drivers/extcon/extcon-adc-jack.c

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