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/drivers/input/misc/wm831x-on.c

https://bitbucket.org/ndreys/linux-sunxi
C | 165 lines | 117 code | 26 blank | 22 comment | 7 complexity | d31f0dd5732d86acf431dd1da407ff2f MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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 __devinit 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 = platform_get_irq(pdev, 0);
 77	int ret;
 78
 79	wm831x_on = kzalloc(sizeof(struct wm831x_on), 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 = input_allocate_device();
 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:
121	input_free_device(wm831x_on->dev);
122err:
123	kfree(wm831x_on);
124	return ret;
125}
126
127static int __devexit 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	kfree(wm831x_on);
136
137	return 0;
138}
139
140static struct platform_driver wm831x_on_driver = {
141	.probe		= wm831x_on_probe,
142	.remove		= __devexit_p(wm831x_on_remove),
143	.driver		= {
144		.name	= "wm831x-on",
145		.owner	= THIS_MODULE,
146	},
147};
148
149static int __init wm831x_on_init(void)
150{
151	return platform_driver_register(&wm831x_on_driver);
152}
153module_init(wm831x_on_init);
154
155static void __exit wm831x_on_exit(void)
156{
157	platform_driver_unregister(&wm831x_on_driver);
158}
159module_exit(wm831x_on_exit);
160
161MODULE_ALIAS("platform:wm831x-on");
162MODULE_DESCRIPTION("WM831x ON pin");
163MODULE_LICENSE("GPL");
164MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
165