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