1/*
2 * Apple Motion Sensor driver (joystick emulation)
3 *
4 * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
5 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13#include <linux/module.h>
14
15#include <linux/types.h>
16#include <linux/errno.h>
17#include <linux/init.h>
18#include <linux/delay.h>
19
20#include "ams.h"
21
22static bool joystick;
23module_param(joystick, bool, S_IRUGO);
24MODULE_PARM_DESC(joystick, "Enable the input class device on module load");
25
26static bool invert;
27module_param(invert, bool, S_IWUSR | S_IRUGO);
28MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");
29
30static DEFINE_MUTEX(ams_input_mutex);
31
32static void ams_idev_poll(struct input_polled_dev *dev)
33{
34	struct input_dev *idev = dev->input;
35	s8 x, y, z;
36
37	mutex_lock(&ams_info.lock);
38
39	ams_sensors(&x, &y, &z);
40
41	x -= ams_info.xcalib;
42	y -= ams_info.ycalib;
43	z -= ams_info.zcalib;
44
45	input_report_abs(idev, ABS_X, invert ? -x : x);
46	input_report_abs(idev, ABS_Y, invert ? -y : y);
47	input_report_abs(idev, ABS_Z, z);
48
49	input_sync(idev);
50
51	mutex_unlock(&ams_info.lock);
52}
53
54/* Call with ams_info.lock held! */
55static int ams_input_enable(void)
56{
57	struct input_dev *input;
58	s8 x, y, z;
59	int error;
60
61	ams_sensors(&x, &y, &z);
62	ams_info.xcalib = x;
63	ams_info.ycalib = y;
64	ams_info.zcalib = z;
65
66	ams_info.idev = input_allocate_polled_device();
67	if (!ams_info.idev)
68		return -ENOMEM;
69
70	ams_info.idev->poll = ams_idev_poll;
71	ams_info.idev->poll_interval = 25;
72
73	input = ams_info.idev->input;
74	input->name = "Apple Motion Sensor";
75	input->id.bustype = ams_info.bustype;
76	input->id.vendor = 0;
77	input->dev.parent = &ams_info.of_dev->dev;
78
79	input_set_abs_params(input, ABS_X, -50, 50, 3, 0);
80	input_set_abs_params(input, ABS_Y, -50, 50, 3, 0);
81	input_set_abs_params(input, ABS_Z, -50, 50, 3, 0);
82
83	set_bit(EV_ABS, input->evbit);
84	set_bit(EV_KEY, input->evbit);
85	set_bit(BTN_TOUCH, input->keybit);
86
87	error = input_register_polled_device(ams_info.idev);
88	if (error) {
89		input_free_polled_device(ams_info.idev);
90		ams_info.idev = NULL;
91		return error;
92	}
93
94	joystick = 1;
95
96	return 0;
97}
98
99static void ams_input_disable(void)
100{
101	if (ams_info.idev) {
102		input_unregister_polled_device(ams_info.idev);
103		input_free_polled_device(ams_info.idev);
104		ams_info.idev = NULL;
105	}
106
107	joystick = 0;
108}
109
110static ssize_t ams_input_show_joystick(struct device *dev,
111	struct device_attribute *attr, char *buf)
112{
113	return sprintf(buf, "%d\n", joystick);
114}
115
116static ssize_t ams_input_store_joystick(struct device *dev,
117	struct device_attribute *attr, const char *buf, size_t count)
118{
119	unsigned long enable;
120	int error = 0;
121	int ret;
122
123	ret = kstrtoul(buf, 0, &enable);
124	if (ret)
125		return ret;
126	if (enable > 1)
127		return -EINVAL;
128
129	mutex_lock(&ams_input_mutex);
130
131	if (enable != joystick) {
132		if (enable)
133			error = ams_input_enable();
134		else
135			ams_input_disable();
136	}
137
138	mutex_unlock(&ams_input_mutex);
139
140	return error ? error : count;
141}
142
143static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
144	ams_input_show_joystick, ams_input_store_joystick);
145
146int ams_input_init(void)
147{
148	if (joystick)
149		ams_input_enable();
150
151	return device_create_file(&ams_info.of_dev->dev, &dev_attr_joystick);
152}
153
154void ams_input_exit(void)
155{
156	device_remove_file(&ams_info.of_dev->dev, &dev_attr_joystick);
157
158	mutex_lock(&ams_input_mutex);
159	ams_input_disable();
160	mutex_unlock(&ams_input_mutex);
161}
162