diff options
Diffstat (limited to 'drivers/input/mouse/gpio_mouse.c')
| -rw-r--r-- | drivers/input/mouse/gpio_mouse.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/input/mouse/gpio_mouse.c b/drivers/input/mouse/gpio_mouse.c new file mode 100644 index 000000000..18ccbd450 --- /dev/null +++ b/drivers/input/mouse/gpio_mouse.c @@ -0,0 +1,170 @@ +// 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 */ |