1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  SGI Volume Button interface driver
4 *
5 *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
6 */
7#include <linux/input.h>
8#include <linux/ioport.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/slab.h>
12
13#ifdef CONFIG_SGI_IP22
14#include <asm/sgi/ioc.h>
15
16static inline u8 button_status(void)
17{
18	u8 status;
19
20	status = readb(&sgioc->panel) ^ 0xa0;
21	return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
22}
23#endif
24
25#ifdef CONFIG_SGI_IP32
26#include <asm/ip32/mace.h>
27
28static inline u8 button_status(void)
29{
30	u64 status;
31
32	status = readq(&mace->perif.audio.control);
33	writeq(status & ~(3U << 23), &mace->perif.audio.control);
34
35	return (status >> 23) & 3;
36}
37#endif
38
39#define BUTTONS_POLL_INTERVAL	30	/* msec */
40#define BUTTONS_COUNT_THRESHOLD	3
41
42static const unsigned short sgi_map[] = {
43	KEY_VOLUMEDOWN,
44	KEY_VOLUMEUP
45};
46
47struct buttons_dev {
48	unsigned short keymap[ARRAY_SIZE(sgi_map)];
49	int count[ARRAY_SIZE(sgi_map)];
50};
51
52static void handle_buttons(struct input_dev *input)
53{
54	struct buttons_dev *bdev = input_get_drvdata(input);
55	u8 status;
56	int i;
57
58	status = button_status();
59
60	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
61		if (status & (1U << i)) {
62			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
63				input_event(input, EV_MSC, MSC_SCAN, i);
64				input_report_key(input, bdev->keymap[i], 1);
65				input_sync(input);
66			}
67		} else {
68			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
69				input_event(input, EV_MSC, MSC_SCAN, i);
70				input_report_key(input, bdev->keymap[i], 0);
71				input_sync(input);
72			}
73			bdev->count[i] = 0;
74		}
75	}
76}
77
78static int sgi_buttons_probe(struct platform_device *pdev)
79{
80	struct buttons_dev *bdev;
81	struct input_dev *input;
82	int error, i;
83
84	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
85	if (!bdev)
86		return -ENOMEM;
87
88	input = devm_input_allocate_device(&pdev->dev);
89	if (!input)
90		return -ENOMEM;
91
92	memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));
93
94	input_set_drvdata(input, bdev);
95
96	input->name = "SGI buttons";
97	input->phys = "sgi/input0";
98	input->id.bustype = BUS_HOST;
99
100	input->keycode = bdev->keymap;
101	input->keycodemax = ARRAY_SIZE(bdev->keymap);
102	input->keycodesize = sizeof(unsigned short);
103
104	input_set_capability(input, EV_MSC, MSC_SCAN);
105	__set_bit(EV_KEY, input->evbit);
106	for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
107		__set_bit(bdev->keymap[i], input->keybit);
108	__clear_bit(KEY_RESERVED, input->keybit);
109
110	error = input_setup_polling(input, handle_buttons);
111	if (error)
112		return error;
113
114	input_set_poll_interval(input, BUTTONS_POLL_INTERVAL);
115
116	error = input_register_device(input);
117	if (error)
118		return error;
119
120	return 0;
121}
122
123static struct platform_driver sgi_buttons_driver = {
124	.probe	= sgi_buttons_probe,
125	.driver	= {
126		.name	= "sgibtns",
127	},
128};
129module_platform_driver(sgi_buttons_driver);
130
131MODULE_LICENSE("GPL");
132