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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/**
2 * wm831x-on.c - WM831X ON pin driver
3 *
4 * Copyright (C) 2009 Wolfson Microelectronics plc
5 *
6 * This file is subject to the terms and conditions of the GNU General
7 * Public License. See the file "COPYING" in the main directory of this
8 * archive for more details.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/slab.h>
23#include <linux/kernel.h>
24#include <linux/errno.h>
25#include <linux/input.h>
26#include <linux/interrupt.h>
27#include <linux/platform_device.h>
28#include <linux/workqueue.h>
29#include <linux/mfd/wm831x/core.h>
30
31struct wm831x_on {
32 struct input_dev *dev;
33 struct delayed_work work;
34 struct wm831x *wm831x;
35};
36
37/*
38 * The chip gives us an interrupt when the ON pin is asserted but we
39 * then need to poll to see when the pin is deasserted.
40 */
41static void wm831x_poll_on(struct work_struct *work)
42{
43 struct wm831x_on *wm831x_on = container_of(work, struct wm831x_on,
44 work.work);
45 struct wm831x *wm831x = wm831x_on->wm831x;
46 int poll, ret;
47
48 ret = wm831x_reg_read(wm831x, WM831X_ON_PIN_CONTROL);
49 if (ret >= 0) {
50 poll = !(ret & WM831X_ON_PIN_STS);
51
52 input_report_key(wm831x_on->dev, KEY_POWER, poll);
53 input_sync(wm831x_on->dev);
54 } else {
55 dev_err(wm831x->dev, "Failed to read ON status: %d\n", ret);
56 poll = 1;
57 }
58
59 if (poll)
60 schedule_delayed_work(&wm831x_on->work, 100);
61}
62
63static irqreturn_t wm831x_on_irq(int irq, void *data)
64{
65 struct wm831x_on *wm831x_on = data;
66
67 schedule_delayed_work(&wm831x_on->work, 0);
68
69 return IRQ_HANDLED;
70}
71
72static int wm831x_on_probe(struct platform_device *pdev)
73{
74 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
75 struct wm831x_on *wm831x_on;
76 int irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
77 int ret;
78
79 wm831x_on = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_on),
80 GFP_KERNEL);
81 if (!wm831x_on) {
82 dev_err(&pdev->dev, "Can't allocate data\n");
83 return -ENOMEM;
84 }
85
86 wm831x_on->wm831x = wm831x;
87 INIT_DELAYED_WORK(&wm831x_on->work, wm831x_poll_on);
88
89 wm831x_on->dev = input_allocate_device();
90 if (!wm831x_on->dev) {
91 dev_err(&pdev->dev, "Can't allocate input dev\n");
92 ret = -ENOMEM;
93 goto err;
94 }
95
96 wm831x_on->dev->evbit[0] = BIT_MASK(EV_KEY);
97 wm831x_on->dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
98 wm831x_on->dev->name = "wm831x_on";
99 wm831x_on->dev->phys = "wm831x_on/input0";
100 wm831x_on->dev->dev.parent = &pdev->dev;
101
102 ret = request_threaded_irq(irq, NULL, wm831x_on_irq,
103 IRQF_TRIGGER_RISING, "wm831x_on",
104 wm831x_on);
105 if (ret < 0) {
106 dev_err(&pdev->dev, "Unable to request IRQ: %d\n", ret);
107 goto err_input_dev;
108 }
109 ret = input_register_device(wm831x_on->dev);
110 if (ret) {
111 dev_dbg(&pdev->dev, "Can't register input device: %d\n", ret);
112 goto err_irq;
113 }
114
115 platform_set_drvdata(pdev, wm831x_on);
116
117 return 0;
118
119err_irq:
120 free_irq(irq, wm831x_on);
121err_input_dev:
122 input_free_device(wm831x_on->dev);
123err:
124 return ret;
125}
126
127static int wm831x_on_remove(struct platform_device *pdev)
128{
129 struct wm831x_on *wm831x_on = platform_get_drvdata(pdev);
130 int irq = platform_get_irq(pdev, 0);
131
132 free_irq(irq, wm831x_on);
133 cancel_delayed_work_sync(&wm831x_on->work);
134 input_unregister_device(wm831x_on->dev);
135
136 return 0;
137}
138
139static struct platform_driver wm831x_on_driver = {
140 .probe = wm831x_on_probe,
141 .remove = wm831x_on_remove,
142 .driver = {
143 .name = "wm831x-on",
144 .owner = THIS_MODULE,
145 },
146};
147module_platform_driver(wm831x_on_driver);
148
149MODULE_ALIAS("platform:wm831x-on");
150MODULE_DESCRIPTION("WM831x ON pin");
151MODULE_LICENSE("GPL");
152MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
153