drivers/extcon/extcon-adc-jack.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * drivers/extcon/extcon-adc-jack.c
0004  *
0005  * Analog Jack extcon driver with ADC-based detection capability.
0006  *
0007  * Copyright (C) 2016 Samsung Electronics
0008  * Chanwoo Choi <cw00.choi@samsung.com>
0009  *
0010  * Copyright (C) 2012 Samsung Electronics
0011  * MyungJoo Ham <myungjoo.ham@samsung.com>
0012  *
0013  * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
0014  */
0015
0016 #include <linux/module.h>
0017 #include <linux/slab.h>
0018 #include <linux/device.h>
0019 #include <linux/platform_device.h>
0020 #include <linux/err.h>
0021 #include <linux/interrupt.h>
0022 #include <linux/workqueue.h>
0023 #include <linux/iio/consumer.h>
0024 #include <linux/extcon/extcon-adc-jack.h>
0025 #include <linux/extcon-provider.h>
0026
0027 /**
0028  * struct adc_jack_data - internal data for adc_jack device driver
0029  * @edev:       extcon device.
0030  * @cable_names:    list of supported cables.
0031  * @adc_conditions: list of adc value conditions.
0032  * @num_conditions: size of adc_conditions.
0033  * @irq:        irq number of attach/detach event (0 if not exist).
0034  * @handling_delay: interrupt handler will schedule extcon event
0035  *          handling at handling_delay jiffies.
0036  * @handler:        extcon event handler called by interrupt handler.
0037  * @chan:       iio channel being queried.
0038  */
0039 struct adc_jack_data {
0040     struct device *dev;
0041     struct extcon_dev *edev;
0042
0043     const unsigned int **cable_names;
0044     struct adc_jack_cond *adc_conditions;
0045     int num_conditions;
0046
0047     int irq;
0048     unsigned long handling_delay; /* in jiffies */
0049     struct delayed_work handler;
0050
0051     struct iio_channel *chan;
0052     bool wakeup_source;
0053 };
0054
0055 static void adc_jack_handler(struct work_struct *work)
0056 {
0057     struct adc_jack_data *data = container_of(to_delayed_work(work),
0058             struct adc_jack_data,
0059             handler);
0060     struct adc_jack_cond *def;
0061     int ret, adc_val;
0062     int i;
0063
0064     ret = iio_read_channel_raw(data->chan, &adc_val);
0065     if (ret < 0) {
0066         dev_err(data->dev, "read channel() error: %d\n", ret);
0067         return;
0068     }
0069
0070     /* Get state from adc value with adc_conditions */
0071     for (i = 0; i < data->num_conditions; i++) {
0072         def = &data->adc_conditions[i];
0073         if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
0074             extcon_set_state_sync(data->edev, def->id, true);
0075             return;
0076         }
0077     }
0078
0079     /* Set the detached state if adc value is not included in the range */
0080     for (i = 0; i < data->num_conditions; i++) {
0081         def = &data->adc_conditions[i];
0082         extcon_set_state_sync(data->edev, def->id, false);
0083     }
0084 }
0085
0086 static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
0087 {
0088     struct adc_jack_data *data = _data;
0089
0090     queue_delayed_work(system_power_efficient_wq,
0091                &data->handler, data->handling_delay);
0092     return IRQ_HANDLED;
0093 }
0094
0095 static int adc_jack_probe(struct platform_device *pdev)
0096 {
0097     struct adc_jack_data *data;
0098     struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev);
0099     int i, err = 0;
0100
0101     data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
0102     if (!data)
0103         return -ENOMEM;
0104
0105     if (!pdata->cable_names) {
0106         dev_err(&pdev->dev, "error: cable_names not defined.\n");
0107         return -EINVAL;
0108     }
0109
0110     data->dev = &pdev->dev;
0111     data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names);
0112     if (IS_ERR(data->edev)) {
0113         dev_err(&pdev->dev, "failed to allocate extcon device\n");
0114         return -ENOMEM;
0115     }
0116
0117     if (!pdata->adc_conditions) {
0118         dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
0119         return -EINVAL;
0120     }
0121     data->adc_conditions = pdata->adc_conditions;
0122
0123     /* Check the length of array and set num_conditions */
0124     for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++);
0125     data->num_conditions = i;
0126
0127     data->chan = devm_iio_channel_get(&pdev->dev, pdata->consumer_channel);
0128     if (IS_ERR(data->chan))
0129         return PTR_ERR(data->chan);
0130
0131     data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
0132     data->wakeup_source = pdata->wakeup_source;
0133
0134     INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
0135
0136     platform_set_drvdata(pdev, data);
0137
0138     err = devm_extcon_dev_register(&pdev->dev, data->edev);
0139     if (err)
0140         return err;
0141
0142     data->irq = platform_get_irq(pdev, 0);
0143     if (data->irq < 0)
0144         return -ENODEV;
0145
0146     err = request_any_context_irq(data->irq, adc_jack_irq_thread,
0147             pdata->irq_flags, pdata->name, data);
0148
0149     if (err < 0) {
0150         dev_err(&pdev->dev, "error: irq %d\n", data->irq);
0151         return err;
0152     }
0153
0154     if (data->wakeup_source)
0155         device_init_wakeup(&pdev->dev, 1);
0156
0157     adc_jack_handler(&data->handler.work);
0158     return 0;
0159 }
0160
0161 static int adc_jack_remove(struct platform_device *pdev)
0162 {
0163     struct adc_jack_data *data = platform_get_drvdata(pdev);
0164
0165     free_irq(data->irq, data);
0166     cancel_work_sync(&data->handler.work);
0167
0168     return 0;
0169 }
0170
0171 #ifdef CONFIG_PM_SLEEP
0172 static int adc_jack_suspend(struct device *dev)
0173 {
0174     struct adc_jack_data *data = dev_get_drvdata(dev);
0175
0176     cancel_delayed_work_sync(&data->handler);
0177     if (device_may_wakeup(data->dev))
0178         enable_irq_wake(data->irq);
0179
0180     return 0;
0181 }
0182
0183 static int adc_jack_resume(struct device *dev)
0184 {
0185     struct adc_jack_data *data = dev_get_drvdata(dev);
0186
0187     if (device_may_wakeup(data->dev))
0188         disable_irq_wake(data->irq);
0189
0190     return 0;
0191 }
0192 #endif /* CONFIG_PM_SLEEP */
0193
0194 static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops,
0195         adc_jack_suspend, adc_jack_resume);
0196
0197 static struct platform_driver adc_jack_driver = {
0198     .probe          = adc_jack_probe,
0199     .remove         = adc_jack_remove,
0200     .driver         = {
0201         .name   = "adc-jack",
0202         .pm = &adc_jack_pm_ops,
0203     },
0204 };
0205
0206 module_platform_driver(adc_jack_driver);
0207
0208 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
0209 MODULE_DESCRIPTION("ADC Jack extcon driver");
0210 MODULE_LICENSE("GPL v2");