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 
24 #define DRIVER_DESC	"Touchright serial touchscreen driver"
25 
26 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
27 MODULE_DESCRIPTION(DRIVER_DESC);
28 MODULE_LICENSE("GPL");
29 
30 /*
31  * Definitions & global arrays.
32  */
33 
34 #define TR_FORMAT_TOUCH_BIT	0x01
35 #define TR_FORMAT_STATUS_BYTE	0x40
36 #define TR_FORMAT_STATUS_MASK	~TR_FORMAT_TOUCH_BIT
37 
38 #define TR_LENGTH 5
39 
40 #define TR_MIN_XC 0
41 #define TR_MAX_XC 0x1ff
42 #define TR_MIN_YC 0
43 #define TR_MAX_YC 0x1ff
44 
45 /*
46  * Per-touchscreen data.
47  */
48 
49 struct tr {
50 	struct input_dev *dev;
51 	struct serio *serio;
52 	int idx;
53 	unsigned char data[TR_LENGTH];
54 	char phys[32];
55 };
56 
57 static irqreturn_t tr_interrupt(struct serio *serio,
58 		unsigned char data, unsigned int flags)
59 {
60 	struct tr *tr = serio_get_drvdata(serio);
61 	struct input_dev *dev = tr->dev;
62 
63 	tr->data[tr->idx] = data;
64 
65 	if ((tr->data[0] & TR_FORMAT_STATUS_MASK) == TR_FORMAT_STATUS_BYTE) {
66 		if (++tr->idx == TR_LENGTH) {
67 			input_report_abs(dev, ABS_X,
68 				(tr->data[1] << 5) | (tr->data[2] >> 1));
69 			input_report_abs(dev, ABS_Y,
70 				(tr->data[3] << 5) | (tr->data[4] >> 1));
71 			input_report_key(dev, BTN_TOUCH,
72 				tr->data[0] & TR_FORMAT_TOUCH_BIT);
73 			input_sync(dev);
74 			tr->idx = 0;
75 		}
76 	}
77 
78 	return IRQ_HANDLED;
79 }
80 
81 /*
82  * tr_disconnect() is the opposite of tr_connect()
83  */
84 
85 static void tr_disconnect(struct serio *serio)
86 {
87 	struct tr *tr = serio_get_drvdata(serio);
88 
89 	input_get_device(tr->dev);
90 	input_unregister_device(tr->dev);
91 	serio_close(serio);
92 	serio_set_drvdata(serio, NULL);
93 	input_put_device(tr->dev);
94 	kfree(tr);
95 }
96 
97 /*
98  * tr_connect() is the routine that is called when someone adds a
99  * new serio device that supports the Touchright protocol and registers it as
100  * an input device.
101  */
102 
103 static int tr_connect(struct serio *serio, struct serio_driver *drv)
104 {
105 	struct tr *tr;
106 	struct input_dev *input_dev;
107 	int err;
108 
109 	tr = kzalloc(sizeof(struct tr), GFP_KERNEL);
110 	input_dev = input_allocate_device();
111 	if (!tr || !input_dev) {
112 		err = -ENOMEM;
113 		goto fail1;
114 	}
115 
116 	tr->serio = serio;
117 	tr->dev = input_dev;
118 	snprintf(tr->phys, sizeof(tr->phys), "%s/input0", serio->phys);
119 
120 	input_dev->name = "Touchright Serial TouchScreen";
121 	input_dev->phys = tr->phys;
122 	input_dev->id.bustype = BUS_RS232;
123 	input_dev->id.vendor = SERIO_TOUCHRIGHT;
124 	input_dev->id.product = 0;
125 	input_dev->id.version = 0x0100;
126 	input_dev->dev.parent = &serio->dev;
127 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
128 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
129 	input_set_abs_params(tr->dev, ABS_X, TR_MIN_XC, TR_MAX_XC, 0, 0);
130 	input_set_abs_params(tr->dev, ABS_Y, TR_MIN_YC, TR_MAX_YC, 0, 0);
131 
132 	serio_set_drvdata(serio, tr);
133 
134 	err = serio_open(serio, drv);
135 	if (err)
136 		goto fail2;
137 
138 	err = input_register_device(tr->dev);
139 	if (err)
140 		goto fail3;
141 
142 	return 0;
143 
144  fail3:	serio_close(serio);
145  fail2:	serio_set_drvdata(serio, NULL);
146  fail1:	input_free_device(input_dev);
147 	kfree(tr);
148 	return err;
149 }
150 
151 /*
152  * The serio driver structure.
153  */
154 
155 static struct serio_device_id tr_serio_ids[] = {
156 	{
157 		.type	= SERIO_RS232,
158 		.proto	= SERIO_TOUCHRIGHT,
159 		.id	= SERIO_ANY,
160 		.extra	= SERIO_ANY,
161 	},
162 	{ 0 }
163 };
164 
165 MODULE_DEVICE_TABLE(serio, tr_serio_ids);
166 
167 static struct serio_driver tr_drv = {
168 	.driver		= {
169 		.name	= "touchright",
170 	},
171 	.description	= DRIVER_DESC,
172 	.id_table	= tr_serio_ids,
173 	.interrupt	= tr_interrupt,
174 	.connect	= tr_connect,
175 	.disconnect	= tr_disconnect,
176 };
177 
178 module_serio_driver(tr_drv);
179