1/*
2 *  Cobalt button interface driver.
3 *
4 *  Copyright (C) 2007-2008  Yoichi Yuasa <yuasa@linux-mips.org>
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#include <linux/slab.h>
26
27#define BUTTONS_POLL_INTERVAL	30	/* msec */
28#define BUTTONS_COUNT_THRESHOLD	3
29#define BUTTONS_STATUS_MASK	0xfe000000
30
31static const unsigned short cobalt_map[] = {
32	KEY_RESERVED,
33	KEY_RESTART,
34	KEY_LEFT,
35	KEY_UP,
36	KEY_DOWN,
37	KEY_RIGHT,
38	KEY_ENTER,
39	KEY_SELECT
40};
41
42struct buttons_dev {
43	struct input_polled_dev *poll_dev;
44	unsigned short keymap[ARRAY_SIZE(cobalt_map)];
45	int count[ARRAY_SIZE(cobalt_map)];
46	void __iomem *reg;
47};
48
49static void handle_buttons(struct input_polled_dev *dev)
50{
51	struct buttons_dev *bdev = dev->private;
52	struct input_dev *input = dev->input;
53	uint32_t status;
54	int i;
55
56	status = ~readl(bdev->reg) >> 24;
57
58	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
59		if (status & (1U << i)) {
60			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
61				input_event(input, EV_MSC, MSC_SCAN, i);
62				input_report_key(input, bdev->keymap[i], 1);
63				input_sync(input);
64			}
65		} else {
66			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
67				input_event(input, EV_MSC, MSC_SCAN, i);
68				input_report_key(input, bdev->keymap[i], 0);
69				input_sync(input);
70			}
71			bdev->count[i] = 0;
72		}
73	}
74}
75
76static int __devinit cobalt_buttons_probe(struct platform_device *pdev)
77{
78	struct buttons_dev *bdev;
79	struct input_polled_dev *poll_dev;
80	struct input_dev *input;
81	struct resource *res;
82	int error, i;
83
84	bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
85	poll_dev = input_allocate_polled_device();
86	if (!bdev || !poll_dev) {
87		error = -ENOMEM;
88		goto err_free_mem;
89	}
90
91	memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));
92
93	poll_dev->private = bdev;
94	poll_dev->poll = handle_buttons;
95	poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
96
97	input = poll_dev->input;
98	input->name = "Cobalt buttons";
99	input->phys = "cobalt/input0";
100	input->id.bustype = BUS_HOST;
101	input->dev.parent = &pdev->dev;
102
103	input->keycode = bdev->keymap;
104	input->keycodemax = ARRAY_SIZE(bdev->keymap);
105	input->keycodesize = sizeof(unsigned short);
106
107	input_set_capability(input, EV_MSC, MSC_SCAN);
108	__set_bit(EV_KEY, input->evbit);
109	for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
110		__set_bit(bdev->keymap[i], input->keybit);
111	__clear_bit(KEY_RESERVED, input->keybit);
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, resource_size(res));
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
152MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
153MODULE_DESCRIPTION("Cobalt button interface driver");
154MODULE_LICENSE("GPL");
155/* work with hotplug and coldplug */
156MODULE_ALIAS("platform:Cobalt buttons");
157
158static struct platform_driver cobalt_buttons_driver = {
159	.probe	= cobalt_buttons_probe,
160	.remove	= __devexit_p(cobalt_buttons_remove),
161	.driver	= {
162		.name	= "Cobalt buttons",
163		.owner	= THIS_MODULE,
164	},
165};
166module_platform_driver(cobalt_buttons_driver);
167