xref: /openbmc/linux/drivers/input/misc/cobalt_btns.c (revision 8fdff1dc)
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/init.h>
21 #include <linux/input-polldev.h>
22 #include <linux/ioport.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/slab.h>
26 
27 #define BUTTONS_POLL_INTERVAL	30	/* msec */
28 #define BUTTONS_COUNT_THRESHOLD	3
29 #define BUTTONS_STATUS_MASK	0xfe000000
30 
31 static const unsigned short cobalt_map[] = {
32 	KEY_RESERVED,
33 	KEY_RESTART,
34 	KEY_LEFT,
35 	KEY_UP,
36 	KEY_DOWN,
37 	KEY_RIGHT,
38 	KEY_ENTER,
39 	KEY_SELECT
40 };
41 
42 struct buttons_dev {
43 	struct input_polled_dev *poll_dev;
44 	unsigned short keymap[ARRAY_SIZE(cobalt_map)];
45 	int count[ARRAY_SIZE(cobalt_map)];
46 	void __iomem *reg;
47 };
48 
49 static void handle_buttons(struct input_polled_dev *dev)
50 {
51 	struct buttons_dev *bdev = dev->private;
52 	struct input_dev *input = dev->input;
53 	uint32_t status;
54 	int i;
55 
56 	status = ~readl(bdev->reg) >> 24;
57 
58 	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
59 		if (status & (1U << i)) {
60 			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
61 				input_event(input, EV_MSC, MSC_SCAN, i);
62 				input_report_key(input, bdev->keymap[i], 1);
63 				input_sync(input);
64 			}
65 		} else {
66 			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
67 				input_event(input, EV_MSC, MSC_SCAN, i);
68 				input_report_key(input, bdev->keymap[i], 0);
69 				input_sync(input);
70 			}
71 			bdev->count[i] = 0;
72 		}
73 	}
74 }
75 
76 static int cobalt_buttons_probe(struct platform_device *pdev)
77 {
78 	struct buttons_dev *bdev;
79 	struct input_polled_dev *poll_dev;
80 	struct input_dev *input;
81 	struct resource *res;
82 	int error, i;
83 
84 	bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
85 	poll_dev = input_allocate_polled_device();
86 	if (!bdev || !poll_dev) {
87 		error = -ENOMEM;
88 		goto err_free_mem;
89 	}
90 
91 	memcpy(bdev->keymap, cobalt_map, sizeof(bdev->keymap));
92 
93 	poll_dev->private = bdev;
94 	poll_dev->poll = handle_buttons;
95 	poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
96 
97 	input = poll_dev->input;
98 	input->name = "Cobalt buttons";
99 	input->phys = "cobalt/input0";
100 	input->id.bustype = BUS_HOST;
101 	input->dev.parent = &pdev->dev;
102 
103 	input->keycode = bdev->keymap;
104 	input->keycodemax = ARRAY_SIZE(bdev->keymap);
105 	input->keycodesize = sizeof(unsigned short);
106 
107 	input_set_capability(input, EV_MSC, MSC_SCAN);
108 	__set_bit(EV_KEY, input->evbit);
109 	for (i = 0; i < ARRAY_SIZE(cobalt_map); i++)
110 		__set_bit(bdev->keymap[i], input->keybit);
111 	__clear_bit(KEY_RESERVED, input->keybit);
112 
113 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
114 	if (!res) {
115 		error = -EBUSY;
116 		goto err_free_mem;
117 	}
118 
119 	bdev->poll_dev = poll_dev;
120 	bdev->reg = ioremap(res->start, resource_size(res));
121 	dev_set_drvdata(&pdev->dev, bdev);
122 
123 	error = input_register_polled_device(poll_dev);
124 	if (error)
125 		goto err_iounmap;
126 
127 	return 0;
128 
129  err_iounmap:
130 	iounmap(bdev->reg);
131  err_free_mem:
132 	input_free_polled_device(poll_dev);
133 	kfree(bdev);
134 	dev_set_drvdata(&pdev->dev, NULL);
135 	return error;
136 }
137 
138 static int cobalt_buttons_remove(struct platform_device *pdev)
139 {
140 	struct device *dev = &pdev->dev;
141 	struct buttons_dev *bdev = dev_get_drvdata(dev);
142 
143 	input_unregister_polled_device(bdev->poll_dev);
144 	input_free_polled_device(bdev->poll_dev);
145 	iounmap(bdev->reg);
146 	kfree(bdev);
147 	dev_set_drvdata(dev, NULL);
148 
149 	return 0;
150 }
151 
152 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
153 MODULE_DESCRIPTION("Cobalt button interface driver");
154 MODULE_LICENSE("GPL");
155 /* work with hotplug and coldplug */
156 MODULE_ALIAS("platform:Cobalt buttons");
157 
158 static struct platform_driver cobalt_buttons_driver = {
159 	.probe	= cobalt_buttons_probe,
160 	.remove	= cobalt_buttons_remove,
161 	.driver	= {
162 		.name	= "Cobalt buttons",
163 		.owner	= THIS_MODULE,
164 	},
165 };
166 module_platform_driver(cobalt_buttons_driver);
167