linux/drivers/extcon/extcon-adc-jack.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * drivers/extcon/extcon-adc-jack.c
   4 *
   5 * Analog Jack extcon driver with ADC-based detection capability.
   6 *
   7 * Copyright (C) 2016 Samsung Electronics
   8 * Chanwoo Choi <cw00.choi@samsung.com>
   9 *
  10 * Copyright (C) 2012 Samsung Electronics
  11 * MyungJoo Ham <myungjoo.ham@samsung.com>
  12 *
  13 * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
  14 */
  15
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18#include <linux/device.h>
  19#include <linux/platform_device.h>
  20#include <linux/err.h>
  21#include <linux/interrupt.h>
  22#include <linux/workqueue.h>
  23#include <linux/iio/consumer.h>
  24#include <linux/extcon/extcon-adc-jack.h>
  25#include <linux/extcon-provider.h>
  26
  27/**
  28 * struct adc_jack_data - internal data for adc_jack device driver
  29 * @edev:               extcon device.
  30 * @cable_names:        list of supported cables.
  31 * @adc_conditions:     list of adc value conditions.
  32 * @num_conditions:     size of adc_conditions.
  33 * @irq:                irq number of attach/detach event (0 if not exist).
  34 * @handling_delay:     interrupt handler will schedule extcon event
  35 *                      handling at handling_delay jiffies.
  36 * @handler:            extcon event handler called by interrupt handler.
  37 * @chan:               iio channel being queried.
  38 */
  39struct adc_jack_data {
  40        struct device *dev;
  41        struct extcon_dev *edev;
  42
  43        const unsigned int **cable_names;
  44        struct adc_jack_cond *adc_conditions;
  45        int num_conditions;
  46
  47        int irq;
  48        unsigned long handling_delay; /* in jiffies */
  49        struct delayed_work handler;
  50
  51        struct iio_channel *chan;
  52        bool wakeup_source;
  53};
  54
  55static void adc_jack_handler(struct work_struct *work)
  56{
  57        struct adc_jack_data *data = container_of(to_delayed_work(work),
  58                        struct adc_jack_data,
  59                        handler);
  60        struct adc_jack_cond *def;
  61        int ret, adc_val;
  62        int i;
  63
  64        ret = iio_read_channel_raw(data->chan, &adc_val);
  65        if (ret < 0) {
  66                dev_err(data->dev, "read channel() error: %d\n", ret);
  67                return;
  68        }
  69
  70        /* Get state from adc value with adc_conditions */
  71        for (i = 0; i < data->num_conditions; i++) {
  72                def = &data->adc_conditions[i];
  73                if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
  74                        extcon_set_state_sync(data->edev, def->id, true);
  75                        return;
  76                }
  77        }
  78
  79        /* Set the detached state if adc value is not included in the range */
  80        for (i = 0; i < data->num_conditions; i++) {
  81                def = &data->adc_conditions[i];
  82                extcon_set_state_sync(data->edev, def->id, false);
  83        }
  84}
  85
  86static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
  87{
  88        struct adc_jack_data *data = _data;
  89
  90        queue_delayed_work(system_power_efficient_wq,
  91                           &data->handler, data->handling_delay);
  92        return IRQ_HANDLED;
  93}
  94
  95static int adc_jack_probe(struct platform_device *pdev)
  96{
  97        struct adc_jack_data *data;
  98        struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev);
  99        int i, err = 0;
 100
 101        data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 102        if (!data)
 103                return -ENOMEM;
 104
 105        if (!pdata->cable_names) {
 106                dev_err(&pdev->dev, "error: cable_names not defined.\n");
 107                return -EINVAL;
 108        }
 109
 110        data->dev = &pdev->dev;
 111        data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names);
 112        if (IS_ERR(data->edev)) {
 113                dev_err(&pdev->dev, "failed to allocate extcon device\n");
 114                return -ENOMEM;
 115        }
 116
 117        if (!pdata->adc_conditions) {
 118                dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
 119                return -EINVAL;
 120        }
 121        data->adc_conditions = pdata->adc_conditions;
 122
 123        /* Check the length of array and set num_conditions */
 124        for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++);
 125        data->num_conditions = i;
 126
 127        data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel);
 128        if (IS_ERR(data->chan))
 129                return PTR_ERR(data->chan);
 130
 131        data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
 132        data->wakeup_source = pdata->wakeup_source;
 133
 134        INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
 135
 136        platform_set_drvdata(pdev, data);
 137
 138        err = devm_extcon_dev_register(&pdev->dev, data->edev);
 139        if (err)
 140                return err;
 141
 142        data->irq = platform_get_irq(pdev, 0);
 143        if (data->irq < 0)
 144                return -ENODEV;
 145
 146        err = request_any_context_irq(data->irq, adc_jack_irq_thread,
 147                        pdata->irq_flags, pdata->name, data);
 148
 149        if (err < 0) {
 150                dev_err(&pdev->dev, "error: irq %d\n", data->irq);
 151                return err;
 152        }
 153
 154        if (data->wakeup_source)
 155                device_init_wakeup(&pdev->dev, 1);
 156
 157        adc_jack_handler(&data->handler.work);
 158        return 0;
 159}
 160
 161static int adc_jack_remove(struct platform_device *pdev)
 162{
 163        struct adc_jack_data *data = platform_get_drvdata(pdev);
 164
 165        free_irq(data->irq, data);
 166        cancel_work_sync(&data->handler.work);
 167        iio_channel_release(data->chan);
 168
 169        return 0;
 170}
 171
 172#ifdef CONFIG_PM_SLEEP
 173static int adc_jack_suspend(struct device *dev)
 174{
 175        struct adc_jack_data *data = dev_get_drvdata(dev);
 176
 177        cancel_delayed_work_sync(&data->handler);
 178        if (device_may_wakeup(data->dev))
 179                enable_irq_wake(data->irq);
 180
 181        return 0;
 182}
 183
 184static int adc_jack_resume(struct device *dev)
 185{
 186        struct adc_jack_data *data = dev_get_drvdata(dev);
 187
 188        if (device_may_wakeup(data->dev))
 189                disable_irq_wake(data->irq);
 190
 191        return 0;
 192}
 193#endif /* CONFIG_PM_SLEEP */
 194
 195static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops,
 196                adc_jack_suspend, adc_jack_resume);
 197
 198static struct platform_driver adc_jack_driver = {
 199        .probe          = adc_jack_probe,
 200        .remove         = adc_jack_remove,
 201        .driver         = {
 202                .name   = "adc-jack",
 203                .pm = &adc_jack_pm_ops,
 204        },
 205};
 206
 207module_platform_driver(adc_jack_driver);
 208
 209MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 210MODULE_DESCRIPTION("ADC Jack extcon driver");
 211MODULE_LICENSE("GPL v2");
 212