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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | // SPDX-License-Identifier: GPL-2.0-only /* * Driver for simulating a mouse on GPIO lines. * * Copyright (C) 2007 Atmel Corporation * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> */ #include <linux/module.h> #include <linux/platform_device.h> #include <linux/input.h> #include <linux/gpio/consumer.h> #include <linux/property.h> #include <linux/of.h> /** * struct gpio_mouse * @scan_ms: the scan interval in milliseconds. * @up: GPIO line for up value. * @down: GPIO line for down value. * @left: GPIO line for left value. * @right: GPIO line for right value. * @bleft: GPIO line for left button. * @bmiddle: GPIO line for middle button. * @bright: GPIO line for right button. * * This struct must be added to the platform_device in the board code. * It is used by the gpio_mouse driver to setup GPIO lines and to * calculate mouse movement. */ struct gpio_mouse { u32 scan_ms; struct gpio_desc *up; struct gpio_desc *down; struct gpio_desc *left; struct gpio_desc *right; struct gpio_desc *bleft; struct gpio_desc *bmiddle; struct gpio_desc *bright; }; /* * Timer function which is run every scan_ms ms when the device is opened. * The dev input variable is set to the input_dev pointer. */ static void gpio_mouse_scan(struct input_dev *input) { struct gpio_mouse *gpio = input_get_drvdata(input); int x, y; if (gpio->bleft) input_report_key(input, BTN_LEFT, gpiod_get_value(gpio->bleft)); if (gpio->bmiddle) input_report_key(input, BTN_MIDDLE, gpiod_get_value(gpio->bmiddle)); if (gpio->bright) input_report_key(input, BTN_RIGHT, gpiod_get_value(gpio->bright)); x = gpiod_get_value(gpio->right) - gpiod_get_value(gpio->left); y = gpiod_get_value(gpio->down) - gpiod_get_value(gpio->up); input_report_rel(input, REL_X, x); input_report_rel(input, REL_Y, y); input_sync(input); } static int gpio_mouse_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct gpio_mouse *gmouse; struct input_dev *input; int error; gmouse = devm_kzalloc(dev, sizeof(*gmouse), GFP_KERNEL); if (!gmouse) return -ENOMEM; /* Assign some default scanning time */ error = device_property_read_u32(dev, "scan-interval-ms", &gmouse->scan_ms); if (error || gmouse->scan_ms == 0) { dev_warn(dev, "invalid scan time, set to 50 ms\n"); gmouse->scan_ms = 50; } gmouse->up = devm_gpiod_get(dev, "up", GPIOD_IN); if (IS_ERR(gmouse->up)) return PTR_ERR(gmouse->up); gmouse->down = devm_gpiod_get(dev, "down", GPIOD_IN); if (IS_ERR(gmouse->down)) return PTR_ERR(gmouse->down); gmouse->left = devm_gpiod_get(dev, "left", GPIOD_IN); if (IS_ERR(gmouse->left)) return PTR_ERR(gmouse->left); gmouse->right = devm_gpiod_get(dev, "right", GPIOD_IN); if (IS_ERR(gmouse->right)) return PTR_ERR(gmouse->right); gmouse->bleft = devm_gpiod_get_optional(dev, "button-left", GPIOD_IN); if (IS_ERR(gmouse->bleft)) return PTR_ERR(gmouse->bleft); gmouse->bmiddle = devm_gpiod_get_optional(dev, "button-middle", GPIOD_IN); if (IS_ERR(gmouse->bmiddle)) return PTR_ERR(gmouse->bmiddle); gmouse->bright = devm_gpiod_get_optional(dev, "button-right", GPIOD_IN); if (IS_ERR(gmouse->bright)) return PTR_ERR(gmouse->bright); input = devm_input_allocate_device(dev); if (!input) return -ENOMEM; input->name = pdev->name; input->id.bustype = BUS_HOST; input_set_drvdata(input, gmouse); input_set_capability(input, EV_REL, REL_X); input_set_capability(input, EV_REL, REL_Y); if (gmouse->bleft) input_set_capability(input, EV_KEY, BTN_LEFT); if (gmouse->bmiddle) input_set_capability(input, EV_KEY, BTN_MIDDLE); if (gmouse->bright) input_set_capability(input, EV_KEY, BTN_RIGHT); error = input_setup_polling(input, gpio_mouse_scan); if (error) return error; input_set_poll_interval(input, gmouse->scan_ms); error = input_register_device(input); if (error) { dev_err(dev, "could not register input device\n"); return error; } dev_dbg(dev, "%d ms scan time, buttons: %s%s%s\n", gmouse->scan_ms, gmouse->bleft ? "" : "left ", gmouse->bmiddle ? "" : "middle ", gmouse->bright ? "" : "right"); return 0; } static const struct of_device_id gpio_mouse_of_match[] = { { .compatible = "gpio-mouse", }, { }, }; MODULE_DEVICE_TABLE(of, gpio_mouse_of_match); static struct platform_driver gpio_mouse_device_driver = { .probe = gpio_mouse_probe, .driver = { .name = "gpio_mouse", .of_match_table = gpio_mouse_of_match, } }; module_platform_driver(gpio_mouse_device_driver); MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>"); MODULE_DESCRIPTION("GPIO mouse driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */ |