GNU Linux-libre 4.14.266-gnu1
[releases.git] / drivers / input / misc / sgi_btns.c
1 /*
2  *  SGI Volume Button interface driver
3  *
4  *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 #include <linux/input-polldev.h>
21 #include <linux/ioport.h>
22 #include <linux/module.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25
26 #ifdef CONFIG_SGI_IP22
27 #include <asm/sgi/ioc.h>
28
29 static inline u8 button_status(void)
30 {
31         u8 status;
32
33         status = readb(&sgioc->panel) ^ 0xa0;
34         return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
35 }
36 #endif
37
38 #ifdef CONFIG_SGI_IP32
39 #include <asm/ip32/mace.h>
40
41 static inline u8 button_status(void)
42 {
43         u64 status;
44
45         status = readq(&mace->perif.audio.control);
46         writeq(status & ~(3U << 23), &mace->perif.audio.control);
47
48         return (status >> 23) & 3;
49 }
50 #endif
51
52 #define BUTTONS_POLL_INTERVAL   30      /* msec */
53 #define BUTTONS_COUNT_THRESHOLD 3
54
55 static const unsigned short sgi_map[] = {
56         KEY_VOLUMEDOWN,
57         KEY_VOLUMEUP
58 };
59
60 struct buttons_dev {
61         struct input_polled_dev *poll_dev;
62         unsigned short keymap[ARRAY_SIZE(sgi_map)];
63         int count[ARRAY_SIZE(sgi_map)];
64 };
65
66 static void handle_buttons(struct input_polled_dev *dev)
67 {
68         struct buttons_dev *bdev = dev->private;
69         struct input_dev *input = dev->input;
70         u8 status;
71         int i;
72
73         status = button_status();
74
75         for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
76                 if (status & (1U << i)) {
77                         if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
78                                 input_event(input, EV_MSC, MSC_SCAN, i);
79                                 input_report_key(input, bdev->keymap[i], 1);
80                                 input_sync(input);
81                         }
82                 } else {
83                         if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
84                                 input_event(input, EV_MSC, MSC_SCAN, i);
85                                 input_report_key(input, bdev->keymap[i], 0);
86                                 input_sync(input);
87                         }
88                         bdev->count[i] = 0;
89                 }
90         }
91 }
92
93 static int sgi_buttons_probe(struct platform_device *pdev)
94 {
95         struct buttons_dev *bdev;
96         struct input_polled_dev *poll_dev;
97         struct input_dev *input;
98         int error, i;
99
100         bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
101         poll_dev = input_allocate_polled_device();
102         if (!bdev || !poll_dev) {
103                 error = -ENOMEM;
104                 goto err_free_mem;
105         }
106
107         memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));
108
109         poll_dev->private = bdev;
110         poll_dev->poll = handle_buttons;
111         poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
112
113         input = poll_dev->input;
114         input->name = "SGI buttons";
115         input->phys = "sgi/input0";
116         input->id.bustype = BUS_HOST;
117         input->dev.parent = &pdev->dev;
118
119         input->keycode = bdev->keymap;
120         input->keycodemax = ARRAY_SIZE(bdev->keymap);
121         input->keycodesize = sizeof(unsigned short);
122
123         input_set_capability(input, EV_MSC, MSC_SCAN);
124         __set_bit(EV_KEY, input->evbit);
125         for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
126                 __set_bit(bdev->keymap[i], input->keybit);
127         __clear_bit(KEY_RESERVED, input->keybit);
128
129         bdev->poll_dev = poll_dev;
130         platform_set_drvdata(pdev, bdev);
131
132         error = input_register_polled_device(poll_dev);
133         if (error)
134                 goto err_free_mem;
135
136         return 0;
137
138  err_free_mem:
139         input_free_polled_device(poll_dev);
140         kfree(bdev);
141         return error;
142 }
143
144 static int sgi_buttons_remove(struct platform_device *pdev)
145 {
146         struct buttons_dev *bdev = platform_get_drvdata(pdev);
147
148         input_unregister_polled_device(bdev->poll_dev);
149         input_free_polled_device(bdev->poll_dev);
150         kfree(bdev);
151
152         return 0;
153 }
154
155 static struct platform_driver sgi_buttons_driver = {
156         .probe  = sgi_buttons_probe,
157         .remove = sgi_buttons_remove,
158         .driver = {
159                 .name   = "sgibtns",
160         },
161 };
162 module_platform_driver(sgi_buttons_driver);
163
164 MODULE_LICENSE("GPL");