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/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
  31 struct 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  */
  41 static 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
  63 static 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
  72 static int 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 = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
  77         int ret;
  78
  79         wm831x_on = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_on),
  80                                  GFP_KERNEL);
  81         if (!wm831x_on) {
  82                 dev_err(&pdev->dev, "Can't allocate data\n");
  83                 return -ENOMEM;
  84         }
  85
  86         wm831x_on->wm831x = wm831x;
  87         INIT_DELAYED_WORK(&wm831x_on->work, wm831x_poll_on);
  88
  89         wm831x_on->dev = devm_input_allocate_device(&pdev->dev);
  90         if (!wm831x_on->dev) {
  91                 dev_err(&pdev->dev, "Can't allocate input dev\n");
  92                 ret = -ENOMEM;
  93                 goto err;
  94         }
  95
  96         wm831x_on->dev->evbit[0] = BIT_MASK(EV_KEY);
  97         wm831x_on->dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
  98         wm831x_on->dev->name = "wm831x_on";
  99         wm831x_on->dev->phys = "wm831x_on/input0";
 100         wm831x_on->dev->dev.parent = &pdev->dev;
 101
 102         ret = request_threaded_irq(irq, NULL, wm831x_on_irq,
 103                                    IRQF_TRIGGER_RISING, "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
 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                 .owner  = THIS_MODULE,
 143         },
 144 };
 145 module_platform_driver(wm831x_on_driver);
 146
 147 MODULE_ALIAS("platform:wm831x-on");
 148 MODULE_DESCRIPTION("WM831x ON pin");
 149 MODULE_LICENSE("GPL");
 150 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 151