1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Copyright (c) 2000-2001 Vojtech Pavlik
4 */
5
6/*
7 * Gunze AHL-51S touchscreen driver for Linux
8 */
9
10#include <linux/errno.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/input.h>
15#include <linux/serio.h>
16
17#define DRIVER_DESC	"Gunze AHL-51S touchscreen driver"
18
19MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
20MODULE_DESCRIPTION(DRIVER_DESC);
21MODULE_LICENSE("GPL");
22
23/*
24 * Definitions & global arrays.
25 */
26
27#define	GUNZE_MAX_LENGTH	10
28
29/*
30 * Per-touchscreen data.
31 */
32
33struct gunze {
34	struct input_dev *dev;
35	struct serio *serio;
36	int idx;
37	unsigned char data[GUNZE_MAX_LENGTH];
38	char phys[32];
39};
40
41static void gunze_process_packet(struct gunze *gunze)
42{
43	struct input_dev *dev = gunze->dev;
44
45	if (gunze->idx != GUNZE_MAX_LENGTH || gunze->data[5] != ',' ||
46		(gunze->data[0] != 'T' && gunze->data[0] != 'R')) {
47		printk(KERN_WARNING "gunze.c: bad packet: >%.*s<\n", GUNZE_MAX_LENGTH, gunze->data);
48		return;
49	}
50
51	input_report_abs(dev, ABS_X, simple_strtoul(gunze->data + 1, NULL, 10));
52	input_report_abs(dev, ABS_Y, 1024 - simple_strtoul(gunze->data + 6, NULL, 10));
53	input_report_key(dev, BTN_TOUCH, gunze->data[0] == 'T');
54	input_sync(dev);
55}
56
57static irqreturn_t gunze_interrupt(struct serio *serio,
58		unsigned char data, unsigned int flags)
59{
60	struct gunze *gunze = serio_get_drvdata(serio);
61
62	if (data == '\r') {
63		gunze_process_packet(gunze);
64		gunze->idx = 0;
65	} else {
66		if (gunze->idx < GUNZE_MAX_LENGTH)
67			gunze->data[gunze->idx++] = data;
68	}
69	return IRQ_HANDLED;
70}
71
72/*
73 * gunze_disconnect() is the opposite of gunze_connect()
74 */
75
76static void gunze_disconnect(struct serio *serio)
77{
78	struct gunze *gunze = serio_get_drvdata(serio);
79
80	input_get_device(gunze->dev);
81	input_unregister_device(gunze->dev);
82	serio_close(serio);
83	serio_set_drvdata(serio, NULL);
84	input_put_device(gunze->dev);
85	kfree(gunze);
86}
87
88/*
89 * gunze_connect() is the routine that is called when someone adds a
90 * new serio device that supports Gunze protocol and registers it as
91 * an input device.
92 */
93
94static int gunze_connect(struct serio *serio, struct serio_driver *drv)
95{
96	struct gunze *gunze;
97	struct input_dev *input_dev;
98	int err;
99
100	gunze = kzalloc(sizeof(struct gunze), GFP_KERNEL);
101	input_dev = input_allocate_device();
102	if (!gunze || !input_dev) {
103		err = -ENOMEM;
104		goto fail1;
105	}
106
107	gunze->serio = serio;
108	gunze->dev = input_dev;
109	snprintf(gunze->phys, sizeof(serio->phys), "%s/input0", serio->phys);
110
111	input_dev->name = "Gunze AHL-51S TouchScreen";
112	input_dev->phys = gunze->phys;
113	input_dev->id.bustype = BUS_RS232;
114	input_dev->id.vendor = SERIO_GUNZE;
115	input_dev->id.product = 0x0051;
116	input_dev->id.version = 0x0100;
117	input_dev->dev.parent = &serio->dev;
118	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
119	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
120	input_set_abs_params(input_dev, ABS_X, 24, 1000, 0, 0);
121	input_set_abs_params(input_dev, ABS_Y, 24, 1000, 0, 0);
122
123	serio_set_drvdata(serio, gunze);
124
125	err = serio_open(serio, drv);
126	if (err)
127		goto fail2;
128
129	err = input_register_device(gunze->dev);
130	if (err)
131		goto fail3;
132
133	return 0;
134
135 fail3:	serio_close(serio);
136 fail2:	serio_set_drvdata(serio, NULL);
137 fail1:	input_free_device(input_dev);
138	kfree(gunze);
139	return err;
140}
141
142/*
143 * The serio driver structure.
144 */
145
146static const struct serio_device_id gunze_serio_ids[] = {
147	{
148		.type	= SERIO_RS232,
149		.proto	= SERIO_GUNZE,
150		.id	= SERIO_ANY,
151		.extra	= SERIO_ANY,
152	},
153	{ 0 }
154};
155
156MODULE_DEVICE_TABLE(serio, gunze_serio_ids);
157
158static struct serio_driver gunze_drv = {
159	.driver		= {
160		.name	= "gunze",
161	},
162	.description	= DRIVER_DESC,
163	.id_table	= gunze_serio_ids,
164	.interrupt	= gunze_interrupt,
165	.connect	= gunze_connect,
166	.disconnect	= gunze_disconnect,
167};
168
169module_serio_driver(gunze_drv);
170