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 
18 static 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 
29 struct buttons_dev {
30 	unsigned short keymap[ARRAY_SIZE(cobalt_map)];
31 	int count[ARRAY_SIZE(cobalt_map)];
32 	void __iomem *reg;
33 };
34 
handle_buttons(struct input_dev * input)35 static 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 
cobalt_buttons_probe(struct platform_device * pdev)61 static 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 
116 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
117 MODULE_DESCRIPTION("Cobalt button interface driver");
118 MODULE_LICENSE("GPL");
119 /* work with hotplug and coldplug */
120 MODULE_ALIAS("platform:Cobalt buttons");
121 
122 static struct platform_driver cobalt_buttons_driver = {
123 	.probe	= cobalt_buttons_probe,
124 	.driver	= {
125 		.name	= "Cobalt buttons",
126 	},
127 };
128 module_platform_driver(cobalt_buttons_driver);
129