LXR linux/drivers/input/misc/da9052

   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
  22struct da9052_onkey {
  23        struct da9052 *da9052;
  24        struct input_dev *input;
  25        struct delayed_work work;
  26};
  27
  28static void da9052_onkey_query(struct da9052_onkey *onkey)
  29{
  30        int ret;
  31
  32        ret = da9052_reg_read(onkey->da9052, DA9052_STATUS_A_REG);
  33        if (ret < 0) {
  34                dev_err(onkey->da9052->dev,
  35                        "Failed to read onkey event err=%d\n", ret);
  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                bool pressed = !(ret & DA9052_STATUSA_NONKEY);
  43
  44                input_report_key(onkey->input, KEY_POWER, pressed);
  45                input_sync(onkey->input);
  46
  47                /*
  48                 * Interrupt is generated only when the ONKEY pin
  49                 * is asserted.  Hence the deassertion of the pin
  50                 * is simulated through work queue.
  51                 */
  52                if (pressed)
  53                        schedule_delayed_work(&onkey->work,
  54                                                msecs_to_jiffies(50));
  55        }
  56}
  57
  58static void da9052_onkey_work(struct work_struct *work)
  59{
  60        struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
  61                                                  work.work);
  62
  63        da9052_onkey_query(onkey);
  64}
  65
  66static irqreturn_t da9052_onkey_irq(int irq, void *data)
  67{
  68        struct da9052_onkey *onkey = data;
  69
  70        da9052_onkey_query(onkey);
  71
  72        return IRQ_HANDLED;
  73}
  74
  75static int da9052_onkey_probe(struct platform_device *pdev)
  76{
  77        struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
  78        struct da9052_onkey *onkey;
  79        struct input_dev *input_dev;
  80        int error;
  81
  82        if (!da9052) {
  83                dev_err(&pdev->dev, "Failed to get the driver's data\n");
  84                return -EINVAL;
  85        }
  86
  87        onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
  88        input_dev = input_allocate_device();
  89        if (!onkey || !input_dev) {
  90                dev_err(&pdev->dev, "Failed to allocate memory\n");
  91                error = -ENOMEM;
  92                goto err_free_mem;
  93        }
  94
  95        onkey->input = input_dev;
  96        onkey->da9052 = da9052;
  97        INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
  98
  99        input_dev->name = "da9052-onkey";
 100        input_dev->phys = "da9052-onkey/input0";
 101        input_dev->dev.parent = &pdev->dev;
 102
 103        input_dev->evbit[0] = BIT_MASK(EV_KEY);
 104        __set_bit(KEY_POWER, input_dev->keybit);
 105
 106        error = da9052_request_irq(onkey->da9052, DA9052_IRQ_NONKEY, "ONKEY",
 107                            da9052_onkey_irq, onkey);
 108        if (error < 0) {
 109                dev_err(onkey->da9052->dev,
 110                        "Failed to register ONKEY IRQ: %d\n", error);
 111                goto err_free_mem;
 112        }
 113
 114        error = input_register_device(onkey->input);
 115        if (error) {
 116                dev_err(&pdev->dev, "Unable to register input device, %d\n",
 117                        error);
 118                goto err_free_irq;
 119        }
 120
 121        platform_set_drvdata(pdev, onkey);
 122        return 0;
 123
 124err_free_irq:
 125        da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
 126        cancel_delayed_work_sync(&onkey->work);
 127err_free_mem:
 128        input_free_device(input_dev);
 129        kfree(onkey);
 130
 131        return error;
 132}
 133
 134static int da9052_onkey_remove(struct platform_device *pdev)
 135{
 136        struct da9052_onkey *onkey = platform_get_drvdata(pdev);
 137
 138        da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
 139        cancel_delayed_work_sync(&onkey->work);
 140
 141        input_unregister_device(onkey->input);
 142        kfree(onkey);
 143
 144        return 0;
 145}
 146
 147static struct platform_driver da9052_onkey_driver = {
 148        .probe  = da9052_onkey_probe,
 149        .remove = da9052_onkey_remove,
 150        .driver = {
 151                .name   = "da9052-onkey",
 152        },
 153};
 154module_platform_driver(da9052_onkey_driver);
 155
 156MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 157MODULE_DESCRIPTION("Onkey driver for DA9052");
 158MODULE_LICENSE("GPL");
 159MODULE_ALIAS("platform:da9052-onkey");
 160