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_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! */
  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
  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
 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
 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
 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
 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 }