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				(tr->data[1] << 5) | (tr->data[2] >> 1));
65			input_report_abs(dev, ABS_Y,
66				(tr->data[3] << 5) | (tr->data[4] >> 1));
67			input_report_key(dev, BTN_TOUCH,
68				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(tr->dev);
86	input_unregister_device(tr->dev);
87	serio_close(serio);
88	serio_set_drvdata(serio, NULL);
89	input_put_device(tr->dev);
90	kfree(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(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(tr->phys, sizeof(tr->phys), "%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(tr->dev, ABS_X, TR_MIN_XC, TR_MAX_XC, 0, 0);
126	input_set_abs_params(tr->dev, ABS_Y, TR_MIN_YC, TR_MAX_YC, 0, 0);
127
128	serio_set_drvdata(serio, 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(input_dev);
143	kfree(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