linux/drivers/input/misc/da9055_onkey.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * ON pin driver for Dialog DA9055 PMICs
   4 *
   5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
   6 *
   7 * Author: David Dajun Chen <dchen@diasemi.com>
   8 */
   9
  10#include <linux/input.h>
  11#include <linux/module.h>
  12#include <linux/platform_device.h>
  13
  14#include <linux/mfd/da9055/core.h>
  15#include <linux/mfd/da9055/reg.h>
  16
  17struct da9055_onkey {
  18        struct da9055 *da9055;
  19        struct input_dev *input;
  20        struct delayed_work work;
  21};
  22
  23static void da9055_onkey_query(struct da9055_onkey *onkey)
  24{
  25        int key_stat;
  26
  27        key_stat = da9055_reg_read(onkey->da9055, DA9055_REG_STATUS_A);
  28        if (key_stat < 0) {
  29                dev_err(onkey->da9055->dev,
  30                        "Failed to read onkey event %d\n", key_stat);
  31        } else {
  32                key_stat &= DA9055_NOKEY_STS;
  33                /*
  34                 * Onkey status bit is cleared when onkey button is released.
  35                 */
  36                if (!key_stat) {
  37                        input_report_key(onkey->input, KEY_POWER, 0);
  38                        input_sync(onkey->input);
  39                }
  40        }
  41
  42        /*
  43         * Interrupt is generated only when the ONKEY pin is asserted.
  44         * Hence the deassertion of the pin is simulated through work queue.
  45         */
  46        if (key_stat)
  47                schedule_delayed_work(&onkey->work, msecs_to_jiffies(10));
  48
  49}
  50
  51static void da9055_onkey_work(struct work_struct *work)
  52{
  53        struct da9055_onkey *onkey = container_of(work, struct da9055_onkey,
  54                                                  work.work);
  55
  56        da9055_onkey_query(onkey);
  57}
  58
  59static irqreturn_t da9055_onkey_irq(int irq, void *data)
  60{
  61        struct da9055_onkey *onkey = data;
  62
  63        input_report_key(onkey->input, KEY_POWER, 1);
  64        input_sync(onkey->input);
  65
  66        da9055_onkey_query(onkey);
  67
  68        return IRQ_HANDLED;
  69}
  70
  71static int da9055_onkey_probe(struct platform_device *pdev)
  72{
  73        struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
  74        struct da9055_onkey *onkey;
  75        struct input_dev *input_dev;
  76        int irq, err;
  77
  78        irq = platform_get_irq_byname(pdev, "ONKEY");
  79        if (irq < 0)
  80                return -EINVAL;
  81
  82        onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
  83        if (!onkey) {
  84                dev_err(&pdev->dev, "Failed to allocate memory\n");
  85                return -ENOMEM;
  86        }
  87
  88        input_dev = input_allocate_device();
  89        if (!input_dev) {
  90                dev_err(&pdev->dev, "Failed to allocate memory\n");
  91                return -ENOMEM;
  92        }
  93
  94        onkey->input = input_dev;
  95        onkey->da9055 = da9055;
  96        input_dev->name = "da9055-onkey";
  97        input_dev->phys = "da9055-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        INIT_DELAYED_WORK(&onkey->work, da9055_onkey_work);
 104
 105        err = request_threaded_irq(irq, NULL, da9055_onkey_irq,
 106                                   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
 107                                   "ONKEY", onkey);
 108        if (err < 0) {
 109                dev_err(&pdev->dev,
 110                        "Failed to register ONKEY IRQ %d, error = %d\n",
 111                        irq, err);
 112                goto err_free_input;
 113        }
 114
 115        err = input_register_device(input_dev);
 116        if (err) {
 117                dev_err(&pdev->dev, "Unable to register input device, %d\n",
 118                        err);
 119                goto err_free_irq;
 120        }
 121
 122        platform_set_drvdata(pdev, onkey);
 123
 124        return 0;
 125
 126err_free_irq:
 127        free_irq(irq, onkey);
 128        cancel_delayed_work_sync(&onkey->work);
 129err_free_input:
 130        input_free_device(input_dev);
 131
 132        return err;
 133}
 134
 135static int da9055_onkey_remove(struct platform_device *pdev)
 136{
 137        struct da9055_onkey *onkey = platform_get_drvdata(pdev);
 138        int irq = platform_get_irq_byname(pdev, "ONKEY");
 139
 140        irq = regmap_irq_get_virq(onkey->da9055->irq_data, irq);
 141        free_irq(irq, onkey);
 142        cancel_delayed_work_sync(&onkey->work);
 143        input_unregister_device(onkey->input);
 144
 145        return 0;
 146}
 147
 148static struct platform_driver da9055_onkey_driver = {
 149        .probe  = da9055_onkey_probe,
 150        .remove = da9055_onkey_remove,
 151        .driver = {
 152                .name   = "da9055-onkey",
 153        },
 154};
 155
 156module_platform_driver(da9055_onkey_driver);
 157
 158MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 159MODULE_DESCRIPTION("Onkey driver for DA9055");
 160MODULE_LICENSE("GPL");
 161MODULE_ALIAS("platform:da9055-onkey");
 162