1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Cobalt button interface driver.
4 *
5 *  Copyright (C) 2007-2008  Yoichi Yuasa <yuasa@linux-mips.org>
6 */
7#include <linux/input.h>
8#include <linux/io.h>
9#include <linux/ioport.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/slab.h>
13
14#define BUTTONS_POLL_INTERVAL	30	/* msec */
15#define BUTTONS_COUNT_THRESHOLD	3
16#define BUTTONS_STATUS_MASK	0xfe000000
17
18static const unsigned short cobalt_map[] = {
19	KEY_RESERVED,
20	KEY_RESTART,
21	KEY_LEFT,
22	KEY_UP,
23	KEY_DOWN,
24	KEY_RIGHT,
25	KEY_ENTER,
26	KEY_SELECT
27};
28
29struct buttons_dev {
30	unsigned short keymap[ARRAY_SIZE(cobalt_map)];
31	int count[ARRAY_SIZE(cobalt_map)];
32	void __iomem *reg;
33};
34
35static void handle_buttons(struct input_dev *input)
36{
37	struct buttons_dev *bdev = input_get_drvdata(input);
38	uint32_t status;
39	int i;
40
41	status = ~readl(bdev->reg) >> 24;
42
43	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
44		if (status & (1U << i)) {
45			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
46				input_event(input, EV_MSC, MSC_SCAN, i);
47				input_report_key(input, bdev->keymap[i], 1);
48				input_sync(input);
49			}
50		} else {
51			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
52				input_event(input, EV_MSC, MSC_SCAN, i);
53				input_report_key(input, bdev->keymap[i], 0);
54				input_sync(input);
55			}
56			bdev->count[i] = 0;
57		}
58	}
59}
60
61static int cobalt_buttons_probe(struct platform_device *pdev)
62{
63	struct buttons_dev *bdev;
64	struct input_dev *input;
65	struct resource *res;
66	int error, i;
67
68	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
69	if (!bdev)
70		return -ENOMEM;
71
72	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
73	if (!res)
74		return -EBUSY;
75
76	bdev->reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
77	if (!bdev->reg)
78		return -ENOMEM;
79
80	memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));
81
82	input = devm_input_allocate_device(&pdev->dev);
83	if (!input)
84		return -ENOMEM;
85
86	input_set_drvdata(input, bdev);
87
88	input->name = "Cobalt buttons";
89	input->phys = "cobalt/input0";
90	input->id.bustype = BUS_HOST;
91
92	input->keycode = bdev->keymap;
93	input->keycodemax = ARRAY_SIZE(bdev->keymap);
94	input->keycodesize = sizeof(unsigned short);
95
96	input_set_capability(input, EV_MSC, MSC_SCAN);
97	__set_bit(EV_KEY, input->evbit);
98	for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
99		__set_bit(bdev->keymap[i], input->keybit);
100	__clear_bit(KEY_RESERVED, input->keybit);
101
102
103	error = input_setup_polling(input, handle_buttons);
104	if (error)
105		return error;
106
107	input_set_poll_interval(input, BUTTONS_POLL_INTERVAL);
108
109	error = input_register_device(input);
110	if (error)
111		return error;
112
113	return 0;
114}
115
116MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
117MODULE_DESCRIPTION("Cobalt button interface driver");
118MODULE_LICENSE("GPL");
119/* work with hotplug and coldplug */
120MODULE_ALIAS("platform:Cobalt buttons");
121
122static struct platform_driver cobalt_buttons_driver = {
123	.probe	= cobalt_buttons_probe,
124	.driver	= {
125		.name	= "Cobalt buttons",
126	},
127};
128module_platform_driver(cobalt_buttons_driver);
129