Commit 552e4047 authored by Oleh Kravchenko's avatar Oleh Kravchenko Committed by Dmitry Torokhov
Browse files

Input: add SparkFun Qwiic Joystick driver 

A simple analog joystick built on Low Power ATtiny85 Microcontroller.
Directional movements are measured with two 10 kΩ potentiometers
connected with a gimbal mechanism that separates the horizontal and
vertical movements. This joystick also has a select button that is actuated
when the joystick is pressed down.

Input events polled over the I2C bus.

Product page:
https://www.sparkfun.com/products/15168
Firmware and hardware sources:
https://github.com/sparkfun/Qwiic_Joystick



Tested on RPi4B and O4-iMX-NANO boards.

Signed-off-by: default avatarOleh Kravchenko <oleg@kaa.org.ua>
Reviewed-by: default avatarJeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20210608223130.16830-2-oleg@kaa.org.ua


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 9b233696

drivers/input/joystick/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -372,6 +372,15 @@ config JOYSTICK_PXRC 
	  To compile this driver as a module, choose M here: the

	  module will be called pxrc.



config JOYSTICK_QWIIC

	tristate "SparkFun Qwiic Joystick"

	depends on I2C

	help

	  Say Y here if you want to use the SparkFun Qwiic Joystick.



	  To compile this driver as a module, choose M here: the

	  module will be called qwiic-joystick.



config JOYSTICK_FSIA6B

	tristate "FlySky FS-iA6B RC Receiver"

	select SERIO

drivers/input/joystick/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ obj-$(CONFIG_JOYSTICK_MAPLE) += maplecontrol.o 
obj-$(CONFIG_JOYSTICK_N64)		+= n64joy.o

obj-$(CONFIG_JOYSTICK_PSXPAD_SPI)	+= psxpad-spi.o

obj-$(CONFIG_JOYSTICK_PXRC)		+= pxrc.o

obj-$(CONFIG_JOYSTICK_QWIIC)		+= qwiic-joystick.o

obj-$(CONFIG_JOYSTICK_SIDEWINDER)	+= sidewinder.o

obj-$(CONFIG_JOYSTICK_SPACEBALL)	+= spaceball.o

obj-$(CONFIG_JOYSTICK_SPACEORB)		+= spaceorb.o

drivers/input/joystick/qwiic-joystick.c

0 → 100644
+146 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) 2021 Oleh Kravchenko <oleg@kaa.org.ua>

 *

 * SparkFun Qwiic Joystick

 * Product page:https://www.sparkfun.com/products/15168

 * Firmware and hardware sources:https://github.com/sparkfun/Qwiic_Joystick

 */



#include <linux/bits.h>

#include <linux/i2c.h>

#include <linux/input.h>

#include <linux/kernel.h>

#include <linux/module.h>



#define DRV_NAME "qwiic-joystick"



#define QWIIC_JSK_REG_VERS	1

#define QWIIC_JSK_REG_DATA	3



#define QWIIC_JSK_MAX_AXIS	GENMASK(9, 0)

#define QWIIC_JSK_FUZZ		2

#define QWIIC_JSK_FLAT		2

#define QWIIC_JSK_POLL_INTERVAL	16

#define QWIIC_JSK_POLL_MIN	8

#define QWIIC_JSK_POLL_MAX	32



struct qwiic_jsk {

	char phys[32];

	struct input_dev *dev;

	struct i2c_client *client;

};



struct qwiic_ver {

	u8 major;

	u8 minor;

};



struct qwiic_data {

	__be16 x;

	__be16 y;

	u8 thumb;

};



static void qwiic_poll(struct input_dev *input)

{

	struct qwiic_jsk *priv = input_get_drvdata(input);

	struct qwiic_data data;

	int err;



	err = i2c_smbus_read_i2c_block_data(priv->client, QWIIC_JSK_REG_DATA,

					    sizeof(data), (u8 *)&data);

	if (err != sizeof(data))

		return;



	input_report_abs(input, ABS_X, be16_to_cpu(data.x) >> 6);

	input_report_abs(input, ABS_Y, be16_to_cpu(data.y) >> 6);

	input_report_key(input, BTN_THUMBL, !data.thumb);

	input_sync(input);

}



static int qwiic_probe(struct i2c_client *client)

{

	struct qwiic_jsk *priv;

	struct qwiic_ver vers;

	int err;



	err = i2c_smbus_read_i2c_block_data(client, QWIIC_JSK_REG_VERS,

					    sizeof(vers), (u8 *)&vers);

	if (err < 0)

		return err;

	if (err != sizeof(vers))

		return -EIO;



	dev_dbg(&client->dev, "SparkFun Qwiic Joystick, FW: %u.%u\n",

		vers.major, vers.minor);



	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;



	priv->client = client;

	snprintf(priv->phys, sizeof(priv->phys),

		 "i2c/%s", dev_name(&client->dev));

	i2c_set_clientdata(client, priv);



	priv->dev = devm_input_allocate_device(&client->dev);

	if (!priv->dev)

		return -ENOMEM;



	priv->dev->id.bustype = BUS_I2C;

	priv->dev->name = "SparkFun Qwiic Joystick";

	priv->dev->phys = priv->phys;

	input_set_drvdata(priv->dev, priv);



	input_set_abs_params(priv->dev, ABS_X, 0, QWIIC_JSK_MAX_AXIS,

			     QWIIC_JSK_FUZZ, QWIIC_JSK_FLAT);

	input_set_abs_params(priv->dev, ABS_Y, 0, QWIIC_JSK_MAX_AXIS,

			     QWIIC_JSK_FUZZ, QWIIC_JSK_FLAT);

	input_set_capability(priv->dev, EV_KEY, BTN_THUMBL);



	err = input_setup_polling(priv->dev, qwiic_poll);

	if (err) {

		dev_err(&client->dev, "failed to set up polling: %d\n", err);

		return err;

	}

	input_set_poll_interval(priv->dev, QWIIC_JSK_POLL_INTERVAL);

	input_set_min_poll_interval(priv->dev, QWIIC_JSK_POLL_MIN);

	input_set_max_poll_interval(priv->dev, QWIIC_JSK_POLL_MAX);



	err = input_register_device(priv->dev);

	if (err) {

		dev_err(&client->dev, "failed to register joystick: %d\n", err);

		return err;

	}



	return 0;

}



#ifdef CONFIG_OF

static const struct of_device_id of_qwiic_match[] = {

	{ .compatible = "sparkfun,qwiic-joystick", },

	{ },

};

MODULE_DEVICE_TABLE(of, of_qwiic_match);

#endif /* CONFIG_OF */



static const struct i2c_device_id qwiic_id_table[] = {

	{ KBUILD_MODNAME, 0 },

	{ },

};

MODULE_DEVICE_TABLE(i2c, qwiic_id_table);



static struct i2c_driver qwiic_driver = {

	.driver = {

		.name		= DRV_NAME,

		.of_match_table	= of_match_ptr(of_qwiic_match),

	},

	.id_table	= qwiic_id_table,

	.probe_new	= qwiic_probe,

};

module_i2c_driver(qwiic_driver);



MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");

MODULE_DESCRIPTION("SparkFun Qwiic Joystick driver");

MODULE_LICENSE("GPL v2");