drivers/extcon/extcon-adc-jack.c

   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  */
  43 struct 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
  59 static 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
  90 static 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
  99 static 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
 167 static 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
 179 static 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
 190 static 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
 201 static SIMPLE_DEV_PM_OPS(adc_jack_pm_ops,
 202                 adc_jack_suspend, adc_jack_resume);
 203
 204 static 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
 213 module_platform_driver(adc_jack_driver);
 214
 215 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 216 MODULE_DESCRIPTION("ADC Jack extcon driver");
 217 MODULE_LICENSE("GPL v2");