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