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
29static 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
41static 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
55static const unsigned short sgi_map[] = {
56	KEY_VOLUMEDOWN,
57	KEY_VOLUMEUP
58};
59
60struct 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
66static 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
93static 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
144static 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
155static struct platform_driver sgi_buttons_driver = {
156	.probe	= sgi_buttons_probe,
157	.remove	= sgi_buttons_remove,
158	.driver	= {
159		.name	= "sgibtns",
160	},
161};
162module_platform_driver(sgi_buttons_driver);
163
164MODULE_LICENSE("GPL");
165