1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Apple Motion Sensor driver (joystick emulation)
4 *
5 * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
6 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
7 */
8
9#include <linux/module.h>
10
11#include <linux/types.h>
12#include <linux/errno.h>
13#include <linux/init.h>
14#include <linux/delay.h>
15
16#include "ams.h"
17
18static bool joystick;
19module_param(joystick, bool, S_IRUGO);
20MODULE_PARM_DESC(joystick, "Enable the input class device on module load");
21
22static bool invert;
23module_param(invert, bool, S_IWUSR | S_IRUGO);
24MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");
25
26static DEFINE_MUTEX(ams_input_mutex);
27
28static void ams_idev_poll(struct input_dev *idev)
29{
30	s8 x, y, z;
31
32	mutex_lock(&ams_info.lock);
33
34	ams_sensors(&x, &y, &z);
35
36	x -= ams_info.xcalib;
37	y -= ams_info.ycalib;
38	z -= ams_info.zcalib;
39
40	input_report_abs(idev, ABS_X, invert ? -x : x);
41	input_report_abs(idev, ABS_Y, invert ? -y : y);
42	input_report_abs(idev, ABS_Z, z);
43
44	input_sync(idev);
45
46	mutex_unlock(&ams_info.lock);
47}
48
49/* Call with ams_info.lock held! */
50static int ams_input_enable(void)
51{
52	struct input_dev *input;
53	s8 x, y, z;
54	int error;
55
56	ams_sensors(&x, &y, &z);
57	ams_info.xcalib = x;
58	ams_info.ycalib = y;
59	ams_info.zcalib = z;
60
61	input = input_allocate_device();
62	if (!input)
63		return -ENOMEM;
64
65	input->name = "Apple Motion Sensor";
66	input->id.bustype = ams_info.bustype;
67	input->id.vendor = 0;
68	input->dev.parent = &ams_info.of_dev->dev;
69
70	input_set_abs_params(input, ABS_X, -50, 50, 3, 0);
71	input_set_abs_params(input, ABS_Y, -50, 50, 3, 0);
72	input_set_abs_params(input, ABS_Z, -50, 50, 3, 0);
73	input_set_capability(input, EV_KEY, BTN_TOUCH);
74
75	error = input_setup_polling(input, ams_idev_poll);
76	if (error)
77		goto err_free_input;
78
79	input_set_poll_interval(input, 25);
80
81	error = input_register_device(input);
82	if (error)
83		goto err_free_input;
84
85	ams_info.idev = input;
86	joystick = true;
87
88	return 0;
89
90err_free_input:
91	input_free_device(input);
92	return error;
93}
94
95static void ams_input_disable(void)
96{
97	if (ams_info.idev) {
98		input_unregister_device(ams_info.idev);
99		ams_info.idev = NULL;
100	}
101
102	joystick = false;
103}
104
105static ssize_t ams_input_show_joystick(struct device *dev,
106	struct device_attribute *attr, char *buf)
107{
108	return sprintf(buf, "%d\n", joystick);
109}
110
111static ssize_t ams_input_store_joystick(struct device *dev,
112	struct device_attribute *attr, const char *buf, size_t count)
113{
114	unsigned long enable;
115	int error = 0;
116	int ret;
117
118	ret = kstrtoul(buf, 0, &enable);
119	if (ret)
120		return ret;
121	if (enable > 1)
122		return -EINVAL;
123
124	mutex_lock(&ams_input_mutex);
125
126	if (enable != joystick) {
127		if (enable)
128			error = ams_input_enable();
129		else
130			ams_input_disable();
131	}
132
133	mutex_unlock(&ams_input_mutex);
134
135	return error ? error : count;
136}
137
138static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
139	ams_input_show_joystick, ams_input_store_joystick);
140
141int ams_input_init(void)
142{
143	if (joystick)
144		ams_input_enable();
145
146	return device_create_file(&ams_info.of_dev->dev, &dev_attr_joystick);
147}
148
149void ams_input_exit(void)
150{
151	device_remove_file(&ams_info.of_dev->dev, &dev_attr_joystick);
152
153	mutex_lock(&ams_input_mutex);
154	ams_input_disable();
155	mutex_unlock(&ams_input_mutex);
156}
157