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   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/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 __devinit 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 = platform_get_irq(pdev, 0);
  76         int ret;
  77
  78         wm831x_on = kzalloc(sizeof(struct wm831x_on), GFP_KERNEL);
  79         if (!wm831x_on) {
  80                 dev_err(&pdev->dev, "Can't allocate data\n");
  81                 return -ENOMEM;
  82         }
  83
  84         wm831x_on->wm831x = wm831x;
  85         INIT_DELAYED_WORK(&wm831x_on->work, wm831x_poll_on);
  86
  87         wm831x_on->dev = input_allocate_device();
  88         if (!wm831x_on->dev) {
  89                 dev_err(&pdev->dev, "Can't allocate input dev\n");
  90                 ret = -ENOMEM;
  91                 goto err;
  92         }
  93
  94         wm831x_on->dev->evbit[0] = BIT_MASK(EV_KEY);
  95         wm831x_on->dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
  96         wm831x_on->dev->name = "wm831x_on";
  97         wm831x_on->dev->phys = "wm831x_on/input0";
  98         wm831x_on->dev->dev.parent = &pdev->dev;
  99
 100         ret = request_threaded_irq(irq, NULL, wm831x_on_irq,
 101                                    IRQF_TRIGGER_RISING, "wm831x_on",
 102                                    wm831x_on);
 103         if (ret < 0) {
 104                 dev_err(&pdev->dev, "Unable to request IRQ: %d\n", ret);
 105                 goto err_input_dev;
 106         }
 107         ret = input_register_device(wm831x_on->dev);
 108         if (ret) {
 109                 dev_dbg(&pdev->dev, "Can't register input device: %d\n", ret);
 110                 goto err_irq;
 111         }
 112
 113         platform_set_drvdata(pdev, wm831x_on);
 114
 115         return 0;
 116
 117 err_irq:
 118         free_irq(irq, wm831x_on);
 119 err_input_dev:
 120         input_free_device(wm831x_on->dev);
 121 err:
 122         kfree(wm831x_on);
 123         return ret;
 124 }
 125
 126 static int __devexit 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         input_unregister_device(wm831x_on->dev);
 134         kfree(wm831x_on);
 135
 136         return 0;
 137 }
 138
 139 static struct platform_driver wm831x_on_driver = {
 140         .probe          = wm831x_on_probe,
 141         .remove         = __devexit_p(wm831x_on_remove),
 142         .driver         = {
 143                 .name   = "wm831x-on",
 144                 .owner  = THIS_MODULE,
 145         },
 146 };
 147
 148 static int __init wm831x_on_init(void)
 149 {
 150         return platform_driver_register(&wm831x_on_driver);
 151 }
 152 module_init(wm831x_on_init);
 153
 154 static void __exit wm831x_on_exit(void)
 155 {
 156         platform_driver_unregister(&wm831x_on_driver);
 157 }
 158 module_exit(wm831x_on_exit);
 159
 160 MODULE_ALIAS("platform:wm831x-on");
 161 MODULE_DESCRIPTION("WM831x ON pin");
 162 MODULE_LICENSE("GPL");
 163 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 164