xref: /openbmc/linux/drivers/input/misc/cobalt_btns.c (revision 4f6cce39)
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 
30 static 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 
41 struct 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 
48 static 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 
75 static 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 
136 static 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 
149 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
150 MODULE_DESCRIPTION("Cobalt button interface driver");
151 MODULE_LICENSE("GPL");
152 /* work with hotplug and coldplug */
153 MODULE_ALIAS("platform:Cobalt buttons");
154 
155 static struct platform_driver cobalt_buttons_driver = {
156 	.probe	= cobalt_buttons_probe,
157 	.remove	= cobalt_buttons_remove,
158 	.driver	= {
159 		.name	= "Cobalt buttons",
160 	},
161 };
162 module_platform_driver(cobalt_buttons_driver);
163