1 /*
2  * Touchright serial touchscreen driver
3  *
4  * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
5  *
6  * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
7  * Copyright (c) 2004 Vojtech Pavlik
8  * and Dan Streetman <ddstreet@ieee.org>
9  */
10 
11 /*
12  * This program is free software; you can redistribute it and/or modify it
13  * under the terms of the GNU General Public License version 2 as published
14  * by the Free Software Foundation.
15  */
16 
17 #include <linux/errno.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/input.h>
22 #include <linux/serio.h>
23 #include <linux/init.h>
24 
25 #define DRIVER_DESC	"Touchright serial touchscreen driver"
26 
27 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
28 MODULE_DESCRIPTION(DRIVER_DESC);
29 MODULE_LICENSE("GPL");
30 
31 /*
32  * Definitions & global arrays.
33  */
34 
35 #define TR_FORMAT_TOUCH_BIT	0x01
36 #define TR_FORMAT_STATUS_BYTE	0x40
37 #define TR_FORMAT_STATUS_MASK	~TR_FORMAT_TOUCH_BIT
38 
39 #define TR_LENGTH 5
40 
41 #define TR_MIN_XC 0
42 #define TR_MAX_XC 0x1ff
43 #define TR_MIN_YC 0
44 #define TR_MAX_YC 0x1ff
45 
46 /*
47  * Per-touchscreen data.
48  */
49 
50 struct tr {
51 	struct input_dev *dev;
52 	struct serio *serio;
53 	int idx;
54 	unsigned char data[TR_LENGTH];
55 	char phys[32];
56 };
57 
58 static irqreturn_t tr_interrupt(struct serio *serio,
59 		unsigned char data, unsigned int flags)
60 {
61 	struct tr *tr = serio_get_drvdata(serio);
62 	struct input_dev *dev = tr->dev;
63 
64 	tr->data[tr->idx] = data;
65 
66 	if ((tr->data[0] & TR_FORMAT_STATUS_MASK) == TR_FORMAT_STATUS_BYTE) {
67 		if (++tr->idx == TR_LENGTH) {
68 			input_report_abs(dev, ABS_X,
69 				(tr->data[1] << 5) | (tr->data[2] >> 1));
70 			input_report_abs(dev, ABS_Y,
71 				(tr->data[3] << 5) | (tr->data[4] >> 1));
72 			input_report_key(dev, BTN_TOUCH,
73 				tr->data[0] & TR_FORMAT_TOUCH_BIT);
74 			input_sync(dev);
75 			tr->idx = 0;
76 		}
77 	}
78 
79 	return IRQ_HANDLED;
80 }
81 
82 /*
83  * tr_disconnect() is the opposite of tr_connect()
84  */
85 
86 static void tr_disconnect(struct serio *serio)
87 {
88 	struct tr *tr = serio_get_drvdata(serio);
89 
90 	input_get_device(tr->dev);
91 	input_unregister_device(tr->dev);
92 	serio_close(serio);
93 	serio_set_drvdata(serio, NULL);
94 	input_put_device(tr->dev);
95 	kfree(tr);
96 }
97 
98 /*
99  * tr_connect() is the routine that is called when someone adds a
100  * new serio device that supports the Touchright protocol and registers it as
101  * an input device.
102  */
103 
104 static int tr_connect(struct serio *serio, struct serio_driver *drv)
105 {
106 	struct tr *tr;
107 	struct input_dev *input_dev;
108 	int err;
109 
110 	tr = kzalloc(sizeof(struct tr), GFP_KERNEL);
111 	input_dev = input_allocate_device();
112 	if (!tr || !input_dev) {
113 		err = -ENOMEM;
114 		goto fail1;
115 	}
116 
117 	tr->serio = serio;
118 	tr->dev = input_dev;
119 	snprintf(tr->phys, sizeof(tr->phys), "%s/input0", serio->phys);
120 
121 	input_dev->name = "Touchright Serial TouchScreen";
122 	input_dev->phys = tr->phys;
123 	input_dev->id.bustype = BUS_RS232;
124 	input_dev->id.vendor = SERIO_TOUCHRIGHT;
125 	input_dev->id.product = 0;
126 	input_dev->id.version = 0x0100;
127 	input_dev->dev.parent = &serio->dev;
128 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
129 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
130 	input_set_abs_params(tr->dev, ABS_X, TR_MIN_XC, TR_MAX_XC, 0, 0);
131 	input_set_abs_params(tr->dev, ABS_Y, TR_MIN_YC, TR_MAX_YC, 0, 0);
132 
133 	serio_set_drvdata(serio, tr);
134 
135 	err = serio_open(serio, drv);
136 	if (err)
137 		goto fail2;
138 
139 	err = input_register_device(tr->dev);
140 	if (err)
141 		goto fail3;
142 
143 	return 0;
144 
145  fail3:	serio_close(serio);
146  fail2:	serio_set_drvdata(serio, NULL);
147  fail1:	input_free_device(input_dev);
148 	kfree(tr);
149 	return err;
150 }
151 
152 /*
153  * The serio driver structure.
154  */
155 
156 static struct serio_device_id tr_serio_ids[] = {
157 	{
158 		.type	= SERIO_RS232,
159 		.proto	= SERIO_TOUCHRIGHT,
160 		.id	= SERIO_ANY,
161 		.extra	= SERIO_ANY,
162 	},
163 	{ 0 }
164 };
165 
166 MODULE_DEVICE_TABLE(serio, tr_serio_ids);
167 
168 static struct serio_driver tr_drv = {
169 	.driver		= {
170 		.name	= "touchright",
171 	},
172 	.description	= DRIVER_DESC,
173 	.id_table	= tr_serio_ids,
174 	.interrupt	= tr_interrupt,
175 	.connect	= tr_connect,
176 	.disconnect	= tr_disconnect,
177 };
178 
179 /*
180  * The functions for inserting/removing us as a module.
181  */
182 
183 static int __init tr_init(void)
184 {
185 	return serio_register_driver(&tr_drv);
186 }
187 
188 static void __exit tr_exit(void)
189 {
190 	serio_unregister_driver(&tr_drv);
191 }
192 
193 module_init(tr_init);
194 module_exit(tr_exit);
195