input/misc/da9052_onkey.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * ON pin driver for Dialog DA9052 PMICs
0004  *
0005  * Copyright(c) 2012 Dialog Semiconductor Ltd.
0006  *
0007  * Author: David Dajun Chen <dchen@diasemi.com>
0008  */
0009
0010 #include <linux/input.h>
0011 #include <linux/module.h>
0012 #include <linux/platform_device.h>
0013 #include <linux/workqueue.h>
0014
0015 #include <linux/mfd/da9052/da9052.h>
0016 #include <linux/mfd/da9052/reg.h>
0017
0018 struct da9052_onkey {
0019     struct da9052 *da9052;
0020     struct input_dev *input;
0021     struct delayed_work work;
0022 };
0023
0024 static void da9052_onkey_query(struct da9052_onkey *onkey)
0025 {
0026     int ret;
0027
0028     ret = da9052_reg_read(onkey->da9052, DA9052_STATUS_A_REG);
0029     if (ret < 0) {
0030         dev_err(onkey->da9052->dev,
0031             "Failed to read onkey event err=%d\n", ret);
0032     } else {
0033         /*
0034          * Since interrupt for deassertion of ONKEY pin is not
0035          * generated, onkey event state determines the onkey
0036          * button state.
0037          */
0038         bool pressed = !(ret & DA9052_STATUSA_NONKEY);
0039
0040         input_report_key(onkey->input, KEY_POWER, pressed);
0041         input_sync(onkey->input);
0042
0043         /*
0044          * Interrupt is generated only when the ONKEY pin
0045          * is asserted.  Hence the deassertion of the pin
0046          * is simulated through work queue.
0047          */
0048         if (pressed)
0049             schedule_delayed_work(&onkey->work,
0050                         msecs_to_jiffies(50));
0051     }
0052 }
0053
0054 static void da9052_onkey_work(struct work_struct *work)
0055 {
0056     struct da9052_onkey *onkey = container_of(work, struct da9052_onkey,
0057                           work.work);
0058
0059     da9052_onkey_query(onkey);
0060 }
0061
0062 static irqreturn_t da9052_onkey_irq(int irq, void *data)
0063 {
0064     struct da9052_onkey *onkey = data;
0065
0066     da9052_onkey_query(onkey);
0067
0068     return IRQ_HANDLED;
0069 }
0070
0071 static int da9052_onkey_probe(struct platform_device *pdev)
0072 {
0073     struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
0074     struct da9052_onkey *onkey;
0075     struct input_dev *input_dev;
0076     int error;
0077
0078     if (!da9052) {
0079         dev_err(&pdev->dev, "Failed to get the driver's data\n");
0080         return -EINVAL;
0081     }
0082
0083     onkey = kzalloc(sizeof(*onkey), GFP_KERNEL);
0084     input_dev = input_allocate_device();
0085     if (!onkey || !input_dev) {
0086         dev_err(&pdev->dev, "Failed to allocate memory\n");
0087         error = -ENOMEM;
0088         goto err_free_mem;
0089     }
0090
0091     onkey->input = input_dev;
0092     onkey->da9052 = da9052;
0093     INIT_DELAYED_WORK(&onkey->work, da9052_onkey_work);
0094
0095     input_dev->name = "da9052-onkey";
0096     input_dev->phys = "da9052-onkey/input0";
0097     input_dev->dev.parent = &pdev->dev;
0098
0099     input_dev->evbit[0] = BIT_MASK(EV_KEY);
0100     __set_bit(KEY_POWER, input_dev->keybit);
0101
0102     error = da9052_request_irq(onkey->da9052, DA9052_IRQ_NONKEY, "ONKEY",
0103                 da9052_onkey_irq, onkey);
0104     if (error < 0) {
0105         dev_err(onkey->da9052->dev,
0106             "Failed to register ONKEY IRQ: %d\n", error);
0107         goto err_free_mem;
0108     }
0109
0110     error = input_register_device(onkey->input);
0111     if (error) {
0112         dev_err(&pdev->dev, "Unable to register input device, %d\n",
0113             error);
0114         goto err_free_irq;
0115     }
0116
0117     platform_set_drvdata(pdev, onkey);
0118     return 0;
0119
0120 err_free_irq:
0121     da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
0122     cancel_delayed_work_sync(&onkey->work);
0123 err_free_mem:
0124     input_free_device(input_dev);
0125     kfree(onkey);
0126
0127     return error;
0128 }
0129
0130 static int da9052_onkey_remove(struct platform_device *pdev)
0131 {
0132     struct da9052_onkey *onkey = platform_get_drvdata(pdev);
0133
0134     da9052_free_irq(onkey->da9052, DA9052_IRQ_NONKEY, onkey);
0135     cancel_delayed_work_sync(&onkey->work);
0136
0137     input_unregister_device(onkey->input);
0138     kfree(onkey);
0139
0140     return 0;
0141 }
0142
0143 static struct platform_driver da9052_onkey_driver = {
0144     .probe  = da9052_onkey_probe,
0145     .remove = da9052_onkey_remove,
0146     .driver = {
0147         .name   = "da9052-onkey",
0148     },
0149 };
0150 module_platform_driver(da9052_onkey_driver);
0151
0152 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
0153 MODULE_DESCRIPTION("Onkey driver for DA9052");
0154 MODULE_LICENSE("GPL");
0155 MODULE_ALIAS("platform:da9052-onkey");