drivers/macintosh/ams/ams-input.c

   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
  28 static void ams_idev_poll(struct input_polled_dev *dev)
  29 {
  30         struct input_dev *idev = dev->input;
  31         s8 x, y, z;
  32
  33         mutex_lock(&ams_info.lock);
  34
  35         ams_sensors(&x, &y, &z);
  36
  37         x -= ams_info.xcalib;
  38         y -= ams_info.ycalib;
  39         z -= ams_info.zcalib;
  40
  41         input_report_abs(idev, ABS_X, invert ? -x : x);
  42         input_report_abs(idev, ABS_Y, invert ? -y : y);
  43         input_report_abs(idev, ABS_Z, z);
  44
  45         input_sync(idev);
  46
  47         mutex_unlock(&ams_info.lock);
  48 }
  49
  50 /* Call with ams_info.lock held! */
  51 static int ams_input_enable(void)
  52 {
  53         struct input_dev *input;
  54         s8 x, y, z;
  55         int error;
  56
  57         ams_sensors(&x, &y, &z);
  58         ams_info.xcalib = x;
  59         ams_info.ycalib = y;
  60         ams_info.zcalib = z;
  61
  62         ams_info.idev = input_allocate_polled_device();
  63         if (!ams_info.idev)
  64                 return -ENOMEM;
  65
  66         ams_info.idev->poll = ams_idev_poll;
  67         ams_info.idev->poll_interval = 25;
  68
  69         input = ams_info.idev->input;
  70         input->name = "Apple Motion Sensor";
  71         input->id.bustype = ams_info.bustype;
  72         input->id.vendor = 0;
  73         input->dev.parent = &ams_info.of_dev->dev;
  74
  75         input_set_abs_params(input, ABS_X, -50, 50, 3, 0);
  76         input_set_abs_params(input, ABS_Y, -50, 50, 3, 0);
  77         input_set_abs_params(input, ABS_Z, -50, 50, 3, 0);
  78
  79         set_bit(EV_ABS, input->evbit);
  80         set_bit(EV_KEY, input->evbit);
  81         set_bit(BTN_TOUCH, input->keybit);
  82
  83         error = input_register_polled_device(ams_info.idev);
  84         if (error) {
  85                 input_free_polled_device(ams_info.idev);
  86                 ams_info.idev = NULL;
  87                 return error;
  88         }
  89
  90         joystick = true;
  91
  92         return 0;
  93 }
  94
  95 static void ams_input_disable(void)
  96 {
  97         if (ams_info.idev) {
  98                 input_unregister_polled_device(ams_info.idev);
  99                 input_free_polled_device(ams_info.idev);
 100                 ams_info.idev = NULL;
 101         }
 102
 103         joystick = false;
 104 }
 105
 106 static ssize_t ams_input_show_joystick(struct device *dev,
 107         struct device_attribute *attr, char *buf)
 108 {
 109         return sprintf(buf, "%d\n", joystick);
 110 }
 111
 112 static ssize_t ams_input_store_joystick(struct device *dev,
 113         struct device_attribute *attr, const char *buf, size_t count)
 114 {
 115         unsigned long enable;
 116         int error = 0;
 117         int ret;
 118
 119         ret = kstrtoul(buf, 0, &enable);
 120         if (ret)
 121                 return ret;
 122         if (enable > 1)
 123                 return -EINVAL;
 124
 125         mutex_lock(&ams_input_mutex);
 126
 127         if (enable != joystick) {
 128                 if (enable)
 129                         error = ams_input_enable();
 130                 else
 131                         ams_input_disable();
 132         }
 133
 134         mutex_unlock(&ams_input_mutex);
 135
 136         return error ? error : count;
 137 }
 138
 139 static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
 140         ams_input_show_joystick, ams_input_store_joystick);
 141
 142 int ams_input_init(void)
 143 {
 144         if (joystick)
 145                 ams_input_enable();
 146
 147         return device_create_file(&ams_info.of_dev->dev, &dev_attr_joystick);
 148 }
 149
 150 void ams_input_exit(void)
 151 {
 152         device_remove_file(&ams_info.of_dev->dev, &dev_attr_joystick);
 153
 154         mutex_lock(&ams_input_mutex);
 155         ams_input_disable();
 156         mutex_unlock(&ams_input_mutex);
 157 }