blob: a84df39d3b2fa6e3d88ba9671cfb693ae3b2d85d [file] [log] [blame]
// 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");