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
18 static bool joystick;
19 module_param(joystick, bool, S_IRUGO);
20 MODULE_PARM_DESC(joystick, "Enable the input class device on module load");
21
22 static bool invert;
23 module_param(invert, bool, S_IWUSR | S_IRUGO);
24 MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");
25
26 static DEFINE_MUTEX(ams_input_mutex);
27
ams_idev_poll(struct input_dev * idev)28 static 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! */
ams_input_enable(void)50 static 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
90 err_free_input:
91 input_free_device(input);
92 return error;
93 }
94
ams_input_disable(void)95 static 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
ams_input_show_joystick(struct device * dev,struct device_attribute * attr,char * buf)105 static 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
ams_input_store_joystick(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)111 static 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
138 static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
139 ams_input_show_joystick, ams_input_store_joystick);
140
ams_input_init(void)141 int 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
ams_input_exit(void)149 void 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