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

   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
 151