This is an interrupt-driven driver for digital joysticks connected to GPIOs. Supports any digital joystick with signals for up, down, left, right and one signal for trigger button press, i.e. C64/Atari joysticks.
Signed-off-by: Hans Holmberg <[email protected]> --- drivers/input/joystick/Kconfig | 10 ++ drivers/input/joystick/Makefile | 1 + drivers/input/joystick/gpio_joy.c | 208 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 219 insertions(+) create mode 100644 drivers/input/joystick/gpio_joy.c diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig index 56eb471..de0220e 100644 --- a/drivers/input/joystick/Kconfig +++ b/drivers/input/joystick/Kconfig @@ -70,6 +70,16 @@ config JOYSTICK_GF2K To compile this driver as a module, choose M here: the module will be called gf2k. +config JOYSTICK_GPIO + tristate "Joysticks connected to GPIOs" + depends on GPIOLIB + help + Say Y here if you have one or more joysticks connected to your + device directly via GPIOs. + + To compile this driver as a module, choose M here: the + module will be called gpio_joy. + config JOYSTICK_GRIP tristate "Gravis GrIP joysticks and gamepads" select GAMEPORT diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile index 92dc0de..c20a51a 100644 --- a/drivers/input/joystick/Makefile +++ b/drivers/input/joystick/Makefile @@ -13,6 +13,7 @@ obj-$(CONFIG_JOYSTICK_COBRA) += cobra.o obj-$(CONFIG_JOYSTICK_DB9) += db9.o obj-$(CONFIG_JOYSTICK_GAMECON) += gamecon.o obj-$(CONFIG_JOYSTICK_GF2K) += gf2k.o +obj-$(CONFIG_JOYSTICK_GPIO) += gpio_joy.o obj-$(CONFIG_JOYSTICK_GRIP) += grip.o obj-$(CONFIG_JOYSTICK_GRIP_MP) += grip_mp.o obj-$(CONFIG_JOYSTICK_GUILLEMOT) += guillemot.o diff --git a/drivers/input/joystick/gpio_joy.c b/drivers/input/joystick/gpio_joy.c new file mode 100644 index 0000000..d0e22b3 --- /dev/null +++ b/drivers/input/joystick/gpio_joy.c @@ -0,0 +1,208 @@ +/* + * Driver for digital joysticks connected using GPIOs + * + * Copyright (C) 2015, Intel Corporation + * Author: Hans Holmberg <[email protected]> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/gpio/consumer.h> +#include <linux/workqueue.h> +#include <linux/kernel.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/timer.h> +#include <linux/jiffies.h> +#include <linux/input.h> +#include <linux/property.h> + +#define DRV_NAME "gpio-joy" +#define DEFAULT_DEBOUNCE_MS 10 + +enum control_pin_indices { + LEFT, + RIGHT, + UP, + DOWN, + BUTTON, + NUM_CONTROL_PINS, +}; + +static const char *gpio_ids[NUM_CONTROL_PINS] = { + "left", "right", "up", "down", "button"}; + +struct control_pin { + struct gpio_desc *gpio; + int irq; +}; + +struct gpio_joy_drvdata { + struct input_dev *input; + struct delayed_work work; + unsigned long debounce_jiffies; + struct control_pin control_pins[NUM_CONTROL_PINS]; +}; + +static void gpio_joy_report_state(struct gpio_joy_drvdata *ddata) +{ + struct input_dev *input = ddata->input; + + input_report_abs(input, ABS_X, + gpiod_get_value_cansleep(ddata->control_pins[RIGHT].gpio) - + gpiod_get_value_cansleep(ddata->control_pins[LEFT].gpio)); + + input_report_abs(input, ABS_Y, + gpiod_get_value_cansleep(ddata->control_pins[DOWN].gpio) - + gpiod_get_value_cansleep(ddata->control_pins[UP].gpio)); + + input_report_key(input, BTN_TRIGGER, + gpiod_get_value_cansleep(ddata->control_pins[BUTTON].gpio)); + + input_sync(input); +} + +static void gpio_joy_work(struct work_struct *work) +{ + struct delayed_work *delayed_work = + container_of(work, struct delayed_work, work); + struct gpio_joy_drvdata *ddata = + container_of(delayed_work, struct gpio_joy_drvdata, work); + + gpio_joy_report_state(ddata); +} + +static irqreturn_t gpio_joy_isr(int irq, void *dev_id) +{ + struct gpio_joy_drvdata *ddata = dev_id; + + mod_delayed_work(system_wq, &ddata->work, ddata->debounce_jiffies); + + return IRQ_HANDLED; +} + +static void gpio_joy_quiesce(void *data) +{ + struct gpio_joy_drvdata *ddata = data; + + cancel_delayed_work_sync(&ddata->work); +} + +static int gpio_joy_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct input_dev *input; + struct gpio_joy_drvdata *ddata; + int i, err; + unsigned int debounce_ms; + + ddata = devm_kzalloc(dev, sizeof(struct gpio_joy_drvdata), GFP_KERNEL); + if (!ddata) + return -ENOMEM; + + input = devm_input_allocate_device(dev); + if (!input) + return -ENOMEM; + + ddata->input = input; + platform_set_drvdata(pdev, ddata); + + input->name = pdev->name; + input->phys = DRV_NAME"/input0"; + input->dev.parent = &pdev->dev; + + input->id.bustype = BUS_HOST; + input->id.vendor = 0x0001; + input->id.product = 0x0001; + input->id.version = 0x0100; + + set_bit(EV_KEY, input->evbit); + set_bit(EV_ABS, input->evbit); + set_bit(BTN_TRIGGER, input->keybit); + + input_set_abs_params(input, ABS_X, -1, 1, 0, 0); + input_set_abs_params(input, ABS_Y, -1, 1, 0, 0); + + /* debounce interval is optional */ + if (device_property_read_u32(dev, "debounce-interval-ms", &debounce_ms)) + debounce_ms = DEFAULT_DEBOUNCE_MS; + ddata->debounce_jiffies = msecs_to_jiffies(debounce_ms); + + for (i = 0; i < ARRAY_SIZE(ddata->control_pins) ; i++) { + struct gpio_desc *gpio; + int irq; + + gpio = devm_gpiod_get(&pdev->dev, + gpio_ids[i]); + if (IS_ERR(gpio)) { + dev_err(dev, "unable to allocate gpio: %s\n", + gpio_ids[i]); + err = PTR_ERR(gpio); + goto fail; + } + ddata->control_pins[i].gpio = gpio; + + irq = gpiod_to_irq(gpio); + if (irq < 0) { + dev_err(dev, "unable to get irq for gpio: %s\n", + gpio_ids[i]); + err = irq; + goto fail; + } + ddata->control_pins[i].irq = irq; + } + + INIT_DELAYED_WORK(&ddata->work, gpio_joy_work); + err = devm_add_action(dev, gpio_joy_quiesce, ddata); + + for (i = 0; i < ARRAY_SIZE(ddata->control_pins) ; i++) { + err = devm_request_any_context_irq(dev, + ddata->control_pins[i].irq, + gpio_joy_isr, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | + IRQF_ONESHOT, + input->name, ddata); + + if (err < 0) { + dev_err(dev, "unable to claim irq %d\n", + ddata->control_pins[i].irq); + goto fail; + } + } + + err = input_register_device(input); + if (err) { + dev_err(dev, "unable to register input device\n"); + goto fail; + } + + return 0; +fail: + return err; +} + +static const struct of_device_id gpio_joy_of_match[] = { + { .compatible = DRV_NAME, }, + { }, +}; + +static struct platform_driver gpio_joy_driver = { + .probe = gpio_joy_probe, + .driver = { + .name = DRV_NAME, + .of_match_table = gpio_joy_of_match, + } +}; + +module_platform_driver(gpio_joy_driver); + +MODULE_ALIAS("platform:" DRV_NAME); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Hans Holmberg <[email protected]>"); +MODULE_DESCRIPTION("Driver for digital joysticks connected via GPIOs"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
