summaryrefslogtreecommitdiffstats
path: root/drivers/input/misc/sgi_btns.c
blob: 829277b4271f9275f54b7578945f431e0a5bc628 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  SGI Volume Button interface driver
 *
 *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
 */
#include <linux/input-polldev.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#ifdef CONFIG_SGI_IP22
#include <asm/sgi/ioc.h>

static inline u8 button_status(void)
{
	u8 status;

	status = readb(&sgioc->panel) ^ 0xa0;
	return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
}
#endif

#ifdef CONFIG_SGI_IP32
#include <asm/ip32/mace.h>

static inline u8 button_status(void)
{
	u64 status;

	status = readq(&mace->perif.audio.control);
	writeq(status & ~(3U << 23), &mace->perif.audio.control);

	return (status >> 23) & 3;
}
#endif

#define BUTTONS_POLL_INTERVAL	30	/* msec */
#define BUTTONS_COUNT_THRESHOLD	3

static const unsigned short sgi_map[] = {
	KEY_VOLUMEDOWN,
	KEY_VOLUMEUP
};

struct buttons_dev {
	unsigned short keymap[ARRAY_SIZE(sgi_map)];
	int count[ARRAY_SIZE(sgi_map)];
};

static void handle_buttons(struct input_polled_dev *dev)
{
	struct buttons_dev *bdev = dev->private;
	struct input_dev *input = dev->input;
	u8 status;
	int i;

	status = button_status();

	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
		if (status & (1U << i)) {
			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
				input_event(input, EV_MSC, MSC_SCAN, i);
				input_report_key(input, bdev->keymap[i], 1);
				input_sync(input);
			}
		} else {
			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
				input_event(input, EV_MSC, MSC_SCAN, i);
				input_report_key(input, bdev->keymap[i], 0);
				input_sync(input);
			}
			bdev->count[i] = 0;
		}
	}
}

static int sgi_buttons_probe(struct platform_device *pdev)
{
	struct buttons_dev *bdev;
	struct input_polled_dev *poll_dev;
	struct input_dev *input;
	int error, i;

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

	poll_dev = devm_input_allocate_polled_device(&pdev->dev);
	if (!poll_dev)
		return -ENOMEM;

	memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));

	poll_dev->private = bdev;
	poll_dev->poll = handle_buttons;
	poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;

	input = poll_dev->input;
	input->name = "SGI buttons";
	input->phys = "sgi/input0";
	input->id.bustype = BUS_HOST;

	input->keycode = bdev->keymap;
	input->keycodemax = ARRAY_SIZE(bdev->keymap);
	input->keycodesize = sizeof(unsigned short);

	input_set_capability(input, EV_MSC, MSC_SCAN);
	__set_bit(EV_KEY, input->evbit);
	for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
		__set_bit(bdev->keymap[i], input->keybit);
	__clear_bit(KEY_RESERVED, input->keybit);

	error = input_register_polled_device(poll_dev);
	if (error)
		return error;

	return 0;
}

static struct platform_driver sgi_buttons_driver = {
	.probe	= sgi_buttons_probe,
	.driver	= {
		.name	= "sgibtns",
	},
};
module_platform_driver(sgi_buttons_driver);

MODULE_LICENSE("GPL");