drivers/input/mouse/gpio_mouse.c

   1 /*
   2  * Driver for simulating a mouse on GPIO lines.
   3  *
   4  * Copyright (C) 2007 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/input-polldev.h>
  14 #include <linux/gpio.h>
  15 #include <linux/gpio_mouse.h>
  16
  17
  18 /*
  19  * Timer function which is run every scan_ms ms when the device is opened.
  20  * The dev input variable is set to the the input_dev pointer.
  21  */
  22 static void gpio_mouse_scan(struct input_polled_dev *dev)
  23 {
  24         struct gpio_mouse_platform_data *gpio = dev->private;
  25         struct input_dev *input = dev->input;
  26         int x, y;
  27
  28         if (gpio->bleft >= 0)
  29                 input_report_key(input, BTN_LEFT,
  30                                 gpio_get_value(gpio->bleft) ^ gpio->polarity);
  31         if (gpio->bmiddle >= 0)
  32                 input_report_key(input, BTN_MIDDLE,
  33                                 gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
  34         if (gpio->bright >= 0)
  35                 input_report_key(input, BTN_RIGHT,
  36                                 gpio_get_value(gpio->bright) ^ gpio->polarity);
  37
  38         x = (gpio_get_value(gpio->right) ^ gpio->polarity)
  39                 - (gpio_get_value(gpio->left) ^ gpio->polarity);
  40         y = (gpio_get_value(gpio->down) ^ gpio->polarity)
  41                 - (gpio_get_value(gpio->up) ^ gpio->polarity);
  42
  43         input_report_rel(input, REL_X, x);
  44         input_report_rel(input, REL_Y, y);
  45         input_sync(input);
  46 }
  47
  48 static int gpio_mouse_probe(struct platform_device *pdev)
  49 {
  50         struct gpio_mouse_platform_data *pdata = dev_get_platdata(&pdev->dev);
  51         struct input_polled_dev *input_poll;
  52         struct input_dev *input;
  53         int pin, i;
  54         int error;
  55
  56         if (!pdata) {
  57                 dev_err(&pdev->dev, "no platform data\n");
  58                 error = -ENXIO;
  59                 goto out;
  60         }
  61
  62         if (pdata->scan_ms < 0) {
  63                 dev_err(&pdev->dev, "invalid scan time\n");
  64                 error = -EINVAL;
  65                 goto out;
  66         }
  67
  68         for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
  69                 pin = pdata->pins[i];
  70
  71                 if (pin < 0) {
  72
  73                         if (i <= GPIO_MOUSE_PIN_RIGHT) {
  74                                 /* Mouse direction is required. */
  75                                 dev_err(&pdev->dev,
  76                                         "missing GPIO for directions\n");
  77                                 error = -EINVAL;
  78                                 goto out_free_gpios;
  79                         }
  80
  81                         if (i == GPIO_MOUSE_PIN_BLEFT)
  82                                 dev_dbg(&pdev->dev, "no left button defined\n");
  83
  84                 } else {
  85                         error = gpio_request(pin, "gpio_mouse");
  86                         if (error) {
  87                                 dev_err(&pdev->dev, "fail %d pin (%d idx)\n",
  88                                         pin, i);
  89                                 goto out_free_gpios;
  90                         }
  91
  92                         gpio_direction_input(pin);
  93                 }
  94         }
  95
  96         input_poll = input_allocate_polled_device();
  97         if (!input_poll) {
  98                 dev_err(&pdev->dev, "not enough memory for input device\n");
  99                 error = -ENOMEM;
 100                 goto out_free_gpios;
 101         }
 102
 103         platform_set_drvdata(pdev, input_poll);
 104
 105         /* set input-polldev handlers */
 106         input_poll->private = pdata;
 107         input_poll->poll = gpio_mouse_scan;
 108         input_poll->poll_interval = pdata->scan_ms;
 109
 110         input = input_poll->input;
 111         input->name = pdev->name;
 112         input->id.bustype = BUS_HOST;
 113         input->dev.parent = &pdev->dev;
 114
 115         input_set_capability(input, EV_REL, REL_X);
 116         input_set_capability(input, EV_REL, REL_Y);
 117         if (pdata->bleft >= 0)
 118                 input_set_capability(input, EV_KEY, BTN_LEFT);
 119         if (pdata->bmiddle >= 0)
 120                 input_set_capability(input, EV_KEY, BTN_MIDDLE);
 121         if (pdata->bright >= 0)
 122                 input_set_capability(input, EV_KEY, BTN_RIGHT);
 123
 124         error = input_register_polled_device(input_poll);
 125         if (error) {
 126                 dev_err(&pdev->dev, "could not register input device\n");
 127                 goto out_free_polldev;
 128         }
 129
 130         dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
 131                         pdata->scan_ms,
 132                         pdata->bleft < 0 ? "" : "left ",
 133                         pdata->bmiddle < 0 ? "" : "middle ",
 134                         pdata->bright < 0 ? "" : "right");
 135
 136         return 0;
 137
 138  out_free_polldev:
 139         input_free_polled_device(input_poll);
 140
 141  out_free_gpios:
 142         while (--i >= 0) {
 143                 pin = pdata->pins[i];
 144                 if (pin)
 145                         gpio_free(pin);
 146         }
 147  out:
 148         return error;
 149 }
 150
 151 static int gpio_mouse_remove(struct platform_device *pdev)
 152 {
 153         struct input_polled_dev *input = platform_get_drvdata(pdev);
 154         struct gpio_mouse_platform_data *pdata = input->private;
 155         int pin, i;
 156
 157         input_unregister_polled_device(input);
 158         input_free_polled_device(input);
 159
 160         for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
 161                 pin = pdata->pins[i];
 162                 if (pin >= 0)
 163                         gpio_free(pin);
 164         }
 165
 166         return 0;
 167 }
 168
 169 static struct platform_driver gpio_mouse_device_driver = {
 170         .probe          = gpio_mouse_probe,
 171         .remove         = gpio_mouse_remove,
 172         .driver         = {
 173                 .name   = "gpio_mouse",
 174         }
 175 };
 176 module_platform_driver(gpio_mouse_device_driver);
 177
 178 MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
 179 MODULE_DESCRIPTION("GPIO mouse driver");
 180 MODULE_LICENSE("GPL");
 181 MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */
 182