linux/drivers/extcon/extcon-adc-jack.c
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   1/*
   2 * drivers/extcon/extcon-adc-jack.c
   3 *
   4 * Analog Jack extcon driver with ADC-based detection capability.
   5 *
   6 * Copyright (C) 2016 Samsung Electronics
   7 * Chanwoo Choi <cw00.choi@samsung.com>
   8 *
   9 * Copyright (C) 2012 Samsung Electronics
  10 * MyungJoo Ham <myungjoo.ham@samsung.com>
  11 *
  12 * Modified for calling to IIO to get adc by <anish.singh@samsung.com>
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License version 2 as
  16 * published by the Free Software Foundation.
  17 *
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/slab.h>
  22#include <linux/device.h>
  23#include <linux/platform_device.h>
  24#include <linux/err.h>
  25#include <linux/interrupt.h>
  26#include <linux/workqueue.h>
  27#include <linux/iio/consumer.h>
  28#include <linux/extcon/extcon-adc-jack.h>
  29#include <linux/extcon.h>
  30
  31/**
  32 * struct adc_jack_data - internal data for adc_jack device driver
  33 * @edev:               extcon device.
  34 * @cable_names:        list of supported cables.
  35 * @adc_conditions:     list of adc value conditions.
  36 * @num_conditions:     size of adc_conditions.
  37 * @irq:                irq number of attach/detach event (0 if not exist).
  38 * @handling_delay:     interrupt handler will schedule extcon event
  39 *                      handling at handling_delay jiffies.
  40 * @handler:            extcon event handler called by interrupt handler.
  41 * @chan:               iio channel being queried.
  42 */
  43struct adc_jack_data {
  44        struct device *dev;
  45        struct extcon_dev *edev;
  46
  47        const unsigned int **cable_names;
  48        struct adc_jack_cond *adc_conditions;
  49        int num_conditions;
  50
  51        int irq;
  52        unsigned long handling_delay; /* in jiffies */
  53        struct delayed_work handler;
  54
  55        struct iio_channel *chan;
  56        bool wakeup_source;
  57};
  58
  59static void adc_jack_handler(struct work_struct *work)
  60{
  61        struct adc_jack_data *data = container_of(to_delayed_work(work),
  62                        struct adc_jack_data,
  63                        handler);
  64        struct adc_jack_cond *def;
  65        int ret, adc_val;
  66        int i;
  67
  68        ret = iio_read_channel_raw(data->chan, &adc_val);
  69        if (ret < 0) {
  70                dev_err(&data->edev->dev, "read channel() error: %d\n", ret);
  71                return;
  72        }
  73
  74        /* Get state from adc value with adc_conditions */
  75        for (i = 0; i < data->num_conditions; i++) {
  76                def = &data->adc_conditions[i];
  77                if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
  78                        extcon_set_state_sync(data->edev, def->id, true);
  79                        return;
  80                }
  81        }
  82
  83        /* Set the detached state if adc value is not included in the range */
  84        for (i = 0; i < data->num_conditions; i++) {
  85                def = &data->adc_conditions[i];
  86                extcon_set_state_sync(data->edev, def->id, false);
  87        }
  88}
  89
  90static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
  91{
  92        struct adc_jack_data *data = _data;
  93
  94        queue_delayed_work(system_power_efficient_wq,
  95                           &data->handler, data->handling_delay);
  96        return IRQ_HANDLED;
  97}
  98
  99static int adc_jack_probe(struct platform_device *pdev)
 100{
 101        struct adc_jack_data *data;
 102        struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev);
 103        int i, err = 0;
 104
 105        data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 106        if (!data)
 107                return -ENOMEM;
 108
 109        if (!pdata->cable_names) {
 110                dev_err(&pdev->dev, "error: cable_names not defined.\n");
 111                return -EINVAL;
 112        }
 113
 114        data->dev = &pdev->dev;
 115        data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names);
 116        if (IS_ERR(data->edev)) {
 117                dev_err(&pdev->dev, "failed to allocate extcon device\n");
 118                return -ENOMEM;
 119        }
 120
 121        if (!pdata->adc_conditions) {
 122                dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
 123                return -EINVAL;
 124        }
 125        data->adc_conditions = pdata->adc_conditions;
 126
 127        /* Check the length of array and set num_conditions */
 128        for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++);
 129        data->num_conditions = i;
 130
 131        data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel);
 132        if (IS_ERR(data->chan))
 133                return PTR_ERR(data->chan);
 134
 135        data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
 136        data->wakeup_source = pdata->wakeup_source;
 137
 138        INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
 139
 140        platform_set_drvdata(pdev, data);
 141
 142        err = devm_extcon_dev_register(&pdev->dev, data->edev);
 143        if (err)
 144                return err;
 145
 146        data->irq = platform_get_irq(pdev, 0);
 147        if (!data->irq) {
 148                dev_err(&pdev->dev, "platform_get_irq failed\n");
 149                return -ENODEV;
 150        }
 151
 152        err = request_any_context_irq(data->irq, adc_jack_irq_thread,
 153                        pdata->irq_flags, pdata->name, data);
 154
 155        if (err < 0) {
 156                dev_err(&pdev->dev, "error: irq %d\n", data->irq);
 157                return err;
 158        }
 159
 160        if (data->wakeup_source)
 161                device_init_wakeup(&pdev->dev, 1);
 162
 163        adc_jack_handler(&data->handler.work);
 164        return 0;
 165}
 166
 167static int adc_jack_remove(struct platform_device *pdev)
 168{
 169        struct adc_jack_data *data = platform_get_drvdata(pdev);
 170
 171        free_irq(data->irq, data);
 172        cancel_work_sync(&data->handler.work);
 173        iio_channel_release(data->chan);
 174
 175        return 0;
 176}
 177
 178#ifdef CONFIG_PM_SLEEP
 179static int adc_jack_suspend(struct device *dev)
 180{
 181        struct adc_jack_data *data = dev_get_drvdata(dev);
 182
 183        cancel_delayed_work_sync(&data->handler);
 184        if (device_may_wakeup(data->dev))
 185                enable_irq_wake(data->irq);
 186
 187        return 0;
 188}
 189
 190static int adc_jack_resume(struct device *dev)
 191{
 192        struct adc_jack_data *data = dev_get_drvdata(dev);
 193
 194        if (device_may_wakeup(data->dev))
 195                disable_irq_wake(data->irq);
 196
 197        return 0;
 198}
 199#endif /* CONFIG_PM_SLEEP */
 200
 201static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops,
 202                adc_jack_suspend, adc_jack_resume);
 203
 204static struct platform_driver adc_jack_driver = {
 205        .probe          = adc_jack_probe,
 206        .remove         = adc_jack_remove,
 207        .driver         = {
 208                .name   = "adc-jack",
 209                .pm = &adc_jack_pm_ops,
 210        },
 211};
 212
 213module_platform_driver(adc_jack_driver);
 214
 215MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 216MODULE_DESCRIPTION("ADC Jack extcon driver");
 217MODULE_LICENSE("GPL v2");
 218
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