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 
22 static bool joystick;
23 module_param(joystick, bool, S_IRUGO);
24 MODULE_PARM_DESC(joystick, "Enable the input class device on module load");
25 
26 static bool invert;
27 module_param(invert, bool, S_IWUSR | S_IRUGO);
28 MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");
29 
30 static DEFINE_MUTEX(ams_input_mutex);
31 
32 static 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! */
55 static 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 
99 static 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 
110 static 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 
116 static 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 
143 static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
144 	ams_input_show_joystick, ams_input_store_joystick);
145 
146 int 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 
154 void 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