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
