drivers/hwmon/ams/ams-input.c

   1 /*
   2  * Apple Motion Sensor driver (joystick emulation)
   3  *
   4  * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
   5  * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14
  15 #include <linux/types.h>
  16 #include <linux/errno.h>
  17 #include <linux/init.h>
  18 #include <linux/delay.h>
  19
  20 #include "ams.h"
  21
  22 static unsigned int joystick;
  23 module_param(joystick, bool, 0644);
  24 MODULE_PARM_DESC(joystick, "Enable the input class device on module load");
  25
  26 static unsigned int invert;
  27 module_param(invert, bool, 0644);
  28 MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");
  29
  30 static int ams_input_kthread(void *data)
  31 {
  32         s8 x, y, z;
  33
  34         while (!kthread_should_stop()) {
  35                 mutex_lock(&ams_info.lock);
  36
  37                 ams_sensors(&x, &y, &z);
  38
  39                 x -= ams_info.xcalib;
  40                 y -= ams_info.ycalib;
  41                 z -= ams_info.zcalib;
  42
  43                 input_report_abs(ams_info.idev, ABS_X, invert ? -x : x);
  44                 input_report_abs(ams_info.idev, ABS_Y, invert ? -y : y);
  45                 input_report_abs(ams_info.idev, ABS_Z, z);
  46
  47                 input_sync(ams_info.idev);
  48
  49                 mutex_unlock(&ams_info.lock);
  50
  51                 msleep(25);
  52         }
  53
  54         return 0;
  55 }
  56
  57 static int ams_input_open(struct input_dev *dev)
  58 {
  59         ams_info.kthread = kthread_run(ams_input_kthread, NULL, "kams");
  60         return IS_ERR(ams_info.kthread) ? PTR_ERR(ams_info.kthread) : 0;
  61 }
  62
  63 static void ams_input_close(struct input_dev *dev)
  64 {
  65         kthread_stop(ams_info.kthread);
  66 }
  67
  68 /* Call with ams_info.lock held! */
  69 static void ams_input_enable(void)
  70 {
  71         s8 x, y, z;
  72
  73         if (ams_info.idev)
  74                 return;
  75
  76         ams_sensors(&x, &y, &z);
  77         ams_info.xcalib = x;
  78         ams_info.ycalib = y;
  79         ams_info.zcalib = z;
  80
  81         ams_info.idev = input_allocate_device();
  82         if (!ams_info.idev)
  83                 return;
  84
  85         ams_info.idev->name = "Apple Motion Sensor";
  86         ams_info.idev->id.bustype = ams_info.bustype;
  87         ams_info.idev->id.vendor = 0;
  88         ams_info.idev->open = ams_input_open;
  89         ams_info.idev->close = ams_input_close;
  90         ams_info.idev->cdev.dev = &ams_info.of_dev->dev;
  91
  92         input_set_abs_params(ams_info.idev, ABS_X, -50, 50, 3, 0);
  93         input_set_abs_params(ams_info.idev, ABS_Y, -50, 50, 3, 0);
  94         input_set_abs_params(ams_info.idev, ABS_Z, -50, 50, 3, 0);
  95
  96         set_bit(EV_ABS, ams_info.idev->evbit);
  97         set_bit(EV_KEY, ams_info.idev->evbit);
  98         set_bit(BTN_TOUCH, ams_info.idev->keybit);
  99
 100         if (input_register_device(ams_info.idev)) {
 101                 input_free_device(ams_info.idev);
 102                 ams_info.idev = NULL;
 103                 return;
 104         }
 105 }
 106
 107 /* Call with ams_info.lock held! */
 108 static void ams_input_disable(void)
 109 {
 110         if (ams_info.idev) {
 111                 input_unregister_device(ams_info.idev);
 112                 ams_info.idev = NULL;
 113         }
 114 }
 115
 116 static ssize_t ams_input_show_joystick(struct device *dev,
 117         struct device_attribute *attr, char *buf)
 118 {
 119         return sprintf(buf, "%d\n", joystick);
 120 }
 121
 122 static ssize_t ams_input_store_joystick(struct device *dev,
 123         struct device_attribute *attr, const char *buf, size_t count)
 124 {
 125         if (sscanf(buf, "%d\n", &joystick) != 1)
 126                 return -EINVAL;
 127
 128         mutex_lock(&ams_info.lock);
 129
 130         if (joystick)
 131                 ams_input_enable();
 132         else
 133                 ams_input_disable();
 134
 135         mutex_unlock(&ams_info.lock);
 136
 137         return count;
 138 }
 139
 140 static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
 141         ams_input_show_joystick, ams_input_store_joystick);
 142
 143 /* Call with ams_info.lock held! */
 144 int ams_input_init(void)
 145 {
 146         int result;
 147
 148         result = device_create_file(&ams_info.of_dev->dev, &dev_attr_joystick);
 149
 150         if (!result && joystick)
 151                 ams_input_enable();
 152         return result;
 153 }
 154
 155 /* Call with ams_info.lock held! */
 156 void ams_input_exit(void)
 157 {
 158         ams_input_disable();
 159         device_remove_file(&ams_info.of_dev->dev, &dev_attr_joystick);
 160 }