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 void ams_idev_poll(struct input_polled_dev *dev)
  31 {
  32         struct input_dev *idev = dev->input;
  33         s8 x, y, z;
  34
  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(idev, ABS_X, invert ? -x : x);
  44         input_report_abs(idev, ABS_Y, invert ? -y : y);
  45         input_report_abs(idev, ABS_Z, z);
  46
  47         input_sync(idev);
  48
  49         mutex_unlock(&ams_info.lock);
  50 }
  51
  52 /* Call with ams_info.lock held! */
  53 static void ams_input_enable(void)
  54 {
  55         struct input_dev *input;
  56         s8 x, y, z;
  57
  58         if (ams_info.idev)
  59                 return;
  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;
  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         if (input_register_polled_device(ams_info.idev)) {
  88                 input_free_polled_device(ams_info.idev);
  89                 ams_info.idev = NULL;
  90                 return;
  91         }
  92 }
  93
  94 /* Call with ams_info.lock held! */
  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
 104 static ssize_t ams_input_show_joystick(struct device *dev,
 105         struct device_attribute *attr, char *buf)
 106 {
 107         return sprintf(buf, "%d\n", joystick);
 108 }
 109
 110 static ssize_t ams_input_store_joystick(struct device *dev,
 111         struct device_attribute *attr, const char *buf, size_t count)
 112 {
 113         if (sscanf(buf, "%d\n", &joystick) != 1)
 114                 return -EINVAL;
 115
 116         mutex_lock(&ams_info.lock);
 117
 118         if (joystick)
 119                 ams_input_enable();
 120         else
 121                 ams_input_disable();
 122
 123         mutex_unlock(&ams_info.lock);
 124
 125         return count;
 126 }
 127
 128 static DEVICE_ATTR(joystick, S_IRUGO | S_IWUSR,
 129         ams_input_show_joystick, ams_input_store_joystick);
 130
 131 /* Call with ams_info.lock held! */
 132 int ams_input_init(void)
 133 {
 134         int result;
 135
 136         result = device_create_file(&ams_info.of_dev->dev, &dev_attr_joystick);
 137
 138         if (!result && joystick)
 139                 ams_input_enable();
 140         return result;
 141 }
 142
 143 /* Call with ams_info.lock held! */
 144 void ams_input_exit(void)
 145 {
 146         ams_input_disable();
 147         device_remove_file(&ams_info.of_dev->dev, &dev_attr_joystick);
 148 }