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 varaible 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 __init 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 /* work with hotplug and coldplug */ 174 MODULE_ALIAS("platform:gpio_mouse"); 175 176 struct platform_driver gpio_mouse_device_driver = { 177 .remove = __devexit_p(gpio_mouse_remove), 178 .driver = { 179 .name = "gpio_mouse", 180 .owner = THIS_MODULE, 181 } 182 }; 183 184 static int __init gpio_mouse_init(void) 185 { 186 return platform_driver_probe(&gpio_mouse_device_driver, 187 gpio_mouse_probe); 188 } 189 module_init(gpio_mouse_init); 190 191 static void __exit gpio_mouse_exit(void) 192 { 193 platform_driver_unregister(&gpio_mouse_device_driver); 194 } 195 module_exit(gpio_mouse_exit); 196 197 MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>"); 198 MODULE_DESCRIPTION("GPIO mouse driver"); 199 MODULE_LICENSE("GPL"); 200