drivers/input/misc/da9052_onkey.c

   1 /*
   2  * ON pin driver for Dialog DA9052 PMICs
   3  *
   4  * Copyright(c) 2012 Dialog Semiconductor Ltd.
   5  *
   6  * Author: David Dajun Chen <dchen@diasemi.com>
   7  *
   8  * This program is free software; you can redistribute  it and/or modify it
   9  * under  the terms of  the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the  License, or (at your
  11  * option) any later version.
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/input.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/workqueue.h>
  19
  20 #include <linux/mfd/da9052/da9052.h>
  21 #include <linux/mfd/da9052/reg.h>
  22
  23 struct da9052_onkey {
  24         struct da9052 *da9052;
  25         struct input_dev *input;
  26         struct delayed_work work;
  27 };
  28
  29 static void da9052_onkey_query(struct da9052_onkey *onkey)
  30 {
  31         int key_stat;
  32
  33         key_stat = da9052_reg_read(onkey->da9052, DA9052_EVENT_B_REG);
  34         if (key_stat < 0) {
  35                 dev_err(onkey->da9052->dev,
  36                         "Failed to read onkey event %d\n", key_stat);
  37         } else {
  38                 /*
  39                  * Since interrupt for deassertion of ONKEY pin is not
  40                  * generated, onkey event state determines the onkey
  41                  * button state.
  42                  */
  43                 key_stat &= DA9052_EVENTB_ENONKEY;
  44                 input_report_key(onkey->input, KEY_POWER, key_stat);
  45                 input_sync(onkey->input);
  46         }
  47
  48         /*
  49          * Interrupt is generated only when the ONKEY pin is asserted.
  50          * Hence the deassertion of the pin is simulated through work queue.
  51          */
  52         if (key_stat)
  53                 schedule_delayed_work(&onkey->work, msecs_to_jiffies(50));
  54 }
  55
  56 static void da9052_onkey_work(struct work_struct *work)
  57 {
  58         struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
  59                                                   work.work);
  60
  61         da9052_onkey_query(onkey);
  62 }
  63
  64 static irqreturn_t da9052_onkey_irq(int irq, void *data)
  65 {
  66         struct da9052_onkey *onkey = data;
  67
  68         da9052_onkey_query(onkey);
  69
  70         return IRQ_HANDLED;
  71 }
  72
  73 static int da9052_onkey_probe(struct platform_device *pdev)
  74 {
  75         struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
  76         struct da9052_onkey *onkey;
  77         struct input_dev *input_dev;
  78         int error;
  79
  80         if (!da9052) {
  81                 dev_err(&pdev->dev, "Failed to get the driver's data\n");
  82                 return -EINVAL;
  83         }
  84
  85         onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
  86         input_dev = input_allocate_device();
  87         if (!onkey || !input_dev) {
  88                 dev_err(&pdev->dev, "Failed to allocate memory\n");
  89                 error = -ENOMEM;
  90                 goto err_free_mem;
  91         }
  92
  93         onkey->input = input_dev;
  94         onkey->da9052 = da9052;
  95         INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
  96
  97         input_dev->name = "da9052-onkey";
  98         input_dev->phys = "da9052-onkey/input0";
  99         input_dev->dev.parent = &pdev->dev;
 100
 101         input_dev->evbit[0] = BIT_MASK(EV_KEY);
 102         __set_bit(KEY_POWER, input_dev->keybit);
 103
 104         error = da9052_request_irq(onkey->da9052, DA9052_IRQ_NONKEY, "ONKEY",
 105                             da9052_onkey_irq, onkey);
 106         if (error < 0) {
 107                 dev_err(onkey->da9052->dev,
 108                         "Failed to register ONKEY IRQ: %d\n", error);
 109                 goto err_free_mem;
 110         }
 111
 112         error = input_register_device(onkey->input);
 113         if (error) {
 114                 dev_err(&pdev->dev, "Unable to register input device, %d\n",
 115                         error);
 116                 goto err_free_irq;
 117         }
 118
 119         platform_set_drvdata(pdev, onkey);
 120         return 0;
 121
 122 err_free_irq:
 123         da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
 124         cancel_delayed_work_sync(&onkey->work);
 125 err_free_mem:
 126         input_free_device(input_dev);
 127         kfree(onkey);
 128
 129         return error;
 130 }
 131
 132 static int da9052_onkey_remove(struct platform_device *pdev)
 133 {
 134         struct da9052_onkey *onkey = platform_get_drvdata(pdev);
 135
 136         da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
 137         cancel_delayed_work_sync(&onkey->work);
 138
 139         input_unregister_device(onkey->input);
 140         kfree(onkey);
 141
 142         return 0;
 143 }
 144
 145 static struct platform_driver da9052_onkey_driver = {
 146         .probe  = da9052_onkey_probe,
 147         .remove = da9052_onkey_remove,
 148         .driver = {
 149                 .name   = "da9052-onkey",
 150                 .owner  = THIS_MODULE,
 151         },
 152 };
 153 module_platform_driver(da9052_onkey_driver);
 154
 155 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 156 MODULE_DESCRIPTION("Onkey driver for DA9052");
 157 MODULE_LICENSE("GPL");
 158 MODULE_ALIAS("platform:da9052-onkey");