diff options
Diffstat (limited to 'drivers/input/joystick/sensehat-joystick.c')
| -rw-r--r-- | drivers/input/joystick/sensehat-joystick.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/input/joystick/sensehat-joystick.c b/drivers/input/joystick/sensehat-joystick.c new file mode 100644 index 0000000000..a84df39d3b --- /dev/null +++ b/drivers/input/joystick/sensehat-joystick.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Raspberry Pi Sense HAT joystick driver + * http://raspberrypi.org + * + * Copyright (C) 2015 Raspberry Pi + * Copyright (C) 2021 Charles Mirabile, Mwesigwa Guma, Joel Savitz + * + * Original Author: Serge Schneider + * Revised for upstream Linux by: Charles Mirabile, Mwesigwa Guma, Joel Savitz + */ + +#include <linux/module.h> +#include <linux/input.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/property.h> + +#define JOYSTICK_SMB_REG 0xf2 + +struct sensehat_joystick { + struct platform_device *pdev; + struct input_dev *keys_dev; + unsigned long prev_states; + struct regmap *regmap; +}; + +static const unsigned int keymap[] = { + BTN_DPAD_DOWN, BTN_DPAD_RIGHT, BTN_DPAD_UP, BTN_SELECT, BTN_DPAD_LEFT, +}; + +static irqreturn_t sensehat_joystick_report(int irq, void *cookie) +{ + struct sensehat_joystick *sensehat_joystick = cookie; + unsigned long curr_states, changes; + unsigned int keys; + int error; + int i; + + error = regmap_read(sensehat_joystick->regmap, JOYSTICK_SMB_REG, &keys); + if (error < 0) { + dev_err(&sensehat_joystick->pdev->dev, + "Failed to read joystick state: %d", error); + return IRQ_NONE; + } + curr_states = keys; + bitmap_xor(&changes, &curr_states, &sensehat_joystick->prev_states, + ARRAY_SIZE(keymap)); + + for_each_set_bit(i, &changes, ARRAY_SIZE(keymap)) + input_report_key(sensehat_joystick->keys_dev, keymap[i], + curr_states & BIT(i)); + + input_sync(sensehat_joystick->keys_dev); + sensehat_joystick->prev_states = keys; + return IRQ_HANDLED; +} + +static int sensehat_joystick_probe(struct platform_device *pdev) +{ + struct sensehat_joystick *sensehat_joystick; + int error, i, irq; + + sensehat_joystick = devm_kzalloc(&pdev->dev, sizeof(*sensehat_joystick), + GFP_KERNEL); + if (!sensehat_joystick) + return -ENOMEM; + + sensehat_joystick->pdev = pdev; + + sensehat_joystick->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!sensehat_joystick->regmap) { + dev_err(&pdev->dev, "unable to get sensehat regmap"); + return -ENODEV; + } + + sensehat_joystick->keys_dev = devm_input_allocate_device(&pdev->dev); + if (!sensehat_joystick->keys_dev) { + dev_err(&pdev->dev, "Could not allocate input device"); + return -ENOMEM; + } + + sensehat_joystick->keys_dev->name = "Raspberry Pi Sense HAT Joystick"; + sensehat_joystick->keys_dev->phys = "sensehat-joystick/input0"; + sensehat_joystick->keys_dev->id.bustype = BUS_I2C; + + __set_bit(EV_KEY, sensehat_joystick->keys_dev->evbit); + __set_bit(EV_REP, sensehat_joystick->keys_dev->evbit); + for (i = 0; i < ARRAY_SIZE(keymap); i++) + __set_bit(keymap[i], sensehat_joystick->keys_dev->keybit); + + error = input_register_device(sensehat_joystick->keys_dev); + if (error) { + dev_err(&pdev->dev, "Could not register input device"); + return error; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + error = devm_request_threaded_irq(&pdev->dev, irq, + NULL, sensehat_joystick_report, + IRQF_ONESHOT, "keys", + sensehat_joystick); + if (error) { + dev_err(&pdev->dev, "IRQ request failed"); + return error; + } + + return 0; +} + +static const struct of_device_id sensehat_joystick_device_id[] = { + { .compatible = "raspberrypi,sensehat-joystick" }, + {}, +}; +MODULE_DEVICE_TABLE(of, sensehat_joystick_device_id); + +static struct platform_driver sensehat_joystick_driver = { + .probe = sensehat_joystick_probe, + .driver = { + .name = "sensehat-joystick", + .of_match_table = sensehat_joystick_device_id, + }, +}; + +module_platform_driver(sensehat_joystick_driver); + +MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver"); +MODULE_AUTHOR("Charles Mirabile <cmirabil@redhat.com>"); +MODULE_AUTHOR("Serge Schneider <serge@raspberrypi.org>"); +MODULE_LICENSE("GPL"); |