1/*
2 *  Cobalt button interface driver.
3 *
4 *  Copyright (C) 2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
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/init.h>
21#include <linux/input-polldev.h>
22#include <linux/ioport.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25
26#define BUTTONS_POLL_INTERVAL	30	/* msec */
27#define BUTTONS_COUNT_THRESHOLD	3
28#define BUTTONS_STATUS_MASK	0xfe000000
29
30struct buttons_dev {
31	struct input_polled_dev *poll_dev;
32	void __iomem *reg;
33};
34
35struct buttons_map {
36	uint32_t mask;
37	int keycode;
38	int count;
39};
40
41static struct buttons_map buttons_map[] = {
42	{ 0x02000000, KEY_RESTART, },
43	{ 0x04000000, KEY_LEFT, },
44	{ 0x08000000, KEY_UP, },
45	{ 0x10000000, KEY_DOWN, },
46	{ 0x20000000, KEY_RIGHT, },
47	{ 0x40000000, KEY_ENTER, },
48	{ 0x80000000, KEY_SELECT, },
49};
50
51static void handle_buttons(struct input_polled_dev *dev)
52{
53	struct buttons_map *button = buttons_map;
54	struct buttons_dev *bdev = dev->private;
55	struct input_dev *input = dev->input;
56	uint32_t status;
57	int i;
58
59	status = readl(bdev->reg);
60	status = ~status & BUTTONS_STATUS_MASK;
61
62	for (i = 0; i < ARRAY_SIZE(buttons_map); i++) {
63		if (status & button->mask) {
64			button->count++;
65		} else {
66			if (button->count >= BUTTONS_COUNT_THRESHOLD) {
67				input_report_key(input, button->keycode, 0);
68				input_sync(input);
69			}
70			button->count = 0;
71		}
72
73		if (button->count == BUTTONS_COUNT_THRESHOLD) {
74			input_report_key(input, button->keycode, 1);
75			input_sync(input);
76		}
77
78		button++;
79	}
80}
81
82static int __devinit cobalt_buttons_probe(struct platform_device *pdev)
83{
84	struct buttons_dev *bdev;
85	struct input_polled_dev *poll_dev;
86	struct input_dev *input;
87	struct resource *res;
88	int error, i;
89
90	bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
91	poll_dev = input_allocate_polled_device();
92	if (!bdev || !poll_dev) {
93		error = -ENOMEM;
94		goto err_free_mem;
95	}
96
97	poll_dev->private = bdev;
98	poll_dev->poll = handle_buttons;
99	poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
100
101	input = poll_dev->input;
102	input->name = "Cobalt buttons";
103	input->phys = "cobalt/input0";
104	input->id.bustype = BUS_HOST;
105	input->cdev.dev = &pdev->dev;
106
107	input->evbit[0] = BIT(EV_KEY);
108	for (i = 0; i < ARRAY_SIZE(buttons_map); i++) {
109		set_bit(buttons_map[i].keycode, input->keybit);
110		buttons_map[i].count = 0;
111	}
112
113	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
114	if (!res) {
115		error = -EBUSY;
116		goto err_free_mem;
117	}
118
119	bdev->poll_dev = poll_dev;
120	bdev->reg = ioremap(res->start, res->end - res->start + 1);
121	dev_set_drvdata(&pdev->dev, bdev);
122
123	error = input_register_polled_device(poll_dev);
124	if (error)
125		goto err_iounmap;
126
127	return 0;
128
129 err_iounmap:
130	iounmap(bdev->reg);
131 err_free_mem:
132	input_free_polled_device(poll_dev);
133	kfree(bdev);
134	dev_set_drvdata(&pdev->dev, NULL);
135	return error;
136}
137
138static int __devexit cobalt_buttons_remove(struct platform_device *pdev)
139{
140	struct device *dev = &pdev->dev;
141	struct buttons_dev *bdev = dev_get_drvdata(dev);
142
143	input_unregister_polled_device(bdev->poll_dev);
144	input_free_polled_device(bdev->poll_dev);
145	iounmap(bdev->reg);
146	kfree(bdev);
147	dev_set_drvdata(dev, NULL);
148
149	return 0;
150}
151
152static struct platform_driver cobalt_buttons_driver = {
153	.probe	= cobalt_buttons_probe,
154	.remove	= __devexit_p(cobalt_buttons_remove),
155	.driver	= {
156		.name	= "Cobalt buttons",
157		.owner	= THIS_MODULE,
158	},
159};
160
161static int __init cobalt_buttons_init(void)
162{
163	return platform_driver_register(&cobalt_buttons_driver);
164}
165
166static void __exit cobalt_buttons_exit(void)
167{
168	platform_driver_unregister(&cobalt_buttons_driver);
169}
170
171module_init(cobalt_buttons_init);
172module_exit(cobalt_buttons_exit);
173