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
30struct 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 */
40static 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
62static 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
71static 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, "wm831x_on",
103				   wm831x_on);
104	if (ret < 0) {
105		dev_err(&pdev->dev, "Unable to request IRQ: %d\n", ret);
106		goto err_input_dev;
107	}
108	ret = input_register_device(wm831x_on->dev);
109	if (ret) {
110		dev_dbg(&pdev->dev, "Can't register input device: %d\n", ret);
111		goto err_irq;
112	}
113
114	platform_set_drvdata(pdev, wm831x_on);
115
116	return 0;
117
118err_irq:
119	free_irq(irq, wm831x_on);
120err_input_dev:
121err:
122	return ret;
123}
124
125static int wm831x_on_remove(struct platform_device *pdev)
126{
127	struct wm831x_on *wm831x_on = platform_get_drvdata(pdev);
128	int irq = platform_get_irq(pdev, 0);
129
130	free_irq(irq, wm831x_on);
131	cancel_delayed_work_sync(&wm831x_on->work);
132
133	return 0;
134}
135
136static struct platform_driver wm831x_on_driver = {
137	.probe		= wm831x_on_probe,
138	.remove		= wm831x_on_remove,
139	.driver		= {
140		.name	= "wm831x-on",
141	},
142};
143module_platform_driver(wm831x_on_driver);
144
145MODULE_ALIAS("platform:wm831x-on");
146MODULE_DESCRIPTION("WM831x ON pin");
147MODULE_LICENSE("GPL");
148MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
149
150