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 
19 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
20 MODULE_DESCRIPTION(DRIVER_DESC);
21 MODULE_LICENSE("GPL");
22 
23 /*
24  * Definitions & global arrays.
25  */
26 
27 #define	GUNZE_MAX_LENGTH	10
28 
29 /*
30  * Per-touchscreen data.
31  */
32 
33 struct 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 
gunze_process_packet(struct gunze * gunze)41 static 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 
gunze_interrupt(struct serio * serio,unsigned char data,unsigned int flags)57 static 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 
gunze_disconnect(struct serio * serio)76 static 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 
gunze_connect(struct serio * serio,struct serio_driver * drv)94 static 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 
146 static 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 
156 MODULE_DEVICE_TABLE(serio, gunze_serio_ids);
157 
158 static 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 
169 module_serio_driver(gunze_drv);
170