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