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, S_IRUGO);
  24 MODULE_PARM_DESC(joystick, "Enable the input class device on module load");
  25
  26 static unsigned int invert;
  27 module_param(invert, bool, S_IWUSR | S_IRUGO);
  28 MODULE_PARM_DESC(invert, "Invert input data on X and Y axis");
  29
  30 static DEFINE_MUTEX(ams_input_mutex);
  31
  32 static void ams_idev_poll(struct input_polled_dev *dev)
  33 {
  34         struct input_dev *idev = dev->input;
  35         s8 x, y, z;
  36
  37         mutex_lock(&ams_info.lock);
  38
  39         ams_sensors(&x, &y, &z);
  40
  41         x -= ams_info.xcalib;
  42         y -= ams_info.ycalib;
  43         z -= ams_info.zcalib;
  44
  45         input_report_abs(idev, ABS_X, invert ? -x : x);
  46         input_report_abs(idev, ABS_Y, invert ? -y : y);
  47         input_report_abs(idev, ABS_Z, z);
  48
  49         input_sync(idev);
  50
  51         mutex_unlock(&ams_info.lock);
  52 }
  53
  54 /* Call with ams_info.lock held! */
  55 static int ams_input_enable(void)
  56 {
  57         struct input_dev *input;
  58         s8 x, y, z;
  59         int error;
  60
  61         ams_sensors(&x, &y, &z);
  62         ams_info.xcalib = x;
  63         ams_info.ycalib = y;
  64         ams_info.zcalib = z;
  65
  66         ams_info.idev = input_allocate_polled_device();
  67         if (!ams_info.idev)
  68                 return -ENOMEM;
  69
  70         ams_info.idev->poll = ams_idev_poll;
  71         ams_info.idev->poll_interval = 25;
  72
  73         input = ams_info.idev->input;
  74         input->name = "Apple Motion Sensor";
  75         input->id.bustype = ams_info.bustype;
  76         input->id.vendor = 0;
  77         input->dev.parent = &ams_info.of_dev->dev;
  78
  79         input_set_abs_params(input, ABS_X, -50, 50, 3, 0);
  80         input_set_abs_params(input, ABS_Y, -50, 50, 3, 0);
  81         input_set_abs_params(input, ABS_Z, -50, 50, 3, 0);
  82
  83         set_bit(EV_ABS, input->evbit);
  84         set_bit(EV_KEY, input->evbit);
  85         set_bit(BTN_TOUCH, input->keybit);
  86
  87         error = input_register_polled_device(ams_info.idev);
  88         if (error) {
  89                 input_free_polled_device(ams_info.idev);
  90                 ams_info.idev = NULL;
  91                 return error;
  92         }
  93
  94         joystick = 1;
  95
  96         return 0;
  97 }
  98
  99 static void ams_input_disable(void)
 100 {
 101         if (ams_info.idev) {
 102                 input_unregister_polled_device(ams_info.idev);
 103                 input_free_polled_device(ams_info.idev);
 104                 ams_info.idev = NULL;
 105         }
 106
 107         joystick = 0;
 108 }
 109
 110 static ssize_t ams_input_show_joystick(struct device *dev,
 111         struct device_attribute *attr, char *buf)
 112 {
 113         return sprintf(buf, "%d\n", joystick);
 114 }
 115
 116 static ssize_t ams_input_store_joystick(struct device *dev,
 117         struct device_attribute *attr, const char *buf, size_t count)
 118 {
 119         unsigned long enable;
 120         int error = 0;
 121
 122         if (strict_strtoul(buf, 0, &enable) || 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 }