kernel/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
  30 struct 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  */
  40 static 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
  62 static 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
  71 static 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
 118 err_irq:
 119         free_irq(irq, wm831x_on);
 120 err_input_dev:
 121 err:
 122         return ret;
 123 }
 124
 125 static 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
 136 static struct platform_driver wm831x_on_driver = {
 137         .probe          = wm831x_on_probe,
 138         .remove         = wm831x_on_remove,
 139         .driver         = {
 140                 .name   = "wm831x-on",
 141         },
 142 };
 143 module_platform_driver(wm831x_on_driver);
 144
 145 MODULE_ALIAS("platform:wm831x-on");
 146 MODULE_DESCRIPTION("WM831x ON pin");
 147 MODULE_LICENSE("GPL");
 148 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 149