179 lines
5 KiB
C
179 lines
5 KiB
C
/*
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* Driver for simulating a mouse on GPIO lines.
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*
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* Copyright (C) 2007 Atmel Corporation
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* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/input-polldev.h>
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#include <linux/gpio/consumer.h>
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#include <linux/property.h>
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#include <linux/of.h>
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/**
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* struct gpio_mouse
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* @scan_ms: the scan interval in milliseconds.
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* @up: GPIO line for up value.
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* @down: GPIO line for down value.
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* @left: GPIO line for left value.
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* @right: GPIO line for right value.
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* @bleft: GPIO line for left button.
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* @bmiddle: GPIO line for middle button.
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* @bright: GPIO line for right button.
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*
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* This struct must be added to the platform_device in the board code.
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* It is used by the gpio_mouse driver to setup GPIO lines and to
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* calculate mouse movement.
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*/
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struct gpio_mouse {
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u32 scan_ms;
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struct gpio_desc *up;
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struct gpio_desc *down;
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struct gpio_desc *left;
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struct gpio_desc *right;
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struct gpio_desc *bleft;
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struct gpio_desc *bmiddle;
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struct gpio_desc *bright;
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};
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/*
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* Timer function which is run every scan_ms ms when the device is opened.
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* The dev input variable is set to the the input_dev pointer.
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*/
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static void gpio_mouse_scan(struct input_polled_dev *dev)
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{
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struct gpio_mouse *gpio = dev->private;
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struct input_dev *input = dev->input;
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int x, y;
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if (gpio->bleft)
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input_report_key(input, BTN_LEFT,
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gpiod_get_value(gpio->bleft));
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if (gpio->bmiddle)
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input_report_key(input, BTN_MIDDLE,
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gpiod_get_value(gpio->bmiddle));
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if (gpio->bright)
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input_report_key(input, BTN_RIGHT,
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gpiod_get_value(gpio->bright));
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x = gpiod_get_value(gpio->right) - gpiod_get_value(gpio->left);
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y = gpiod_get_value(gpio->down) - gpiod_get_value(gpio->up);
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input_report_rel(input, REL_X, x);
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input_report_rel(input, REL_Y, y);
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input_sync(input);
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}
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static int gpio_mouse_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct gpio_mouse *gmouse;
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struct input_polled_dev *input_poll;
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struct input_dev *input;
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int ret;
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gmouse = devm_kzalloc(dev, sizeof(*gmouse), GFP_KERNEL);
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if (!gmouse)
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return -ENOMEM;
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/* Assign some default scanning time */
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ret = device_property_read_u32(dev, "scan-interval-ms",
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&gmouse->scan_ms);
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if (ret || gmouse->scan_ms == 0) {
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dev_warn(dev, "invalid scan time, set to 50 ms\n");
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gmouse->scan_ms = 50;
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}
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gmouse->up = devm_gpiod_get(dev, "up", GPIOD_IN);
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if (IS_ERR(gmouse->up))
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return PTR_ERR(gmouse->up);
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gmouse->down = devm_gpiod_get(dev, "down", GPIOD_IN);
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if (IS_ERR(gmouse->down))
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return PTR_ERR(gmouse->down);
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gmouse->left = devm_gpiod_get(dev, "left", GPIOD_IN);
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if (IS_ERR(gmouse->left))
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return PTR_ERR(gmouse->left);
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gmouse->right = devm_gpiod_get(dev, "right", GPIOD_IN);
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if (IS_ERR(gmouse->right))
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return PTR_ERR(gmouse->right);
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gmouse->bleft = devm_gpiod_get_optional(dev, "button-left", GPIOD_IN);
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if (IS_ERR(gmouse->bleft))
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return PTR_ERR(gmouse->bleft);
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gmouse->bmiddle = devm_gpiod_get_optional(dev, "button-middle",
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GPIOD_IN);
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if (IS_ERR(gmouse->bmiddle))
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return PTR_ERR(gmouse->bmiddle);
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gmouse->bright = devm_gpiod_get_optional(dev, "button-right",
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GPIOD_IN);
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if (IS_ERR(gmouse->bright))
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return PTR_ERR(gmouse->bright);
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input_poll = devm_input_allocate_polled_device(dev);
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if (!input_poll) {
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dev_err(dev, "not enough memory for input device\n");
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return -ENOMEM;
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}
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platform_set_drvdata(pdev, input_poll);
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/* set input-polldev handlers */
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input_poll->private = gmouse;
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input_poll->poll = gpio_mouse_scan;
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input_poll->poll_interval = gmouse->scan_ms;
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input = input_poll->input;
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input->name = pdev->name;
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input->id.bustype = BUS_HOST;
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input->dev.parent = &pdev->dev;
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input_set_capability(input, EV_REL, REL_X);
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input_set_capability(input, EV_REL, REL_Y);
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if (gmouse->bleft)
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input_set_capability(input, EV_KEY, BTN_LEFT);
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if (gmouse->bmiddle)
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input_set_capability(input, EV_KEY, BTN_MIDDLE);
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if (gmouse->bright)
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input_set_capability(input, EV_KEY, BTN_RIGHT);
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ret = input_register_polled_device(input_poll);
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if (ret) {
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dev_err(dev, "could not register input device\n");
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return ret;
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}
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dev_dbg(dev, "%d ms scan time, buttons: %s%s%s\n",
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gmouse->scan_ms,
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gmouse->bleft ? "" : "left ",
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gmouse->bmiddle ? "" : "middle ",
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gmouse->bright ? "" : "right");
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return 0;
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}
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static const struct of_device_id gpio_mouse_of_match[] = {
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{ .compatible = "gpio-mouse", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, gpio_mouse_of_match);
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static struct platform_driver gpio_mouse_device_driver = {
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.probe = gpio_mouse_probe,
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.driver = {
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.name = "gpio_mouse",
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.of_match_table = gpio_mouse_of_match,
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}
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};
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module_platform_driver(gpio_mouse_device_driver);
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MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>");
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MODULE_DESCRIPTION("GPIO mouse driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:gpio_mouse"); /* work with hotplug and coldplug */
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