1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * D-Link DIR-685 router I2C-based Touchkeys input driver |
4 | * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> |
5 | * |
6 | * This is a one-off touchkey controller based on the Cypress Semiconductor |
7 | * CY8C214 MCU with some firmware in its internal 8KB flash. The circuit |
8 | * board inside the router is named E119921 |
9 | */ |
10 | |
11 | #include <linux/module.h> |
12 | #include <linux/i2c.h> |
13 | #include <linux/interrupt.h> |
14 | #include <linux/delay.h> |
15 | #include <linux/input.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/bitops.h> |
18 | |
19 | struct dir685_touchkeys { |
20 | struct device *dev; |
21 | struct i2c_client *client; |
22 | struct input_dev *input; |
23 | unsigned long cur_key; |
24 | u16 codes[7]; |
25 | }; |
26 | |
27 | static irqreturn_t dir685_tk_irq_thread(int irq, void *data) |
28 | { |
29 | struct dir685_touchkeys *tk = data; |
30 | const int num_bits = min_t(int, ARRAY_SIZE(tk->codes), 16); |
31 | unsigned long changed; |
32 | u8 buf[6]; |
33 | unsigned long key; |
34 | int i; |
35 | int err; |
36 | |
37 | memset(buf, 0, sizeof(buf)); |
38 | err = i2c_master_recv(client: tk->client, buf, count: sizeof(buf)); |
39 | if (err != sizeof(buf)) { |
40 | dev_err(tk->dev, "short read %d\n" , err); |
41 | return IRQ_HANDLED; |
42 | } |
43 | |
44 | dev_dbg(tk->dev, "IN: %*ph\n" , (int)sizeof(buf), buf); |
45 | key = be16_to_cpup(p: (__be16 *) &buf[4]); |
46 | |
47 | /* Figure out if any bits went high or low since last message */ |
48 | changed = tk->cur_key ^ key; |
49 | for_each_set_bit(i, &changed, num_bits) { |
50 | dev_dbg(tk->dev, "key %d is %s\n" , i, |
51 | test_bit(i, &key) ? "down" : "up" ); |
52 | input_report_key(dev: tk->input, code: tk->codes[i], test_bit(i, &key)); |
53 | } |
54 | |
55 | /* Store currently down keys */ |
56 | tk->cur_key = key; |
57 | input_sync(dev: tk->input); |
58 | |
59 | return IRQ_HANDLED; |
60 | } |
61 | |
62 | static int dir685_tk_probe(struct i2c_client *client) |
63 | { |
64 | static const u8 bl_data[] = { 0xa7, 0x40 }; |
65 | struct device *dev = &client->dev; |
66 | struct dir685_touchkeys *tk; |
67 | int err; |
68 | int i; |
69 | |
70 | tk = devm_kzalloc(dev: &client->dev, size: sizeof(*tk), GFP_KERNEL); |
71 | if (!tk) |
72 | return -ENOMEM; |
73 | |
74 | tk->input = devm_input_allocate_device(dev); |
75 | if (!tk->input) |
76 | return -ENOMEM; |
77 | |
78 | tk->client = client; |
79 | tk->dev = dev; |
80 | |
81 | tk->input->keycodesize = sizeof(u16); |
82 | tk->input->keycodemax = ARRAY_SIZE(tk->codes); |
83 | tk->input->keycode = tk->codes; |
84 | tk->codes[0] = KEY_UP; |
85 | tk->codes[1] = KEY_DOWN; |
86 | tk->codes[2] = KEY_LEFT; |
87 | tk->codes[3] = KEY_RIGHT; |
88 | tk->codes[4] = KEY_ENTER; |
89 | tk->codes[5] = KEY_WPS_BUTTON; |
90 | /* |
91 | * This key appears in the vendor driver, but I have |
92 | * not been able to activate it. |
93 | */ |
94 | tk->codes[6] = KEY_RESERVED; |
95 | |
96 | __set_bit(EV_KEY, tk->input->evbit); |
97 | for (i = 0; i < ARRAY_SIZE(tk->codes); i++) |
98 | __set_bit(tk->codes[i], tk->input->keybit); |
99 | __clear_bit(KEY_RESERVED, tk->input->keybit); |
100 | |
101 | tk->input->name = "D-Link DIR-685 touchkeys" ; |
102 | tk->input->id.bustype = BUS_I2C; |
103 | |
104 | err = input_register_device(tk->input); |
105 | if (err) |
106 | return err; |
107 | |
108 | /* Set the brightness to max level */ |
109 | err = i2c_master_send(client, buf: bl_data, count: sizeof(bl_data)); |
110 | if (err != sizeof(bl_data)) |
111 | dev_warn(tk->dev, "error setting brightness level\n" ); |
112 | |
113 | if (!client->irq) { |
114 | dev_err(dev, "no IRQ on the I2C device\n" ); |
115 | return -ENODEV; |
116 | } |
117 | err = devm_request_threaded_irq(dev, irq: client->irq, |
118 | NULL, thread_fn: dir685_tk_irq_thread, |
119 | IRQF_ONESHOT, |
120 | devname: "dir685-tk" , dev_id: tk); |
121 | if (err) { |
122 | dev_err(dev, "can't request IRQ\n" ); |
123 | return err; |
124 | } |
125 | |
126 | return 0; |
127 | } |
128 | |
129 | static const struct i2c_device_id dir685_tk_id[] = { |
130 | { "dir685tk" , 0 }, |
131 | { } |
132 | }; |
133 | MODULE_DEVICE_TABLE(i2c, dir685_tk_id); |
134 | |
135 | #ifdef CONFIG_OF |
136 | static const struct of_device_id dir685_tk_of_match[] = { |
137 | { .compatible = "dlink,dir685-touchkeys" }, |
138 | {}, |
139 | }; |
140 | MODULE_DEVICE_TABLE(of, dir685_tk_of_match); |
141 | #endif |
142 | |
143 | static struct i2c_driver dir685_tk_i2c_driver = { |
144 | .driver = { |
145 | .name = "dlink-dir685-touchkeys" , |
146 | .of_match_table = of_match_ptr(dir685_tk_of_match), |
147 | }, |
148 | .probe = dir685_tk_probe, |
149 | .id_table = dir685_tk_id, |
150 | }; |
151 | module_i2c_driver(dir685_tk_i2c_driver); |
152 | |
153 | MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>" ); |
154 | MODULE_DESCRIPTION("D-Link DIR-685 touchkeys driver" ); |
155 | MODULE_LICENSE("GPL" ); |
156 | |