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