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/init.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/input-polldev.h>
  15 #include <linux/gpio_mouse.h>
  16
  17 #include <asm/gpio.h>
  18
  19 /*
  20  * Timer function which is run every scan_ms ms when the device is opened.
  21  * The dev input variable is set to the the input_dev pointer.
  22  */
  23 static void gpio_mouse_scan(struct input_polled_dev *dev)
  24 {
  25         struct gpio_mouse_platform_data *gpio = dev->private;
  26         struct input_dev *input = dev->input;
  27         int x, y;
  28
  29         if (gpio->bleft >= 0)
  30                 input_report_key(input, BTN_LEFT,
  31                                 gpio_get_value(gpio->bleft) ^ gpio->polarity);
  32         if (gpio->bmiddle >= 0)
  33                 input_report_key(input, BTN_MIDDLE,
  34                                 gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
  35         if (gpio->bright >= 0)
  36                 input_report_key(input, BTN_RIGHT,
  37                                 gpio_get_value(gpio->bright) ^ gpio->polarity);
  38
  39         x = (gpio_get_value(gpio->right) ^ gpio->polarity)
  40                 - (gpio_get_value(gpio->left) ^ gpio->polarity);
  41         y = (gpio_get_value(gpio->down) ^ gpio->polarity)
  42                 - (gpio_get_value(gpio->up) ^ gpio->polarity);
  43
  44         input_report_rel(input, REL_X, x);
  45         input_report_rel(input, REL_Y, y);
  46         input_sync(input);
  47 }
  48
  49 static int __devinit gpio_mouse_probe(struct platform_device *pdev)
  50 {
  51         struct gpio_mouse_platform_data *pdata = pdev->dev.platform_data;
  52         struct input_polled_dev *input_poll;
  53         struct input_dev *input;
  54         int pin, i;
  55         int error;
  56
  57         if (!pdata) {
  58                 dev_err(&pdev->dev, "no platform data\n");
  59                 error = -ENXIO;
  60                 goto out;
  61         }
  62
  63         if (pdata->scan_ms < 0) {
  64                 dev_err(&pdev->dev, "invalid scan time\n");
  65                 error = -EINVAL;
  66                 goto out;
  67         }
  68
  69         for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
  70                 pin = pdata->pins[i];
  71
  72                 if (pin < 0) {
  73
  74                         if (i <= GPIO_MOUSE_PIN_RIGHT) {
  75                                 /* Mouse direction is required. */
  76                                 dev_err(&pdev->dev,
  77                                         "missing GPIO for directions\n");
  78                                 error = -EINVAL;
  79                                 goto out_free_gpios;
  80                         }
  81
  82                         if (i == GPIO_MOUSE_PIN_BLEFT)
  83                                 dev_dbg(&pdev->dev, "no left button defined\n");
  84
  85                 } else {
  86                         error = gpio_request(pin, "gpio_mouse");
  87                         if (error) {
  88                                 dev_err(&pdev->dev, "fail %d pin (%d idx)\n",
  89                                         pin, i);
  90                                 goto out_free_gpios;
  91                         }
  92
  93                         gpio_direction_input(pin);
  94                 }
  95         }
  96
  97         input_poll = input_allocate_polled_device();
  98         if (!input_poll) {
  99                 dev_err(&pdev->dev, "not enough memory for input device\n");
 100                 error = -ENOMEM;
 101                 goto out_free_gpios;
 102         }
 103
 104         platform_set_drvdata(pdev, input_poll);
 105
 106         /* set input-polldev handlers */
 107         input_poll->private = pdata;
 108         input_poll->poll = gpio_mouse_scan;
 109         input_poll->poll_interval = pdata->scan_ms;
 110
 111         input = input_poll->input;
 112         input->name = pdev->name;
 113         input->id.bustype = BUS_HOST;
 114         input->dev.parent = &pdev->dev;
 115
 116         input_set_capability(input, EV_REL, REL_X);
 117         input_set_capability(input, EV_REL, REL_Y);
 118         if (pdata->bleft >= 0)
 119                 input_set_capability(input, EV_KEY, BTN_LEFT);
 120         if (pdata->bmiddle >= 0)
 121                 input_set_capability(input, EV_KEY, BTN_MIDDLE);
 122         if (pdata->bright >= 0)
 123                 input_set_capability(input, EV_KEY, BTN_RIGHT);
 124
 125         error = input_register_polled_device(input_poll);
 126         if (error) {
 127                 dev_err(&pdev->dev, "could not register input device\n");
 128                 goto out_free_polldev;
 129         }
 130
 131         dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
 132                         pdata->scan_ms,
 133                         pdata->bleft < 0 ? "" : "left ",
 134                         pdata->bmiddle < 0 ? "" : "middle ",
 135                         pdata->bright < 0 ? "" : "right");
 136
 137         return 0;
 138
 139  out_free_polldev:
 140         input_free_polled_device(input_poll);
 141         platform_set_drvdata(pdev, NULL);
 142
 143  out_free_gpios:
 144         while (--i >= 0) {
 145                 pin = pdata->pins[i];
 146                 if (pin)
 147                         gpio_free(pin);
 148         }
 149  out:
 150         return error;
 151 }
 152
 153 static int __devexit gpio_mouse_remove(struct platform_device *pdev)
 154 {
 155         struct input_polled_dev *input = platform_get_drvdata(pdev);
 156         struct gpio_mouse_platform_data *pdata = input->private;
 157         int pin, i;
 158
 159         input_unregister_polled_device(input);
 160         input_free_polled_device(input);
 161
 162         for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
 163                 pin = pdata->pins[i];
 164                 if (pin >= 0)
 165                         gpio_free(pin);
 166         }
 167
 168         platform_set_drvdata(pdev, NULL);
 169
 170         return 0;
 171 }
 172
 173 static struct platform_driver gpio_mouse_device_driver = {
 174         .probe          = gpio_mouse_probe,
 175         .remove         = __devexit_p(gpio_mouse_remove),
 176         .driver         = {
 177                 .name   = "gpio_mouse",
 178                 .owner  = THIS_MODULE,
 179         }
 180 };
 181
 182 static int __init gpio_mouse_init(void)
 183 {
 184         return platform_driver_register(&gpio_mouse_device_driver);
 185 }
 186 module_init(gpio_mouse_init);
 187
 188 static void __exit gpio_mouse_exit(void)
 189 {
 190         platform_driver_unregister(&gpio_mouse_device_driver);
 191 }
 192 module_exit(gpio_mouse_exit);
 193
 194 MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
 195 MODULE_DESCRIPTION("GPIO mouse driver");
 196 MODULE_LICENSE("GPL");
 197 MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */
 198