1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2021 Oleh Kravchenko <oleg@kaa.org.ua>
  4 *
  5 * SparkFun Qwiic Joystick
  6 * Product page:https://www.sparkfun.com/products/15168
  7 * Firmware and hardware sources:https://github.com/sparkfun/Qwiic_Joystick
  8 */
  9
 10#include <linux/bits.h>
 11#include <linux/i2c.h>
 12#include <linux/input.h>
 13#include <linux/kernel.h>
 14#include <linux/module.h>
 15
 16#define DRV_NAME "qwiic-joystick"
 17
 18#define QWIIC_JSK_REG_VERS	1
 19#define QWIIC_JSK_REG_DATA	3
 20
 21#define QWIIC_JSK_MAX_AXIS	GENMASK(9, 0)
 22#define QWIIC_JSK_FUZZ		2
 23#define QWIIC_JSK_FLAT		2
 24#define QWIIC_JSK_POLL_INTERVAL	16
 25#define QWIIC_JSK_POLL_MIN	8
 26#define QWIIC_JSK_POLL_MAX	32
 27
 28struct qwiic_jsk {
 29	char phys[32];
 30	struct input_dev *dev;
 31	struct i2c_client *client;
 32};
 33
 34struct qwiic_ver {
 35	u8 major;
 36	u8 minor;
 37};
 38
 39struct qwiic_data {
 40	__be16 x;
 41	__be16 y;
 42	u8 thumb;
 43};
 44
 45static void qwiic_poll(struct input_dev *input)
 46{
 47	struct qwiic_jsk *priv = input_get_drvdata(input);
 48	struct qwiic_data data;
 49	int err;
 50
 51	err = i2c_smbus_read_i2c_block_data(priv->client, QWIIC_JSK_REG_DATA,
 52					    sizeof(data), (u8 *)&data);
 53	if (err != sizeof(data))
 54		return;
 55
 56	input_report_abs(input, ABS_X, be16_to_cpu(data.x) >> 6);
 57	input_report_abs(input, ABS_Y, be16_to_cpu(data.y) >> 6);
 58	input_report_key(input, BTN_THUMBL, !data.thumb);
 59	input_sync(input);
 60}
 61
 62static int qwiic_probe(struct i2c_client *client)
 63{
 64	struct qwiic_jsk *priv;
 65	struct qwiic_ver vers;
 66	int err;
 67
 68	err = i2c_smbus_read_i2c_block_data(client, QWIIC_JSK_REG_VERS,
 69					    sizeof(vers), (u8 *)&vers);
 70	if (err < 0)
 71		return err;
 72	if (err != sizeof(vers))
 73		return -EIO;
 74
 75	dev_dbg(&client->dev, "SparkFun Qwiic Joystick, FW: %u.%u\n",
 76		vers.major, vers.minor);
 77
 78	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
 79	if (!priv)
 80		return -ENOMEM;
 81
 82	priv->client = client;
 83	snprintf(priv->phys, sizeof(priv->phys),
 84		 "i2c/%s", dev_name(&client->dev));
 85	i2c_set_clientdata(client, priv);
 86
 87	priv->dev = devm_input_allocate_device(&client->dev);
 88	if (!priv->dev)
 89		return -ENOMEM;
 90
 91	priv->dev->id.bustype = BUS_I2C;
 92	priv->dev->name = "SparkFun Qwiic Joystick";
 93	priv->dev->phys = priv->phys;
 94	input_set_drvdata(priv->dev, priv);
 95
 96	input_set_abs_params(priv->dev, ABS_X, 0, QWIIC_JSK_MAX_AXIS,
 97			     QWIIC_JSK_FUZZ, QWIIC_JSK_FLAT);
 98	input_set_abs_params(priv->dev, ABS_Y, 0, QWIIC_JSK_MAX_AXIS,
 99			     QWIIC_JSK_FUZZ, QWIIC_JSK_FLAT);
100	input_set_capability(priv->dev, EV_KEY, BTN_THUMBL);
101
102	err = input_setup_polling(priv->dev, qwiic_poll);
103	if (err) {
104		dev_err(&client->dev, "failed to set up polling: %d\n", err);
105		return err;
106	}
107	input_set_poll_interval(priv->dev, QWIIC_JSK_POLL_INTERVAL);
108	input_set_min_poll_interval(priv->dev, QWIIC_JSK_POLL_MIN);
109	input_set_max_poll_interval(priv->dev, QWIIC_JSK_POLL_MAX);
110
111	err = input_register_device(priv->dev);
112	if (err) {
113		dev_err(&client->dev, "failed to register joystick: %d\n", err);
114		return err;
115	}
116
117	return 0;
118}
119
120#ifdef CONFIG_OF
121static const struct of_device_id of_qwiic_match[] = {
122	{ .compatible = "sparkfun,qwiic-joystick", },
123	{ },
124};
125MODULE_DEVICE_TABLE(of, of_qwiic_match);
126#endif /* CONFIG_OF */
127
128static const struct i2c_device_id qwiic_id_table[] = {
129	{ KBUILD_MODNAME },
130	{ }
131};
132MODULE_DEVICE_TABLE(i2c, qwiic_id_table);
133
134static struct i2c_driver qwiic_driver = {
135	.driver = {
136		.name		= DRV_NAME,
137		.of_match_table	= of_match_ptr(of_qwiic_match),
138	},
139	.id_table	= qwiic_id_table,
140	.probe		= qwiic_probe,
141};
142module_i2c_driver(qwiic_driver);
143
144MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>");
145MODULE_DESCRIPTION("SparkFun Qwiic Joystick driver");
146MODULE_LICENSE("GPL v2");