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/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#define BUTTONS_POLL_INTERVAL	30	/* msec */
27#define BUTTONS_COUNT_THRESHOLD	3
28#define BUTTONS_STATUS_MASK	0xfe000000
29
30static const unsigned short cobalt_map[] = {
31	KEY_RESERVED,
32	KEY_RESTART,
33	KEY_LEFT,
34	KEY_UP,
35	KEY_DOWN,
36	KEY_RIGHT,
37	KEY_ENTER,
38	KEY_SELECT
39};
40
41struct buttons_dev {
42	struct input_polled_dev *poll_dev;
43	unsigned short keymap[ARRAY_SIZE(cobalt_map)];
44	int count[ARRAY_SIZE(cobalt_map)];
45	void __iomem *reg;
46};
47
48static void handle_buttons(struct input_polled_dev *dev)
49{
50	struct buttons_dev *bdev = dev->private;
51	struct input_dev *input = dev->input;
52	uint32_t status;
53	int i;
54
55	status = ~readl(bdev->reg) >> 24;
56
57	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
58		if (status & (1U << i)) {
59			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
60				input_event(input, EV_MSC, MSC_SCAN, i);
61				input_report_key(input, bdev->keymap[i], 1);
62				input_sync(input);
63			}
64		} else {
65			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
66				input_event(input, EV_MSC, MSC_SCAN, i);
67				input_report_key(input, bdev->keymap[i], 0);
68				input_sync(input);
69			}
70			bdev->count[i] = 0;
71		}
72	}
73}
74
75static int cobalt_buttons_probe(struct platform_device *pdev)
76{
77	struct buttons_dev *bdev;
78	struct input_polled_dev *poll_dev;
79	struct input_dev *input;
80	struct resource *res;
81	int error, i;
82
83	bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
84	poll_dev = input_allocate_polled_device();
85	if (!bdev || !poll_dev) {
86		error = -ENOMEM;
87		goto err_free_mem;
88	}
89
90	memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));
91
92	poll_dev->private = bdev;
93	poll_dev->poll = handle_buttons;
94	poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
95
96	input = poll_dev->input;
97	input->name = "Cobalt buttons";
98	input->phys = "cobalt/input0";
99	input->id.bustype = BUS_HOST;
100	input->dev.parent = &pdev->dev;
101
102	input->keycode = bdev->keymap;
103	input->keycodemax = ARRAY_SIZE(bdev->keymap);
104	input->keycodesize = sizeof(unsigned short);
105
106	input_set_capability(input, EV_MSC, MSC_SCAN);
107	__set_bit(EV_KEY, input->evbit);
108	for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
109		__set_bit(bdev->keymap[i], input->keybit);
110	__clear_bit(KEY_RESERVED, input->keybit);
111
112	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
113	if (!res) {
114		error = -EBUSY;
115		goto err_free_mem;
116	}
117
118	bdev->poll_dev = poll_dev;
119	bdev->reg = ioremap(res->start, resource_size(res));
120	dev_set_drvdata(&pdev->dev, bdev);
121
122	error = input_register_polled_device(poll_dev);
123	if (error)
124		goto err_iounmap;
125
126	return 0;
127
128 err_iounmap:
129	iounmap(bdev->reg);
130 err_free_mem:
131	input_free_polled_device(poll_dev);
132	kfree(bdev);
133	return error;
134}
135
136static int cobalt_buttons_remove(struct platform_device *pdev)
137{
138	struct device *dev = &pdev->dev;
139	struct buttons_dev *bdev = dev_get_drvdata(dev);
140
141	input_unregister_polled_device(bdev->poll_dev);
142	input_free_polled_device(bdev->poll_dev);
143	iounmap(bdev->reg);
144	kfree(bdev);
145
146	return 0;
147}
148
149MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
150MODULE_DESCRIPTION("Cobalt button interface driver");
151MODULE_LICENSE("GPL");
152/* work with hotplug and coldplug */
153MODULE_ALIAS("platform:Cobalt buttons");
154
155static struct platform_driver cobalt_buttons_driver = {
156	.probe	= cobalt_buttons_probe,
157	.remove	= cobalt_buttons_remove,
158	.driver	= {
159		.name	= "Cobalt buttons",
160	},
161};
162module_platform_driver(cobalt_buttons_driver);
163