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

http://github.com/mirrors/linux
C | 150 lines | 104 code | 24 blank | 22 comment | 7 complexity | 828df4b17e3300d50ef515a1ea778d7a MD5 | raw file
  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 | 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
119err_irq:
120	free_irq(irq, wm831x_on);
121err_input_dev:
122err:
123	return ret;
124}
125
126static 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
137static struct platform_driver wm831x_on_driver = {
138	.probe		= wm831x_on_probe,
139	.remove		= wm831x_on_remove,
140	.driver		= {
141		.name	= "wm831x-on",
142	},
143};
144module_platform_driver(wm831x_on_driver);
145
146MODULE_ALIAS("platform:wm831x-on");
147MODULE_DESCRIPTION("WM831x ON pin");
148MODULE_LICENSE("GPL");
149MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
150