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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
131b3de7 LW |
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(tk->client, buf, 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((__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(tk->input, tk->codes[i], test_bit(i, &key)); | |
53 | } | |
54 | ||
55 | /* Store currently down keys */ | |
56 | tk->cur_key = key; | |
57 | input_sync(tk->input); | |
58 | ||
59 | return IRQ_HANDLED; | |
60 | } | |
61 | ||
62 | static int dir685_tk_probe(struct i2c_client *client, | |
63 | const struct i2c_device_id *id) | |
64 | { | |
65 | struct dir685_touchkeys *tk; | |
66 | struct device *dev = &client->dev; | |
67 | u8 bl_data[] = { 0xa7, 0x40 }; | |
68 | int err; | |
69 | int i; | |
70 | ||
71 | tk = devm_kzalloc(&client->dev, sizeof(*tk), GFP_KERNEL); | |
72 | if (!tk) | |
73 | return -ENOMEM; | |
74 | ||
75 | tk->input = devm_input_allocate_device(dev); | |
76 | if (!tk->input) | |
77 | return -ENOMEM; | |
78 | ||
79 | tk->client = client; | |
80 | tk->dev = dev; | |
81 | ||
82 | tk->input->keycodesize = sizeof(u16); | |
83 | tk->input->keycodemax = ARRAY_SIZE(tk->codes); | |
84 | tk->input->keycode = tk->codes; | |
85 | tk->codes[0] = KEY_UP; | |
86 | tk->codes[1] = KEY_DOWN; | |
87 | tk->codes[2] = KEY_LEFT; | |
88 | tk->codes[3] = KEY_RIGHT; | |
89 | tk->codes[4] = KEY_ENTER; | |
90 | tk->codes[5] = KEY_WPS_BUTTON; | |
91 | /* | |
92 | * This key appears in the vendor driver, but I have | |
93 | * not been able to activate it. | |
94 | */ | |
95 | tk->codes[6] = KEY_RESERVED; | |
96 | ||
97 | __set_bit(EV_KEY, tk->input->evbit); | |
98 | for (i = 0; i < ARRAY_SIZE(tk->codes); i++) | |
99 | __set_bit(tk->codes[i], tk->input->keybit); | |
100 | __clear_bit(KEY_RESERVED, tk->input->keybit); | |
101 | ||
102 | tk->input->name = "D-Link DIR-685 touchkeys"; | |
103 | tk->input->id.bustype = BUS_I2C; | |
104 | ||
105 | err = input_register_device(tk->input); | |
106 | if (err) | |
107 | return err; | |
108 | ||
109 | /* Set the brightness to max level */ | |
110 | err = i2c_master_send(client, bl_data, sizeof(bl_data)); | |
111 | if (err != sizeof(bl_data)) | |
112 | dev_warn(tk->dev, "error setting brightness level\n"); | |
113 | ||
114 | if (!client->irq) { | |
115 | dev_err(dev, "no IRQ on the I2C device\n"); | |
116 | return -ENODEV; | |
117 | } | |
118 | err = devm_request_threaded_irq(dev, client->irq, | |
119 | NULL, dir685_tk_irq_thread, | |
120 | IRQF_ONESHOT, | |
121 | "dir685-tk", tk); | |
122 | if (err) { | |
123 | dev_err(dev, "can't request IRQ\n"); | |
124 | return err; | |
125 | } | |
126 | ||
127 | return 0; | |
128 | } | |
129 | ||
130 | static const struct i2c_device_id dir685_tk_id[] = { | |
131 | { "dir685tk", 0 }, | |
132 | { } | |
133 | }; | |
134 | MODULE_DEVICE_TABLE(i2c, dir685_tk_id); | |
135 | ||
136 | #ifdef CONFIG_OF | |
137 | static const struct of_device_id dir685_tk_of_match[] = { | |
138 | { .compatible = "dlink,dir685-touchkeys" }, | |
139 | {}, | |
140 | }; | |
141 | MODULE_DEVICE_TABLE(of, dir685_tk_of_match); | |
142 | #endif | |
143 | ||
144 | static struct i2c_driver dir685_tk_i2c_driver = { | |
145 | .driver = { | |
38347374 | 146 | .name = "dlink-dir685-touchkeys", |
131b3de7 LW |
147 | .of_match_table = of_match_ptr(dir685_tk_of_match), |
148 | }, | |
149 | .probe = dir685_tk_probe, | |
150 | .id_table = dir685_tk_id, | |
151 | }; | |
152 | module_i2c_driver(dir685_tk_i2c_driver); | |
153 | ||
154 | MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); | |
155 | MODULE_DESCRIPTION("D-Link DIR-685 touchkeys driver"); | |
156 | MODULE_LICENSE("GPL"); |