1/*
2 * iNexio serial touchscreen driver
3 *
4 * Copyright (c) 2008 Richard Lemon
5 * Based on the mtouch driver (c) Vojtech Pavlik and Dan Streetman
6 *
7 */
8
9/*
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published by
12 * the Free Software Foundation.
13 */
14
15/*
16 * 2008/06/19 Richard Lemon <richard@codelemon.com>
17 *   Copied mtouch.c and edited for iNexio protocol
18 */
19
20#include <linux/errno.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/slab.h>
24#include <linux/input.h>
25#include <linux/serio.h>
26
27#define DRIVER_DESC	"iNexio serial touchscreen driver"
28
29MODULE_AUTHOR("Richard Lemon <richard@codelemon.com>");
30MODULE_DESCRIPTION(DRIVER_DESC);
31MODULE_LICENSE("GPL");
32
33/*
34 * Definitions & global arrays.
35 */
36
37#define INEXIO_FORMAT_TOUCH_BIT 0x01
38#define INEXIO_FORMAT_LENGTH 5
39#define INEXIO_RESPONSE_BEGIN_BYTE 0x80
40
41/* todo: check specs for max length of all responses */
42#define INEXIO_MAX_LENGTH 16
43
44#define INEXIO_MIN_XC 0
45#define INEXIO_MAX_XC 0x3fff
46#define INEXIO_MIN_YC 0
47#define INEXIO_MAX_YC 0x3fff
48
49#define INEXIO_GET_XC(data) (((data[1])<<7) | data[2])
50#define INEXIO_GET_YC(data) (((data[3])<<7) | data[4])
51#define INEXIO_GET_TOUCHED(data) (INEXIO_FORMAT_TOUCH_BIT & data[0])
52
53/*
54 * Per-touchscreen data.
55 */
56
57struct inexio {
58	struct input_dev *dev;
59	struct serio *serio;
60	int idx;
61	unsigned char data[INEXIO_MAX_LENGTH];
62	char phys[32];
63};
64
65static void inexio_process_data(struct inexio *pinexio)
66{
67	struct input_dev *dev = pinexio->dev;
68
69	if (INEXIO_FORMAT_LENGTH == ++pinexio->idx) {
70		input_report_abs(dev, ABS_X, INEXIO_GET_XC(pinexio->data));
71		input_report_abs(dev, ABS_Y, INEXIO_GET_YC(pinexio->data));
72		input_report_key(dev, BTN_TOUCH, INEXIO_GET_TOUCHED(pinexio->data));
73		input_sync(dev);
74
75		pinexio->idx = 0;
76	}
77}
78
79static irqreturn_t inexio_interrupt(struct serio *serio,
80		unsigned char data, unsigned int flags)
81{
82	struct inexio* pinexio = serio_get_drvdata(serio);
83
84	pinexio->data[pinexio->idx] = data;
85
86	if (INEXIO_RESPONSE_BEGIN_BYTE&pinexio->data[0])
87		inexio_process_data(pinexio);
88	else
89		printk(KERN_DEBUG "inexio.c: unknown/unsynchronized data from device, byte %x\n",pinexio->data[0]);
90
91	return IRQ_HANDLED;
92}
93
94/*
95 * inexio_disconnect() is the opposite of inexio_connect()
96 */
97
98static void inexio_disconnect(struct serio *serio)
99{
100	struct inexio* pinexio = serio_get_drvdata(serio);
101
102	input_get_device(pinexio->dev);
103	input_unregister_device(pinexio->dev);
104	serio_close(serio);
105	serio_set_drvdata(serio, NULL);
106	input_put_device(pinexio->dev);
107	kfree(pinexio);
108}
109
110/*
111 * inexio_connect() is the routine that is called when someone adds a
112 * new serio device that supports iNexio protocol and registers it as
113 * an input device. This is usually accomplished using inputattach.
114 */
115
116static int inexio_connect(struct serio *serio, struct serio_driver *drv)
117{
118	struct inexio *pinexio;
119	struct input_dev *input_dev;
120	int err;
121
122	pinexio = kzalloc(sizeof(struct inexio), GFP_KERNEL);
123	input_dev = input_allocate_device();
124	if (!pinexio || !input_dev) {
125		err = -ENOMEM;
126		goto fail1;
127	}
128
129	pinexio->serio = serio;
130	pinexio->dev = input_dev;
131	snprintf(pinexio->phys, sizeof(pinexio->phys), "%s/input0", serio->phys);
132
133	input_dev->name = "iNexio Serial TouchScreen";
134	input_dev->phys = pinexio->phys;
135	input_dev->id.bustype = BUS_RS232;
136	input_dev->id.vendor = SERIO_INEXIO;
137	input_dev->id.product = 0;
138	input_dev->id.version = 0x0001;
139	input_dev->dev.parent = &serio->dev;
140	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
141	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
142	input_set_abs_params(pinexio->dev, ABS_X, INEXIO_MIN_XC, INEXIO_MAX_XC, 0, 0);
143	input_set_abs_params(pinexio->dev, ABS_Y, INEXIO_MIN_YC, INEXIO_MAX_YC, 0, 0);
144
145	serio_set_drvdata(serio, pinexio);
146
147	err = serio_open(serio, drv);
148	if (err)
149		goto fail2;
150
151	err = input_register_device(pinexio->dev);
152	if (err)
153		goto fail3;
154
155	return 0;
156
157 fail3:	serio_close(serio);
158 fail2:	serio_set_drvdata(serio, NULL);
159 fail1:	input_free_device(input_dev);
160	kfree(pinexio);
161	return err;
162}
163
164/*
165 * The serio driver structure.
166 */
167
168static struct serio_device_id inexio_serio_ids[] = {
169	{
170		.type	= SERIO_RS232,
171		.proto	= SERIO_INEXIO,
172		.id	= SERIO_ANY,
173		.extra	= SERIO_ANY,
174	},
175	{ 0 }
176};
177
178MODULE_DEVICE_TABLE(serio, inexio_serio_ids);
179
180static struct serio_driver inexio_drv = {
181	.driver		= {
182		.name	= "inexio",
183	},
184	.description	= DRIVER_DESC,
185	.id_table	= inexio_serio_ids,
186	.interrupt	= inexio_interrupt,
187	.connect	= inexio_connect,
188	.disconnect	= inexio_disconnect,
189};
190
191module_serio_driver(inexio_drv);
192