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/slab.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/input.h>
25 #include <linux/interrupt.h>
26 #include <linux/platform_device.h>
27 #include <linux/workqueue.h>
28 #include <linux/mfd/wm831x/core.h>
29
30 struct wm831x_on {
31 struct input_dev *dev;
32 struct delayed_work work;
33 struct wm831x *wm831x;
34 };
35
36 /*
37 * The chip gives us an interrupt when the ON pin is asserted but we
38 * then need to poll to see when the pin is deasserted.
39 */
wm831x_poll_on(struct work_struct * work)40 static void wm831x_poll_on(struct work_struct *work)
41 {
42 struct wm831x_on *wm831x_on = container_of(work, struct wm831x_on,
43 work.work);
44 struct wm831x *wm831x = wm831x_on->wm831x;
45 int poll, ret;
46
47 ret = wm831x_reg_read(wm831x, WM831X_ON_PIN_CONTROL);
48 if (ret >= 0) {
49 poll = !(ret & WM831X_ON_PIN_STS);
50
51 input_report_key(wm831x_on->dev, KEY_POWER, poll);
52 input_sync(wm831x_on->dev);
53 } else {
54 dev_err(wm831x->dev, "Failed to read ON status: %d\n", ret);
55 poll = 1;
56 }
57
58 if (poll)
59 schedule_delayed_work(&wm831x_on->work, 100);
60 }
61
wm831x_on_irq(int irq,void * data)62 static irqreturn_t wm831x_on_irq(int irq, void *data)
63 {
64 struct wm831x_on *wm831x_on = data;
65
66 schedule_delayed_work(&wm831x_on->work, 0);
67
68 return IRQ_HANDLED;
69 }
70
wm831x_on_probe(struct platform_device * pdev)71 static int wm831x_on_probe(struct platform_device *pdev)
72 {
73 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
74 struct wm831x_on *wm831x_on;
75 int irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
76 int ret;
77
78 wm831x_on = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_on),
79 GFP_KERNEL);
80 if (!wm831x_on) {
81 dev_err(&pdev->dev, "Can't allocate data\n");
82 return -ENOMEM;
83 }
84
85 wm831x_on->wm831x = wm831x;
86 INIT_DELAYED_WORK(&wm831x_on->work, wm831x_poll_on);
87
88 wm831x_on->dev = devm_input_allocate_device(&pdev->dev);
89 if (!wm831x_on->dev) {
90 dev_err(&pdev->dev, "Can't allocate input dev\n");
91 ret = -ENOMEM;
92 goto err;
93 }
94
95 wm831x_on->dev->evbit[0] = BIT_MASK(EV_KEY);
96 wm831x_on->dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
97 wm831x_on->dev->name = "wm831x_on";
98 wm831x_on->dev->phys = "wm831x_on/input0";
99 wm831x_on->dev->dev.parent = &pdev->dev;
100
101 ret = request_threaded_irq(irq, NULL, wm831x_on_irq,
102 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
103 "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
119 err_irq:
120 free_irq(irq, wm831x_on);
121 err_input_dev:
122 err:
123 return ret;
124 }
125
wm831x_on_remove(struct platform_device * pdev)126 static int wm831x_on_remove(struct platform_device *pdev)
127 {
128 struct wm831x_on *wm831x_on = platform_get_drvdata(pdev);
129 int irq = platform_get_irq(pdev, 0);
130
131 free_irq(irq, wm831x_on);
132 cancel_delayed_work_sync(&wm831x_on->work);
133
134 return 0;
135 }
136
137 static struct platform_driver wm831x_on_driver = {
138 .probe = wm831x_on_probe,
139 .remove = wm831x_on_remove,
140 .driver = {
141 .name = "wm831x-on",
142 },
143 };
144 module_platform_driver(wm831x_on_driver);
145
146 MODULE_ALIAS("platform:wm831x-on");
147 MODULE_DESCRIPTION("WM831x ON pin");
148 MODULE_LICENSE("GPL");
149 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
150
151
