xref: /openbmc/linux/drivers/input/misc/sgi_btns.c (revision 275876e2)
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 		.owner	= THIS_MODULE,
161 	},
162 };
163 module_platform_driver(sgi_buttons_driver);
164 
165 MODULE_LICENSE("GPL");
166