LXR linux/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
  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