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 */ 182 183