data[0] & TR_FORMAT_TOUCH_BIT);
69 input_sync(dev);
70 tr->idx = 0;
71 }
72 }
73
74 return IRQ_HANDLED;
75}
76
77/*
78 * tr_disconnect() is the opposite of tr_connect()
79 */
80
81static void tr_disconnect(struct serio *serio)
82{
83 struct tr *tr = serio_get_drvdata(serio);
84
85 input_get_device(dev: tr->dev);
86 input_unregister_device(tr->dev);
87 serio_close(serio);
88 serio_set_drvdata(serio, NULL);
89 input_put_device(dev: tr->dev);
90 kfree(objp: tr);
91}
92
93/*
94 * tr_connect() is the routine that is called when someone adds a
95 * new serio device that supports the Touchright protocol and registers it as
96 * an input device.
97 */
98
99static int tr_connect(struct serio *serio, struct serio_driver *drv)
100{
101 struct tr *tr;
102 struct input_dev *input_dev;
103 int err;
104
105 tr = kzalloc(size: sizeof(struct tr), GFP_KERNEL);
106 input_dev = input_allocate_device();
107 if (!tr || !input_dev) {
108 err = -ENOMEM;
109 goto fail1;
110 }
111
112 tr->serio = serio;
113 tr->dev = input_dev;
114 snprintf(buf: tr->phys, size: sizeof(tr->phys), fmt: "%s/input0", serio->phys);
115
116 input_dev->name = "Touchright Serial TouchScreen";
117 input_dev->phys = tr->phys;
118 input_dev->id.bustype = BUS_RS232;
119 input_dev->id.vendor = SERIO_TOUCHRIGHT;
120 input_dev->id.product = 0;
121 input_dev->id.version = 0x0100;
122 input_dev->dev.parent = &serio->dev;
123 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
124 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
125 input_set_abs_params(dev: tr->dev, ABS_X, TR_MIN_XC, TR_MAX_XC, fuzz: 0, flat: 0);
126 input_set_abs_params(dev: tr->dev, ABS_Y, TR_MIN_YC, TR_MAX_YC, fuzz: 0, flat: 0);
127
128 serio_set_drvdata(serio, data: tr);
129
130 err = serio_open(serio, drv);
131 if (err)
132 goto fail2;
133
134 err = input_register_device(tr->dev);
135 if (err)
136 goto fail3;
137
138 return 0;
139
140 fail3: serio_close(serio);
141 fail2: serio_set_drvdata(serio, NULL);
142 fail1: input_free_device(dev: input_dev);
143 kfree(objp: tr);
144 return err;
145}
146
147/*
148 * The serio driver structure.
149 */
150
151static const struct serio_device_id tr_serio_ids[] = {
152 {
153 .type = SERIO_RS232,
154 .proto = SERIO_TOUCHRIGHT,
155 .id = SERIO_ANY,
156 .extra = SERIO_ANY,
157 },
158 { 0 }
159};
160
161MODULE_DEVICE_TABLE(serio, tr_serio_ids);
162
163static struct serio_driver tr_drv = {
164 .driver = {
165 .name = "touchright",
166 },
167 .description = DRIVER_DESC,
168 .id_table = tr_serio_ids,
169 .interrupt = tr_interrupt,
170 .connect = tr_connect,
171 .disconnect = tr_disconnect,
172};
173
174module_serio_driver(tr_drv);
175

source code of linux/drivers/input/touchscreen/touchright.c