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 | |
28 | struct qwiic_jsk { |
29 | char phys[32]; |
30 | struct input_dev *dev; |
31 | struct i2c_client *client; |
32 | }; |
33 | |
34 | struct qwiic_ver { |
35 | u8 major; |
36 | u8 minor; |
37 | }; |
38 | |
39 | struct qwiic_data { |
40 | __be16 x; |
41 | __be16 y; |
42 | u8 thumb; |
43 | }; |
44 | |
45 | static void qwiic_poll(struct input_dev *input) |
46 | { |
47 | struct qwiic_jsk *priv = input_get_drvdata(dev: input); |
48 | struct qwiic_data data; |
49 | int err; |
50 | |
51 | err = i2c_smbus_read_i2c_block_data(client: priv->client, QWIIC_JSK_REG_DATA, |
52 | length: sizeof(data), values: (u8 *)&data); |
53 | if (err != sizeof(data)) |
54 | return; |
55 | |
56 | input_report_abs(dev: input, ABS_X, be16_to_cpu(data.x) >> 6); |
57 | input_report_abs(dev: input, ABS_Y, be16_to_cpu(data.y) >> 6); |
58 | input_report_key(dev: input, BTN_THUMBL, value: !data.thumb); |
59 | input_sync(dev: input); |
60 | } |
61 | |
62 | static 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 | length: sizeof(vers), values: (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(dev: &client->dev, size: sizeof(*priv), GFP_KERNEL); |
79 | if (!priv) |
80 | return -ENOMEM; |
81 | |
82 | priv->client = client; |
83 | snprintf(buf: priv->phys, size: sizeof(priv->phys), |
84 | fmt: "i2c/%s" , dev_name(dev: &client->dev)); |
85 | i2c_set_clientdata(client, data: 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(dev: priv->dev, data: priv); |
95 | |
96 | input_set_abs_params(dev: priv->dev, ABS_X, min: 0, QWIIC_JSK_MAX_AXIS, |
97 | QWIIC_JSK_FUZZ, QWIIC_JSK_FLAT); |
98 | input_set_abs_params(dev: priv->dev, ABS_Y, min: 0, QWIIC_JSK_MAX_AXIS, |
99 | QWIIC_JSK_FUZZ, QWIIC_JSK_FLAT); |
100 | input_set_capability(dev: priv->dev, EV_KEY, BTN_THUMBL); |
101 | |
102 | err = input_setup_polling(dev: priv->dev, poll_fn: 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(dev: priv->dev, QWIIC_JSK_POLL_INTERVAL); |
108 | input_set_min_poll_interval(dev: priv->dev, QWIIC_JSK_POLL_MIN); |
109 | input_set_max_poll_interval(dev: 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 |
121 | static const struct of_device_id of_qwiic_match[] = { |
122 | { .compatible = "sparkfun,qwiic-joystick" , }, |
123 | { }, |
124 | }; |
125 | MODULE_DEVICE_TABLE(of, of_qwiic_match); |
126 | #endif /* CONFIG_OF */ |
127 | |
128 | static const struct i2c_device_id qwiic_id_table[] = { |
129 | { KBUILD_MODNAME, 0 }, |
130 | { }, |
131 | }; |
132 | MODULE_DEVICE_TABLE(i2c, qwiic_id_table); |
133 | |
134 | static 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 | }; |
142 | module_i2c_driver(qwiic_driver); |
143 | |
144 | MODULE_AUTHOR("Oleh Kravchenko <oleg@kaa.org.ua>" ); |
145 | MODULE_DESCRIPTION("SparkFun Qwiic Joystick driver" ); |
146 | MODULE_LICENSE("GPL v2" ); |
147 | |