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: &x, y: &y, z: &z);
35
36 x -= ams_info.xcalib;
37 y -= ams_info.ycalib;
38 z -= ams_info.zcalib;
39
40 input_report_abs(dev: idev, ABS_X, value: invert ? -x : x);
41 input_report_abs(dev: idev, ABS_Y, value: invert ? -y : y);
42 input_report_abs(dev: idev, ABS_Z, value: z);
43
44 input_sync(dev: idev);
45
46 mutex_unlock(lock: &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: &x, y: &y, z: &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(dev: input, ABS_X, min: -50, max: 50, fuzz: 3, flat: 0);
71 input_set_abs_params(dev: input, ABS_Y, min: -50, max: 50, fuzz: 3, flat: 0);
72 input_set_abs_params(dev: input, ABS_Z, min: -50, max: 50, fuzz: 3, flat: 0);
73 input_set_capability(dev: input, EV_KEY, BTN_TOUCH);
74
75 error = input_setup_polling(dev: input, poll_fn: ams_idev_poll);
76 if (error)
77 goto err_free_input;
78
79 input_set_poll_interval(dev: input, interval: 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(dev: 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, fmt: "%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(s: buf, base: 0, res: &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(lock: &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(device: &ams_info.of_dev->dev, entry: &dev_attr_joystick);
147}
148
149void ams_input_exit(void)
150{
151 device_remove_file(dev: &ams_info.of_dev->dev, attr: &dev_attr_joystick);
152
153 mutex_lock(&ams_input_mutex);
154 ams_input_disable();
155 mutex_unlock(lock: &ams_input_mutex);
156}
157

source code of linux/drivers/macintosh/ams/ams-input.c