drivers/input/misc/da9055_onkey.c

   1 /*
   2  * ON pin driver for Dialog DA9055 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
  18 #include <linux/mfd/da9055/core.h>
  19 #include <linux/mfd/da9055/reg.h>
  20
  21 struct da9055_onkey {
  22         struct da9055 *da9055;
  23         struct input_dev *input;
  24         struct delayed_work work;
  25 };
  26
  27 static void da9055_onkey_query(struct da9055_onkey *onkey)
  28 {
  29         int key_stat;
  30
  31         key_stat = da9055_reg_read(onkey->da9055, DA9055_REG_STATUS_A);
  32         if (key_stat < 0) {
  33                 dev_err(onkey->da9055->dev,
  34                         "Failed to read onkey event %d\n", key_stat);
  35         } else {
  36                 key_stat &= DA9055_NOKEY_STS;
  37                 /*
  38                  * Onkey status bit is cleared when onkey button is released.
  39                  */
  40                 if (!key_stat) {
  41                         input_report_key(onkey->input, KEY_POWER, 0);
  42                         input_sync(onkey->input);
  43                 }
  44         }
  45
  46         /*
  47          * Interrupt is generated only when the ONKEY pin is asserted.
  48          * Hence the deassertion of the pin is simulated through work queue.
  49          */
  50         if (key_stat)
  51                 schedule_delayed_work(&onkey->work, msecs_to_jiffies(10));
  52
  53 }
  54
  55 static void da9055_onkey_work(struct work_struct *work)
  56 {
  57         struct da9055_onkey *onkey = container_of(work, struct da9055_onkey,
  58                                                   work.work);
  59
  60         da9055_onkey_query(onkey);
  61 }
  62
  63 static irqreturn_t da9055_onkey_irq(int irq, void *data)
  64 {
  65         struct da9055_onkey *onkey = data;
  66
  67         input_report_key(onkey->input, KEY_POWER, 1);
  68         input_sync(onkey->input);
  69
  70         da9055_onkey_query(onkey);
  71
  72         return IRQ_HANDLED;
  73 }
  74
  75 static int da9055_onkey_probe(struct platform_device *pdev)
  76 {
  77         struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
  78         struct da9055_onkey *onkey;
  79         struct input_dev *input_dev;
  80         int irq, err;
  81
  82         irq = platform_get_irq_byname(pdev, "ONKEY");
  83         if (irq < 0) {
  84                 dev_err(&pdev->dev,
  85                         "Failed to get an IRQ for input device, %d\n", irq);
  86                 return -EINVAL;
  87         }
  88
  89         onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
  90         if (!onkey) {
  91                 dev_err(&pdev->dev, "Failed to allocate memory\n");
  92                 return -ENOMEM;
  93         }
  94
  95         input_dev = input_allocate_device();
  96         if (!input_dev) {
  97                 dev_err(&pdev->dev, "Failed to allocate memory\n");
  98                 return -ENOMEM;
  99         }
 100
 101         onkey->input = input_dev;
 102         onkey->da9055 = da9055;
 103         input_dev->name = "da9055-onkey";
 104         input_dev->phys = "da9055-onkey/input0";
 105         input_dev->dev.parent = &pdev->dev;
 106
 107         input_dev->evbit[0] = BIT_MASK(EV_KEY);
 108         __set_bit(KEY_POWER, input_dev->keybit);
 109
 110         INIT_DELAYED_WORK(&onkey->work, da9055_onkey_work);
 111
 112         err = request_threaded_irq(irq, NULL, da9055_onkey_irq,
 113                                    IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
 114                                    "ONKEY", onkey);
 115         if (err < 0) {
 116                 dev_err(&pdev->dev,
 117                         "Failed to register ONKEY IRQ %d, error = %d\n",
 118                         irq, err);
 119                 goto err_free_input;
 120         }
 121
 122         err = input_register_device(input_dev);
 123         if (err) {
 124                 dev_err(&pdev->dev, "Unable to register input device, %d\n",
 125                         err);
 126                 goto err_free_irq;
 127         }
 128
 129         platform_set_drvdata(pdev, onkey);
 130
 131         return 0;
 132
 133 err_free_irq:
 134         free_irq(irq, onkey);
 135         cancel_delayed_work_sync(&onkey->work);
 136 err_free_input:
 137         input_free_device(input_dev);
 138
 139         return err;
 140 }
 141
 142 static int da9055_onkey_remove(struct platform_device *pdev)
 143 {
 144         struct da9055_onkey *onkey = platform_get_drvdata(pdev);
 145         int irq = platform_get_irq_byname(pdev, "ONKEY");
 146
 147         irq = regmap_irq_get_virq(onkey->da9055->irq_data, irq);
 148         free_irq(irq, onkey);
 149         cancel_delayed_work_sync(&onkey->work);
 150         input_unregister_device(onkey->input);
 151
 152         return 0;
 153 }
 154
 155 static struct platform_driver da9055_onkey_driver = {
 156         .probe  = da9055_onkey_probe,
 157         .remove = da9055_onkey_remove,
 158         .driver = {
 159                 .name   = "da9055-onkey",
 160         },
 161 };
 162
 163 module_platform_driver(da9055_onkey_driver);
 164
 165 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 166 MODULE_DESCRIPTION("Onkey driver for DA9055");
 167 MODULE_LICENSE("GPL");
 168 MODULE_ALIAS("platform:da9055-onkey");