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
button_status(void)16 static 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
button_status(void)28 static 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
42 static const unsigned short sgi_map[] = {
43 KEY_VOLUMEDOWN,
44 KEY_VOLUMEUP
45 };
46
47 struct buttons_dev {
48 unsigned short keymap[ARRAY_SIZE(sgi_map)];
49 int count[ARRAY_SIZE(sgi_map)];
50 };
51
handle_buttons(struct input_dev * input)52 static 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
sgi_buttons_probe(struct platform_device * pdev)78 static 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
123 static struct platform_driver sgi_buttons_driver = {
124 .probe = sgi_buttons_probe,
125 .driver = {
126 .name = "sgibtns",
127 },
128 };
129 module_platform_driver(sgi_buttons_driver);
130
131 MODULE_DESCRIPTION("SGI Indy/O2 volume button interface driver");
132 MODULE_LICENSE("GPL");
133