summaryrefslogtreecommitdiff
path: root/drivers/input/keyboard/dlink-dir685-touchkeys.c
blob: b0ead7199c405a0e702ee478bfde94f0c6f433b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
// SPDX-License-Identifier: GPL-2.0-only
/*
 * D-Link DIR-685 router I2C-based Touchkeys input driver
 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
 *
 * This is a one-off touchkey controller based on the Cypress Semiconductor
 * CY8C214 MCU with some firmware in its internal 8KB flash. The circuit
 * board inside the router is named E119921
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/bitops.h>

struct dir685_touchkeys {
	struct device		*dev;
	struct i2c_client	*client;
	struct input_dev	*input;
	unsigned long		cur_key;
	u16			codes[7];
};

static irqreturn_t dir685_tk_irq_thread(int irq, void *data)
{
	struct dir685_touchkeys *tk = data;
	const int num_bits = min_t(int, ARRAY_SIZE(tk->codes), 16);
	unsigned long changed;
	u8 buf[6];
	unsigned long key;
	int i;
	int err;

	memset(buf, 0, sizeof(buf));
	err = i2c_master_recv(tk->client, buf, sizeof(buf));
	if (err != sizeof(buf)) {
		dev_err(tk->dev, "short read %d\n", err);
		return IRQ_HANDLED;
	}

	dev_dbg(tk->dev, "IN: %*ph\n", (int)sizeof(buf), buf);
	key = be16_to_cpup((__be16 *) &buf[4]);

	/* Figure out if any bits went high or low since last message */
	changed = tk->cur_key ^ key;
	for_each_set_bit(i, &changed, num_bits) {
		dev_dbg(tk->dev, "key %d is %s\n", i,
			test_bit(i, &key) ? "down" : "up");
		input_report_key(tk->input, tk->codes[i], test_bit(i, &key));
	}

	/* Store currently down keys */
	tk->cur_key = key;
	input_sync(tk->input);

	return IRQ_HANDLED;
}

static int dir685_tk_probe(struct i2c_client *client,
			   const struct i2c_device_id *id)
{
	struct dir685_touchkeys *tk;
	struct device *dev = &client->dev;
	u8 bl_data[] = { 0xa7, 0x40 };
	int err;
	int i;

	tk = devm_kzalloc(&client->dev, sizeof(*tk), GFP_KERNEL);
	if (!tk)
		return -ENOMEM;

	tk->input = devm_input_allocate_device(dev);
	if (!tk->input)
		return -ENOMEM;

	tk->client = client;
	tk->dev = dev;

	tk->input->keycodesize = sizeof(u16);
	tk->input->keycodemax = ARRAY_SIZE(tk->codes);
	tk->input->keycode = tk->codes;
	tk->codes[0] = KEY_UP;
	tk->codes[1] = KEY_DOWN;
	tk->codes[2] = KEY_LEFT;
	tk->codes[3] = KEY_RIGHT;
	tk->codes[4] = KEY_ENTER;
	tk->codes[5] = KEY_WPS_BUTTON;
	/*
	 * This key appears in the vendor driver, but I have
	 * not been able to activate it.
	 */
	tk->codes[6] = KEY_RESERVED;

	__set_bit(EV_KEY, tk->input->evbit);
	for (i = 0; i < ARRAY_SIZE(tk->codes); i++)
		__set_bit(tk->codes[i], tk->input->keybit);
	__clear_bit(KEY_RESERVED, tk->input->keybit);

	tk->input->name = "D-Link DIR-685 touchkeys";
	tk->input->id.bustype = BUS_I2C;

	err = input_register_device(tk->input);
	if (err)
		return err;

	/* Set the brightness to max level */
	err = i2c_master_send(client, bl_data, sizeof(bl_data));
	if (err != sizeof(bl_data))
		dev_warn(tk->dev, "error setting brightness level\n");

	if (!client->irq) {
		dev_err(dev, "no IRQ on the I2C device\n");
		return -ENODEV;
	}
	err = devm_request_threaded_irq(dev, client->irq,
					NULL, dir685_tk_irq_thread,
					IRQF_ONESHOT,
					"dir685-tk", tk);
	if (err) {
		dev_err(dev, "can't request IRQ\n");
		return err;
	}

	return 0;
}

static const struct i2c_device_id dir685_tk_id[] = {
	{ "dir685tk", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, dir685_tk_id);

#ifdef CONFIG_OF
static const struct of_device_id dir685_tk_of_match[] = {
	{ .compatible = "dlink,dir685-touchkeys" },
	{},
};
MODULE_DEVICE_TABLE(of, dir685_tk_of_match);
#endif

static struct i2c_driver dir685_tk_i2c_driver = {
	.driver = {
		.name	= "dlin-dir685-touchkeys",
		.of_match_table = of_match_ptr(dir685_tk_of_match),
	},
	.probe		= dir685_tk_probe,
	.id_table	= dir685_tk_id,
};
module_i2c_driver(dir685_tk_i2c_driver);

MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("D-Link DIR-685 touchkeys driver");
MODULE_LICENSE("GPL");