kernel/drivers/input/misc/e3x0-button.c

   1 /*
   2  * Copyright (c) 2014, National Instruments Corp. All rights reserved.
   3  *
   4  * Driver for NI Ettus Research USRP E3x0 Button Driver
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   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
  16 #include <linux/device.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/input.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/of.h>
  23 #include <linux/slab.h>
  24
  25 static irqreturn_t e3x0_button_release_handler(int irq, void *data)
  26 {
  27         struct input_dev *idev = data;
  28
  29         input_report_key(idev, KEY_POWER, 0);
  30         input_sync(idev);
  31
  32         return IRQ_HANDLED;
  33 }
  34
  35 static irqreturn_t e3x0_button_press_handler(int irq, void *data)
  36 {
  37         struct input_dev *idev = data;
  38
  39         input_report_key(idev, KEY_POWER, 1);
  40         pm_wakeup_event(idev->dev.parent, 0);
  41         input_sync(idev);
  42
  43         return IRQ_HANDLED;
  44 }
  45
  46 static int __maybe_unused e3x0_button_suspend(struct device *dev)
  47 {
  48         struct platform_device *pdev = to_platform_device(dev);
  49
  50         if (device_may_wakeup(dev))
  51                 enable_irq_wake(platform_get_irq_byname(pdev, "press"));
  52
  53         return 0;
  54 }
  55
  56 static int __maybe_unused e3x0_button_resume(struct device *dev)
  57 {
  58         struct platform_device *pdev = to_platform_device(dev);
  59
  60         if (device_may_wakeup(dev))
  61                 disable_irq_wake(platform_get_irq_byname(pdev, "press"));
  62
  63         return 0;
  64 }
  65
  66 static SIMPLE_DEV_PM_OPS(e3x0_button_pm_ops,
  67                          e3x0_button_suspend, e3x0_button_resume);
  68
  69 static int e3x0_button_probe(struct platform_device *pdev)
  70 {
  71         struct input_dev *input;
  72         int irq_press, irq_release;
  73         int error;
  74
  75         irq_press = platform_get_irq_byname(pdev, "press");
  76         if (irq_press < 0) {
  77                 dev_err(&pdev->dev, "No IRQ for 'press', error=%d\n",
  78                         irq_press);
  79                 return irq_press;
  80         }
  81
  82         irq_release = platform_get_irq_byname(pdev, "release");
  83         if (irq_release < 0) {
  84                 dev_err(&pdev->dev, "No IRQ for 'release', error=%d\n",
  85                         irq_release);
  86                 return irq_release;
  87         }
  88
  89         input = devm_input_allocate_device(&pdev->dev);
  90         if (!input)
  91                 return -ENOMEM;
  92
  93         input->name = "NI Ettus Research USRP E3x0 Button Driver";
  94         input->phys = "e3x0_button/input0";
  95         input->dev.parent = &pdev->dev;
  96
  97         input_set_capability(input, EV_KEY, KEY_POWER);
  98
  99         error = devm_request_irq(&pdev->dev, irq_press,
 100                                  e3x0_button_press_handler, 0,
 101                                  "e3x0-button", input);
 102         if (error) {
 103                 dev_err(&pdev->dev, "Failed to request 'press' IRQ#%d: %d\n",
 104                         irq_press, error);
 105                 return error;
 106         }
 107
 108         error = devm_request_irq(&pdev->dev, irq_release,
 109                                  e3x0_button_release_handler, 0,
 110                                  "e3x0-button", input);
 111         if (error) {
 112                 dev_err(&pdev->dev, "Failed to request 'release' IRQ#%d: %d\n",
 113                         irq_release, error);
 114                 return error;
 115         }
 116
 117         error = input_register_device(input);
 118         if (error) {
 119                 dev_err(&pdev->dev, "Can't register input device: %d\n", error);
 120                 return error;
 121         }
 122
 123         platform_set_drvdata(pdev, input);
 124         device_init_wakeup(&pdev->dev, 1);
 125         return 0;
 126 }
 127
 128 static int e3x0_button_remove(struct platform_device *pdev)
 129 {
 130         device_init_wakeup(&pdev->dev, 0);
 131         return 0;
 132 }
 133
 134 #ifdef CONFIG_OF
 135 static const struct of_device_id e3x0_button_match[] = {
 136         { .compatible = "ettus,e3x0-button", },
 137         { }
 138 };
 139 MODULE_DEVICE_TABLE(of, e3x0_button_match);
 140 #endif
 141
 142 static struct platform_driver e3x0_button_driver = {
 143         .driver         = {
 144                 .name   = "e3x0-button",
 145                 .of_match_table = of_match_ptr(e3x0_button_match),
 146                 .pm     = &e3x0_button_pm_ops,
 147         },
 148         .probe          = e3x0_button_probe,
 149         .remove         = e3x0_button_remove,
 150 };
 151
 152 module_platform_driver(e3x0_button_driver);
 153
 154 MODULE_LICENSE("GPL v2");
 155 MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
 156 MODULE_DESCRIPTION("NI Ettus Research USRP E3x0 Button driver");
 157 MODULE_ALIAS("platform:e3x0-button");