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 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
  58 static 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
  66 static 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
  75 static 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
 124 err_free_irq:
 125         da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
 126         cancel_delayed_work_sync(&onkey->work);
 127 err_free_mem:
 128         input_free_device(input_dev);
 129         kfree(onkey);
 130
 131         return error;
 132 }
 133
 134 static 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
 147 static struct platform_driver da9052_onkey_driver = {
 148         .probe  = da9052_onkey_probe,
 149         .remove = da9052_onkey_remove,
 150         .driver = {
 151                 .name   = "da9052-onkey",
 152                 .owner  = THIS_MODULE,
 153         },
 154 };
 155 module_platform_driver(da9052_onkey_driver);
 156
 157 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 158 MODULE_DESCRIPTION("Onkey driver for DA9052");
 159 MODULE_LICENSE("GPL");
 160 MODULE_ALIAS("platform:da9052-onkey");